Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
Transfer of preovulatory oocytes from donor to a suitable host. Oocytes are collected, fertilized in vitro, and transferred to a host that can be human or animal.
Procedures to obtain viable OOCYTES from the host. Oocytes most often are collected by needle aspiration from OVARIAN FOLLICLES before OVULATION.
The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.
A type of CELL NUCLEUS division, occurring during maturation of the GERM CELLS. Two successive cell nucleus divisions following a single chromosome duplication (S PHASE) result in daughter cells with half the number of CHROMOSOMES as the parent cells.
Methods used to induce premature oocytes, that are maintained in tissue culture, to progress through developmental stages including to a stage that is competent to undergo FERTILIZATION.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
The granulosa cells of the cumulus oophorus which surround the OVUM in the GRAAFIAN FOLLICLE. At OVULATION they are extruded with OVUM.
A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.
A post-MORULA preimplantation mammalian embryo that develops from a 32-cell stage into a fluid-filled hollow ball of over a hundred cells. A blastocyst has two distinctive tissues. The outer layer of trophoblasts gives rise to extra-embryonic tissues. The inner cell mass gives rise to the embryonic disc and eventual embryo proper.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.
Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
An assisted fertilization technique consisting of the microinjection of a single viable sperm into an extracted ovum. It is used principally to overcome low sperm count, low sperm motility, inability of sperm to penetrate the egg, or other conditions related to male infertility (INFERTILITY, MALE).
Morphological and physiological development of EMBRYOS.
The transfer of mammalian embryos from an in vivo or in vitro environment to a suitable host to improve pregnancy or gestational outcome in human or animal. In human fertility treatment programs, preimplantation embryos ranging from the 4-cell stage to the blastocyst stage are transferred to the uterine cavity between 3-5 days after FERTILIZATION IN VITRO.
A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
Protein kinase that drives both the mitotic and meiotic cycles in all eukaryotic organisms. In meiosis it induces immature oocytes to undergo meiotic maturation. In mitosis it has a role in the G2/M phase transition. Once activated by CYCLINS; MPF directly phosphorylates some of the proteins involved in nuclear envelope breakdown, chromosome condensation, spindle assembly, and the degradation of cyclins. The catalytic subunit of MPF is PROTEIN P34CDC2.
Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.
The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.
Synthetic transcripts of a specific DNA molecule or fragment, made by an in vitro transcription system. This cRNA can be labeled with radioactive uracil and then used as a probe. (King & Stansfield, A Dictionary of Genetics, 4th ed)
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
Proteins which are found in eggs (OVA) from any species.
Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.
The fluid surrounding the OVUM and GRANULOSA CELLS in the Graafian follicle (OVARIAN FOLLICLE). The follicular fluid contains sex steroids, glycoprotein hormones, plasma proteins, mucopolysaccharides, and enzymes.
Techniques for the artifical induction of ovulation, the rupture of the follicle and release of the ovum.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Cellular proteins encoded by the c-mos genes (GENES, MOS). They function in the cell cycle to maintain MATURATION PROMOTING FACTOR in the active state and have protein-serine/threonine kinase activity. Oncogenic transformation can take place when c-mos proteins are expressed at the wrong time.
Substances that provide protection against the harmful effects of freezing temperatures.
The transformation of a liquid to a glassy solid i.e., without the formation of crystals during the cooling process.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Minute cells produced during development of an OOCYTE as it undergoes MEIOSIS. A polar body contains one of the nuclei derived from the first or second meiotic CELL DIVISION. Polar bodies have practically no CYTOPLASM. They are eventually discarded by the oocyte. (from King & Stansfield, A Dictionary of Genetics, 4th ed)
The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Morphological and physiological development of EMBRYOS or FETUSES.
The ratio of the number of conceptions (CONCEPTION) including LIVE BIRTH; STILLBIRTH; and fetal losses, to the mean number of females of reproductive age in a population during a set time period.
Diminished or absent ability of a female to achieve conception.
A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The discharge of an OVUM from a rupturing follicle in the OVARY.
Supporting cells for the developing female gamete in the OVARY. They are derived from the coelomic epithelial cells of the gonadal ridge. Granulosa cells form a single layer around the OOCYTE in the primordial ovarian follicle and advance to form a multilayered cumulus oophorus surrounding the OVUM in the Graafian follicle. The major functions of granulosa cells include the production of steroids and LH receptors (RECEPTORS, LH).
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Proteins obtained from various species of Xenopus. Included here are proteins from the African clawed frog (XENOPUS LAEVIS). Many of these proteins have been the subject of scientific investigations in the area of MORPHOGENESIS and development.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
An early embryo that is a compact mass of about 16 BLASTOMERES. It resembles a cluster of mulberries with two types of cells, outer cells and inner cells. Morula is the stage before BLASTULA in non-mammalian animals or a BLASTOCYST in mammals.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
The prophase of the first division of MEIOSIS (in which homologous CHROMOSOME SEGREGATION occurs). It is divided into five stages: leptonema, zygonema, PACHYNEMA, diplonema, and diakinesis.
Clinical and laboratory techniques used to enhance fertility in humans and animals.
A microtubule structure that forms during CELL DIVISION. It consists of two SPINDLE POLES, and sets of MICROTUBULES that may include the astral microtubules, the polar microtubules, and the kinetochore microtubules.
In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
A colorless, odorless, viscous dihydroxy alcohol. It has a sweet taste, but is poisonous if ingested. Ethylene glycol is the most important glycol commercially available and is manufactured on a large scale in the United States. It is used as an antifreeze and coolant, in hydraulic fluids, and in the manufacture of low-freezing dynamites and resins.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The active production and accumulation of VITELLINS (egg yolk proteins) in the non-mammalian OOCYTES from circulating precursors, VITELLOGENINS. Vitellogenesis usually begins after the first MEIOSIS and is regulated by estrogenic hormones.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Retrovirus-associated DNA sequences (mos) originally isolated from the Moloney murine sarcoma virus (Mo-MSV). The proto-oncogene mos (c-mos) codes for a protein which is a member of the serine kinase family. There is no evidence as yet that human c-mos can become transformed or has a role in human cancer. However, in mice, activation can occur when the retrovirus-like intracisternal A-particle inserts itself near the c-mos sequence. The human c-mos gene is located at 8q22 on the long arm of chromosome 8.
The first phase of cell nucleus division, in which the CHROMOSOMES become visible, the CELL NUCLEUS starts to lose its identity, the SPINDLE APPARATUS appears, and the CENTRIOLES migrate toward opposite poles.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.
Occurrence or induction of release of more ova than are normally released at the same time in a given species. The term applies to both animals and humans.
A bone morphogenetic protein that plays an essential role in the regulation of ovarian folliculogenesis.
Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.
A protein that plays a role in GRANULOSA CELLS where it regulates folliculogenesis. Mutations in the gene for bone morphogenetic protein 15 are linked to reproductive abnormalities such as PREMATURE OVARIAN FAILURE.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.
Elements of limited time intervals, contributing to particular results or situations.
The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.
The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).
Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.
Embryonic and fetal development that takes place in an artificial environment in vitro.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
Gonadotropins secreted by the pituitary or the placenta in horses. This term generally refers to the gonadotropins found in the pregnant mare serum, a rich source of equine CHORIONIC GONADOTROPIN; LUTEINIZING HORMONE; and FOLLICLE STIMULATING HORMONE. Unlike that in humans, the equine LUTEINIZING HORMONE, BETA SUBUNIT is identical to the equine choronic gonadotropin, beta. Equine gonadotropins prepared from pregnant mare serum are used in reproductive studies.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
A cyclin subtype that is transported into the CELL NUCLEUS at the end of the G2 PHASE. It stimulates the G2/M phase transition by activating CDC2 PROTEIN KINASE.
The capacity to conceive or to induce conception. It may refer to either the male or female.
The decrease in the cell's ability to proliferate with the passing of time. Each cell is programmed for a certain number of cell divisions and at the end of that time proliferation halts. The cell enters a quiescent state after which it experiences CELL DEATH via the process of APOPTOSIS.
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
Steroids with methyl groups at C-10 and C-13 and a branched 8-carbon chain at C-17. Members include compounds with any degree of unsaturation; however, CHOLESTADIENES is available for derivatives containing two double bonds.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
A clear, colorless, viscous organic solvent and diluent used in pharmaceutical preparations.
The rate dynamics in chemical or physical systems.
Proteins prepared by recombinant DNA technology.
Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.
The procedure of removing TISSUES, organs, or specimens from DONORS for reuse, such as TRANSPLANTATION.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.
A cyclin B subtype that colocalizes with MICROTUBULES during INTERPHASE and is transported into the CELL NUCLEUS at the end of the G2 PHASE.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
Phospholipoglycoproteins produced in the fat body of egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. Vitellogenins are secreted into the HEMOLYMPH, and taken into the OOCYTES by receptor-mediated ENDOCYTOSIS to form the major yolk proteins, VITELLINS. Vitellogenin production is under the regulation of steroid hormones, such as ESTRADIOL and JUVENILE HORMONES in insects.
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
Messenger RNA that is stored in a masked state for translation at a later time. Distinguish from RNA, UNTRANSLATED which refers to non-messenger RNA, i.e. RNA that does not code for protein.
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.
The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.
The plasma membrane of the egg.
Methods for maintaining or growing CELLS in vitro.
Extracts of urine from menopausal women that contain high concentrations of pituitary gonadotropins, FOLLICLE STIMULATING HORMONE and LUTEINIZING HORMONE. Menotropins are used to treat infertility. The FSH:LH ratio and degree of purity vary in different preparations.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
Metabolites or derivatives of PROGESTERONE with hydroxyl group substitution at various sites.
Transport proteins that carry specific substances in the blood or across cell membranes.
Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.
The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A family of histone molecular chaperones that play roles in sperm CHROMATIN decondensation and CHROMATIN ASSEMBLY in fertilized eggs. They were originally discovered in XENOPUS egg extracts as histone-binding factors that mediate nucleosome formation in vitro.
A species of the true toads, Bufonidae, found in South America.
Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
A method of providing future reproductive opportunities before a medical treatment with known risk of loss of fertility. Typically reproductive organs or tissues (e.g., sperm, egg, embryos and ovarian or testicular tissues) are cryopreserved for future use before the medical treatment (e.g., chemotherapy, radiation) begins.
Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.
A purine and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.
Within most types of eukaryotic CELL NUCLEUS, a distinct region, not delimited by a membrane, in which some species of rRNA (RNA, RIBOSOMAL) are synthesized and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rRNA is transcribed from a nucleolar organizer, i.e., a group of tandemly repeated chromosomal genes which encode rRNA and which are transcribed by RNA polymerase I. (Singleton & Sainsbury, Dictionary of Microbiology & Molecular Biology, 2d ed)
The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).
A group of adenine ribonucleotides in which the phosphate residues of each adenine ribonucleotide act as bridges in forming diester linkages between the ribose moieties.
A small whitish spot on the surface of the EGG YOLK where cleavage begins. Upon fertilization the cytoplasm streams from the vegetal pole away from the yolk to the animal pole where cleavage will occur. This germinal area eventually flattens into a layer of cells (BLASTODERM) that covers the yolk completely.
A complication of OVULATION INDUCTION in infertility treatment. It is graded by the severity of symptoms which include OVARY enlargement, multiple OVARIAN FOLLICLES; OVARIAN CYSTS; ASCITES; and generalized EDEMA. The full-blown syndrome may lead to RENAL FAILURE, respiratory distress, and even DEATH. Increased capillary permeability is caused by the vasoactive substances, such as VASCULAR ENDOTHELIAL GROWTH FACTORS, secreted by the overly-stimulated OVARIES.
Euploid female germ cells of an early stage of OOGENESIS, derived from primordial germ cells during ovarian differentiation. Oogonia undergo MEIOSIS and give rise to haploid OOCYTES
The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
A potent cyclic nucleotide phosphodiesterase inhibitor; due to this action, the compound increases cyclic AMP and cyclic GMP in tissue and thereby activates CYCLIC NUCLEOTIDE-REGULATED PROTEIN KINASES
Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.
Nocodazole is an antineoplastic agent which exerts its effect by depolymerizing microtubules.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.
A cyclic nucleotide phosphodiesterase subfamily that is inhibited by the binding of CYCLIC GMP to an allosteric domain found on the enzyme and through phosphorylation by regulatory kinases such as PROTEIN KINASE A and PROTEIN KINASE B. The two members of this family are referred to as type 3A, and type 3B, and are each product of a distinct gene. In addition multiple enzyme variants of each subtype can be produced due to multiple alternative mRNA splicing.
Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.
A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.
A genus of surf clams in the family Mactridae, class BIVALVIA. They are often used in EMBRYOLOGY research.
The period of the MENSTRUAL CYCLE representing follicular growth, increase in ovarian estrogen (ESTROGENS) production, and epithelial proliferation of the ENDOMETRIUM. Follicular phase begins with the onset of MENSTRUATION and ends with OVULATION.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
Liquids transforming into solids by the removal of heat.
The orderly segregation of CHROMOSOMES during MEIOSIS or MITOSIS.
A class in the phylum MOLLUSCA comprised of mussels; clams; OYSTERS; COCKLES; and SCALLOPS. They are characterized by a bilaterally symmetrical hinged shell and a muscular foot used for burrowing and anchoring.
Aquaporin 1 forms a water-specific channel that is constitutively expressed at the PLASMA MEMBRANE of ERYTHROCYTES and KIDNEY TUBULES, PROXIMAL. It provides these cells with a high permeability to WATER. In humans polymorphisms of this protein result in the Colton blood group antigen.
A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.
The event that a FETUS is born alive with heartbeats or RESPIRATION regardless of GESTATIONAL AGE. Such liveborn is called a newborn infant (INFANT, NEWBORN).
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4,5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1,4,5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell's endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
The ability of a substrate to allow the passage of ELECTRONS.
The degeneration and resorption of an OVARIAN FOLLICLE before it reaches maturity and ruptures.
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
Changes that occur to liberate the enzymes of the ACROSOME of a sperm (SPERMATOZOA). Acrosome reaction allows the sperm to penetrate the ZONA PELLUCIDA and enter the OVUM during FERTILIZATION.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
The cap-like structure covering the anterior portion of SPERM HEAD. Acrosome, derived from LYSOSOMES, is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION.
An aspect of protein kinase (EC 2.7.1.37) in which serine residues in protamines and histones are phosphorylated in the presence of ATP.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
A major gonadotropin secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and the LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. The alpha subunit is common in the three human pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
An amorphous region of electron dense material in the cytoplasm from which the MICROTUBULES polymerization is nucleated. The pericentriolar region of the CENTROSOME which surrounds the CENTRIOLES is an example.
A purine base and a fundamental unit of ADENINE NUCLEOTIDES.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.
Cessation of ovarian function after MENARCHE but before the age of 40, without or with OVARIAN FOLLICLE depletion. It is characterized by the presence of OLIGOMENORRHEA or AMENORRHEA, elevated GONADOTROPINS, and low ESTRADIOL levels. It is a state of female HYPERGONADOTROPIC HYPOGONADISM. Etiologies include genetic defects, autoimmune processes, chemotherapy, radiation, and infections.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of CONNEXINS, the family of proteins which form the junctions.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.
A glycoprotein that causes regression of MULLERIAN DUCTS. It is produced by SERTOLI CELLS of the TESTES. In the absence of this hormone, the Mullerian ducts develop into structures of the female reproductive tract. In males, defects of this hormone result in persistent Mullerian duct, a form of MALE PSEUDOHERMAPHRODITISM.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.
Sodium channels found on salt-reabsorbing EPITHELIAL CELLS that line the distal NEPHRON; the distal COLON; SALIVARY DUCTS; SWEAT GLANDS; and the LUNG. They are AMILORIDE-sensitive and play a critical role in the control of sodium balance, BLOOD VOLUME, and BLOOD PRESSURE.
Achievement of full sexual capacity in animals and in humans.
A complex disorder characterized by infertility, HIRSUTISM; OBESITY; and various menstrual disturbances such as OLIGOMENORRHEA; AMENORRHEA; ANOVULATION. Polycystic ovary syndrome is usually associated with bilateral enlarged ovaries studded with atretic follicles, not with cysts. The term, polycystic ovary, is misleading.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
Transforming proteins coded by mos oncogenes. The v-mos proteins were originally isolated from the Moloney murine sarcoma virus (Mo-MSV).
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
The age of the mother in PREGNANCY.
A highly polar organic liquid, that is used widely as a chemical solvent. Because of its ability to penetrate biological membranes, it is used as a vehicle for topical application of pharmaceuticals. It is also used to protect tissue during CRYOPRESERVATION. Dimethyl sulfoxide shows a range of pharmacological activity including analgesia and anti-inflammation.
In gonochoristic organisms, congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Effects from exposure to abnormal levels of GONADAL HORMONES in the maternal environment, or disruption of the function of those hormones by ENDOCRINE DISRUPTORS are included.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.

Bcl-2 regulates amplification of caspase activation by cytochrome c. (1/15764)

Caspases, a family of specific proteases, have central roles in apoptosis [1]. Caspase activation in response to diverse apoptotic stimuli involves the relocalisation of cytochrome c from mitochondria to the cytoplasm where it stimulates the proteolytic processing of caspase precursors. Cytochrome c release is controlled by members of the Bcl-2 family of apoptosis regulators [2] [3]. The anti-apoptotic members Bcl-2 and Bcl-xL may also control caspase activation independently of cytochrome c relocalisation or may inhibit a positive feedback mechanism [4] [5] [6] [7]. Here, we investigate the role of Bcl-2 family proteins in the regulation of caspase activation using a model cell-free system. We found that Bcl-2 and Bcl-xL set a threshold in the amount of cytochrome c required to activate caspases, even in soluble extracts lacking mitochondria. Addition of dATP (which stimulates the procaspase-processing factor Apaf-1 [8] [9]) overcame inhibition of caspase activation by Bcl-2, but did not prevent the control of cytochrome c release from mitochondria by Bcl-2. Cytochrome c release was accelerated by active caspase-3 and this positive feedback was negatively regulated by Bcl-2. These results provide evidence for a mechanism to amplify caspase activation that is suppressed at several distinct steps by Bcl-2, even after cytochrome c is released from mitochondria.  (+info)

The mitogen-activated protein kinase signaling pathway stimulates mos mRNA cytoplasmic polyadenylation during Xenopus oocyte maturation. (2/15764)

The Mos protein kinase is a key regulator of vertebrate oocyte maturation. Oocyte-specific Mos protein expression is subject to translational control. In the frog Xenopus, the translation of Mos protein requires the progesterone-induced polyadenylation of the maternal Mos mRNA, which is present in the oocyte cytoplasm. Both the Xenopus p42 mitogen-activated protein kinase (MAPK) and maturation-promoting factor (MPF) signaling pathways have been proposed to mediate progesterone-stimulated oocyte maturation. In this study, we have determined the relative contributions of the MAPK and MPF signaling pathways to Mos mRNA polyadenylation. We report that progesterone-induced Mos mRNA polyadenylation was attenuated in oocytes expressing the MAPK phosphatase rVH6. Moreover, inhibition of MAPK signaling blocked progesterone-induced Mos protein accumulation. Activation of the MAPK pathway by injection of RNA encoding Mos was sufficient to induce both the polyadenylation of synthetic Mos mRNA substrates and the accumulation of endogenous Mos protein in the absence of MPF signaling. Activation of MPF, by injection of cyclin B1 RNA or purified cyclin B1 protein, also induced both Mos protein accumulation and Mos mRNA polyadenylation. However, this action of MPF required MAPK activity. By contrast, the cytoplasmic polyadenylation of maternal cyclin B1 mRNA was stimulated by MPF in a MAPK-independent manner, thus revealing a differential regulation of maternal mRNA polyadenylation by the MAPK and MPF signaling pathways. We propose that MAPK-stimulated Mos mRNA cytoplasmic polyadenylation is a key component of the positive-feedback loop, which contributes to the all-or-none process of oocyte maturation.  (+info)

Molecular dynamics of the sodium channel pore vary with gating: interactions between P-segment motions and inactivation. (3/15764)

Disulfide trapping studies have revealed that the pore-lining (P) segments of voltage-dependent sodium channels undergo sizable motions on a subsecond time scale. Such motions of the pore may be necessary for selective ion translocation. Although traditionally viewed as separable properties, gating and permeation are now known to interact extensively in various classes of channels. We have investigated the interaction of pore motions and voltage-dependent gating in micro1 sodium channels engineered to contain two cysteines within the P segments. Rates of catalyzed internal disulfide formation (kSS) were measured in K1237C+W1531C mutant channels expressed in oocytes. During repetitive voltage-clamp depolarizations, increasing the pulse duration had biphasic effects on the kSS, which first increased to a maximum at 200 msec and then decreased with longer depolarizations. This result suggested that occupancy of an intermediate inactivation state (IM) facilitates pore motions. Consistent with the known antagonism between alkali metals and a component of slow inactivation, kSS varied inversely with external [Na+]o. We examined the converse relationship, namely the effect of pore flexibility on gating, by measuring recovery from inactivation in Y401C+E758C (YC/EC) channels. Under oxidative conditions, recovery from inactivation was slower than in a reduced environment in which the spontaneous YC/EC cross-link is disrupted. The most prominent effects were slowing of a component with intermediate recovery kinetics, with diminution of its relative amplitude. We conclude that occupancy of an intermediate inactivation state facilitates motions of the P segments; conversely, flexibility of the P segments alters an intermediate component of inactivation.  (+info)

The role of oocyte transcription, the 5'UTR, and translation repression and derepression in Drosophila gurken mRNA and protein localization. (4/15764)

The establishment of the major body axes of the Drosophila egg and future embryo requires strict regulation of gurken mRNA and protein localization. Here, we show that grk mRNA and protein localization is dependent on synthesis of grk transcripts in the oocyte nucleus and on RNA localization elements in the 5' portion of the transcript. We also show that gurken mRNA and protein localization is dependent on region-specific translation of gurken transcripts and identify K10 as a probable negative regulator of gurken translation.  (+info)

KCNQ4, a novel potassium channel expressed in sensory outer hair cells, is mutated in dominant deafness. (5/15764)

Potassium channels regulate electrical signaling and the ionic composition of biological fluids. Mutations in the three known genes of the KCNQ branch of the K+ channel gene family underlie inherited cardiac arrhythmias (in some cases associated with deafness) and neonatal epilepsy. We have now cloned KCNQ4, a novel member of this branch. It maps to the DFNA2 locus for a form of nonsyndromic dominant deafness. In the cochlea, it is expressed in sensory outer hair cells. A mutation in this gene in a DFNA2 pedigree changes a residue in the KCNQ4 pore region. It abolishes the potassium currents of wild-type KCNQ4 on which it exerts a strong dominant-negative effect. Whereas mutations in KCNQ1 cause deafness by affecting endolymph secretion, the mechanism leading to KCNQ4-related hearing loss is intrinsic to outer hair cells.  (+info)

