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 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 ...
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 ...
Supplementary MaterialsS1 Fig: Nuclear state of goat oocytes cultured maturation (IVM) is normally compromised because of asynchronous nuclear and cytoplasmic maturation. recommended that CNP may be used to hold off meiotic resumption and improve the developmental competence of goat oocytes matured is certainly compromised weighed against that of their counterparts [14C15]. The indegent embryonic developmental capacity is thought to be because of asynchronous cytoplasmic and nuclear maturation [16]. maturation (IVM) could synchronize nuclear and cytoplasmic maturation and enhance the developmental competence of IVM oocytes [17C20]. Being a physiological meiotic inhibitor existing in follicles, CNP offers a new option to synchronize cytoplasmic and nuclear maturation. Although the appearance of CNP in granulosa cells of goat follicles continues to be reported [21], the result of CNP on meiotic resumption of goat oocytes continues to be to be motivated. In todays study, the result of CNP on ...
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. ...
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 ... An oocyte (UK: /ˈoʊəsaɪt/, US: /ˈoʊoʊ-/), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In ... Oocytes are rich in cytoplasm, which contains yolk granules to nourish the cell early in development. During the primary oocyte ...
... 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 ...
Oocyte (or ovum/egg) activation is a series of processes that occur in the oocyte during fertilization. Sperm entry causes ... Indications for artificial oocyte activation include : Oocyte related activation deficiency In vitro maturation Low number of ... Oocyte activation may be artificially facilitated by calcium ionophores, something that is speculated to be useful in case of ... The meiotic cycle of the oocyte was suspended in metaphase of the second meiotic division. Once PLCζ is introduced into the ...
Degenerated oocytes are classified as damaged oocytes or oocytes without a zona pellucida. Dysmorphic oocytes are oocytes with ... Here the oocyte splits where sister chromatids migrate to the same pole and the first polar body is formed. The oocyte now ... Oocytes are immature egg cells that develop to maturity within a follicle in the ovary. Oocyte abnormalities can occur due to ... Until puberty, oocytes are kept in a dormant state in primordial follicles. At puberty the oocyte must exit its dormant stage ...
Human oocyte cryopreservation (egg freezing) is a procedure to preserve a woman's eggs (oocytes). This technique has been used ... Vitrification eliminates ice formation inside and outside of oocytes on cooling, during cryostorage and as the oocytes warm. ... with fresh oocytes when [both when] vitrified and warmed oocytes are used as part of IVF/ICSI". These studies were completed ... "Delivery rate using cyropreserved oocytes is comparable to conventional in vitro fertilization using fresh oocytes: potential ...
... (TVOR), also referred to as oocyte retrieval (OCR), is a technique used in in vitro fertilization ... Transvaginal oocyte retrieval is more properly referred to as transvaginal ovum retrieval when the oocytes have matured into ... Steptoe and Edwards used laparoscopy to recover oocytes when IVF was introduced, and laparoscopy was the major method of oocyte ... Once the extraction is done, the sample is analyzed in the microscope to select and carry out the oocyte decumulation, a ...
The oocyte maturation inhibitor (OMI) is an inhibitory factor created by follicular cells during a primary oocyte maturation. ... "Decline of follicular oocyte maturation inhibitor coincident with maturation and achievement of fertilizability of oocytes ... It is believed to be the reason why the oocyte remains for so long in the immature dictyate state of meiosis. Channing CP, Liu ...
In females, meiosis occurs in cells known as oocytes (singular: oocyte). Each primary oocyte divides twice in meiosis, ... Female mammals and birds are born possessing all the oocytes needed for future ovulations, and these oocytes are arrested at ... Maturing oocytes are arrested in prophase I of meiosis I and lie dormant within a protective shell of somatic cells called the ... If these oocytes are fertilized by sperm, they will resume and complete meiosis. During folliculogenesis in humans, usually one ...
Expression in Xenopus oocytes". FEBS Letters. 261 (2): 353-7. doi:10.1016/0014-5793(90)80590-f. PMID 1690150. Coats WD, Navarro ... J (Apr 1990). "Functional reconstitution of fMet-Leu-Phe receptor in Xenopus laevis oocytes". The Journal of Biological ...
Expression in Xenopus oocytes". FEBS Letters. 261 (2): 353-7. doi:10.1016/0014-5793(90)80590-f. PMID 1690150. Coats WD, Navarro ... J (Apr 1990). "Functional reconstitution of fMet-Leu-Phe receptor in Xenopus laevis oocytes". The Journal of Biological ...