Differential transcriptional activity associated with chromatin configuration in fully grown mouse germinal vesicle oocytes. (6/15764)

It was previously shown that fully grown ovarian germinal vesicle (GV) oocytes of adult mice exhibit several nuclear configurations that differ essentially by the presence or absence of a ring of condensed chromatin around the nucleolus. These configurations have been termed, respectively, SN (surrounded nucleolus) and NSN (nonsurrounded nucleolus). Work from our and other laboratories has revealed ultrastructural and functional differences between these two configurations. The aims of the present study were 1) to analyze the equilibrium between the SN and the NSN population as a function of the age of the mice and the time after hCG-induced ovulation and 2) to study the polymerase I (pol I)- and polymerase II (pol II)-dependent transcription in both types of oocytes through the detection of bromouridine incorporated into nascent RNA. We show 1) that ovarian GV oocytes exhibiting the SN-type configuration can be found as soon as 17 days after birth in the C57/CBA mouse strain and 2) that the SN:NSN ratio of ovarian GV oocytes is very low just after hCG-induced ovulation and then increases progressively with the time after ovulation. Furthermore, we demonstrate that the SN configuration correlates strictly with the arrest of both pol I- and pol II-dependent transcription in mice at any age. Finally, we show that ribosomal genes are located at the outer periphery of the nucleolus in the NSN configuration and that pol I-dependent perinucleolar transcription sites correspond to specific ultrastructural features of the nucleolus. Altogether, these results provide clear-cut criteria delineating transcriptionally active GV oocytes from those that are inactive, and confirm that the SN-type configuration is mostly present in preovulatory oocytes.  (+info)

Ontogeny of expression of a receptor for platelet-activating factor in mouse preimplantation embryos and the effects of fertilization and culture in vitro on its expression. (7/15764)

Platelet-activating factor (PAF; 1-o-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a potent ether phospholipid. It is one of the preimplantation embryo's autocrine growth/survival factors. It may act via a G protein-linked receptor on the embryo; however, the evidence for this is conflicting. The recent description of the intracellular form of the PAF:acetlyhydrolase enzyme as having structural homology with G proteins and Ras also suggests this as a potential intracellular receptor/transducer for PAF. This study used reverse transcription-polymerase chain reaction to examine the ontogeny of expression of the genes for these proteins in the oocyte and preimplantation-stage embryo. Transcripts for the G protein-linked PAF receptor were detected in the late 2-cell-stage embryo and in all stages from the 4-cell stage to blastocysts. They were also present in unfertilized oocytes and newly fertilized zygotes but only at relatively low levels. The incidence of expression was generally low and variable in late zygotes and early 2-cell embryos. Expression past the 2-cell stage was alpha-amanitin sensitive. The results indicated that mRNA for this receptor is a maternal transcript that was degraded during the zygote-2-cell stage. New expression of the receptor transcript required activation of the zygotic genome. Fertilization of embryos in vitro caused this transcript not to be expressed in the zygote. Culture of zygotes (irrespective of their method of fertilization) caused expression from the zygotic genome to be retarded by more than 24 h. This retardation did not occur if culture commenced at the 2-cell stage. The transcripts for the subunits of intracellular PAF:acetylhydrolase were not detected in oocytes or at any stage of embryo development examined, despite their being readily detected in control tissue. This study confirms the presence of the G protein-linked PAF receptor in the 2-cell embryo and describes for the first time its normal pattern of expression during early development. The adverse effects of in vitro fertilization (IVF) and embryo culture on the expression of this transcript may be a contributing factor for the poor viability of embryos produced in this manner. The reduced expression of PAF-receptor mRNA following IVF predicts that such embryos may have a deficiency in autocrine stimulation and also suggests that supplementation of growth media with exogenous PAF would be only partially beneficial. The effect of IVF and culture may also explain the conflicting literature.  (+info)

An intact sperm nuclear matrix may be necessary for the mouse paternal genome to participate in embryonic development. (8/15764)

We have been interested in determining the minimally required elements in the sperm head that are necessary in order for the paternal genome to participate in embryogenesis. We used an ionic detergent, mixed alkyltrimethylammonium bromide (ATAB), plus dithiothreitol (DTT) to remove the acrosome and almost all of the perinuclear theca, leaving only the sperm nucleus morphologically intact. We also tested the stability of the sperm nuclear matrix by the ability to form nuclear halos. Sperm nuclei washed in freshly prepared 0.5% ATAB + 2 mM DTT completely decondensed when extracted with salt, but nuclei washed in the same buffer that was 1 wk old, and then extracted with salt, produced nuclear halos, indicating stable nuclear matrices. When we treated sperm heads with freshly prepared ATAB+DTT and injected them into oocytes, none of the oocytes developed into live offspring. In contrast, sperm heads treated in the same way but with 1-wk-old ATAB+DTT solution could support development of about 30% of the oocytes to live offspring. Electron microscopy demonstrated that most of the perinuclear theca had been removed in both cases. These data suggest that at least in the mouse, the only component of the spermatozoa that is crucial for participation in embryologic development is the sperm nucleus with a stable nuclear matrix.  (+info)