Expression in Xenopus oocytes". FEBS Letters. 261 (2): 353-7. doi:10.1016/0014-5793(90)80590-f. PMID 1690150. Coats WD, Navarro ... Murphy PM, McDermott D (Jul 1991). "Functional expression of the human formyl peptide receptor in Xenopus oocytes requires a ... J (Apr 1990). "Functional reconstitution of fMet-Leu-Phe receptor in Xenopus laevis oocytes". The Journal of Biological ...
The transcriptome of human oocytes. Proceedings of the National Academy of Sciences, 103(38), 14027-14032. Group, Schuler. "EST ...
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 or 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 only one sperm cell per oocyte, while IVF needs 50,000-100,000. This is because the ...
In mice, Xi reactivation is known to occur in three developmental stages: In the oocyte after fertilization, the paternal X ... Kratzer, P G; Chapman, V M (May 1981). "X chromosome reactivation in oocytes of Mus caroli". Proceedings of the National ... Regarding female mouse germ cells, mature mammalian oocytes were observed to have two active X chromosomes by studies that ... Epstein, Charles J. (1969-03-07). "Mammalian Oocytes: X Chromosome Activity". Science. 163 (3871): 1078-1079. Bibcode:1969Sci ...
Males use their front and hind limbs to squeeze the sides of the corpse's belly until oocytes are ejected. The oocytes are then ...
Another experiment demonstrated that metaphase II oocyte cells were shown to have more expression of FAM76A compared to control ... sapiens metaphase II oocytes and control (consisting of a mixture of skeletal muscle, kidney, lung, colon, liver, spleen, ... "The transcriptome of human oocytes". Proceedings of the National Academy of Sciences of the United States of America. 103 (38 ... "The transcriptome of human oocytes". Proceedings of the National Academy of Sciences of the United States of America. 103 (38 ...
Less mature oocytes are harvested. Moreover, obesity leads to decreased pregnancy rates after IVF and a smaller chance of the ... Oocytes (but not spermatocytes) then undergo a prolonged arrest at the end of diplotene, until meiosis resumes at the beginning ... It is also possible for the uterus to have different levels of receptivity with regards to oocyte attachment, as a result of a ... During the oocyte's prolonged arrest, chromosomes exist as bivalents. This means that homologous chromosomes have paired, and ...
Pai, H. D.; Baid, R.; Palshetkar, N. P.; Pai, A.; Pai, R. D.; Palshetkar, R. (2021). "Oocyte Cryopreservation". Journal of ... "Oocyte Cryopreservation - Current Scenario and Future Perspectives: A Narrative Review", 2021, Hrishikesh D Pai,1 Rashmi Baid,1 ...
Donor oocyte. Oocyte donation is the most successful method for producing pregnancy in perimenopausal women. In the UK the use ... Poor ovarian reserve is a condition of low fertility characterized by 1): low numbers of remaining oocytes in the ovaries or 2 ... A 2008 study concluded that diminished reserve did not affect the quality of oocytes and any reduction in quality in diminished ... A 1995 study reported that women age fifty or higher experience similar pregnancy rates after oocyte donation as younger women ...
Oocytes and spermatocytes are reproductive cells. Sclerocytes secrete the mineralized spicules ("little spines") that form the ... Mesohyl Pinacocyte Choanocyte Lophocyte Porocyte Oocyte Archeocyte Sclerocyte Spicule Water flow A sponge's body is hollow and ...
Some lines of iPSCs have the potential to differentiate into male germ cells and oocyte-like cells in an appropriate niche (by ... October 2011). "Human oocytes reprogram somatic cells to a pluripotent state". Nature. 478 (7367): 70-5. Bibcode:2011Natur.478 ... Hayashi K, Ogushi S, Kurimoto K, Shimamoto S, Ohta H, Saitou M (November 2012). "Offspring from oocytes derived from in vitro ... Gurdon JB, Wilmut I (June 2011). "Nuclear transfer to eggs and oocytes". Cold Spring Harbor Perspectives in Biology. 3 (6): ...
... oocytes are well suited for this research as they are large and easy to handle, transparent, simple to maintain in sea ... Female starfish produce large numbers of oocytes that are easily isolated; these can be stored in a pre-meiosis phase and ... "Cytoskeletal dynamics and function in oocytes". European Molecular Biology Laboratory. Archived from the original on 1 August ...
Xu YW, Wang B, Ding CH, Li T, Gu F, Zhou C (June 2011). "Differentially expressed micoRNAs in human oocytes". Journal of ...
"Genome Analyses of Single Human Oocytes". Cell. 155 (7): 1492-1506. doi:10.1016/j.cell.2013.11.040. PMID 24360273. Zong, ...