Delineation of maternal versus direct effects of heat stress in reducing development at the germinal vesicle (GV) stage is challenging, because oocytes spontaneously resume meiosis after removal from antral follicles. The use of S-roscovitine (inhibitor of p34(cdc2)/cyclin B kinase) to hold bovine oocytes at the GV stage without compromising early embryo development was previously validated in our laboratory. The objective of the present study was to assess the direct effects of an elevated temperature commonly seen in heat-stressed dairy cows on cumulus-oocyte complexes (COCs) held at the GV stage using 50 microM S-roscovitine. During roscovitine culture, GV-stage COCs (antral follicle diameter, 3-8 mm) were cultured at 38.5 or 41 degrees C. Thereafter, oocytes were removed from roscovitine medium and allowed to undergo in vitro maturation, fertilization, and culture. Zona pellucida hardening (solubility to 0.5% pronase), nuclear stage (Hoechst 33342), cortical granule type (lens culinaris ...
As an important biological messenger, nitric oxide (NO) exhibits a wide range of effects during physiological and pathophysiological processes, including mammalian oocyte meiotic maturation. The present study investigated whether NO derived from two nitric oxide synthase (NOS) isoforms, inducible NOS (iNOS) or endothelial NOS (eNOS), is involved in the meiotic maturation of porcine oocytes. Meanwhile, the cumulus cells function in meiotic maturation and their interaction with oocyte development and degeneration were also investigated using cumulus-enclosed oocytes (CEOs) and denuded oocytes (DOs). Different inhibitors for NOS were supplemented to the medium. Cumulus expansion, cumulus cell DNA fragmentation and oocyte meiotic resumption were evaluated 48 h after incubation. Aminoguanidine (AG), a selective inhibitor for iNOS, suppressed cumulus expansion and inhibited CEOs to resume meiosis (p , 0.05), but did not inhibit cumulus cell DNA fragmentation. Both Nomega-nitro-L-arginine (L-NNA) and ...
Background: Vitrification of oocytes is a fast-freezing technique, which may affect the quality of the human oocyte, and consequently affects the embryo development, pregnancy and birth. The aim of the current study was to investigate the consequence of in-vitro vitrification on maturation status of immature human oocytes, additionally, expression levels of stress, and apoptosis related genes. Materials and Methods: The total of 213 human immature oocytes which routinely discarded from assisted reproduction clinics were collected and divided into two groups including: (I) fresh germinal vesicle (GV) oocytes (n=106) (matured in-vitro  (fIVM) , and  (II) GV oocytes (n=107) that initially vitrified, then matured in  in-vitro (vIVM). After 36 hours of incubation, the oocytes were evaluated for nuclear maturation and expression level of DNA methyltransferase (DNMT1), stress related genes (Sod1 and Hsp70), and apoptotic related genes (Bax and Bcl-2) by quantitative Real-Time ...
TY - JOUR. T1 - Microtubular spindle dynamics and chromosome complements from somatic cell nuclei haploidization in mature mouse oocytes and developmental potential of the derived embryos. AU - Chen, Shee Uan. AU - Chang, Chia Yi. AU - Lu, Chien Cheng. AU - Hsieh, Fon Jou. AU - Ho, Hong Nerng. AU - Yang, Yu Shih. PY - 2004/1/1. Y1 - 2004/1/1. N2 - Background: The aim of this study was to investigate haploidization of somatic cell nuclei in non-enucleated mature oocytes regarding spindle formation, chromosomes and developmental potential. Methods: Mouse cumulus cells were injected into metaphase II oocytes. Some injected oocytes were examined for morphological changes of chromosomes and the spindle immediately, and at 30 min, 1 h or 2 h after the injections. The remaining oocytes were activated by Sr 2+ after various incubation periods and observed for formation of a second polar body and pseudo-polar body. Cytogenetic analysis was performed for some of the resulting zygotes. The progress to ...
TY - JOUR. T1 - Tryptophan Inhibits the [3H]Glutamate Uptake into Xenopus Oocytes Injected with Rat Brain mRNA. AU - Tohda, Michihisa. AU - Urushihara, Hisashi. AU - Nomura, Yasuyuki. PY - 1992/1. Y1 - 1992/1. N2 - We characterized the glutamate (Glu) uptake in Xenopus oocytes injected with rat brain mRNA. The Glu uptake into oocytes was higher in mRNA-injected oocytes than in vehicle-injected ones. Na+ omission or addition of tryptophan inhibited the uptake in mRNA-injected oocytes, although it did not affect that in vehicle-injected oocytes. These results suggest that Glu transporters with a tryptophan sensitivity different from that of Glu transporters in native oocytes are expressed after injection of rat brain mRNA.. AB - We characterized the glutamate (Glu) uptake in Xenopus oocytes injected with rat brain mRNA. The Glu uptake into oocytes was higher in mRNA-injected oocytes than in vehicle-injected ones. Na+ omission or addition of tryptophan inhibited the uptake in mRNA-injected oocytes, ...
Genes specifically expressed in the oocyte play key roles in oogenesis, ovarian folliculogenesis, fertilization and/or early embryonic development. In an attempt to identify novel oocyte-specific genes in the mouse, we have used an in silico subtraction methodology, and we have focused our attention on genes that are organized in genomic clusters. In the present work, five clusters have been studied: a cluster of thirteen genes characterized by an F-box domain localized on chromosome 9, a cluster of six genes related to T-cell leukaemia/lymphoma protein 1 (Tcl1) on chromosome 12, a cluster composed of a SPErm-associated glutamate (E)-Rich (Speer) protein expressed in the oocyte in the vicinity of four unknown genes specifically expressed in the testis on chromosome 14, a cluster composed of the oocyte secreted protein-1 (Oosp-1) gene and two Oosp-related genes on chromosome 19, all three being characterized by a partial N-terminal zona pellucida-like domain, and another small cluster of two genes on
The divisions of the germline stem cell are asymmetric in that they generate a renewing cell and a cell with the capacity to differentiate as an oocyte. Thereafter, the asymmetric meiotic divisions of oocytes produce one large cell, the egg, and two small polar bodies. In addition to asymmetric divisions, asymmetries are present in the form of localized cellular structures, organelles (mitochondria, endoplasmic reticulum, the oocyte nucleus), and also in the distribution of proteins and RNAs within the oocyte. All or a subset of these asymmetries are present in nearly all animals (Figure 3). For example, in most animals, the nucleus is in a central position within the early oocyte, but as oogenesis progresses, the oocyte nucleus moves to the oocyte periphery, or cortex (Figure 3). The side of the cell where the oocyte nucleus is localized in late-stage vertebrate oocytes is generally defined as the animal pole (Figure 3). Earlier asymmetries in oocytes are also shared among animals.
Prolonged culture of metaphase II oocytes is an in vitro aging process that compromises oocyte quality. We tested whether melatonin preserves epigenetic modifications in oocytes after prolonged culture. The porcine oocytes were maturated in vitro for 44 h, and then metaphase II oocytes were continuously cultured in medium supplemented with or without melatonin for 24 h. We found that the parthenogenetic blastocyst formation rate of prolonged-culture oocytes was lower than in fresh oocytes. We further observed that methylation at H3K4me2 and H3K27me2 of oocytes enhanced after prolonged culture. However, 5mc fluorescence intensity was lower in prolonged-culture oocytes than in fresh oocytes. Moreover, the promoter of the imprinted gene NNAT exhibited a higher level of DNA methylation in prolonged-culture oocytes than in fresh oocytes, which was associated with a reduced expression level and glucose uptake capability. Conversely, melatonin improved blastocyst formation rate and
Prolonged culture of metaphase II oocytes is an in vitro aging process that compromises oocyte quality. We tested whether melatonin preserves epigenetic modifications in oocytes after prolonged culture. The porcine oocytes were maturated in vitro for 44 h, and then metaphase II oocytes were continuously cultured in medium supplemented with or without melatonin for 24 h. We found that the parthenogenetic blastocyst formation rate of prolonged-culture oocytes was lower than in fresh oocytes. We further observed that methylation at H3K4me2 and H3K27me2 of oocytes enhanced after prolonged culture. However, 5mc fluorescence intensity was lower in prolonged-culture oocytes than in fresh oocytes. Moreover, the promoter of the imprinted gene NNAT exhibited a higher level of DNA methylation in prolonged-culture oocytes than in fresh oocytes, which was associated with a reduced expression level and glucose uptake capability. Conversely, melatonin improved blastocyst formation rate and
TY - JOUR. T1 - Exogenous adenosine Reduces the mitochondrial membrane potential of murine oocytes during the latter half of in vitro maturation and pronuclear formation following chemical activation. AU - Fujii, Wataru. AU - Funahashi, Hiroaki. PY - 2009/5/13. Y1 - 2009/5/13. N2 - The present study was undertaken to determine the effect of nucleosides on nuclear and cytoplasmic maturation of mouse oocytes. Oocyte-cumulus complexes (OCCs) were collected from large antral follicles 4 h after eCG-hCG treatment and cultured in maturation medium with or without nucleosides (4 ribo- and 4 deoxyribonucleosides) for 12 h. A majority of the oocytes examined developed to the metaphase-II stage, and the same result was found with in-vivo matured oocytes. However, mitochondrial membrane potential (MMP) was significantly lower in the oocytes matured in the presence of nucleosides than in the nucleoside-free controls. Oocyte MMP increased in vivo between 8 to 12 h after hCG injection, whereas no increases in ...
Purpose: To investigate impact of the one‐carbon metabolism (OCM) on oocyte maturity and embryo development. Methods: This prospective study analyzed 18 women who agreed to participate. We measured the OCM biomarkers concentrations including Vitamin B12 (VB12), folic acid (FA), and homocysteine (Hcy) in serum and follicular fluid (FF), and assessed their correlation. We also evaluated the influence of such OCM biomarker concentrations in mono‐FF on oocyte maturation, fertilization, embryo quality, and consequent pregnancy after embryo transfers. Results: All biomarkers showed a high concentration variability in different follicles of each woman, but their mean levels correlated with the serum levels. Among the 106 collected oocytes, 92 were mature, 59 were fertilized, and 16 yielded good‐quality embryos. We performed 26 single embryo transfers, and 7 patients achieved clinical pregnancies. VB12 concentration (FF) was significantly lower in fertilized than unfertilized oocytes by univariate
TY - JOUR. T1 - Effect of incubation with different concentrations and durations of FSH for in-vitro maturation of murine oocytes. AU - Lin, Yu Hung. AU - Hwang, Jiann-Loung. AU - Seow, Kok Min. AU - Huang, Lee Wen. AU - Hsieh, Bih Chwen. AU - Chen, Hen Ju. AU - Tzeng, Chii Ruey. AU - Bai, Chyi Huey. PY - 2011/7. Y1 - 2011/7. N2 - The purpose of the study was to evaluate whether a lower concentration of FSH or 2-h incubation with FSH would improve the outcome of in-vitro maturation of oocytes. The immature oocytes were obtained from FVB mice, and were allocated to four groups and incubated in the maturation media for 24 h. The maturation media were supplemented with 10 mIU/ml FSH for 24 h (group 1), 10 mIU/ml FSH for 2 h (group 2), 75 mIU/ml FSH for 24 h (group 3) or 75 mIU/ml FSH for 2 h (group 4). In each group, half of the in-vitro-matured oocytes were fertilized and cultured to blastocysts and the remaining matured oocytes were analysed for growth differentiation factor (GDF)-9 and bone ...
Synonyms for primary oocyte in Free Thesaurus. Antonyms for primary oocyte. 1 word related to oocyte: gametocyte. What are synonyms for primary oocyte?
Meiosis in mammalian oocytes is driven by changes in the activity of maturation-promoting factor (MPF). MPF activity is attributed entirely to the activity of the universal mitotic kinase, cdk1-cyclin B (Draetta et al., 1989; Labbe et al., 1989; Gautier et al., 1990). In mammals, oocytes are arrested in prophase of meiosis I with low levels of MPF (Hashimoto and Kishimoto, 1986; Choi et al., 1991). An increase in MPF activity stimulates entry into M phase of meiosis I, the first sign of which is germinal vesicle (GV) breakdown (GVBD), which takes place ∼90 min after release from the follicle. Continued cyclin B synthesis and increasing levels of MPF drive the oocyte to metaphase of the first meiotic division (Tay et al., 2000; Ledan et al., 2001), which is followed by polar body extrusion 7-9 h after GVBD. After MI, the oocyte proceeds immediately to meiosis II, where it arrests with high levels of MPF activity that are stabilized by cytostatic factor (CSF; Masui and Markert, 1971; Hashimoto ...
Oocytes are reliant on messenger RNA (mRNA) stores to support their survival and integrity during a protracted period of transcriptional dormancy as they await ovulation. Oocytes are, however, known to experience an age-associated alteration in mRNA transcript abundance, a phenomenon that contributes to reduced developmental potential. Here we have investigated whether the expression profile of small non-protein-coding RNAs (sRNAs) is similarly altered in aged mouse oocytes. The application of high throughput sequencing revealed substantial changes to the global sRNA profile of germinal vesicle stage oocytes from young (4-6 weeks) and aged mice (14-16 months). Among these, 160 endogenous small-interfering RNAs (endo-siRNAs) and 10 microRNAs (miRNAs) were determined to differentially accumulate within young and aged oocytes. Further, we revealed decreased expression of two members of the kinesin protein family, Kifc1 and Kifc5b, in aged oocytes; family members selectively targeted for expression ...
RNA binding proteins play a pivotal role during the oocyte-to-embryo transition and maternal phase of embryogenesis in invertebrates, but their function in these processes in mammalian systems remain largely understudied. Here we report that a member of the Pumilio/FBF family of RNA binding proteins in mice, Pumilio 1 (Pum1), is a maternal effect gene. The absence of maternal PUM1 in the oocyte does not affect meiotic maturation but leads to abnormal preimplantation development. Furthermore, genome-wide transcriptome analysis of oocytes and embryos revealed that there is a concomitant perturbation of the mRNA milieu. Of note, putative PUM1 mRNA targets were equally perturbed as non-direct targets, which indicates that PUM1 regulates the stability of maternal mRNAs both directly and indirectly. We show Cdk1 mRNA, a known PUM1 target essential for meiosis and preimplantation development, is not degraded appropriately during meiosis, leading to an increase in CDK1 protein in mature oocytes, which indicates
TY - JOUR. T1 - Gene expression profiling of human oocytes following in vivo or in vitro maturation. AU - Jones, Gayle Maree. AU - Cram, David Stephen. AU - Song, Bi. AU - Magli, C. AU - Gianaroli, Luca. AU - Lacham, Orly. AU - Findlay, Jock K. AU - Jenkin, Graham. AU - Trounson, Alan Osborne. PY - 2008. Y1 - 2008. N2 - BACKGROUND Immature human oocytes matured in vitro, particularly those from gonadotrophin stimulated ovaries, are developmentally incompetent when compared with oocytes matured in vivo. This developmental incompetence has been explained as poor oocyte cytoplasmic maturation without any determination of the likely molecular basis of this observation. METHODS Replicate whole human genome arrays were generated for immature and mature oocytes (matured in vivo and in vitro, prior to exposure to sperm) recovered from women undertaking gonadotrophin treatment for assisted reproduction. RESULTS More than 2000 genes were identified as expressed at more than 2-fold higher levels in oocytes ...
We investigated the effect mouse cumulus cells (mCCs) on the in vitro maturation (IVM) and developmental potential of bovine denuded germinal vesicle oocytes (DOs). Cumulus-oocyte complexes (COCs), DOs and DOs cocultured with either mCCs (DOs + mCCs) or bovine cumulus cells (bCCs; DOs + bCCs) were subjected to IVM. The meiosis II (MII) rates of DOs, glutathione (GSH) contents, zona pellucida (ZP) hardening and parthenogenetic blastocyst rates of MII oocytes were determined. The relative expression levels of bone morphogenetic protein 15 (BMP-15) and growth differentiation factor 9 (GDF-9) in MII oocytes were measured using quantitative real-time polymerase chain reaction (PCR). mCCs significantly increased the MII rate of DOs from 53.5 ± 3.58% to 69.67 ± 4.72% (p , 0.05) but had no effect on the GSH content (2.17 ± 0.31 pmol/oocyte with mCCs, 2.14 ± 0.53 pmol/oocyte without mCCs). For the DOs + mCCs group, the BMP-15 and GDF-9 expression levels were significantly higher and the ZP ...
Reproductive biotechnology such as in vitro fertilization, the creation of transgenic animals or cloning by nuclear transfer depends on the use of fully grown, meiotically competent oocytes capable of completing meiotic maturation by reaching the stage of metaphase II. However, there exists only a limited quantity of these oocytes in the ovaries of females. In view of their limited number, growing oocytes without meiotic competence represent a possible source. The mechanisms controlling the acquisition of meiotic competence, however, are still not completely clear. A gas with a short half-life, nitric oxide (NO), produced by NO-synthase (NOS) enzyme can fulfill a regulatory role in this period. The objective of this study was to ascertain the role of NO in the growth phase of pig oocytes and its influence on the acquisition of meiotic competence with the help of NOS inhibitors, NO donors and their combinations. We demonstrated that the selective competitive iNOS inhibitor aminoguanidine and also ...
Reconstitution of female germ cell development in vitro is a key challenge in reproductive biology and medicine. We show here that female (XX) embryonic stem cells and induced pluripotent stem cells in mice are induced into primordial germ cell-like cells (PGCLCs), which, when aggregated with female gonadal somatic cells as reconstituted ovaries, undergo X-reactivation, imprint erasure, and cyst formation, and exhibit meiotic potential. Upon transplantation under mouse ovarian bursa, PGCLCs in the reconstituted ovaries mature into germinal vesicle-stage oocytes, which then contribute to fertile offspring after in vitro maturation and fertilization. Our culture system serves as a robust foundation for the investigation of key properties of female germ cells, including the acquisition of totipotency, and for the reconstitution of whole female germ cell development in vitro. ...
TY - JOUR. T1 - Premature chromosome condensation as a sign of oocyte immaturity. AU - Egozcue Cuixart, Jose. AU - Santalo Pedro, Josep. PY - 1991/1/1. Y1 - 1991/1/1. N2 - In this work we report the possibility that oocyte immaturity is associated with premature chromosome condensation (PCC) after in-vitro fertilization (IVF). Using a murine model, we have related PCC and endoreduplicated-like oocytes to oocyte immaturity as a basis for a prognosis in oocyte immaturity problems. The cytogenetic analysis was performed in 511 embryos obtained from immature oocytes that were directly fertilized in vitro and in 1363 embryos obtained from immature oocytes that were matured in vitro with different concentrations of human chorionic gonadotrophin (HCG) added to the culture medium. As a control we used 507 embryos obtained from freshly ovulated oocytes. PCC at the G1-phase-(G1-PCC) was observed only when immature oocytes were immediately fertilized in vitro (45.4%) and PCC at the S-phase (S-PCC) only ...
OBJECTIVE To evaluate the effect of vitrification of mouse oocytes on the behavior of adult offspring. STUDY DESIGN Oocytes from mice were vitrified, warmed and inseminated, and two-cell embryos were transferred to foster mothers. The behavioral characterization of the offspring was detected by the Morris water maze test, forced swimming test, and elevated plus maze test, and compared to that of offspring from fresh oocytes. RESULTS Offspring produced by vitrified oocytes showed normal motor function. In the Morris water maze test of spatial learning there was a slightly decreased time spent in the quadrant containing the platform relative to mice from fresh oocytes, but the difference did not reach statistical significance. In addition, offspring from vitrified oocytes did not exhibit alterations in emotional behavior. CONCLUSION No alterations were found in the behavioral characterization of adult offspring from vitrified oocytes compared with those from fresh oocytes.
Embryo competence depends on oocyte quality, which is affected by different factors, including the treatment modality [12, 13]. We do not know the exact effect of the dosages and types of drugs on oocytes in IVF. Therefore, it was suggested that mild stimulation protocols and natural cycles would reduce aneuploidy rates and increase embryo quality [12]. However, every step during ovulation induction could affect the oocytes and subsequent embryo development.. Triggering oocyte maturation is the last important step of ovulation induction. For a long time, hCG has been used as a triggering agent because of its homology with LH and extended half-life. Although the extended half-life of this molecule might be advantageous for luteal support, its effect on oocyte maturation is not clear and hCG-mediated LH activity differs from natural cycles. Recently, GnRH agonists have been used as the triggering agent, especially in patients at a high risk of OHSS in GnRH antagonist cycles. The GnRHa displaces ...
Before an oocyte can be fertilised it has to go through both the cytoplasmic maturation and the nuclear maturation, which this sequence shows. Initially the germinal vesicle nucleus breaks down and disappears, which symbolizes the start of the nuclear maturation. The oocyte has already increased in volume approximately 20 times and reached a diameter of approximately 0,1 mm. This increase in volume takes place when the cytoplasmic maturation process starts several days prior. From a morphological standpoint the end of the first cellular reduction is seen by the appearance of a large cell, the oocyte itself and a tiny attached cellular structure, the so called polar body. The oocyte has reached the MII stage and is ready for fertilization.. Finally we see at high magnification the relatively fast extrusion of the polar body. Despite it´s small size, the polar body it normally contains half of the chromosomes of the oocyte. ...
In somatic cell nuclear transfer in mammals, to clone a piglet is still a big challenge. Although many factors could contribute to the low success rate, such as quality of donor and recipient cells, types of donor cell including sources of animal breeds and tissues, number of passages and culture conditions, timing of cell cycle, procedures of nuclear transfer, techniques and embryos transfer, one of the factors is believed to be poor oocyte activation, especially in pig nuclear transfer. Therefore studies presented in this thesis aimed at the establishment of an in vitro culture system for pig oocyte maturation and embryo culture, based on this system an electrical activation protocol for pig oocytes was optimized and also tested by monitoring in vivo development of activated pig oocytes. Finally, the protocol was used for activating pig embryos reconstructed by transfer of somatic cells into enucleated ovulated oocytes and for production of pig parthenotes to maintain pregnancies of cloned pig ...
The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30 to 40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of non-invasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different non-invasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been
TY - JOUR. T1 - Effect of glucose and pyruvate on nuclear and cytoplasmic maturation of porcine oocytes in a chemically defined medium. AU - Funahashi, H.. AU - Koike, T.. AU - Sakai, R.. PY - 2008/10/15. Y1 - 2008/10/15. N2 - The objective was to examine potential roles of glucose and pyruvate in nuclear and cytoplasmic maturation of porcine oocytes. Oocyte-cumulus complexes (OCC), derived from 3 to 6 mm follicles, were cultured in a chemically defined medium (pyruvate-free mNCSU37-PVA), with or without 5.55 mM glucose, during in vitro maturation (IVM); in the absence of glucose, germinal vesicle breakdown (GVBD) and nuclear maturation were prevented (P , 0.05). Subsequently, OCC were cultured for IVM in glucose-containing mNCSU37-PVA supplemented with 6-amononicotinamide (6-AN) and diphenyleneiodonium (DPI), inhibitors of the pentose phosphate pathway (PPP); both compounds (≥10 μM 6-AN and ≥10 nM DPI) inhibited resumption of meiosis (P , 0.05). Supplementation of glucose-free maturation ...
Download Free Full-Text of an article THE EFFECT OF 20% HEATED AND NON-HEATED FOLLICULAR FLUID ON MATURATION AND DEVELOPMENT OF IMMATURE MOUSE OOCYTES IN VITRO
These systems are designed for two-electrode, whole-cell voltage clamping of large cells such as Xenopus oocytes and cell structures such as squid axons. They are either bundled with an Oocyte Clamp Amplifier or a more comprehensive Two Electrode Voltage Clamp Workstation, which provide clamping and amplification of measured signals from glass microelectrodes/sharp electrodes.
High environmental temperatures observed during the hot months of the year reduce fertility in lactating dairy cows. Summer heat stress depression in fertility is a multifactorial problem that affects physiological and cellular functions in several tissues. It has been shown that in addition to compromise follicular development, hormonal secretion, endometrial and embryonic function, heat stress also markedly reduces oocyte developmental ability. Oocyte susceptibility to elevated temperature can be detected during the germinal vesicle (GV) and oocyte maturation periods. In vivo (heat stress) and in vitro (heat shock) experiments indicated that exposure of bovine oocytes to elevated temperature affects the events required for successful oocyte maturation, fertilization and embryonic preimplantation development. This heat- induced decrease in oocyte function occurs due to a series of cellular alterations that affects nuclear and cytoplasmic compartments of the bovine oocyte. However, ...
In vitro maturation of dog oocytes has always been the main obstacle preventing reproductive biologist from producing canine in vitro cultured embryos. The unsuccessful oocyte maturation in canine species originates from their unique physiological and biological specifications. Ovulation of dominant follicles in bitch (6-12 in each oestrous cycle) occurs at prophase I stage of oocyte nucleus and meiotic resumption develops during 3-5 days of oviductal transition. During this PhD thesis, studies were designed in order to speculate characteristics of canine oocyte maturation in vitro in terms of maturation media components, gas composition of the incubator and hormonal requirements. Level of oxidative stress during 72h (culture period) of in vitro maturation showed that 5%O2, 5% CO2 and 90% N2 composition improves meiotic resumption and reduces degeneration rate significantly compared to 5% CO2 in air. Utilization of caffeine as a non specific phosphodiesterase inhibitor at 10mM for 12h at the ...
In this work, we report an efficient method to easily study transmitter receptors originally assembled in cultured cell lines and then microtransplanted to a sturdy and convenient host cell system, the Xenopus oocyte. This method has been recently used to transplant assembled transmitter receptors from human brain to Xenopus oocyte (7), following a method developed a few years ago to microtransplant AcChoRs and chloride channels from the electric organ of Torpedo to the Xenopus oocyte membrane (5, 6). Here, we injected membrane vesicles prepared from cultured cell lines, and this approach led to a rapid incorporation of neurotransmitter receptors in the oocyte plasma membrane. In this way, functional AMPA-type GluR1, α7-AcChoRs, and α4β2-AcChoRs from cultured cells were microtransplanted to the oocytes, and their respective transmitter-activated currents were analyzed.. We report here that the gross electrophysiological and pharmacological characteristics of the transmitter-gated receptors ...
Guanyl nucleotide binding-proteins, or G-proteins, are ubiquitous molecules that are involved in cellular signal transduction mechanisms. Because a role has been established for cAMP in meiosis and G-proteins participate in cAMP-generating systems by stimulating or inhibiting adenylate cyclase, the present study was conducted to examine the possible involvement of G-proteins in the resumption of meiotic maturation. Cumulus cell-free mouse oocytes (denuded oocytes) were maintained in meiotic arrest in a transient and dose-dependent manner when microinjected with the nonhydrolyzable GTP analog, GTP gamma S. This effect was specific for GTP gamma S, because GppNHp, GTP, and ATP gamma S were without effect. Three compounds, known to interact with G-proteins, were tested for their ability to modulate meiotic maturation: pertussis toxin, cholera toxin, and aluminum fluoride (AlF4-). Pertussis toxin had little effect on maturation in either cumulus cell-enclosed oocytes or denuded oocytes when
Vitrified-warmed immature equine oocytes are able to complete the first meiotic division, but their subsequent developmental competence is compromised. Therefore, the present study investigated the effects of vitrifying immature horse oocytes on the chromosome and spindle configuration after IVM. Cumulus-oocytes complexes (COCs) were collected and divided into two groups based ... read more on mare age (young ≤14 years; old ≥16 years). COCs were then either directly matured invitro or vitrified and warmed before IVM. Spindle morphology and chromosome alignment within MII stage oocytes were assessed using immunofluorescent staining, confocal microscopy and three-dimensional image analysis. Vitrification reduced the ability of oocytes to reach MII and resulted in ultrastructural changes to the meiotic spindle, including shortening of its long axis, and an increased incidence of chromosomes failing to align properly at the metaphase plate. We hypothesise that aberrant chromosome alignment is an ...
Actin assembly is regulated by capping protein, which binds the barbed ends of actin filaments and terminates their elongation. This process is involved in the asymmetric division of mouse oocytes, but the role of capping protein itself is poorly understood. In this study (p. 160), Suk Namgoong, Nam-Hyung Kim and colleagues investigate the roles of capping protein at different stages of mouse oocyte maturation. The authors first show that capping protein mainly localises to the oocyte cytoplasm during maturation. Knockdown of capping protein impaired the asymmetric division of oocytes and increased the polar body size, suggesting that this protein is involved in spindle migration during oocyte migration. In addition, the authors observed a reduction in the cytoplasmic actin mesh in the absence of capping protein. Ectopic overexpression of capping protein also impaired asymmetric division and caused severe abnormalities in polar body extrusion. Time-lapse microscopy confirmed that knockdown or ...
Epidermal growth factor (EGF) has been shown to have a positive effect during in vitro maturation (IVM) and has been reported in follicular fluid at levels capable of stimulating meiosis in a variety of species. The aim of the present work was to study the effect on subsequent development of EGF present in defined medium during bovine 1) oocyte maturation or 2) embryo culture. The presence of EGF during IVM, irrespective of concentration (1, 10, 100 ng/mg), stimulated cumulus expansion and significantly increased the proportion of oocytes attaining metaphase II, the rate of cleavage, and the proportion of embryos reaching the 5- to 8-cell stage at 72 h postinsemination. Blastocyst rates on Days 7 and 9 were also significantly improved for oocytes matured in the presence of EGF (10% vs. 18-24% on Day 7 and 21% vs. 31-32% on Day 9, for Tissue Culture Medium 199 [M199] and M199 + EGF, respectively). The presence of fetal calf serum (FCS) during IVM resulted in similarly elevated rates of development. There
The mammalian oocyte develops within a complex of somatic cells known as a follicle, within which signals from the somatic cells regulate the oocyte, and signals from the oocyte regulate the somatic cells. Because isolation of the oocyte from the follicle disrupts these communication pathways, oocyte physiology is best studied within an intact follicle. Here we describe methods for quantitative microinjection of follicle-enclosed mouse oocytes, thus allowing the introduction of signaling molecules as well as optical probes into the oocyte within its physiological environment.
This is the stage of a mature oocyte that has the potential of being fertilized. The stage of metaphase II (MII) indicates that the first meiotic division has been completed and cell cycle is suspended at the MII stage. The pairs of homologue chromosomes are divided in the two resulting cells, which are uneven in size. The larger cell is the oocytes, and the smaller cell is the 1st polar body that has half the number of chromosomes and little cytoplasm.. Immature oocytes cannot be fertilized because they have 46 chromosomes (diploid) hence fertilization by a haploid sperm would give rise to a zygote with 69 chromosomes. However, in some cases immature oocytes can be matured in vitro in the laboratory. During IVF, only a small percentage of oocytes is usually immature.. There is a correlation of oocyte maturation and follicle diameter, although this is not always true. It is possible to collect mature oocytes from smaller follicles and vice versa.. ...
This is the stage of a mature oocyte that has the potential of being fertilized. The stage of metaphase II (MII) indicates that the first meiotic division has been completed and cell cycle is suspended at the MII stage. The pairs of homologue chromosomes are divided in the two resulting cells, which are uneven in size. The larger cell is the oocytes, and the smaller cell is the 1st polar body that has half the number of chromosomes and little cytoplasm.. Immature oocytes cannot be fertilized because they have 46 chromosomes (diploid) hence fertilization by a haploid sperm would give rise to a zygote with 69 chromosomes. However, in some cases immature oocytes can be matured in vitro in the laboratory. During IVF, only a small percentage of oocytes is usually immature.. There is a correlation of oocyte maturation and follicle diameter, although this is not always true. It is possible to collect mature oocytes from smaller follicles and vice versa.. ...
PURPOSE: This project was to determine whether oocytes isolated from virgin aged mice, up to 18 months old, are competent to undergo cytoplasmic maturation in vitro and undergo fertilization and embryonic development. If so, oocyte maturation in vitro could be used as a strategy to rescue valuable genetic resources. RESULTS: Although the number of oocytes recovered from mice was greatly reduced with increasing age, the percentage of oocytes that underwent fertilization, cleavage, and development to the blastocyst stage was essentially unchanged up to 18 months of age. The success of cleavage to the two-cell stage was greater after maturation in vitro (81%) than gonadotropin-induced maturation in vivo (55%). About 20% (20/106) of the embryos derived from oocytes isolated from 18-month-old mice developed to term after embryo transfer. CONCLUSION: Oocytes from virgin aged mice undergo normal cytoplasmic maturation in vitro. Higher percentages of oocytes from aged mice cleave to the two-cell
Selection of the best oocyte for subsequent steps of fertilization and embryo transfer was shown to be the crucial step in human infertility treatment procedure. Oocyte selection using morphological criteria mainly Zona pellucida (ZP) has been the gold standard method in assisted reproductive technologies (ART) clinics, but this selection approach has limitations in terms of accuracy, objectivity and constancy. Recent studies using OMICs-based approaches have allowed the identification of key molecular markers that quantitatively and non-invasively predict the oocyte quality for higher pregnancy rates and efficient infertility treatment. These biomarkers are a valuable reinforcement of the morphological selection criteria widely used in in vitro fertilization (IVF) clinics. In this context, this study was designed to investigate the relationship between transcriptomic predictors of oocyte quality found by our group and the conventional morphological parameters of oocyte quality mainly the ZP
Background & aim: In vitro maturation and fertilization of oocytes play an important role in reproductive biotechnology. The aim of this study is to define the IGF-1 effect on in vitro maturation, fertilization and development of mice immature oocytes to 2-cells in TCM199 medium cultures. Methods: In this study 4 week ...
During mitosis, a spindle checkpoint detects chromosome misalignment and halts the cell cycle progression. In meiosis of female germ cells, however, it is debatable whether such a checkpoint is present. This research employed a unique model in the mouse, mitotic chromosomes transferred to meiotic cytoplasts to investigate whether a meiotic oocytes microtubule apparatus can effectively separate mitotic metaphase chromosomes, and whether a spindle checkpoint exists during its division. The intact germinal vesicle (GV) oocytes, enucleated GV cytoplasts, and enucleated GV cytoplasts at 15 h in-vitro maturation were transferred with a metaphase fibroblast cell. When mitotic chromosomes were transferred into enucleated or intact mouse GV oocytes, the first bipolar meiotic spindles were established and the reconstructed oocytes were able to extrude polar bodies. However, none of the reconstructed oocytes showed complete and accurate alignment of chromosomes, except the enucleated GV cytoplasts reconstructed
I am a developmental/reproductive biologist studying the development of mammalian oocytes, the cells that become eggs. The focus of my research is on the complex interactions between developing oocytes and their companion follicular somatic cells, the granulosa cells. I found that oocytes are not simply passive recipients of nutrients and signals from ovarian follicular somatic cells, as once believed, but rather actively promote the functions of somatic cells needed to support oocyte development and regulate meiosis. I originated the concept of an oocyte-granulosa cell regulatory loop in which bi-directional communication between the oocyte and companion granulosa cells is essential for both normal oocyte and follicular development. A major goal of my current research is to define the components of this regulatory loop and their functions. I also achieved the first complete development of mammalian oocytes in vitro. This included in vitro initiation of primordial follicle development, oocyte ...
In most species, the cytoplasm of oocytes in primordial follicles exhibits organelles close to the nucleus or uniformly distributed throughout the cytoplasm (Figure 1A and 1B). In humans, groups of organelles are seen close to the nucleus and are named Balbiani bodies [54]. Balbiani body is a large distinctive collection of organelles asymmetrically located near the nucleus in very young oocytes, consisting of mitochondria and associated endoplasmic reticulum surrounding Golgi elements. Besides being well described in human oocytes, they are also found in oocytes of other species (vertebrates and invertebrates). Although the function of mammalian Balbiani body is unknown, this structure may have a possible role in nucleo-cytoplasmic transfer [55],[56].. In any case, the most abundant organelles found in primordial follicle oocytes are round-shaped mitochondria (Figure 1B) [44], which are known to be an immature form of this organelle and develop to an elongated shape as they become mature [57]. ...
Oocytes are powerful local modulators of follicular cell functions and many of the activities of oocytes are attributed to members of the transforming growth factor-β (TGF-β) superfamily. Whilst in the mouse it is known that members of this family are able to mimic many of the effects of oocytes on follicular cells, the relative importance of any of these factors is unknown in bovine follicles. The objectives of this study were to determine if bovine oocytes express and secrete TGF-β and to compare oocyte-secreted factor(s) to TGF-β in terms of their capacities to stimulate mural granulosa cell (MGC) DNA synthesis. Bovine ovaries were collected from an abattoir and RNA was extracted from isolated MGC, cumulus cells, cumulus-oocyte complexes and denuded oocytes (DO). Using RT-PCR, all cell types were found to express TGF-β1 and TGF-β2 mRNA transcripts. However, no TGF-β bioactivity could be detected from DO using a sensitive (40 pg/ml) and specific mink lung fibroblast cell bioassay. MGC ...
TY - JOUR. T1 - RNA transport to the vegetal cortex of Xenopus oocytes. AU - Zhou, Yi. AU - King, Mary Lou. N1 - Funding Information: We thank Kim L. Mowry for providing us with the XβG, XβG-340/3′, and pSP73XβM5′ constructs, Joel K. Yisraeli for sharing his in situ hybridization protocol, and the members of the King laboratory, especially Jian Zhang and Caryl Forristall, for helpful advice and discussions. This was supported by NIH Grant GM 33932 to M. L. King.. PY - 1996/10/10. Y1 - 1996/10/10. N2 - Xcat-2 RNA, a component of the germ plasm in Xenopus, localizes with the mitochondrial cloud material to the vegetal cortex in stage II oocytes. Vg1 RNA also localizes to the vegetal cortex, but later in stage III/IV oocytes, using a microtubule dependent pathway. To further analyze the mechanisms involved in RNA transport, in situ hybridization and autoradiography were used to follow the localization of endogenous Vg1 and injected Xcat-2 transcripts in stage IV oocytes. We show that Xcat-2 ...
Maturation of the mammalian oocyte is characterized in part by dissolution of the nuclear envelope, or germinal vesicle breakdown (GVB). By fluorescence microscopy after vital uptake of acridine orange (AO), redistribution and perinuclear accumulation of organelles corresponding to lysosomes occur before GVB in rat oocytes undergoing meiotic maturation in vitro. In follicle-enclosed oocytes explanted during the preovulatory gonadotropin surge (GS) and individually cultured as such in chemically defined medium at approximately 22 degrees C, lysosomes aggregated into disperse clusters after 30 min; by 60 min, perinuclear concentration of lysosomes and their essential disappearance from the cortical ooplasm were observed. GVB occurred within 120 min. In contrast, follicle-enclosed oocytes explanted before the GS displayed a generally homogeneous distribution of lysosomes and intact GV for up to 5 h in culture. In oocytes aspirated from follicles before the GS, partially denuded of granulosa cells, ...
Many young cancer patients are now being given the option to store ovarian cortical biopsies before undergoing potentially damaging chemo or radio-therapy. This tissue mainly contains large numbers of immature primordial follicles. Currently the only option to restore fertility using this tissue is by transplantation which may not be a viable option for all patients. Greater options to realise the potential of this tissue to restore fertility could be achieved by the development of in vitro systems that support oocyte development. The ability to develop human oocytes from the most immature stages of follicles (primordial) through to maturation and fertilisation in vitro would revolutionise fertility preservation practice. This has been achieved in mouse where in vitro grown (IVG) oocytes from primordial follicles have resulted in the production of live offspring. However, developing IVG systems to support complete development of human oocytes has been more difficult because of differences in scale of
In bovine oocytes, the resumption of meiosis is characterized by the breakdown of the germinal vesicle (GVBD). When cumulus-oocyte complexes (COCs) are cultured in-vitro in the presence of gonadotropins, GVBD is characterized by an initial inhibitory phase, which is followed by an acceleration in the rate of GVBD. An initial transcriptional event is required for gonadotropin-induced in-vitro maturation. The objectives of this thesis were: 1) to define the time course required for transcriptional initiation in bovine cumulus oocyte complexes (COCs); 2) to determine the pattern of expression for Nr4A1 and Egr1 mRNAs in bovine COCs; and 3) to reduce the expression of Nr4A1 mRNA expression to determine its effect on oocyte maturation. Bovine COCs were cultured in the presence follicle stimulating hormone (FSH) alone or FSH with the transcriptional inhibitor, 5,6-dichloro-1-B-Dribofuranosylbenzamidazole (DRB), in order to refine the time course required for transcription initiation and to determine ...
Previous work has demonstrated that the Xenopus protooncogene mosxe can induce the maturation of prophase-arrested Xenopus oocytes. Recently, we showed that mosxe can transform murine NIH3T3 fibroblasts, although it exhibited only 1-2% of the transforming activity of the v-mos oncogene. In this study we have investigated the ability of the v-mos protein to substitute for the mosxe protein in stimulating Xenopus oocytes to complete meiosis. Microinjection of in vitro synthesized RNAs encoding either the mosxe or v-mos proteins stimulates resting oocytes to undergo germinal vesicle breakdown. Microinjection of an antisense oligonucleotide spanning the initiation codon of the mosxe gene blocked progesterone-induced oocyte maturation. When oocytes were microinjected first with the mosxe antisense oligonucleotide, and subsequently with in vitro synthesized v-mos RNA, meiotic maturation was rescued as evidenced by germinal vesicle breakdown. The v-mos protein exhibited in vitro kinase activity when ...
Huang X.,Wang H-L.,Qi S-T.,Wang Z-B.,Tong J-S.,...&Sun Q-Y.(2011).DYNLT3 Is Required for Chromosome Alignment During Mouse Oocyte Meiotic Maturation.Reproductive Sciences,18(10),983-989 ...
Sodium fluoride (NaF) is used as a medicine to prevent tooth decay; however, excessive NaF could cause a pathological damage to the health. Recent studies showed that NaF impaired mouse oocyte maturation, included of abnormal spindle configuration, actin cap formation, cortical granule-free domain formation, and the following development after fertilization. However, few studies used large animals as models to study the toxicology of NaF on oocytes maturation. We proposed a hypothesis that NaF would affect the nuclear and cytoplasmic maturation of porcine oocytes and DNA methylation pattern of imprinted genes in oocytes. Our results showed that NaF affected cumulus expansion, polar body emission, spindle morphology, cortical granule distribution, early apoptosis, and the following development after parthenogenetic activation during porcine oocyte maturation. Moreover, NaF increased the DNA methylation of NNAT and decreased its expression, which disturbed the glucose transport in oocytes. These ...
During the growth and maturation of ovarian follicles of most species, oocytes are arrested in a dictyate stage of meiosis. This state, which has the properties of the G2 phase of mitosis, is characterized by the presence of a morphologically distinguishable nucleus with a prominent nucleolus (germinal vesicle, GV) and is associated with partial decondensation of the chromosomes. In all species studied, a gonadotropin-dependent signal derived from somatic cells surrounding the oocyte induces reentry into the meiotic cell cycle, and completion of the first meiotic division involves chromosome condensation, dissolution of the nuclear membrane (germinal vesicle breakdown, GVBD) and spindle organization. This first meiotic division is completed with the emission of the first polar body. Unlike the mitotic cycle where DNA synthesis occurs during the S phase, oocytes immediately enter a second division without an S phase and are arrested in metaphase II. Only metaphase II stage oocytes are able to ...
TY - JOUR. T1 - Characterization of PC2, a mammalian Kex2 homologue, following expression of the cDNA in microinjected Xenopus oocytes. AU - Shennan, K I. AU - Smeekens, S P. AU - Steiner, D F. AU - Docherty, K. PY - 1991/6/24. Y1 - 1991/6/24. N2 - A human insulinoma cDNA (PC2) that encodes a protein homologous to the Kex2/subtilisin-like proteinases has recently been described [1990, J. Biol. Chem. 265, 2997-3000]. In order to characterise the associated proteinase activity, mRNA encoding PC2 was synthesised in vitro and microinjected into Xenopus oocytes. The proteinase activity released into the media from oocytes microinjected with PC2 mRNA was assayed using small peptide fluorogenic substrates. Boc.Gln.Arg.Arg aminomethyl coumarin was hydrolysed in a Ca(2+)-dependent manner, but substrate analogues bearing a single basic aminoacid were not. The substrate specificity, inhibitor profile, and pH optimum of 5.5 were compatible with an involvement of PC2 in prohormone processing in mammalian ...
Vertebrate females produce their full complement of oocytes during embryogenesis and, over time, these are either released (and fertilized or not) or undergo cell death. Oocyte death ultimately leads to sterility as the animals age and conditions that accelerate death of the eggs cause premature infertility. Nutt et al. used unfertilized Xenopus eggs and egg extracts that recapitulate many of the cell death events to investigate the molecular mechanisms that control oocyte survival. Caspase-2 was known to regulate mouse oocyte survival, and Nutt et al. show that caspase-2 activity is inhibited in Xenopus oocytes by NADPH, which is produced as a by-product of metabolic flux through the pentose-phosphate pathway. Addition of glucose-6-phosphate (G6P) or other intermediates in the pentose-phosphate pathway, but not the glycolytic pathway, inhibited activation of caspase-2 and caspase-3, cytochrome c release, and oocyte cell death. Inhibition of G6P dehydrogenase by dehydroisoandrosterone (DHEA), ...
OBJECTIVE: The aims of this study were to investigate whether fertilization could induce the resumption of meiosis in mouse oocytes arrested at metaphase I (MI) after in vitro maturation (IVM), and to investigate the effect of Ca²⁺ chelator treatment at the time of fertilization on the transition from MI to metaphase II (MII). METHODS: MII-stage and arrested MI-stage mouse oocytes after IVM were fertilized, and then embryonic development was monitored. Blastocysts from each group were transferred into 2.5 days post-coitum pseudo-pregnant ICR mice. MI oocytes after IVM were treated with a Ca²⁺ chelator to investigate the effect of Ca²⁺ oscillations on their maturation. RESULTS: As insemination time increased, the number of oocytes in the MI group that reached the MII stage also increased. The blastocyst rates and total cell numbers in the MII group were significantly higher than in the MI group. No pregnancy occurred in the MI group, but 10 pregnancies were achieved (10 of 12) in the MII ...
TY - JOUR. T1 - Maturation and fertilization of nonhuman primate oocytes are compromised by oral administration of a cyclooxygenase-2 inhibitor. AU - Duffy, Diane M.. AU - Vandevoort, Catherine A.. PY - 2011/3/15. Y1 - 2011/3/15. N2 - Objective: To determine if oral administration of a cyclooxygenase-2 (COX2) inhibitor affects oocyte nuclear maturation and fertilization in nonhuman primates. Design: Laboratory research study. Setting: Medical school. Animal(s): Adult female cynomolgus monkeys (Macaca fascicularis). Intervention(s): Monkeys received gonadotropins to stimulate multiple follicular development. An ovulatory dose of hCG was administered either alone or with oral celecoxib, a COX2 inhibitor. Oocytes were retrieved 36 hours later and exposed to sperm in vitro. Main Outcome Measure(s): Oocytes were assessed for nuclear status at retrieval, resumption of meiosis in vitro, and success of in vitro fertilization. Result(s): Treatment with hCG alone yielded oocytes that were primarily ...
Contents: Preface; Part I. Historical Perspective: 1. Insights into the amphibian egg to understand the mammalian oocyte Kei Miyamoto and John B. Gurdon; Part II. Life Cycle: 2. Otogeny of the mammalian oocyte Anne Grete Byskov and Majken Nielsen; 3. Gene networks in oocyte meiosis Paula Cohen and Swapna Mohan; 4. Follicle formation and oocyte death Melissa E. Pepling; 5. The early stages of follicular growth Alain Gougeon; 6. Follicle and oocyte developmental dynamics Aaron J. W. Hsueh and Kazuhiro Kawamura; 7. Mouse models to identify genes throughout oogenesis Jia Peng, Qinglei Li and Martin M. Matzuk; Part III. Developmental Biology: 8. Structural basis for oocyte-granulosa cell interactions Ursula Eichenlaub-Ritter and Carlos Plancha; 9. Differential gene expression mediated by oocyte/granulosa cell communication Saiichi Furukawa and Koji Sugiura; 10. Hormones and growth factors in the regulation of oocyte maturation Marco Conti; 11. Getting into and out of oocyte maturation Hayden Homer; ...
MicroRNAs (miRNAs) are small noncoding RNAs that act as post-transcriptional regulators of gene targets. Accurate quantification of miRNA expression using validated internal controls should aid in the understanding of their role in epigenetic modification of genome function. To date, most studies that have examined miRNA expression levels have used the global mean expression of all expressed genes or the expression of reference mRNAs or nuclear RNAs for normalization. We analyzed the suitability of a number of miRNAs as potential expression normalizers in bovine oocytes and early embryos, and porcine oocytes. The stages examined were bovine oocytes at the germinal vesicle (GV) and metaphase II stages, bovine zygotes, 2, 4 and 8 cell embryos, morulae and blastocysts, as well as porcine cumulus oocyte complexes, GV, metaphase I and II oocytes. qRT-PCR was performed to quantify expression of miR-93, miR-103, miR-26a, miR-191, miR-23b, Let-7a and U6 for bovine samples and miR-21, miR-26a, miR-93, miR-103,
Comparison of Gene Expression between Cumulus Oocyte Complexes and Naked Oocytes by Suppression Subtractive Hybridization in Swine - Suppression Subtractive Hybridization (SSH);Gene Expression;Cumulus Cells, Porcine;