Oocyte maturation is the following phase of oocyte development. It occurs at sexual maturity when hormones stimulate the oocyte ... Oocyte maturation stands by at metaphase II in most vertebrates. During ovulation, the arrested secondary oocyte leaves the ... Most follicular granulosa cells stay around the oocyte and so form the cumulus layer. Large non-mammalian oocytes accumulate ... These cells are connected by cytoplasmic bridges with oocytes. The nurse cells of insects provide oocytes macromolecules such ...
Female oocytes measure 1.5 mm in length. Barratt, I. & Allcock, L. (2014). "Abraliopsis felis". The IUCN Red List of Threatened ...
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. Juvenile males have soft, small claspers and ...
... increased both their peak currents in oocyte expression studies, and slowed the activation of the latter., KCNE1 also ... Finally, KCNE1 inhibited Kv12.2 in Xenopus oocytes. The large majority of studies into the structural basis for KCNE1 ... No effects were observed upon oocyte co-expression of KCNE1 and Kv4.2, but KCNE1 was found to slow the gating and increase ... subunits in Xenopus oocytes". Cellular Physiology and Biochemistry. 18 (1-3): 57-66. doi:10.1159/000095158. PMID 16914890. ...
To understand why the method was unsuccessful, they began comparing duplex RNA in both oocytes and embryos. This led them to ... Previous research on Xenopus oocytes was successful. However, when Bass and Weintraub applied identical protocols to Xenopus ...
The insect vitelline envelope is the outer proteinaceous layer outside the oocyte and egg. The vitelline envelope, not being a ... This layer thins as the oocyte grows to reach a final thickness of ~0.4 um. Upon egg activation, peroxidase-mediated ... Calcium waves occur as Drosophila oocytes activate. Proceedings of the National Academy of Sciences of the United States of ...
What is the relationship between the number of oocytes retrieved during IVF and the risk of serious, potentially life ... Number of oocytes retrieved. ,10. 10-14. 15-19. ≥20. Total. codes. Number of oocyte retrievals. 44 312. 20 827. 8919. 3898. 77 ... per oocyte retrieval, increased up to approximately 20 oocytes where it reached 45.8%. The adjusted odds ratio (AOR) for live ... if a higher number of oocytes is retrieved. A high number of retrieved oocytes is also associated with a higher risk of ovarian ...
You have to enable JavaScript in your browsers settings in order to use the eReader.. Or try downloading the content offline. DOWNLOAD ...
... o interaction between oocytes and surrounding somatic cells o culture of oocyte-cumulus complexes o regulation of oocyte cell ... target of this RFA is to study oocyte maturation in which the oocyte undergoes germinal vesicle break down (GVBD), first polar ... o regulation of growth and differentiation of oocytes o regulation of meiosis o role of hormones in oocyte maturation in vitro ... Full Text HD-94-004 GENETICS AND PHYSIOLOGY OF HUMAN OOCYTES NIH GUIDE, Volume 22, Number 17, April 30, 1993 RFA: HD-94-004 P.T ...
A technique used in in vitro fertilization for retrieval of oocytes (eggs) from the ovaries. While this technique is also used ... oocyte. Mens magazines. pap smear. How about NO. ultrasound. The next 100 years according to Sir Arthur C. Clarke. sore throat ... A technique used in in vitro fertilization for retrieval of oocytes (eggs) from the ovaries. While this technique is also used ... hCG induces a response in the granulosa cells which surround each oocyte inside the follicles. In response to the trigger ...
BALTIMORE, MD. (SatireWire.com) - A sperm cells hopeful attempts today to convince an egg they should "try it from behind" have so far been rejected by the egg, who called… Read more ...
... led to a significant reduction in Vg accumulation in developing oocytes. Functional assays of these two GPCRs showed that JH ... we defined the primary oocyte without yolk as the previtellogenic oocyte and the oocyte with yolk as the vitellogenic oocyte. ... However, no Vg protein was taken up into oocytes14. These studies suggest that JH signaling plays a key role in Vg uptake into ... In the meantime, yolk and lipid droplets begin to appear on day 3 PAE and accumulation of yolk or Vg in the primary oocytes ...
Ethical issues in oocyte banking for nonautologous use: an Ethics Committee opinion (2021) From: Ethics Committee Opinions ... Planned oocyte cryopreservation for women seeking to preserve their future fertility: an Ethics Committee opinion (2018) From: ... Ethics Webinar: Planned Oocyte Cryopreservation: Medical, Ethical and Social Considerations * Micro-presentation: Fertility ... Micro-presentation: Planned Oocyte Cryopreservation for Women Seeking to Preserve Future Reproductive Potential ...