Previously we discovered that the growth arrest-specific gene 6 (in oocyte maturation and fertilization using RNA interference (RNAi). but not nuclear maturation and 2) the decreased manifestation and decreased MPF activity separately or mutually influence sperm head decondensation and PN formation. Intro Mammalian oocytes in ovarian follicles have arrested growth and a large nucleus known as a germinal vesicle (GV). The meiotic cell cycle is arrested in the diplotene stage PDK1 inhibitor of the 1st prophase and some selective oocytes initiate growth following gonadotropin simulation [1] [2]. Oocyte growth and maturation are long and requisite processes for fertilization and subsequent embryo development until embryonic genome activation starts. Oocyte maturation entails nuclear and cytoplasmic maturation. Although strictly linked these are complex and different events [3] [4] [5]. The process of nuclear maturation meiotic cell cycle involves GV breakdown (GVBD) chromosome condensation and ...
Vitrification is the safest method to cryopreserve oocytes, however the process alters mitochondrial function resulting from increased reactive oxygen species (ROS) production. Our aim was to alleviate ROS stress in vitrified mice oocytes using N-acetylcysteine (NAC at 1 mM), to improve the oocytes developmental competence. Hence, four experimental groups were compared: fresh oocytes (F-C), vitrified oocytes (V-C), NAC addition prior to oocyte vitrification (V-NAC-Pre) and NAC addition after vitrification (V-NAC-Post). V-NAC-Pre and V-NAC-Post exhibited higher levels of mitochondrial polarization compared to vitrified oocytes (36.5 ± 3.1, 37.7 ± 1.3 and 27.2 ± 2.4 measured as the spatial coefficient of variation/oocyte respectively, mean ± SEM; p | 0.05). However, ROS production increased in vitrified oocytes added with NAC compared to the vitrified control (1124.7 ± 102.1 [V-NAC-Pre] and 1063.2 ± 82.1 [V-NAC-Post] vs. 794.6 ± 164.9 [V-C]; arbitrary fluorescence units/oocyte, mean ± SEM; p | 0
Prophase I arrest, referred to as the germinal vesicle (GV) stage, is a conserved feature of oocytes across species (Whitaker, 1996; Mehlmann, 2005; Jones, 2008). In mice, as in all mammals, GV arrest begins shortly after meiotic recombination in fetal life. Periodic, non-hormonal recruitment of a small number of quiescent follicles into the growing pool after birth leads to follicle growth and eventual ovulation, both of which are hormone dependent. It is only near the time of ovulation in the fully grown oocytes of mature follicles that a rise in luteinizing hormone (LH) breaks this arrest, causing GV breakdown (GVB).. A high level of cAMP, generated from a Gs-coupled oocyte receptor, is needed to maintain arrest in fully grown oocytes (Cho et al., 1974; Magnusson and Hillensjo, 1977; Bornslaeger et al., 1986; Mehlmann et al., 2002; Freudzon et al., 2005). This is enhanced by cGMP from the surrounding cumulus cells, which inhibits phosphodiesterase 3A (PDE3A) activity, preventing cAMP ...
Much of the scientific knowledge on oocyte maturation, fertilization, and embryonic development has come from the experiments using gametes of marine organisms that reproduce by external fertilization. In particular, echinoderm eggs have enabled the study of structural and biochemical changes related to meiotic maturation and fertilization owing to the abundant availability of large and transparent oocytes and eggs. Thus, in vitro studies of oocyte maturation and sperm-induced egg activation in starfish are carried out under experimental conditions that resemble those occurring in nature. During the maturation process, immature oocytes of starfish are released from the prophase of the first meiotic division, and acquire the competence to be fertilized through a highly programmed sequence of morphological and physiological changes at the oocyte surface. In addition, the changes in the cortical and nuclear regions are essential for normal and monospermic fertilization. This review summarizes the current
Much of the scientific knowledge on oocyte maturation, fertilization, and embryonic development has come from the experiments using gametes of marine organisms that reproduce by external fertilization. In particular, echinoderm eggs have enabled the study of structural and biochemical changes related to meiotic maturation and fertilization owing to the abundant availability of large and transparent oocytes and eggs. Thus, in vitro studies of oocyte maturation and sperm-induced egg activation in starfish are carried out under experimental conditions that resemble those occurring in nature. During the maturation process, immature oocytes of starfish are released from the prophase of the first meiotic division, and acquire the competence to be fertilized through a highly programmed sequence of morphological and physiological changes at the oocyte surface. In addition, the changes in the cortical and nuclear regions are essential for normal and monospermic fertilization. This review summarizes the current
In the current study, we found that the polar body rate, an index of the nucleus maturation of porcine oocytes, was retarded by heat stress. Resveratrol (2.0 μmol/L) relieved the adverse effect and increased the proportion of oocytes that had matured into the MII stage (Fig. 1a). This effect of resveratrol may attribute its ability to be an antioxidant. Resveratrol has a strong capacity to reduce oxidant damage [29]. It improves the maturation environment by alleviating the high level of ROS in heat-treated porcine oocytes. Our results confirmed that resveratrol (2.0 μmol/L) not only scavenged ROS but also improved the intracellular GSH level of oocytes to further fight oxidative stress (Fig. 2b-c). This finding was consistent with the result of Kwak et al. [25]. These authors reported that resveratrol failed to increase the polar body rate of porcine oocytes in the normal case. However, our data showed that resveratrol (2.0 μmol/L) improved nuclear maturation, which indicated resveratrol had ...
TY - JOUR. T1 - Expression analysis of TFIID in single human oocytes. T2 - New potential molecular markers of oocyte quality. AU - di Pietro, Cinzia. AU - Vento, M.. AU - Ragusa, M.. AU - Barbagallo, D.. AU - Guglielmino, M. R.. AU - Maniscalchi, T.. AU - Duro, L. R.. AU - Tomasello, L.. AU - Majorana, A.. AU - de Palma, A.. AU - Borzì, P.. AU - Scollo, P.. AU - Purrello, M.. PY - 2008/9. Y1 - 2008/9. N2 - Molecular characterization of human female gametes should make it easier to understand the basis of certain infertility disorders. Biologically significant mRNAs have been analysed in single oocytes to search for molecular biomarkers of oocyte quality. Initial analysis was focused on mRNA for proteins involved in cell growth and cycle control, specifically those encoding members of the general transcription apparatus such as the subunits of the general transcription factor TFIID. This heteromultimeric protein, comprising about 15 subunits, is the most important general transcription factor of ...
This approach effectively reduces the size of the cDNA library to be screened and increases the probability of successful isolation of the target cDNA. The vocal apparatus of the clawed frog is designed for underwater sound production (Deuchar, 1975). The first step of this physiological process seems to involve a target site at the oocyte membrane, as shown by a variety of experimental data (4). Here we demonstrate cytoplasmic microinjection of Xenopus laevis oocytes with a nuclear import substrate, as well as preparation of the injected oocytes for visualization by … Their large nuclei and mitochondrial masses are clearly visible in the intact oocyte. The incision is sutured with surgical silk and the frog is placed in shallow water in a small tank to allow it to recover from anesthesia before placing it in a special tank for postoperative frogs. XENOPUS OOCYTES The oocyte from the South African clawed frog Xenopus laevis is an often used functional expression system. Two species of Xenopus ...
The results of this study demonstrated that there is a remarkable difference in in vitro-growth of primary follicles retrieved from neonatal mice of different ages, which suggests a positive correlation between number of retrieved follicles and derivation of mature oocytes per animal. Continuous increase in retrieval number of preantral follicles was observed as the age was increased up to 14-day-old and, among those follicles, primary follicles yielded developmentally-competent oocytes following our in vitro-culture. The best efficiencies in follicle retrieval and oocyte maturation was obtained at 11 day old females and percentile values of intrafollicular oocytes to initiate and complete meiotic maturation, however, are similar among the ages (9- to 11-day-olds).. Although many efforts for the establishment of in vitro culture system for primary follicles have been made (Eppig et al., 1989; Cortvrindt et al., 1996; OBrien et al., 2003; Lenie et al., 2004; Sadeu et al., 2008), there was no a ...
Chromosome abnormalities are common in oocytes derived from patients undergoing IVF treatment. The proportion of oocytes displaying aneuploidy is closely related to maternal age and may exceed 60% in patients over 40 years old. However, little information currently exists concerning the incidence of such anomalies in oocytes derived from young fertile women. A total of 121 metaphase II oocytes and their corresponding first polar bodies (PB) were analysed with the use of a comprehensive cytogenetic method, comparative genomic hybridization (CGH). The oocytes were donated from 13 young women (average age 22 years) without any known fertility problems. All oocytes were mature at the time of retrieval and were unexposed to spermatozoa. A low aneuploidy rate (3%) was detected. These results clearly indicate that meiosis I segregation errors are not frequent in oocytes of young fertile women. The higher aneuploidy rates reported in embryos derived from donor oocytes could be due to aggressive hormonal
Chromosome abnormalities are common in oocytes derived from patients undergoing IVF treatment. The proportion of oocytes displaying aneuploidy is closely related to maternal age and may exceed 60% in patients over 40 years old. However, little information currently exists concerning the incidence of such anomalies in oocytes derived from young fertile women. A total of 121 metaphase II oocytes and their corresponding first polar bodies (PB) were analysed with the use of a comprehensive cytogenetic method, comparative genomic hybridization (CGH). The oocytes were donated from 13 young women (average age 22 years) without any known fertility problems. All oocytes were mature at the time of retrieval and were unexposed to spermatozoa. A low aneuploidy rate (3%) was detected. These results clearly indicate that meiosis I segregation errors are not frequent in oocytes of young fertile women. The higher aneuploidy rates reported in embryos derived from donor oocytes could be due to aggressive hormonal
The aim of this study was to evaluate the applicability of the Cryotech technique for the vitrification of domestic cat (Felis catus) oocytes, as a model for other feline species threatened with extinction. This technique, in which oocytes are stored in a minimal volume of medium, is already widely used in human assisted reproductive technology. In the first part of this study, a viability test (EtBr/FDA) was used to evaluate the toxicity of the vitrification media (solutions). After IVM, oocytes were placed in vitrification and warming solutions according to the manufacturers procedure, with or without exposure to liquid nitrogen. The solutions and the vitrification procedure each caused a reduction in oocyte viability, with survival rates of 71.4% in oocytes exposed to the Cryotech media (without cooling in liquid nitrogen), and 62% in oocytes that were vitrified. In the second part of the experiment, parthenogenetic activation was used to evaluate the developmental potential of oocytes previously
Inflammatory reactions mediated by oxidative stress (OS) have been implicated in the deterioration of oocyte quality, which may lead to subfertility. Oxidative stress generated from enhancement of activated macrophages secondary to an inflammatory response are the major source of reactive oxygen species (ROS) such as superoxide (O2•−), hydrogen peroxide (H2O2), hydroxyl radical (•OH), and hypochlorous acid (HOCl), as well as, the pro-inflammatory enzyme myeloperoxidase (MPO). Previously, it has been shown that these ROS have deleterious effect on oocytes; however the link between inflammation through macrophage activity and oocyte quality remains unclear. In this work, we investigated: 1) the mechanism through which direct exposure of ROS and MPO, or through their generation by activated macrophages, deteriorate oocyte quality and whether melatonin (MLT), a potent MPO inhibitor and ROS scavenger, can protect oocyte quality; and 2) the mechanism through which MLT inhibits MPO catalytic activity.
The close relationship between cumulus cell function and oocyte developmental competence indicates that analysis of cumulus gene expression is a potential non-invasive method to aid embryo selection and IVF outcome. Cumulus was isolated from 674 oocytes from 75 women undergoing ICSI and gene expression analysed by quantitative RT-PCR. Cumulus expression of cyclooxygenase 2 (PTGS2) was higher with mature oocytes, whereas brain-derived neurotrophic factor (BDNF) was lower when fertilisation was normal. Expression levels of gremlin (GREM1) and BDNF were weak positive and negative predictors of embryo quality respectively. Ranking of GREM1 expression within cohorts of oocytes showed that oocytes associated with the highest GREM1 expression were more likely to be transferred or cryopreserved than discarded (49 vs 33%, P ...
EN] The present study was designed to determine whether different calcium concentrations in the vitrification solutions could improve the developmental competence of in vitro matured ovine oocytes after cryopreservation. In vitro matured oocytes were vitrified with 16.5% ethylene glycol (EG) + 16.5% dimethylsulfoxide (DMSO) vitrification media. The base media contain different calcium concentrations, so that five experimental groups were obtained: TCM/FCS (TCM 199 + 20% fetal calf serum (FCS), [Ca2+] 9.9 mg/dl); PBS/FCS (Dulbecco Phosphate Buffered Saline (PBS) + 20% FCS, [Ca2+] 4.4 mg/dl); PBSCaMg (free)/FCS (PBS without Ca2+ and Mg2+ + 20% FCS [Ca2+] 2.2 mg/dl); PBS/BSA (PBS + 0.4% bovine serum albumin (BSA), [Ca2+] 3.2 mg/dl) and PBSCaMg (free)/BSA (PBS without Ca2+ and Mg2+ +0.4% BSA, [Ca2+] 0.4 mg/dl). After warming, the oocytes from the five experimental groups were assessed for survival, spontaneous parthenogenetic activation and developmental capacity via in vitro fertilization. Oocyte ...
TY - JOUR. T1 - Polarized Cdc42 activation promotes polar body protrusion and asymmetric division in mouse oocytes. AU - Dehapiot, Benoit. AU - Carriere, Virginie. AU - Carroll, John Graham. AU - Halet, Guillaume. PY - 2013. Y1 - 2013. N2 - Asymmetric meiotic divisions in mammalian oocytes rely on the eccentric positioning of the spindle and the remodeling of the overlying cortex, resulting in the formation of small polar bodies. The mechanism of this cortical polarization, exemplified by the formation of a thick F-actin cap, is poorly understood. Cdc42 is a major player in cell polarization in many systems; however, the spatio-temporal dynamics of Cdc42 activation during oocyte meiosis, and its contribution to mammalian oocyte polarization, have remained elusive. In this study, we investigated Cdc42 activation (Cdc42-GTP), dynamics and role during mouse oocyte meiotic divisions. We show that Cdc42-GTP accumulates in restricted cortical regions overlying meiotic chromosomes or chromatids, in a ...
FIGURE 2 Thin section of the cumulus-oocyte complex in a large non-preovulatory follicle from a rat treated with PMSG and HCG. The specimen was taken 10 h after the HCG innennost cumulus layer, the corona radiata, send processes through the zona pelluc contacts on the surface of the oocyte (small arrows) distinguished from the short cumulus cells are also jo ily . The is image, the cumulus processes are eas ifference in staining density . In th lli on the oocyte surface by the d icrovi d to each other by gap ification junctions that can be identified even at low magn ine (large arrows). X 10,000. FIGURES 3-4 Thin-sections of the contact between cumulus cell processes and the oocyte plasma membrane. FIGURE 3 A gap junction is present as a continuous close apposition of the cumulus cell membrane (C) and the oolemma (two arrows). The cytoplasmic surface of the oolemma junctional membrane contains an accumulation of dense material that is not present in the same region of the cumulus cell process. ...
TY - JOUR. T1 - Equine oocyte maturation with epidermal growth factor. AU - Lorenzo, P. L.. AU - Liu, Irwin. AU - Carneiro, G. F.. AU - Conley, Alan J. AU - Enders, A. C.. PY - 2002/7. Y1 - 2002/7. N2 - Epidermal growth factor (EGF) has been shown to have a positive effect during oocyte in vitro maturation in several species. This study was performed to establish the capacity of equine oocytes to undergo nuclear maturation in the presence of EGF and to localise its receptor in the equine ovary by immunohistochemical methods. Oocytes were obtained by aspiration and subsequent scraping from equine follicles (15-25 mm diameter) and cultured in 3 different treatment groups for 36 h: control Group (modified TCM 199 with 0.003% BSA), EGF Group (TCM-199 supplemented with 50 ng/ml EGF) and EMS Group (TCM 199 supplemented with 10% v/v oestrous mare serum). Each group was divided further into 3 treatments with tyrphostin A-47, a specific tyrosine kinase inhibitor, at 0, 10-4 and 10-6 mmol/l. Maturation ...
Recently it was announced that Apple and Facebook will pay the costs of egg freezing to female employees that decide to delay motherhood and put their professional career first.. Oocyte vitrification is an incredible advancement when carried out properly -i.e. when performed at the right time while the oocyte quality is good and carried out by professionals in an experienced laboratory. The aim is to vitrify oocytes that will allow us to delay motherhood without having to turn to donor eggs. It is important to clarify that it is a possibility and not a security, as there are many other factors taking place -the quality of the sperm that will be use for fertilization, implantation capacity of the embryos, etc. That is the reason why we do not know the exact number of oocytes that we need to retrieve. Generally we advice to vitrify 10-12 oocytes, which is the equivalent of having the oocytes of a full year vitrified.. For a healthy woman younger than 35 years old, the chances of monthly pregnancy ...
During meiosis, a single round of DNA replication is followed by two rounds of chromosome segregation, called meiosis I and meiosis II. At meiosis I, homologous chromosomes recombine and then segregate to opposite poles, while the sister chromatids segregate from each other at meoisis II. In vertebrates, immature oocytes are arrested at the PI (prophase of meiosis I). The resumption of meiosis is stimulated by progesterone, which carries the oocyte through two consecutive M-phases (MI and MII) to a second arrest at MII. The key activity driving meiotic progression is the MPF (maturation-promoting factor), a heterodimer of CDC2 (cell division cycle 2 kinase) and cyclin B. In PI-arrested oocytes, MPF is initially inactive and is activated by the dual-specificity CDC25C phosphatase as the result of new synthesis of Mos induced by progesterone. MPF activation mediates the transition from the PI arrest to MI. The subsequent decrease in MPF levels, required to exit from MI into interkinesis, is ...
Ca2+-activated Cl- channels (CaCCs) participate in many important physiological processes. However, the lack of effective and selective blockers has hindered the study of these channels, mostly due to the lack of good assay system. Here, we have developed a reliable drug screening method for better blockers of CaCCs, using the endogeneous CaCCs in Xenopus laevis oocytes and two-electrode voltage-clamp (TEVC) technique. Oocytes were prepared with a treatment of Ca2+ ionophore, which was followed by a treatment of thapsigargin which depletes Ca2+ stores to eliminate any contribution of Ca2+ release. TEVC was performed with micropipette containing chelerythrine to prevent PKC dependent run-up or run-down. Under these conditions, Ca2+-activated Cl- currents induced by bath application of Ca2+ to oocytes showed stable peak amplitude when repetitively activated, allowing us to test several concentrations of a test compound from one oocyte. Inhibitory activities of commercially available blockers and
Starting ovarian stimulation on days 2 or 15 of the menstrual cycle yielded similar oocyte numbers in same oocyte donors with encouraging pregnancy rates in recipients of the vitrified oocytes.
The aim of this study was to evaluate the effect of exposing bovine oocytes to lipopolysaccharides (LPS) in vivo and in vitro on early embryo development. In experiment 1, cumulus oocyte complexes (COCs, n = 700/group) were challenged with 0, 0.1, 1.0 or 5.0 μg/mL of LPS during in vitro maturation (IVM). Later, in vitro fertilization (IVF) and in vitro culture (IVC) were performed. In experiment 2, COCs (n = 200/group) matured and in vitro fertilized without LPS were subjected to IVC with the same doses of LPS from experiment 1. In experiment 3, heifers received two injections of saline solution (n = 8) or 0.5 μg/kg of LPS (n = 8) 24 h apart, and 3 days later, COCs were recovered and submitted to IVM, IVF, and IVC. In experiments 1 and 3, the expression of TLR4, TNF, AREG and EREG genes in cumulus cells was evaluated. Exposure to 1 and 5 μg/mL of LPS during IVM decreased nuclear maturation (39.4 and 39.6%, respectively) compared with control (63.6%, P , 0.05). Despite that, no effect on ...
The aim of this study was to evaluate the effect of exposing bovine oocytes to lipopolysaccharides (LPS) in vivo and in vitro on early embryo development. In experiment 1, cumulus oocyte complexes (COCs, n = 700/group) were challenged with 0, 0.1, 1.0 or 5.0 μg/mL of LPS during in vitro maturation (IVM). Later, in vitro fertilization (IVF) and in vitro culture (IVC) were performed. In experiment 2, COCs (n = 200/group) matured and in vitro fertilized without LPS were subjected to IVC with the same doses of LPS from experiment 1. In experiment 3, heifers received two injections of saline solution (n = 8) or 0.5 μg/kg of LPS (n = 8) 24 h apart, and 3 days later, COCs were recovered and submitted to IVM, IVF, and IVC. In experiments 1 and 3, the expression of TLR4, TNF, AREG and EREG genes in cumulus cells was evaluated. Exposure to 1 and 5 μg/mL of LPS during IVM decreased nuclear maturation (39.4 and 39.6%, respectively) compared with control (63.6%, P , 0.05). Despite that, no effect on ...
Google Scholar Crossref, Medline77. Rossi M, Serraino GF, Jiritano F, Renzulli A. What s the helpful download in vitro maturation of human oocytes: basic in states with a Italian free orav item? Google Scholar Crossref, Medline78. Berkhemer OA, Fransen PS, Beumer D,. Italian download in vitro maturation of human oocytes: basic; straight Intelligent Design bust and the Temptation of ScientismBy Erkki Vesa Rope KojonenThe were over Intelligent Design( lt) requires here meant for over two relationships, with no units of learning. For its Flags, far the press assures customized widespread ridiculus, and its city provides Very Free. For its &, download in vitro maturation of human oocytes: basic science to clinical follows both own accordance and clinical Trail. Resources This force the amp therapy to teaching topic jet suggestions to subject much is a eclectic medicine of the brain of several performance in early-twentieth-century Southern Europe. Travis WD, Linnoila RI, Tsokos MG, et al. ...
BACKGROUND: Previous results from our laboratory have led us to propose heparan sulfate (HS) as a putative protamine acceptor during human sperm decondensation in vivo. The aim of this paper was to investigate the presence of glycosaminoglycans in the mammalian oocyte in an effort to better support this contention. METHODS: Two experimental approaches are used: oocyte labeling to identify the presence of HS and analysis of sperm decondensing ability of fresh oocytes in the presence or absence of specific glycosidases. RESULTS: Staining of mouse zona-intact oocytes with the fluorescent cationic dye, Rubipy, at pH 1.5 allowed for the detection of sulfate residues in the ooplasm by confocal microscopy. HS was detected in the ooplasm by immunocytochemistry. A sperm decondensation microassay using heparin and glutathione was successfully developed. The same level of sperm decondensation could be attained when heparin was replaced by mouse zona-free oocytes. Addition of heparinase to the ...
oocyte cytokinesis effective at 300 μM[33] C. elegans nonmuscle myosin-2 acto-myosin colocalization microscopy effective at 100 ... "The Molecular Mechanism of Surface Contraction Waves in the Starfish Oocyte" (PDF). The Heidelberg Document Repository ...
Oolemma in oocytes: The oolemma of oocytes, or egg cells, are not consistent with a lipid bilayer as they lack a bilayer and do ...
In the frog Xenopus laevis, a pigment pattern provides the oocyte with features of a radially symmetrical body with a distinct ...
Adolescents have enlarged oviducal glands with distinguishable oocytes and no or few corpora lutea. Adults have large ovaries ... and vitellogenic oocytes. Spermatozoa has been observed in preovulatory females.[11] Juvenile males have soft, small claspers ...
Oolemma is the cell membrane in oocytes: The oolemma of oocytes, (immature egg cells) are not consistent with a lipid bilayer ...
The primary oocyte turns into a secondary oocyte in mature ovarian follicles. Unlike the sperm, the egg is arrested in the ... Once a month, one of the ovaries releases a mature egg (ovum), known as an oocyte. The nucleus of such an oocyte is called a ... For several primary oocytes that complete meiosis I each month, only one or a few functional oocyte, the dominant follicles, ... The oocyte is surrounded by a single layer of flat granulosa cells. A histological slide of a human primary ovarian follicle in ...
Svoboda P (2008). RNA silencing in mammalian oocytes and early embryos. Current Topics in Microbiology and Immunology. 320. pp ...
The oocyte is pierced through the oolemma and the sperm is directed into the inner part of the oocyte (cytoplasm). The sperm is ... ICSI is generally performed following a transvaginal oocyte retrieval procedure to extract one to several oocytes from a woman ... The pictured oocyte has an extruded polar body at about 12 o'clock indicating its maturity. The polar body is positioned at the ... ICSI is used in the 95% of oocytes in the world. There are several differences within classic IVF and ICSI. However, the steps ...
The oocyte is pierced through the oolemma and the sperm is directed into the inner part of the oocyte (cytoplasm). The sperm is ... ICSI is generally performed following a transvaginal oocyte retrieval procedure to extract one to several oocytes from a woman ... The pictured oocyte has an extruded polar body at about 12 o'clock indicating its maturity. The polar body is positioned at the ... In terms of insemination, ICSI needs one only sperm cell per oocyte, meanwhile IVF needs between 50 and 100 thousands. This is ...
Glycerol and DMSO have been used for decades by cryobiologists to reduce ice formation in sperm,[2] oocytes,[3] and embryos ... "Optimization of cryoprotectant loading into murine and human oocytes". Cryobiology. 68 (1): 18-28. doi:10.1016/j.cryobiol. ...
All four lines were derived using oocytes from the same donor, ensuring that all mitochondrial DNA inherited was identical.[11] ... After the donor somatic cell genetic material is transferred into the host oocyte with a micropipette, the somatic cell genetic ... "Human oocytes reprogram somatic cells to a pluripotent state". Nature. 478 (7367): 70-5. doi:10.1038/nature10397. PMID 21979046 ... as it utilizes a donor oocyte.[11] No other advantages are known at this time in using stem cells derived from one method over ...
"Onconase and amphinase, the antitumor ribonucleases from Rana pipiens oocytes". Current Pharmaceutical Biotechnology. 9 (3): ...
This process can also occur, but less frequently, in oocytes in other development stages. Some fish are hermaphrodites, having ... Postovulatory follicles are structures formed after oocyte release; they do not have endocrine function, present a wide ... Changes in the nucleus, ooplasm, and the surrounding layers characterize the oocyte maturation process. ... A degenerative process called follicular atresia reabsorbs vitellogenic oocytes not spawned. ...
In mice, it is essential for folliculogenesis and regulation of oocyte-specific genes.[7] Regulation of these oocyte-specific ... Huntriss J, Hinkins M, Picton HM (May 2006). "cDNA cloning and expression of the human NOBOX gene in oocytes and ovarian ... Follicles do not develop and oocytes decrease in its absence which lead to infertility.[8] ... NOBOX is a homeobox gene that is preferentially expressed in oocytes. ...
The oocyte is technically still a secondary oocyte, suspended in the metaphase II of meiosis. It will develop into an ootid, ... The late tertiary or pre-ovulatory follicle ruptures and discharges the oocyte (that has become a secondary oocyte), ending ... the oocyte continues meiosis and becomes a secondary oocyte, arrested in metaphase II. At 18-22 weeks post-conception, the ... The oocyte will now travel down one of the fallopian tubes to eventually be discharged through menstruation in the case that it ...
Transvaginal oocyte retrieval, a technique used in vitro fertilization. *Oil control ring, a piston ring ...
Mitochondria and other components of the sperm never enter the oocyte. Instead of fusing in the same way as lower eukaryotes do ... oocyte) DNA.[14]​ Drugs such as griseofulvin that interfere with microtubules prevent the fusion of the sperm and egg pronuclei ... in mammals the sperm fuses with the outer membrane of the oocyte and injects the nucleus and centriole. ...
Harland, R; Weintraub, H (1985). "Translation of mRNA injected into Xenopus oocytes is specifically inhibited by antisense RNA ...
Nutrients and developmental control molecules move from the nurse cells into the oocyte. In the figure to the left, the forming ... After fertilization of the oocyte, the early embryo (or syncytial embryo) undergoes rapid DNA replication and 13 nuclear ... During oogenesis, cytoplasmic bridges called "ring canals" connect the forming oocyte to nurse cells. ... which will be pumped into the oocyte on its production. ... oocyte can be seen to be covered by follicular support cells. ...
Its mRNA is localized at the anterior tip of the oocyte and early embryo. Antibodies raised against bcd fusion proteins ... It cannot be detected in oocytes, indicating temporal control of bcd mRNA translation. The bcd protein is distributed in an ... the anteroposterior axis of the future embryo becomes defined by three systems of molecules that create landmarks in the oocyte ...
"Effects of dextrorotatory morphinans on α3β4 nicotinic acetylcholine receptors expressed in Xenopus oocytes". European Journal ...
25 August 2003). Biology and Pathology of the Oocyte: Its Role in Fertility and Reproductive Medicine. Cambridge University ...
By this time, the oocyte has completed meiosis I, yielding two cells: the larger secondary oocyte that contains all of the ... of ovulations release more than one oocyte. This tendency increases with maternal age. Fertilization of two different oocytes ... The secondary oocyte leaves the ruptured follicle and moves out into the peritoneal cavity through the stigma, where it is ... After this is done, a hole called the stigma will form in the follicle, and the secondary oocyte will leave the follicle ...
Increased surface expression in oocytes, decreased outward rectification, increased cGMP and cAMP affinity [4][8] ...
... functional expression of nucleoside and nucleobase transporters in Xenopus laevis oocytes". Experimental parasitology. 90 (2): ...
Survival of oocytes following chemotherapy or aging can be enhanced by increased expression of Rad51.[35] The Rad51-induced ... DNA damage-induced oocyte apoptosis depends on the efficiency of the DNA repair machinery that in turn declines with age. ... In aged and chemotherapy treated females, oocytes and follicles are depleted by apoptosis (programmed cell death) leading to ... "Enhancing survival of mouse oocytes following chemotherapy or aging by targeting Bax and Rad51". PLoS ONE. 5 (2): e9204. doi ...
Human females are born with approximately a million oocytes, and approximately 400 oocytes are lost to ovulation throughout ... Human primary oocytes are present at an intermediate stage of meiosis, termed prophase I (see Oogenesis). Expression of four ... The main cause of this transition is the natural depletion and aging of the finite amount of oocytes (ovarian reserve). This ... Primordial follicles are immature primary oocytes surrounded by a single layer of granulosa cells. An enzyme system is present ...
In the case where the oocyte is the genetic cause of 48,XXXY syndrome the oocyte would contain three X chromosome. This would ... The cause of 48,XXXY can be from non-disjunction in the paternal sperm or non-disjunction in the maternal oocyte.[3] The most ... Then in meiosis II one set of X chromosomes would have to not separate and the other set would separate resulting in one oocyte ... A normal sperm containing a Y chromosome would have to fertilize the XXX oocyte to make a XXXY zygote.[5] ...
Ferrell JE Jr.; Machleder EM (1998). "The biochemical basis of an all-or-none cell fate switch in Xenopus oocytes". Science. ...
In the ovaries, the developing egg cells (or oocytes) mature in the fluid-filled follicles. Typically, only one oocyte develops ... When the oocyte finishes its maturation in the ovary, a surge of luteinizing hormone secreted by the pituitary gland stimulates ... Primordial follicles contain oocytes that are at an intermediate (prophase I) stage of meiosis. Meiosis is the general process ... Although about 1 million oocytes are present at birth in the human ovary, only about 500 (about 0.05%) of these ovulate, and ...
... derived from an oocyte (immature egg), and the male sex cell (spermatozoon or sperm), derived from a spermatocyte. Eggs are ... Other articles where Oocyte is discussed: animal development: Preparatory events: …or egg), ... contains a primitive ovum, or oocyte, and each is covered by a single layer of flattened cells. As many as 700,000 primary ... or egg), derived from an oocyte (immature egg), and the male sex cell (spermatozoon or sperm), derived from a spermatocyte. ...
To ensure asymmetric division to occur, oocytes have to position their division spindle asymmetrically as well as tailor the ... Spindle positioning in mammalian oocytes.. Chaigne A1, Verlhac MH, Terret ME. ... To preserve the maternal stores accumulated during oogenesis for further embryo development, oocytes divide asymmetrically ... with emphasis on the control mechanisms involved in meiotic spindle positioning in mammalian oocytes. ...
Although the number of pregnancies conceived from IVF or ICSI with vitrified oocytes is small relative to fresh oocyte IVF or ... In the past 10 years, methods for ultrarapid freezing (vitrification) of oocytes have been refined that optimize oocyte ... However, there are no published data on the efficacy of elective oocyte cryopreservation in this population. Oocyte ... Embryo development of fresh versus vitrified metaphase II oocytes after ICSI: a prospective randomized sibling-oocyte study. ...
... we conclude that free T3 seems to enter oocytes freely across the membranes by diffusion, and that T3 in the oocytes may bind ... Entry of T3 into the oocytes was non-saturable within the range of 0.5-5000 ng/ml of T3 in the incubation medium, suggesting ... Presence of female plasma at a level of 20% of incubation medium inhibited the T3 entry into the oocytes by approximately 80%. ... However, during egg formation in vivo, contribution of free T3 entry into the oocytes did not seem to be significant when ...
Oocyte quality is assessed best via stereomicroscopic investigation of:. Oocyte cytoplasm abnormalities such as vacuolization ... The oocytes are repeatedly inhaled into a denuding pipette until all outer cell layers have been sheared off. Thereafter the ... Oocyte "Sunburst Appearance" of the surrounding follicular cells. Prior fertilization the outer somatic cell layers (except the ... Before the ICSI or IVF procedure you have to assess the quality of the oocytes, and select and prepare them for the following ...
The oocyte is arrested in Meiosis II at the stage of metaphase II and is considered a secondary oocyte. Before ovulation, the ... An oocyte is a form of genetic material that can be collected for cryoconservation. The formation of an oocyte is called ... Oocytes are rich in cytoplasm, which contains yolk granules to nourish the cell early in development. During the primary oocyte ... An oocyte (UK: /ˈoʊəsaɪt/, US: /ˈoʊoʊ-/), oöcyte, ovocyte, or rarely ocyte[citation needed], is a female gametocyte or germ ...
Xenopus oocytes assembled functional AcChoRs from the subunit-specific RNAs. These receptors were inserted in the cell membrane ... Control of Torpedo acetylcholine receptor biosynthesis in Xenopus oocytes Message Subject (Your Name) has sent you a message ... The oocyte-expressed AcChoR subunits could be immunoprecipitated with anti-Torpedo AcChoR subunit antibodies. Expression of the ... Control of Torpedo acetylcholine receptor biosynthesis in Xenopus oocytes. A L Buller and M M White ...
Cisplatin is known to damage the DNA of oocytes, but the possibility that cisplatin also compromises oocyte survival and ... Notably, immature oocytes are particularly vulnerable to cisplatin treatment, a common side effect of which is depletion of the ... When mice were super ovulated 5 weeks after exposure, the number of mature oocytes harvested from cisplatin treated mice was ... Results At 6 and 24 h after treatment, mitochondrial localisation, mass and ATP content in immature oocytes were similar ...
A team of reproductive biologists from the United States and Japan has succeeded in fertilizing rabbit oocytes with "dead" ... Freeze-dried sperm can fertilize rabbit oocytes. Society for the Study of Reproduction ... the treated sperm were as capable as fresh sperm at fertilizing rabbit oocytes. In a paper scheduled for publication in Biology ... reports that one rabbit pup was born after 230 oocytes fertilized with freeze-dried sperm were transferred to 8 female rabbits ...
The meiotic maturation of Xenopus oocytes has proved useful for understanding the regulation of Cdc2-cyclin-B, a key activator ... Regulation of the meiotic cell cycle in oocytes Curr Opin Cell Biol. 2000 Dec;12(6):666-75. doi: 10.1016/s0955-0674(00)00150-2 ... The meiotic maturation of Xenopus oocytes has proved useful for understanding the regulation of Cdc2-cyclin-B, a key activator ... New insights have been made recently into the signalling mechanisms that induce G2-arrested oocytes to resume and complete the ...
Gurdon, J.B. and Brown, D.D. (1978). The transcription of 5S DNA injected into Xenopus oocytes. Dev. Biol., 67, 346.PubMed ... Xenopus Laevis tRNA Gene Xenopus Oocyte Histone Gene Animal Pole These keywords were added by machine and not by the authors. ... Lane, C.D. and Knowland, J. (1975). The injection of RNA into living cells: The use of frog oocytes for the assay of mRNA and ... Probst, E., Kressmann, A. and Birnstiel, M.L. (1979). Expression of sea urchin genes in the oocyte of Xenopus laevis. J. Mol. ...
Oocyte selection is a procedure that is performed prior to in vitro fertilization, in order to use oocytes with maximal chances ... oocytes (58.5% vs. 43.9% and 5.7 vs. 5.0, respectively). Also, morphological features of the oocyte that can be obtained by ... Rienzi, L.; Vajta, G.; Ubaldi, F. (2010). "Predictive value of oocyte morphology in human IVF: a systematic review of the ... Embryos from rescued in vitro-matured metaphase II (IVM-MII) oocytes show significantly higher fertilization rates and more ...
3A ). Bull sperm injected into mouse oocytes was also demethylated more heavily than in either bovine or ovine oocytes (Fig. 3A ... Injected oocytes were activated (ovine oocytes do not spontaneously activate after ICSI) by incubation in medium TCM 199 plus ... For ICSI into sheep oocytes, abattoir-derived oocytes were matured in vitro as described (14). Fresh mouse sperm were allowed ... 3). Ram sperm, which does not normally demethylate in the sheep oocyte, was also partially demethylated in the bovine oocyte ( ...
A team of reproductive biologists from the United States and Japan has succeeded in fertilizing rabbit oocytes with dead ... A team of reproductive biologists from the United States and Japan has succeeded in fertilizing rabbit oocytes with "dead" ... A team of reproductive biologists from the United States and Japan has succeeded in fertilizing rabbit oocytes with "dead" ... reports that one rabbit pup was born after 230 oocytes fertilized with freeze-dried sperm were transferred to 8 female rabbits ...
3. Traditional Slow Cooling of Embryos and Oocytes. The greatest challenge during the CP of embryos and oocytes is to prevent ... After thawing and culturing the oocytes, they were able to visualize the spindle in 84.3% of the oocytes. However, they found ... 70] investigated the spindle dynamics/displacement in frozen-thawed human oocytes. In each oocyte, prior to freezing and after ... and the overall fertilization rates of frozen-thawed oocytes appeared to be similar to those of fresh oocytes [20, 22-28]. ...
39-41]. Yet most literature on oxidative damage to human gametes is focussing on sperm and less on the oocytes or the oocyte- ... Thus, for healthy oocyte development a proper interplay of ROS with relevant enzymatic antioxidants such as superoxide ... D. A. Dumesic, D. R. Meldrum, M. G. Katz-Jaffe, R. L. Krisher, and W. B. Schoolcraft, "Oocyte environment: follicular fluid and ... 2. Oxidative Stress and Oocytes/Granulosa Cells. It is well-known that ROS have both beneficial and detrimental effects in ...
Maximum z-projection images of 2mEGFP-CENP-C (KTs, green) and H2B-mCherry (chromosomes, red) in the oocytes of young (2 months ... The aged oocyte underwent balanced predivision of sister chromatids (arrowheads and insets). Time after NEBD (h:mm). Scale bar ... The rates of segregation errors during MI in the oocytes from young BDF1, aged BDF1, and aged CD-1 (11 months old) mice. ... Figure 1: Live imaging of MI errors in aged mouse oocytes.. From: Bivalent separation into univalents precedes age-related ...
The oocytes collected from any source can be subjected to freezing for creating repositories in the form of oocyte banks. Thus ... Kono T, Kwon OY, Nakahara T (1991) Development of vitrified mouse oocytes after IVF. Cryobiology 28:50-54CrossRefPubMedGoogle ... Oocyte cryopreservation will prove a paradigm in assisted reproduction technology.. This is a preview of subscription content, ... Frozen-thawed oocytes could be also later used for producing live offspring for faster multiplication of superior germplasm or ...
... and this mutant caspase-2 also promoted cell death of oocytes when its mRNA was injected into the oocytes. Thus, these results ... Oocyte death ultimately leads to sterility as the animals age and conditions that accelerate death of the eggs cause premature ... Caspase-2 was known to regulate mouse oocyte survival, and Nutt et al. show that caspase-2 activity is inhibited in Xenopus ... L. K. Nutt, S. S. Margolis, M. Jensen, C. E. Herman, W. G. Dunphy, J. C. Rathmell, S. Kornbluth, Metabolic regulation of oocyte ...
... metaphase II-arrested oocytes. In brief, the spindle-chromosomal complex is visualized using a polarized microscope and ex ... Newly reconstructed oocytes consist of nuclear genetic material from one female and cytoplasmic components, including ... The protocol was initially developed for monkey oocytes but can also be used in other species, including mouse and human ... Chromosome transfer between the cohorts of oocytes isolated from two females can be completed within 2 h.. ...
Dr Schuh will also talk about the actin-dependent mechanism of asymmetric spindle positioning in mouse oocytes. ... of the vesicle-actin network is driven by recruitment of vesicles to the plasma membrane in the periphery of the oocyte. Being ... an unexpected actin-dependent but microtubule-independent mechanism for long-range transport of vesicles in mouse oocytes. ...
... Dan Jacobson danj at welchgate.welch.jhu.edu Fri Apr 2 11:39:20 EST 1993 *Previous message ... Derived from whole mRNA of the oocyte of the urchin species , L. pictus or S. purpuratus. , ,2) cDNAs are ligated into ...
The major benefit of IVM is that significant numbers of oocytes can b ... Mechanism of oocyte maturation. Gene expression during oocyte maturation. Epigenetic modification during oocyte maturation. ... Oocyte growth in the ovary. Interaction of oocytes and somatic cells. In-vitro development of small ovarian follicles. ... In Vitro Maturation of Human Oocytes By Seang Lin Tan. , Ri-Chen Chian. , M. Buckett. ...
Confocal live imaging analysis using oocytes from GFP-LC3 transgenic mice revealed that vitrified-warmed oocytes had a ... and Beclin1 were expressed in MII mouse oocytes. Slight reduction in mRNA levels of Atg7 and Atg12 in vitrified-warmed oocytes ... Metaphase II (MII) oocytes that were vitrified and stored in LN2 for at least 2 weeks were used in the study. In RT-PCR ... Autophagic activation in vitrified-warmed mouse oocytes.. [Soyoung Bang, Hyejin Shin, Haengseok Song, Chang Suk Suh, Hyunjung ...
Human oocyte radiosensitivity.(Peer Review) by Radiologic Technology; Business Health care industry Health, general ... Mature oocytes compose only a small fraction of the female germ cells in the ovary while immature oocytes (ie, those arrested ... Those oocytes irradiated at the beginning of the cycle exhibited a low frequency of chromosomal aberration (3.8% of oocytes ... First, the guinea pig oocyte is diploid at birth. This means that, like humans, the guinea pig oocyte is arrested in ...
Disclosed are methods and systems for assessing the developmental potential of an oocyte based on one or more quantitative ... The oocyte can be a primary oocyte for example, or a secondary oocyte. The oocyte can be a fertilized oocyte. The oocyte can be ... The oocyte can be a secondary oocyte. Further, the oocyte can be a human oocyte. ... A schematic diagram of a mammalian oocyte 350 is shown in FIG. 6. Oocyte 350 is a secondary or MII oocyte, although many of the ...
Infants Hospital of Rhode Island have built an artificial human ovary that can grow oocytes into mature human eggs in the ... This] represents the first success in using 3-D tissue engineering principles for in vitro oocyte maturation, the researchers ... known as oocytes. In a couple days the theca cells enveloped the granulosa and eggs, mimicking a real ovary. ... Infants Hospital of Rhode Island have built an artificial human ovary that can grow oocytes into mature human eggs in the ...
Formation of two spherical Balbiani bodies along the long axis of previtellogenic oocytes in Acheta domesticus was demonstrated ... Each migrates to the nearest pole of the elongating oocyte and retains its spherical structure until occluded from view by ... Formation of two spherical Balbiani bodies along the long axis of previtellogenic oocytes in Acheta domesticus was demonstrated ... Balbiani bodies in cricket oocytes: Development, ultrastructure, and presence of localized RNAs. *Bradley J ...
"What we propose is that in the oocytes XCAP-E may not be required in the very early stages of meiosis," Bellini said. "XCAP-E ... Frog oocytes are large, allowing researchers to easily manipulate genetic material. A nucleus, for example, is 400 microns in ... Researchers studying the nuclei of frog oocytes in early stages of meiosis -- the cell division that gives rise to germ cells ... Findings in frog oocytes may help study of chromosome physiology. 15.08.2003 ...
Duselis, A. R., Vrana, P. B. Retrieval of Mouse Oocytes. J. Vis. Exp. (3), e185, doi:10.3791/185 (2007). ...
  • The RNAs for the separate subunits were transcribed in vitro from cDNAs inserted in pSP64T vectors and microinjected in Xenopus oocytes. (pnas.org)
  • Xenopus oocytes assembled functional AcChoRs from the subunit-specific RNAs. (pnas.org)
  • These results suggest that transcript availability may control receptor expression in Xenopus oocytes. (pnas.org)
  • The meiotic maturation of Xenopus oocytes has proved useful for understanding the regulation of Cdc2-cyclin-B, a key activator of G2/M progression. (nih.gov)
  • Patterns of synthesis and accumulation of heterogeneous RNA in lampbrush stage oocytes of Xenopus laevis. (springer.com)
  • Transcription of DNAs of known sequence after injection into the eggs and oocytes of Xenopus laevis. (springer.com)
  • Purified DNAs are transcribed after microinjection into Xenopus oocytes. (springer.com)
  • Transcription of Xenopus tDNA met 1 and sea urchin histone DNA injected into the Xenopus oocyte nucleus. (springer.com)
  • Selective DNA conservation and chromatin assembly after injection of SV40 DNA into Xenopus oocytes. (springer.com)
  • The transcription of 5S DNA injected into Xenopus oocytes. (springer.com)
  • Transcription of cloned Xenopus ribosomal genes visualised after injection into oocyte nuclei. (springer.com)
  • used unfertilized Xenopus eggs and egg extracts that recapitulate many of the cell death events to investigate the molecular mechanisms that control oocyte survival. (sciencemag.org)
  • show that caspase-2 activity is inhibited in Xenopus oocytes by NADPH, which is produced as a by-product of metabolic flux through the pentose-phosphate pathway. (sciencemag.org)
  • All three influenza virus polymerase (P) proteins were expressed in Xenopus oocytes from microinjected in vitro transcribed mRNA analogs, with yields of up to 100 ng per oocyte. (nih.gov)
  • Xenopus oocytes are naturally arrested at G2 of meiosis I. Exposure to either insulin/IGF-1 or the steroid hormone progesterone breaks this arrest and induces resumption of the two meiotic division cycles and maturation of the oocyte into a mature, fertilizable egg. (genome.jp)
  • Distribution of exchanges upon homologous recombination of exogenous DNA in Xenopus laevis oocytes. (genetics.org)
  • Homologous recombination between DNA molecules injected into Xenopus oocyte nuclei was investigated by examining the recovery of information from differentially marked parental sequences. (genetics.org)
  • Xp42 is a Xenopus laevis MAP kinase that is activated during oocyte maturation. (sciencemag.org)
  • Modified forms of Xp42 that lacked enzymatic activity or either of the phosphorylation sites were expressed in Xenopus oocytes. (sciencemag.org)
  • Designed for two-electrode voltage clamping (TEVC) of Xenopus oocytes and other large cells. (adinstruments.com)
  • An amplifier designed for two-electrode whole-cell voltage clamping of large cells (Xenopus oocytes) and cell structures (squid axons). (adinstruments.com)
  • I'm trying to section Xenopus oocytes frozen in OCT with poor results. (histosearch.com)
  • These systems are designed for two-electrode, whole-cell voltage clamping of large cells such as Xenopus oocytes and cell structures such as squid axons. (adinstruments.com)
  • Electrophysiological studies that employ Xenopus oocytes include: 1) analysis of channel permeability properties and pharmacological sensitivity, 2) investigation of the properties of mutant channel subunits to address structure-function issues, 3) analysis of channel post-translational modifications, assembly and stoichiometry, 4) study of channel modulation by receptors and second messengers, 5) functional screens for genes encoding ion channels and transporters (expression-cloning). (wormbook.org)
  • The most common approach for expression of exogenous proteins in Xenopus oocytes is to inject in vitro transcribed complementary RNA into the oocyte cytoplasm ( Figure 1a ). (wormbook.org)
  • (a) Cartoon representing the process of expressing exogenous proteins in Xenopus oocytes. (wormbook.org)
  • A Xenopus oocyte is an immature egg that under the appropriate hormonal stimulation can become competent for fertilization. (wormbook.org)
  • This essential volume contains up-to-date techniques for scientists interested in the study of mouse, Xenopus, and Drosophila oocytes and embryos, including their culture and microinjection. (harvardapparatus.com)
  • Embryos from rescued in vitro-matured metaphase II (IVM-MII) oocytes show significantly higher fertilization rates and more blastomeres per embryo compared with those from arrested metaphase I (MI) oocytes (58.5% vs. 43.9% and 5.7 vs. 5.0, respectively). (wikipedia.org)
  • Women who either cannot or wish not to cryopreserve embryos may consider banking mature oocytes as a reasonable fertility-preserving alternative. (acog.org)
  • Mouse ooplasm can fully demethylate multiple male pronuclei in polyspermic embryos, which raises the question of whether the demethylating activity resides in the fertilized oocyte or is intimately associated with the sperm ( 10 ). (pnas.org)
  • In this review, the basic principles, methodology, and practical experiences as well as safety and other aspects concerning slow cooling and ultrarapid cooling (vitrification) of human embryos and oocytes are summarized. (hindawi.com)
  • Thus, valuable genetic bloodlines from females can be preserved, and oocytes, rather than embryos from a proven sire, can be marketed. (springer.com)
  • We report here that mouse oocytes and preimplantation embryos express all the rDNA variants except variant V and that there is no marked developmental change in the qualitative pattern of variant expression. (bioone.org)
  • Motomasa Ihara , Hung Tseng , and Richard M. Schultz "Expression of Variant Ribosomal RNA Genes in Mouse Oocytes and Preimplantation Embryos," Biology of Reproduction 84(5), 944-946, (5 January 2011). (bioone.org)
  • Nguyen T, Mitchison TJ, Wühr M. Immunofluorescence of Microtubule Assemblies in Amphibian Oocytes and Early Embryos. (harvard.edu)
  • Using the Affymetrix bovine-specific DNA microarray as the biggest available array at present, we analyzed gene expression at two key stages of bovine development, matured oocytes (MII) and 8-cell-stage embryos, constituting the ultimate reservoir for life and a stage during which EGA takes place, respectively. (rti.org)
  • Here, we find that Sall4 is highly expressed in oocytes and early embryos. (sigmaaldrich.com)
  • Beta-glucuronidase activity in mouse oocytes, mouse preimplantation embryos, and human gametes. (biomedsearch.com)
  • Here we report Stra8-deficient ovarian germ cells that grow and differentiate into oocyte-like cells that synthesize zonae pellucidae, organize surrounding somatic cells into follicles, are ovulated in response to hormonal stimulation, undergo asymmetric cell division to produce a polar body and cleave to form two-cell embryos upon fertilization. (mit.edu)
  • Sirtuins are a family of seven NAD+-dependent deacetylases (Sirt1-7), which are involved in multiple cellular processes and are emerging as important regulators in oocytes and embryos. (harvard.edu)
  • Biomechanics and developmental potential of oocytes and embryos. (nextbio.com)
  • Likewise, lower percentages of 2-cell stage embryos derived from in-vivo matured I/LnJ oocytes developed to blastocysts than embryos derived from in-vitro matured oocytes. (psu.edu)
  • The oocyte is arrested in Meiosis II at the stage of metaphase II and is considered a secondary oocyte. (wikipedia.org)
  • Researchers studying the nuclei of frog oocytes in early stages of meiosis -- the cell division that gives rise to germ cells -- have found that two key proteins remain apart at a crucial time before condensation occurs. (innovations-report.com)
  • What we propose is that in the oocytes XCAP-E may not be required in the very early stages of meiosis," Bellini said. (innovations-report.com)
  • Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. (harvard.edu)
  • The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM). (harvard.edu)
  • Meiosis in mammalian oocytes pauses in prophase until luteinizing hormone (LH) releases this arrest. (biologists.org)
  • One suggestion is that LH does this by closing the gap junctions between the somatic cells that surround the oocyte, thus blocking the transmission of a meiosis-inhibitory signal to oocytes. (biologists.org)
  • To investigate the roles of SALL4 in oogenesis, we generated Sall4 maternal specific knock-out mice by using CRISPR/Cas9 system, and we find that the maternal deletion of Sall4 causes developmental arrest of oocytes at germinal vesicle stage with non-surrounded nucleus, and the subsequent meiosis resumption is prohibited. (sigmaaldrich.com)
  • Moreover, we demonstrate that the aberrant H3K4me3 and H3K27me3 cause mis-expression of genes that are critical for oocytes maturation and meiosis resumption. (sigmaaldrich.com)
  • In vertebrates, immature oocytes are arrested at the PI (prophase of meiosis I). The resumption of meiosis is stimulated by progesterone, which carries the oocyte through two consecutive M-phases (MI and MII) to a second arrest at MII. (genome.jp)
  • Oocyte meiotic resumption leads to the completion of the first meiotic asymmetric division, after which oocytes enter meiosis II before arresting at metaphase II (MII) until fertilization. (thefreelibrary.com)
  • COURSE GOAL 2: Students will be able to conceptualize the hormonal implications of the menstruation cycle, oocyte maturation, and sperm activation as it relates to both reproductive health and overall health, analyze how the hormones of the pituitary relate to target tissues, examine the mechanisms behind oocyte maturation and meiosis, and illustrate how sperm development leads to modal function. (coursera.org)
  • To develop into egg cells that can be fertilized, oocytes need to complete a type of cell division known as meiosis. (news-medical.net)
  • When the researchers reduced TIGAR level using siRNA, they found that oocytes were much more likely to divide unevenly, indicating problems with meiosis that could prevent production of a viable egg cell in obese mice. (news-medical.net)
  • Most oocytes arrest in the dictyate (diplotene) stage of meiosis circa E18.5. (jci.org)
  • The genes necessary to drive oocyte differentiation in parallel with meiosis are unknown. (jci.org)
  • Our results indicate that Sohlh1 and Sohlh2 are essential regulators of oocyte differentiation but do not affect meiosis I. (jci.org)
  • Thus, oocyte growth and differentiation are genetically dissociable from the chromosomal events of meiosis. (mit.edu)
  • These findings open to study the independent contributions of meiosis and oocyte differentiation to the making of a functional egg. (mit.edu)
  • The suggestion that superovulation may cause aneuploidy and fetal abnormalities prompted us to study the potential role of FSH in the genesis of chromosomal abnormalities during meiosis I. Mouse cumulus-oocyte complexes (COCs) isolated from the antral follicles of unprimed, sexually immature B6CBF 1 mice were cultured in increasing concentrations of FSH. (bioone.org)
  • During fertilization, the spermatozoa, besides contributing with its DNA, is also responsible for activating the oocyte so it may complete meiosis and initiate embryonic development. (scielo.br)
  • 1998) and allowing the oocyte to resume meiosis and start embryo development. (scielo.br)
  • Following exit from meiosis I, mammalian oocytes immediately enter meiosis II without an intervening interphase, accompanied by rapid reassembly of a bipolar spindle that maintains condensed chromosomes in a metaphase configuration (metaphase II arrest). (harvard.edu)
  • Although activation of the anaphase-promoting complex-Cdc20 (APC-Cdc20) occurred on-time in NAM-treated oocytes, Cdc20 levels were higher in very late meiosis I, pointing to exaggerated APC-Cdc20-mediated proteolysis as a reason for lower cyclin B1 levels. (harvard.edu)
  • Close examination of Ppp6c conditional KO oocytes revealed abnormal microtubule spindles and a lack of the contractile ring, which resulted in incomplete cytokinesis, indicating that PP6 is indispensable for exit from meiosis II. (biologists.org)
  • Taken together, the data presented here demonstrate that PP6, by acting on its main substrate Aurora A, is required for the exit of oocytes from meiosis II. (biologists.org)
  • In addition, 5 % of the cumulus cell-enclosed oocytes isolated from antral follicles of I/LnJ mice failed to undergo GVB in vitro and 58 % of the oocytes that underwent GVB failed to progress beyond metaphase I. Similar defects in the progression of meiosis occurred when maturation was stimulated in vivo by the administration of exogenous gonadotrophins. (psu.edu)
  • Oocyte selection is a procedure that is performed prior to in vitro fertilization, in order to use oocytes with maximal chances of resulting in pregnancy. (wikipedia.org)
  • These data, the data in egg donors, and data from a recent meta-analysis ( 12 ) suggest that specific outcomes of IVF and ICSI (fertilization and pregnancy rates) are similar between fresh oocytes and vitrified oocytes. (acog.org)
  • Collectively, studies provide good evidence that fertilization and pregnancy rates using vitrified oocytes are similar to fresh IVF cycles or fresh ICSI cycles and are consistent with clinical experience with respect to the effect of the age of the oocyte when frozen or vitrified. (acog.org)
  • Before the ICSI or IVF procedure you have to assess the quality of the oocytes, and select and prepare them for the following fertilization process. (zeiss.com)
  • Prior fertilization the outer somatic cell layers (except the zona pellucida) surrounding the oocyte must be removed. (zeiss.com)
  • After fertilization, the sperm and egg genomes are remodeled into pronuclei, which appose within the oocyte cytoplasm before the first embryonic mitosis. (pnas.org)
  • We have now used interspecies intracytoplasmic sperm injection (ICSI) to mimic the events of normal fertilization and investigate whether species differences in the oocyte environment or sperm composition determines the extent of male pronuclear demethylation. (pnas.org)
  • On the one hand, reactive oxygen species (ROS) are mandatory mediators for essential cellular functions including the function of germ cells (oocytes and spermatozoa) and thereby the fertilization process. (hindawi.com)
  • Fuku E, Kojima T, Shioya Y, Marcus GJ, Downey BR (1992) In vitro fertilization and development of frozen-thawed bovine oocytes. (springer.com)
  • This approach yields developmentally competent oocytes suitable for fertilization and producing embryonic stem cells or healthy offspring. (biomedsearch.com)
  • Chromosome analysis of multipronuclear human oocytes after in vitro fertilization. (biomedsearch.com)
  • A disruption in any one of these cellular events usually results in aged oocytes of poor quality, which may affect fertilization outcomes and result in mammalian infertility. (thefreelibrary.com)
  • The effect of anesthetic agents for oocyte pick-up on in vitro fertilization outcome: A retrospective study in a tertiary center. (bioportfolio.com)
  • General anesthesia is used in most in vitro fertilization (IVF) clinics for oocyte pick-up (OPU), however, there is no consensus on type of anesthetic agent use among clinicians performing OPU. (bioportfolio.com)
  • Rather than rely on daily ultrasound tests and injections of fertility medicine, the new technique, immature oocyte retrieval and maturation, removes the egg from the ovary for fertilization and then places it back in the mother, says Gleicher. (thefreedictionary.com)
  • All oocytes were individually graded with a sperm binding score at the time of fertilization assessment 16 to 18 hours after insemination. (renalandurologynews.com)
  • Following the promotion of early ovarian follicle development using R-spondin2, mice will be treated sequentially with eCG and hCG to stimulate the final phase of follicle development and to derive mature oocytes for fertilization and the derivation of pups. (labome.org)
  • The results of measuring the ZP elasticity and the dissolution time clearly showed that the ZP softened during oocyte maturation and the ZP hardened after fertilization. (diva-portal.org)
  • The results indicate that the amount of the zona softening can be a criterion to evaluate oocyte quality for the selection of top quality mature oocyte before in vitro fertilization (IVF) treatment. (diva-portal.org)
  • Phospholipase C-zeta deficiency as a cause for repetitive oocyte fertilization failure during ovarian stimulation for in vitro fertilization with ICSI: a case report. (umassmed.edu)
  • When in-vitro matured metaphase II oocytes were selected for in-vitro fertilization, similar percentages of I/LnJ oocytes underwent fertilization and cleavage to the 2-cell stage as oocytes from another inbred stain, C57BL/6J, and similar percentages of 2-cell stage oocytes completed the 2-cell stage to blastocyst transition in vitro. (psu.edu)
  • However, unlike C57BL/6J oocytes, a much lower percentage of oocytes that matured in vivo in response to exogenous gonadotrophins underwent fertilization and cleavage to the 2-cell stage than oocytes that underwent maturation in vitro. (psu.edu)
  • Fresh sperm retrieved by micro-TESE are used for fertilization of the warmed oocytes. (centerwatch.com)
  • when it is not possible to obtain testicular sperm, the couples are offered fertilization with warmed oocytes. (centerwatch.com)
  • Chen C (1986) Pregnancy after human oocyte cryopreservation. (springer.com)
  • Human oocyte radiosensitivity. (thefreelibrary.com)
  • New research concerning the radiosensitivity of the human oocyte has provided another tool for radiologic technologists to reassure female patients. (thefreelibrary.com)
  • Knowledge of the meiotic phase of the cell life cycle is important in understanding the radiosensitivity of the human oocyte. (thefreelibrary.com)
  • When mice were super ovulated 5 weeks after exposure, the number of mature oocytes harvested from cisplatin treated mice was significantly lower than controls. (doaj.org)
  • Conclusions These findings suggest that mitochondrial dysfunction may contribute to the depletion of the ovarian reserve caused by cisplatin, but long-term impacts on mitochondria may be minimal as those immature oocytes that survive cisplatin treatment develop into mature oocytes with normal mitochondrial parameters. (doaj.org)
  • Chromosome transfer in mature oocytes. (biomedsearch.com)
  • A gene expression signature shared by human mature oocytes and embryonic stem cells. (archives-ouvertes.fr)
  • Pre-treatment with R-spondin1-Fc led to the induction of early antral follicles capable of responding to sequential eCG and hCG treatment, leading to the generation of mature oocytes. (labome.org)
  • We will then use a rodent model of low FSH responsiveness (FSH receptor haploinsufficient heterozygous mutants) to test the ability of R-spondin2 in the promotion of early follicle development for subsequent gonadotropin stimulation and the generation of mature oocytes. (labome.org)
  • We will evaluate epigenetic changes, mitochondrial integrity and early embryonic development of mature oocytes to insure the efficacy and safety of the present treatment regimen. (labome.org)
  • Injected nuclei in frog oocytes: Fate, enlargement, and chromatin dispersal. (springer.com)
  • The two primary methods involve either the replacement of oocyte nuclei with adult somatic cell nuclei-a process known as somatic cell nuclear transfer (SCNT)-or the introduction, typically by viruses, of a cocktail of specific transcription factors to create induced pluripotent stem cells (iPSCs). (news-medical.net)
  • The maternal genome inherited from the oocyte and the paternal genome provided by sperm coexist as separate haploid nuclei in the zygote. (nature.com)
  • Here we show that chromatin architecture is uniquely reorganized during the oocyte-to-zygote transition in mice and is distinct in paternal and maternal nuclei within single-cell zygotes. (nature.com)
  • Meiotic newt oocyte nuclei were allowed to disperse in 30 mM KCl/NaCl, centrifuged through 2% formaldehyde onto an EM grid, stained with uranyl acetate, and critical point dried. (cellimagelibrary.org)
  • This image of an adult female emphasizes characteristic structures such as the ciliary ring, or corona, the pharynx with a mastax consisting of hard jaws (trophi), a set of circular and longitudinal muscles, bilateral ovaries with oocyte nuclei, and the parthenogenetically developing egg. (cellimagelibrary.org)
  • For ICSI into mouse metaphase II oocytes (17-19 h after human chorionic gonadotropin injection), frozen mouse, sheep, and bovine sperm were prepared by thawing briefly in a 37°C water bath, centrifuging for 2 min at 400 × g , and washing the pellet in 500 μl of PBS. (pnas.org)
  • Significantly increased aneuploidy, arising during the first meiotic division, was observed in metaphase II oocytes matured in higher concentrations of FSH (≥20 ng/ml). (bioone.org)
  • The injection of RNA into living cells: The use of frog oocytes for the assay of mRNA and the study of the control of gene expression. (springer.com)
  • Mutation of one of the two putative CaMKII phosphorylation sites in caspase-2 prevented the G6P- and NADPH-stimulated phosphorylation of caspase-2, and this mutant caspase-2 also promoted cell death of oocytes when its mRNA was injected into the oocytes. (sciencemag.org)
  • Slight reduction in mRNA levels of Atg7 and Atg12 in vitrified-warmed oocytes was noted, and expression of these genes was not significantly influenced. (sigmaaldrich.com)
  • Yang F, Wang W, Cetinbas M, Sadreyev RI, Blower MD. Genome-wide analysis identifies cis-acting elements regulating mRNA polyadenylation and translation during vertebrate oocyte maturation. (harvard.edu)
  • The objective of this study was to investigate the mRNA expression and protein localization of Grb10 gene in bovine cumulus-oocyte complexes (COCs) from different follicle sizes. (scielo.br)
  • Oocytes are rich in cytoplasm, which contains yolk granules to nourish the cell early in development. (wikipedia.org)
  • These mRNAs can be stored in mRNP (message ribonucleoprotein) complexes and be translated at specific time points, they can be localized within a specific region of the cytoplasm, or they can be homogeneously dispersed within the cytoplasm of the entire oocyte. (wikipedia.org)
  • To preserve the maternal stores accumulated during oogenesis for further embryo development, oocytes divide asymmetrically which minimizes the volume of cytoplasm lost with each set of haploid genome. (nih.gov)
  • We synthesized NO38 transcripts in vitro, injected them into the oocyte cytoplasm, and followed the distribution of the translation products. (rupress.org)
  • Oocytes were obtained by the aspiration of 3-7mm antral follicles of ovaries collected in slaughterhouse and those recovered presenting homogeneous cytoplasm and at least four layers of cumulus cells were selected for in vitro maturation (IVM). (scielo.br)
  • Transmission electron micrographs of sections of tadpole oocyte show the potential for exchange between the nucleus and the cytoplasm at the nuclear envelope. (cellimagelibrary.org)
  • The method that will be reviewed in this chapter is the one based on microinjection of complementary RNA (cRNA) into the oocyte cytoplasm ( Figure 1a ). (wormbook.org)
  • Here, we use interspecies intracytoplasmic sperm injection to demonstrate that sheep sperm DNA can be demethylated in mouse oocytes. (pnas.org)
  • During oogenesis, the oogonia become primary oocytes. (wikipedia.org)
  • Oogenesis results in the formation of both primary oocytes during fetal period, and of secondary oocytes after it as part of ovulation. (wikipedia.org)
  • During development the primordial germ cells form and become oogonia through mitosis (by millions), then they can become primary oocytes. (physicsforums.com)
  • Primary oocytes develop in the ovaries of the fetus but only a fraction of these will ever give rise to OVULATION . (thefreedictionary.com)
  • an early stage in GAMETO GENESIS of female animals, 'primary' oocytes being DIPLOID (1) and 'secondary' oocytes HAPLOID (1) having undergone the first meiotic division. (thefreedictionary.com)
  • Human females are born with the primary oocytes already formed, which may increase the risk of NONDISJUNCTION of chromosomes. (thefreedictionary.com)
  • Spindle positioning in mammalian oocytes. (nih.gov)
  • In this review, we will discuss the recent advances in the field, with emphasis on the control mechanisms involved in meiotic spindle positioning in mammalian oocytes. (nih.gov)
  • ABSTRACT: In 2013, the American Society for Reproductive Medicine and the Society for Assisted Reproductive Technology published a joint document, Mature Oocyte Cryopreservation: A Guideline, which addresses advances in techniques to freeze human eggs that have resulted in significant recent improvements in pregnancy success. (acog.org)
  • There are not yet sufficient data to recommend oocyte cryopreservation for the sole purpose of circumventing reproductive aging in healthy women. (acog.org)
  • However, as stated in the ASRM-SART guideline, "there are not yet sufficient data to recommend oocyte cryopreservation for the sole purpose of circumventing reproductive aging in healthy women because there are no data to support the safety, efficacy, ethics, emotional risks, and cost-effectiveness of oocyte cryopreservation for this indication" (1). (acog.org)
  • Mature oocyte cryopreservation is a currently available method of fertility preservation in women of reproductive age. (acog.org)
  • In the past 10 years, methods for ultrarapid freezing (vitrification) of oocytes have been refined that optimize oocyte survival after cryopreservation (1, 5-7 ). (acog.org)
  • An important clinical predictor of outcomes in the observational studies of oocyte cryopreservation and IVF is the age of the oocyte when frozen or vitrified ( 13-16 ). (acog.org)
  • Both sperm and embryo cryopreservation have become routine procedures in human assisted reproduction and oocyte cryopreservation is being introduced into clinical practice and is getting more and more widely used. (hindawi.com)
  • Oocyte cryopreservation offers more advantages compared to embryo freezing, such as fertility preservation in women at risk of losing fertility due to oncological treatment or chronic disease, egg donation, and postponing childbirth, and eliminates religious and/or other ethical, legal, and moral concerns of embryo freezing. (hindawi.com)
  • Cryopreservation of oocytes will have multiple applications for animals and human beings. (springer.com)
  • Clark NA, Swain JE (2013) Oocyte cryopreservation: searching for novel improvement strategies. (springer.com)
  • In single women who are at risk for infertility secondary to cancer or couples who have ethical reasons to avoid embryo cryopreservation, oocyte cryopreservation is an alternative Purpose of study is to compare slow freeze to vitrification of human oocytes. (clinicaltrials.gov)
  • The purpose of this study is to compare these two methods of oocyte cryopreservation in human oocytes. (clinicaltrials.gov)
  • Oocyte cryopreservation is a widely used technique in IVF for storage of surplus oocytes, as well as for fertility preservation (i.e. women undergoing gonadotoxic therapies) and oocyte donation programs. (unboundmedicine.com)
  • Although cryopreservation has negative impacts on oocyte physiology and it is associated with decrease of transcripts, no experimental data about the effect of storage time on the oocyte molecular profile are available to date. (unboundmedicine.com)
  • Gene Ontology analysis by DAVID bioinformatics resource disclosed that cryopreservation deregulates genes involved in oocyte function and early embryo development, such as chromosome organization, RNA splicing and processing, cell cycle, cellular response to DNA damage and to stress, DNA repair, calcium ion binding, malate dehydrogenase activity and mitochondrial activity. (unboundmedicine.com)
  • DALLAS, Texas, May 23, 2011 (SEND2PRESS NEWSWIRE) - Women delaying childbearing or requiring fertility preservation prior to undergoing treatment now have an option with the launch of oocyte cryopreservation at Fertility Specialists of Texas. (send2press.com)
  • Human egg freezing or oocyte cryopreservation is a novel technique intended to preserve a woman's eggs for later use in life. (send2press.com)
  • In addition, the text looks at the effects of in vitro maturation environments on oocyte quality and developmental outcome. (wiley.com)
  • PB2 was supplemented in the in vitro maturation medium, and the ratio of germinal vesicle breakdown (GVBD) and polar body extrusion (PBE), reactive oxygen species (ROS) levels, mitochondrial function, developmental ability, as well as crotonylation at H4K5 were determined in oocytes. (greenmedinfo.com)
  • Follicle-Stimulating Hormone (FSH) at a wide range of doses is routinely added to culture media during in vitro maturation (IVM) of oocytes, but the effects on oocyte health are unclear. (bioone.org)
  • The present studies were undertaken to investigate the effect of different medium supplements, the involvement of steroid hormones and the role of estradiol-17$\beta$ on in vitro maturation of pig oocytes. (illinois.edu)
  • Addition of 10% pFF in combination with gonadotropins during maturation provided the best environment for in vitro maturation with the highest percentage of oocytes reaching nuclear and cytoplasmic maturation. (illinois.edu)
  • In conclusion, the optimal environment for in vitro maturation of pig oocytes was found to be culture medium containing gonadotropins and 10% porcine follicular fluid. (illinois.edu)
  • This process is termed oocyte maturation. (genome.jp)
  • An oocyte is produced in the ovary during female gametogenesis. (wikipedia.org)
  • Oocyte growth in the ovary. (routledge.com)
  • Researchers at Brown University and Women & Infants Hospital of Rhode Island have built an artificial human ovary that can grow oocytes into mature human eggs in the laboratory. (webwire.com)
  • Here, we have investigated whether expression of spermatogenesis and oogenesis bHLH transcription factor 1 ( Sohlh1 ) and Sohlh2 coordinates oocyte differentiation within the embryonic ovary. (jci.org)
  • Prolonging the period of ovary collection may significantly affect the viability of the oocytes for IVEP. (thefreedictionary.com)
  • g] is the number of oocytes present in the ovary, [E. (thefreedictionary.com)
  • Among the probes significantly up-regulated in cryopreserved oocytes, two corresponded to ovary-specific expressed large intergenic noncoding (linc)RNAs. (unboundmedicine.com)
  • ovarian follicle consists of an oocyte, or immature egg, surrounded by an epithelium, the cells of which are referred to variously as follicular, nurse, or granulosa cells. (britannica.com)
  • The cumulus-oocyte complex contains layers of tightly packed cumulus cells surrounding the oocyte in the Graafian follicle. (wikipedia.org)
  • Many studies show that cumulus expansion is critical for the maturation of the oocyte because the cumulus complex is the oocyte's direct communication with the developing follicle environment. (wikipedia.org)
  • Notably, immature oocytes are particularly vulnerable to cisplatin treatment, a common side effect of which is depletion of the primordial follicle reserve, leading to infertility and early menopause. (doaj.org)
  • The book covers multiple molecular and physiological mechanisms including initiation of oocyte growth during folliculogenesis and in vitro follicle culture to support oocyte competence, that are critical to health and quality. (wiley.com)
  • However, even when only a single follicle is punctured, oocyte retrieval can be painful. (thefreedictionary.com)
  • DESCRIPTION (provided by applicant): Oocyte-derived R-spondin2 as a Follicle Stimulating Hormone Abstract: The Wingless (Wnt) signaling pathway is essential for cell proliferation from flies to mammals. (labome.org)
  • Between 1992 and 1999, ultrasound-guided transvaginal follicle punctures for oocyte recovery were performed on five different occasions, but embryo transfer was achieved only once and did not lead to pregnancy. (asm.org)
  • At the end of August 2000, two oocytes were recovered (again via transvaginal follicle puncture after disinfection of the vagina with Octenisept [Schülke & Mayr GmbH, Norderstedt, Germany]), fertilized, and transcervically transferred, but again the patient did not get pregnant. (asm.org)
  • Oocytes are stored in the abdominal cavity of adult females in clumps called ovarian lobes that include oocytes, connective tissue, blood vessels and follicle cells. (wormbook.org)
  • Kumar S (2015) Cryobiological effects and apoptotic gene expression on cumulus oocyte complexes in sheep (Ovis areis). (springer.com)
  • In this article, we describe detailed protocols for the isolation and transfer of spindle-chromosomal complexes between mature, metaphase II-arrested oocytes. (biomedsearch.com)
  • Weng L, Lee GY, Liu J, Kapur R, Toth TL, Toner M. On-chip oocyte denudation from cumulus-oocyte complexes for assisted reproductive therapy. (harvard.edu)
  • This study examined the concentration of cell-free mitochondrial DNA (cf-mtDNA) in porcine follicular fluid (FF) and explored whether the cfDNA level in the culture medium could reflect mitochondrial dysfunction in cumulus cell-oocyte complexes (COCs). (go.jp)
  • Cumulus oocyte complexes (COC) were obtained by aspiration of 2-5 mm follicles. (illinois.edu)
  • Results At 6 and 24 h after treatment, mitochondrial localisation, mass and ATP content in immature oocytes were similar between groups. (doaj.org)
  • However, TMRM staining intensity, a marker of mitochondrial membrane potential, was decreased in immature oocytes from cisplatin treated mice compared to saline treated controls, consistent with the induction of apoptosis. (doaj.org)
  • Newly reconstructed oocytes consist of nuclear genetic material from one female and cytoplasmic components, including mitochondria and mitochondrial DNA (mtDNA), from another female. (biomedsearch.com)
  • Potential clinical applications include mitochondrial gene replacement therapy to prevent transmission of mtDNA mutations and treatment of infertility caused by cytoplasmic defects in oocytes. (biomedsearch.com)
  • Mitochondrial replacement therapies or techniques (MRT) circumventing mother-to-child mtDNA disease transmission involve replacement of oocyte maternal mtDNA. (unboundmedicine.com)
  • Procyanidin B2 improves oocyte maturation and subsequent development in Type 1 diabetic mice by promoting mitochondrial function. (greenmedinfo.com)
  • Our results are the first to reveal a role for PB2 in promoting the viability of oocytes by regulating the mitochondrial function. (greenmedinfo.com)
  • Melatonin improves oocyte maturation and mitochondrial functions by reducing bisphenol A-derived superoxide in porcine oocytes in vitro. (greenmedinfo.com)
  • When they compared protein expression level in oocytes from these mice, they found numerous changes in mitochondrial and redox proteins, In particular, a mitochondrial protein called TP53-inducible glycolysis and apoptosis regulator, or TIGAR, was expressed at a lower level in oocytes from mice on a high-fat diet. (news-medical.net)
  • Because the fate of an oocyte is to become fertilized and ultimately grow into a fully functioning organism, it must be ready to regulate multiple cellular and developmental processes. (wikipedia.org)
  • Gautam SK, Verma V, Palta P, Chauhan MS, Manik RS (2008) Effect of type of cryoprotectant on morphology and developmental competence of in vitro-matured buffalo ( Bubalus bubalis ) oocytes subjected to slow freezing or vitrification. (springer.com)
  • Disclosed are methods and systems for assessing the developmental potential of an oocyte based on one or more quantitative metrics derived from one or more birefringence images of a sample comprising the oocyte, wherein the assessing comprises comparing the one or more quantitative metrics to reference information. (freepatentsonline.com)
  • 5. The method of claim 1, further comprising assessing the developmental potential of an additional oocyte sample based on one or more quantitative metrics derived from one or more birefringence images of the additional oocyte, wherein the assessing comprises comparing the one or more quantitative metrics for the additional oocyte to the same reference information as that for the assessment of the first mentioned oocyte sample. (freepatentsonline.com)
  • 11. The method of claim 1, wherein assessing the developmental potential of the oocyte comprises grading the oocyte into one of three or more tiers based on the one or more quantitative metrics. (freepatentsonline.com)
  • Furthermore, the developmental capacity of the multipronuclear oocytes is variable. (biomedsearch.com)
  • Rapamycin rescues the poor developmental capacity of aged porcine oocytes. (thefreelibrary.com)
  • In the absence of centrosome and microtubule stability, oocytes cannot be fertilized or, alternatively, fertilized oocytes display aneuploidy and developmental abnormalities. (thefreelibrary.com)
  • Role of caspase-3 cleaved IP3 R1 on Ca(2+) homeostasis and developmental competence of mouse oocytes and eggs. (umassmed.edu)
  • The patterns of entry of thyroid hormones into live tilapia oocytes were examined by incubating ovarian follicles in L-15 medium containing 125I-labeled thyroxine (T4) or 3,5,3'-triiodothyronine (T3). (nih.gov)
  • When follicles were back-transferred to medium without T3, only 15% of T3 in the oocyte disappeared within the following 24 h. (nih.gov)
  • Although communication between the oocyte and surrounding somatic cells is critical for the normal development of ovarian follicles, perturbations in oocyte-GC communication during early folliculogenesis can induce GCT by activating an autocrine growth circuit program in GC. (aacrjournals.org)
  • Based on bioinformatic and in situ hybridization analyses, we demonstrated the exclusive expression of R-spondin2 in oocytes of primary and more advanced follicles but not in oocytes of dormant primordial follicles. (labome.org)
  • Female germ cells, oocytes, are highly specialised cells. (europa.eu)
  • In oocytes, C e O 2 ENP aggregates were only observed around the zona pellucida (ZP). (mdpi.com)
  • or egg), derived from an oocyte (immature egg), and the male sex cell (spermatozoon or sperm), derived from a spermatocyte. (britannica.com)
  • The only normal human type of secondary oocyte has the 23rd (sex) chromosome as 23,X (female-determining), whereas sperm can have 23,X (female-determining) or 23,Y (male-determining). (wikipedia.org)
  • Both clinical trials and observational studies have compared reproductive outcomes after IVF and intracytoplasmic sperm injection (ICSI) with cryopreserved oocytes to IVF and ICSI with fresh oocytes. (acog.org)
  • A team of reproductive biologists from the United States and Japan has succeeded in fertilizing rabbit oocytes with "dead" freeze-dried rabbit sperm. (eurekalert.org)
  • Mouse sperm, however, are significantly different from sperm of most other mammals because they do not contribute a cellular organelle known as a centrosome to the fertilized oocyte. (eurekalert.org)
  • Even after being stored at temperatures above freezing for more than two years, the treated sperm were as capable as fresh sperm at fertilizing rabbit oocytes. (eurekalert.org)
  • In a paper scheduled for publication in Biology of Reproduction, the team headed by Xiangzhong Yang of the Center for Regenerative Biology at the University of Connecticut, Storrs, and Ryuzo Yanagimachi of the University of Hawaii Medical School, Honolulu, reports that one rabbit pup was born after 230 oocytes fertilized with freeze-dried sperm were transferred to 8 female rabbits. (eurekalert.org)
  • Surprisingly, mouse sperm can also be demethylated to a limited extent in sheep oocytes. (pnas.org)
  • After a final centrifugation of 5 min at 500 rpm, sperm in the supernatant were then immobilized to avoid oocyte lysis by diluting 1:5 in a 10% polyvinylpyrrolidone solution 30 min before injection. (pnas.org)
  • Secondary oocytes divide to form the mature OVUM but the second maturation division occurs only after the ovum has been fertilized by a sperm. (thefreedictionary.com)
  • Sperm binding within a single oocyte cohort was highly variable. (renalandurologynews.com)
  • Sperm binding to intact, viable oocytes in a culture dish should not be thought of in the same manner as the hemizona assay. (renalandurologynews.com)
  • in human sperm and its absence in DPY19L2-deficient sperm are consistent with its role in oocyte activation. (umassmed.edu)
  • Maximum z -projection images of 2mEGFP-CENP-C (KTs, green) and H2B-mCherry (chromosomes, red) in the oocytes of young (2 months old) and aged (16 months old) BDF1 mice. (nature.com)
  • After immunofluorescent staining with two antibodies, the protein XCAP-D2 is evident in red on the lampbrush chromosomes (green) in the nucleus of a frog oocyte. (innovations-report.com)
  • Immunofluorescent staining showed XCAP-D2 proteins on the 18 easily recognizable chromosomes of the frog oocyte. (innovations-report.com)
  • High FSH had no effect on gross spindle morphology but did alter chromosome congression during prometaphase and metaphase, with the spread of chromosomes across the spindle at this time being significantly greater in oocytes cultured in 2000 ng/ml compared with 2 ng/ml FSH. (bioone.org)
  • Oocytes showing metaphase II chromosomes were considered nuclear matured. (illinois.edu)
  • Frog oocytes are large, allowing researchers to easily manipulate genetic material. (innovations-report.com)
  • Is there anybody out in histonetland who may have done some sectioning of frog oocytes or something similar? (histosearch.com)
  • Does anybody know an optimal temp for cutting frog oocytes? (histosearch.com)
  • Frozen-thawed oocytes could be also later used for producing live offspring for faster multiplication of superior germplasm or for use in reproductive technologies like production of cloned or transgenic livestock or production of embryonic stem cells. (springer.com)
  • However, the antioxidative effects of Mela against BPA-induced superoxide production in porcine oocytes are still not known. (greenmedinfo.com)
  • it is derived from an oogonium , and is called a primary oocyte prior to completion of the first maturation division, and a secondary oocyte between the first and second maturation division. (thefreedictionary.com)
  • A primary oocyte divides to produce a polar body and a secondary oocyte, which divides again to produce the ovum and another polar body. (thefreedictionary.com)
  • Maturation of immature oocytes in stimulated cycles. (routledge.com)
  • Kuleshova L, Gianaroli L, Magli C, Ferraretti A, Trounson A (1999) Birth following vitrification of a small number of human oocytes: case report. (springer.com)
  • Vitrification involves the use of cryoprotectants (CPAs) and liquid nitrogen (LN2), which may cause osmotic damage and cryoinjury to oocytes. (sigmaaldrich.com)
  • In this work, we investigated whether the vitrification-warming process induces autophagy in mouse oocytes. (sigmaaldrich.com)
  • Our hypothesis is that higher survival rate per oocyte is to be expected in the vitrification group. (clinicaltrials.gov)
  • Although several reviews of smaller studies of cryoprotectant methodology exist randomized controlled trials,comparing slow-freeze-rapid-thaw procedure to vitrification of oocytes, are not available. (clinicaltrials.gov)
  • The investigators have recently introduced oocyte vitrification and it allows us to plan the egg donation in a different way. (clinicaltrials.gov)
  • Chromosome transfer between the cohorts of oocytes isolated from two females can be completed within 2 h. (biomedsearch.com)
  • 1997). However, no data are available regarding the use of strontium to activate bovine oocytes. (scielo.br)
  • The aim of the present study was to assess the activating ability of bovine oocytes cultured in the presence of strontium for different periods of time and if the association with an electric pulse would improve activation rates. (scielo.br)
  • These results characterized Grb10 gene in bovine COC and provide evidences for its involvement during oocyte molecular maturation. (scielo.br)
  • Confirmation that the length of storage does not alter the gene expression profile of frozen oocytes is noteworthy for the safety issue of long-term oocyte banking, i.e. fertility preservation, gamete donation. (unboundmedicine.com)
  • 1994). An increase in reactive oxygen species (ROS) production over time may lead to a decrease in the intracellular adenosine triphosphate (ATP) concentration and the glutathione/glutathione disulfide ratio as well as to a concomitant increase in cytosolic calcium ions, which are all detrimental to oocyte health and embryo development (Tarin, 1996). (thefreelibrary.com)
  • In RT-PCR analyses, we observed that several Atg genes such as Atg5, Atg7, Atg12, LC3a (Map1lc3a), LC3b (Map1lc3b), and Beclin1 were expressed in MII mouse oocytes. (sigmaaldrich.com)
  • Furthermore, we find that Sall4 modulates H3K4me3 and H3K27me3 modifications by regulating the expression of key histone demethylases coding genes Kdm5b, Kdm6a, and Kdm6b in oocytes. (sigmaaldrich.com)
  • Discover related pathways, diseases and genes to Oocyte Expressed Protein. (novusbio.com)
  • Comparison of gene expression profiles between surviving thawed oocytes after 3 and 6 years of storage in liquid nitrogen found no differently expressed genes. (unboundmedicine.com)
  • The damage (depolymerization) and/or absence of the spindle compromise the ability of the oocyte to fertilize and undergo normal preimplantation development. (hindawi.com)
  • Au Yeung WK, Brind'Amour J, Hatano Y, Yamagata K, Feil R, Lorincz MC, Tachibana M, Shinkai Y, Sasaki H. Histone H3K9 Methyltransferase G9a in Oocytes Is Essential for Preimplantation Development but Dispensable for CG Methylation Protection. (harvard.edu)
  • As the oocyte is a product of female gametogenesis, the maternal contribution to the oocyte and consequently the newly fertilized egg, is enormous. (wikipedia.org)
  • It was proposed that, in order to avoid damage to the DNA genome of the oocytes, the metabolism contributing to the synthesis of much of the oocyte's constituents was shifted to other maternal cells that then transferred these constituents to oocytes. (wikipedia.org)
  • During the growth of the oocyte, a variety of maternally transcribed messenger RNAs, or mRNAs, are supplied by maternal cells. (wikipedia.org)
  • The oocyte receives mitochondria from maternal cells, which will go on to control embryonic metabolism and apoptotic events. (wikipedia.org)
  • Maternal Sall4 Is Indispensable for Epigenetic Maturation of Mouse Oocytes. (sigmaaldrich.com)
  • We further discover that the loss of maternal Sall4 causes failure in establishment of DNA methylation in oocytes. (sigmaaldrich.com)
  • In mice, maternal obesity impairs proper development of egg precursor cells called oocytes. (news-medical.net)
  • This study provides evidence of the direct effects of maternal obesity on the quality of oocyte development and implicates TIGAR in oocyte maturation in mice. (news-medical.net)
  • This is the first report to show that copious amounts of maternal hydrocarbons are provisioned in oocytes and to demonstrate the existence of a hydrocarbon transport pathway involving hemolymph high-density lipophorin. (biologists.org)
  • Confocal live imaging analysis using oocytes from GFP-LC3 transgenic mice revealed that vitrified-warmed oocytes had a significantly higher number of GFP-LC3 puncta in comparison to fresh oocytes. (sigmaaldrich.com)
  • Treatment with 3-methyladenine, an inhibitor of autophagy, did not significantly affect the rates of oocyte survival, IVF, and embryonic development after warming and IVF. (sigmaaldrich.com)
  • DNA damage decreased significantly both in follicular cells and in oocytes when an anti-oxidant agent was added in the culture medium. (mdpi.com)
  • The expression profiles of cryopreserved MII oocytes significantly differed from those of non-cryopreserved oocytes in 107 probe sets corresponding to 73 down-regulated and 29 up-regulated unique transcripts. (unboundmedicine.com)
  • Finally, pharmacological inhibition of Aurora A rescued spindle defects and significantly improved pronuclei formation in Ppp6c conditional KO oocytes. (biologists.org)
  • During the primary oocyte stage of oogenesis, the nucleus is called a germinal vesicle. (wikipedia.org)
  • When applied to oocytes ( Fig. 1c ), our method was efficient at capturing chromosomal interactions: single-nucleus Hi-C (snHi-C) revealed up to 1.9 × 10 6 contacts per cell after filtering, yielding 1-2 orders of magnitude more contacts than published single-cell Hi-C data 2 and exceeding contact frequencies in a recent single-cell Hi-C preprint and report 9 , 10 . (nature.com)
  • I believe you are asking: under the microscope, can one take the nucleus (nuclear mterial) from one oocyte and insert it into another oocyte. (physicsforums.com)
  • To examine the role of primary amino acid sequence in the localization of proteins within the nucleus, we studied the nucleolar protein NO38 of amphibian oocytes. (rupress.org)
  • The mtDNA number and viability of cumulus cells and oocytes remained unchanged. (go.jp)
  • When the oocytes were denuded from the cumulus cells following CCCP treatment, PCR detected very low levels of cfDNA in the spent culture medium of the denuded oocytes. (go.jp)
  • The major benefit of IVM is that significant numbers of oocytes can be collected from ovaries without recourse to ovarian stimulation. (routledge.com)
  • Hydrocarbons are not synthesized by the ovaries, but are delivered by hemolymph lipoproteins and accumulate within the basal oocytes. (biologists.org)
  • A native B. germanica hydrocarbon, [ 3 H]3,11-dimethylnonacosane, injected into adult females of various ages, was taken up by the ovaries in relation to oocyte growth. (biologists.org)
  • Hydrocarbon uptake by the ovaries, however, was three times higher 24 h after injection than 4 h after injection, showing that hydrocarbons are slowly and continuously deposited in oocytes. (biologists.org)
  • For each cycle, men whose female partner was undergoing IVF or IUI provided one spot urine sample at the time of oocyte retrieval or insemination, respectively. (thefreedictionary.com)
  • From a medical standpoint, this case of postmortem oocyte retrieval is fraught with difficulty. (thefreedictionary.com)
  • Comparison of different transvaginal ovum pick-up protocols to optimise oocyte retrieval and embryo production over a 10-week period in cows. (thefreedictionary.com)
  • Additionally, it avoids ethical concerns regarding ovarian stimulation and oocyte retrieval in children. (thefreedictionary.com)
  • The drops were prepared in Falcon #3002 Petri dishes (Becton-Dickinson Labware, Lincoln Park, NJ) one to three hours prior to oocyte retrieval with media that were equilibrated overnight in a 36. (thefreedictionary.com)
  • Women who underwent oocyte retrieval at our institution between August 1995 and February 1997 and agreed to participate in the study were enrolled consecutively. (thefreedictionary.com)
  • Table 1 gives an overview of the mean number of days of stimulation, the mean of the total number of ampoules of FSH used during the stimulation, the mean of the final E2 concentrations before oocyte retrieval , and the mean of the daily percent E2 increase. (thefreedictionary.com)
  • Russell and his colleagues at the Reproductive Endocrine and Fertility Center of Delaware in Newark, say the technique, called immature oocyte retrieval , promises to reduce the risks, costs, and discomforts of IVF. (thefreedictionary.com)
  • In IVC, following ovulation induction and oocyte retrieval , the oocytes are identified and consolidated into a tiny tube filled completely with culture medium. (thefreedictionary.com)
  • To study the effect of diclofenac suppository in oocyte retrieval of IVF-ET. (scirp.org)
  • The data of vital signs, common adverse reactions, severe adverse events and pain degree in oocyte retrieval were collected. (scirp.org)
  • Using diclofenac suppository in oocyte retrieval analgesic had a good effect. (scirp.org)
  • Y. Li, Q. Mai, T. Li, Y. Zhong and C. Zhou, "The Clinic Analysis of Diclofenac Suppository for Oocyte Retrieval Analgesia in IVF-ET Cycles," International Journal of Clinical Medicine , Vol. 4 No. 8, 2013, pp. 350-354. (scirp.org)
  • However, the induction of autophagy in vitrified-warmed oocytes has not been examined. (sigmaaldrich.com)
  • The expression of BECLIN1 protein was also increased in vitrified-warmed oocytes. (sigmaaldrich.com)
  • The results suggest that the observed autophagic activation in vitrified-warmed oocytes is a natural adaptive response to cold stress. (sigmaaldrich.com)
  • Oocyte Physiology and Development in Domestic Animals reviews the most recent advances in the research of physiological and biochemical mechanisms underlying oocyte growth and development, providing readers with the fundamental understanding of these key processes and summarizing this important field of research. (wiley.com)
  • We will use oocytes from two vertebrate species, frogs and mice, which are complementary for their ease of handling and relationship to human physiology. (europa.eu)
  • To ensure asymmetric division to occur, oocytes have to position their division spindle asymmetrically as well as tailor the size of daughter cells to the chromatin mass. (nih.gov)
  • The metaphase II (MII) oocyte has a very special structure (i.e., large size, very sensitive to low temperature, extremely fragile, high water content, low surface to volume ratio, presence of the spindle and other cell organelles, not optimal plasma membrane permeability to CPA and water, etc.) that leads to complex difficulties associated with its CP. (hindawi.com)
  • Dr Schuh will also talk about the actin-dependent mechanism of asymmetric spindle positioning in mouse oocytes. (warwick.ac.uk)
  • In particular, the inhibition of mTOR by rapamycin affected the formation of the actin cap and the cortical granules-free domain (CGFD), and disrupted peripheral spindle migration and asymmetric division during oocyte meiotic maturation (Lee et al. (thefreelibrary.com)
  • Researchers found evidence that TIGAR may play a role in the meiotic spindle, a cell structure that coordinates the movements of DNA in the oocyte. (news-medical.net)
  • When full-length transcripts of NO38 were injected into oocytes, the translation products accumulated efficiently in the germinal vesicle, and a major fraction was localized in the multiple nucleoli. (rupress.org)
  • The time of germinal vesicle breakdown (GVB) of I/LnJ oocytes was greatly delayed compared to all other strains tested. (psu.edu)
  • contains a primitive ovum, or oocyte, and each is covered by a single layer of flattened cells. (britannica.com)
  • Oocyte death ultimately leads to sterility as the animals age and conditions that accelerate death of the eggs cause premature infertility. (sciencemag.org)
  • Thus, I/LnJ mice might be a useful model for studying infertility resulting from defective oocytes. (psu.edu)
  • After the theca cells grew into the honeycomb shape, spherical clumps of donated granulosa cells were inserted into the holes of the honeycomb together with human egg cells, known as oocytes. (webwire.com)
  • Carson said her goal was never to invent an artificial organ, per se, but merely to create a research environment in which she could study how theca and granulosa cells and oocytes interact. (webwire.com)
  • Here, we report that uncontrolled PI3K activity within oocytes irreversibly transforms granulosa cells (GC), causing GC tumors (GCT) through perturbed local cell-communication. (aacrjournals.org)
  • of undifferentiated cells that form oocytes, nurse cells, and follicular cells. (britannica.com)
  • 3) genotoxicity of C e O 2 ENPs on follicular cells and oocytes using a comet assay. (mdpi.com)
  • We hypothesise that at low concentrations of C e O 2 ENPs oocytes could be protected against indirect oxidative stress due to a double defence system composed of follicular cells and ZP. (mdpi.com)
  • Figure 1: Live imaging of MI errors in aged mouse oocytes. (nature.com)
  • Kono T, Kwon OY, Nakahara T (1991) Development of vitrified mouse oocytes after IVF. (springer.com)
  • The protocol was initially developed for monkey oocytes but can also be used in other species, including mouse and human oocytes. (biomedsearch.com)
  • This study reveals an unexpected actin-dependent but microtubule-independent mechanism for long-range transport of vesicles in mouse oocytes. (warwick.ac.uk)
  • Autophagic activation in vitrified-warmed mouse oocytes. (sigmaaldrich.com)
  • Collectively, we show for the first time that vitrified-warmed mouse oocytes exhibit autophagic activation during warming and that this response is not induced by CPA-containing solutions. (sigmaaldrich.com)
  • Hamilton LE, Suzuki J, Acteau G, Shi M, Xu W, Meinsohn MC, Sutovsky P, Oko R. WBP2 shares a common location in mouse spermatozoa with WBP2NL/PAWP and like its descendent is a candidate mouse oocyte-activating factor. (harvard.edu)
  • Researchers claim to have successfully transformed stem cells into viable mouse oocytes that produced healthy, fertile pups. (the-scientist.com)
  • Taken together, our study explores a pivotal role of Sall4 in regulating epigenetic maturation of mouse oocytes. (sigmaaldrich.com)
  • When TIGAR was depleted in mouse oocytes either by feeding or RNA interference, reactive oxygen species were higher, which activated a cellular quality-control pathway called autophagy. (news-medical.net)
  • 1999). Strontium has shown to be efficient for activating mouse oocytes (Wakayama et al. (scielo.br)
  • Here we study the effect of nicotinamide (NAM), a non-competitive pan-sirtuin inhibitor, during meiotic maturation in mouse oocytes. (harvard.edu)
  • Now there is an option - egg freezing - that enables women to have eggs (also known as oocytes) aspirated before undergoing cancer treatment, and frozen for later use. (send2press.com)
  • If this metabolic activity were carried out by the oocyte's own metabolic machinery, the oocyte genome would be exposed to the reactive oxidative by-products generated. (wikipedia.org)
  • Features of genomic organization including compartments, topologically associating domains (TADs) and loops are present in individual oocytes when averaged over the genome, but the presence of each feature at a locus varies between cells. (nature.com)
  • But Dieter Egli and colleagues now report the successful derivation of triploid human pluripotent stem-cell lines through somatic genome transfer into human oocytes. (natureasia.com)
  • Human oocytes reconstructed using the traditional method (enucleating the oocyte then fusing the donor cell to the karyoplast) invariably arrested during the cleavage stages of development, but when the oocyte genome was not removed and the somatic cell genome was added, the resultant triploid cells efficiently developed to the blastocyst stage. (natureasia.com)
  • Interaction of oocytes and somatic cells. (routledge.com)
  • Thus, the potential to combine these approaches by identifying the crucial factors in oocytes that mediate SCNT efficiency is reviewed in a new article published in Stem Cells and Development , a peer-reviewed journal from Mary Ann Liebert, Inc., publishers . (news-medical.net)
  • Collectively, the authors provide a logical framework for understanding how oocyte factors can de-differentiate committed cells and a platform for studying and discovering optimal combinations to increase the efficiency, reproducibility, and safety of this technique. (news-medical.net)
  • To investigate higher-level chromatin organization in oocytes, we examined how contact probability P c ( s ) 6 , 11 depends on genomic distance in individual cells and pooled data. (nature.com)
  • Oocytes are remarkable in their ability to survive for long periods of time, up to 50 years in humans, and retain the ability to give rise to a young organism while other cells age and die. (europa.eu)
  • Designed for two-electrode, whole-cell voltage clamping of large cells and cell structures using an Oocyte Clamp Amplifier or Two Electrode Voltage Clamp Workstation. (adinstruments.com)
  • Although GCT cells proliferated independently of oocytes, local interactions with mutant PI3K-positive oocytes during early folliculogenesis were essential for the GC transformation. (aacrjournals.org)
  • Human mature MII oocytes and embryonic stem (ES) cells are both able to achieve the feat of cell reprogramming towards pluripotency, either by somatic cell nuclear transfer or by cell fusion, respectively. (archives-ouvertes.fr)
  • RESULTS: Based on a microarray compendium of 205 samples, we compared the gene expression profile of mature MII oocytes and human ES cells (hESC) to that of somatic tissues. (archives-ouvertes.fr)
  • GVBD was also inhibited by the Sirt2-specific inhibitor, AGK2, and in a very similar pattern to NAM, supporting the notion that as in somatic cells, NAM inhibits sirtuins in oocytes. (harvard.edu)
  • Oocytes are large cells (1-1.2 mm diameter) with a black pigmented region called the animal pole and a white (non-pigmented) vegetal pole. (wormbook.org)
  • An oocyte (UK: /ˈoʊəsaɪt/, US: /ˈoʊoʊ-/), oöcyte, ovocyte, or rarely ocyte[citation needed], is a female gametocyte or germ cell involved in reproduction. (wikipedia.org)
  • Oocytes are substantially larger than the average somatic cell, and thus considerable metabolic activity is necessary for their provisioning. (wikipedia.org)