Characterization of oxygen and calcium fluxes from early mouse embryos and oocytes. by The Biological Bulletin; Biological ... APA style: Characterization of oxygen and calcium fluxes from early mouse embryos and oocytes.. (n.d.) >The Free Library. (2014 ... One reason for this gap in our knowledge lies in the difficulty in studying a single oocyte or embryo. The goal of the project ... MLA style: "Characterization of oxygen and calcium fluxes from early mouse embryos and oocytes.." The Free Library. 1998 ...
... oocyte and embryo protein 19,oocyte expressed protein homolog (dog),oocyte- and embryo-specific protein 19,oocyte-expressed ... Oocyte expressed protein, alias OOEP, is a component of the subcortical maternal complex (SCMC) that play its roles in oocytes ... and it is hypotized that it could play a role in the formation/stabilization of the oocyte cytoskeleton, called oocyte ... OOEP (Oocyte expressed protein). 2019-03-01 Luigi Cristiano Affiliation Aesthetic and medical biotechnologies research unit, ...
Chick brain mRNA was isolated and injected into Xenopus oocytes. This led to the expression in the surface membrane of ... Allosteric modulation by benzodiazepine receptor ligands of the GABAA receptor channel expressed in Xenopus oocytes. E Sigel ... Allosteric modulation by benzodiazepine receptor ligands of the GABAA receptor channel expressed in Xenopus oocytes ... Allosteric modulation by benzodiazepine receptor ligands of the GABAA receptor channel expressed in Xenopus oocytes ...
The Potential of Sperm Retrieved by Micro-TESE to Fertilize Vitrified/Warmed Oocytes. The safety and scientific validity of ... Fresh sperm retrieved by micro-TESE are used for fertilization of the warmed oocytes. when it is not possible to obtain ... Measurement of % of cleavage among the warmed oocytes. *Pregnancy rate [ Time Frame: six years ]. Measurement of serum-hCG and ... The women are stimulated with FSH in IVF protocols and the aspirated oocytes vitrified with usual applied techniques. ...
Metabolic control of oocyte development: linking maternal nutrition and reproductive outcomes. by Ling Gu, Honglin Liu, Xi Gu, ... To date, much of our understanding of oocyte metabolism comes from the effects of extrinsic nutrients on oocyte maturation. In ... by oocyte metabolism. Well-balanced and timed energy metabolism is critical for optimal development of oocytes. ... Metabolic control of oocyte development: linking maternal nutrition and reproductive outcomes.. Cellular and molecular life ...
... neurones was compared with that of cloned receptors expressed in Xenopus oocytes by pairwise injections of alpha 3-beta 2 or ... Comparison of neuronal nicotinic receptors in rat sympathetic neurones with subunit pairs expressed in Xenopus oocytes J ... Receptors expressed in oocytes by injection of alpha 3 and beta 2 subunits had a relatively high sensitivity to DMPP and low ... neurones was compared with that of cloned receptors expressed in Xenopus oocytes by pairwise injections of alpha 3-beta 2 or ...
... is well known that female reproduction ability decreases during the forth decade of life due to age-related changes in oocyte ... In vitro matured oocyte indicating the semiperipheral distribution of mitochondria in the oocyte. (E) In vitro matured oocyte ... Class C. Oocyte is surrounded by dispersed cumulus cells. Oocyte has a granular cytoplasm. Reproduced from Lasiene et al. (2009 ... A) GV oocyte displays the distribution of mitochondria in the peripheral zone. (B) GV oocyte with mitochondria diffused fairly ...
Progesterone-mediated oocyte maturation - Xenopus laevis (African clawed frog) [ Pathway menu , Pathway entry , Download KGML ... Xenopus oocytes are naturally arrested at G2 of meiosis I. Exposure to either insulin/IGF-1 or the steroid hormone progesterone ... This process is termed oocyte maturation. The transition is accompanied by an increase in maturation promoting factor (MPF or ... breaks this arrest and induces resumption of the two meiotic division cycles and maturation of the oocyte into a mature, ...
Comparison of the somatic TADs and lampbrush chromomere-loop complexes in transcriptionally active prophase I oocytes. View ... Comparison of the somatic TADs and lampbrush chromomere-loop complexes in transcriptionally active prophase I oocytes ... Comparison of the somatic TADs and lampbrush chromomere-loop complexes in transcriptionally active prophase I oocytes ... Comparison of the somatic TADs and lampbrush chromomere-loop complexes in transcriptionally active prophase I oocytes ...
From Embryonic Stem Cells to Oocytes: A stepwise approach to nuclear transfer therapy ... From Embryonic Stem Cells to Oocytes: A stepwise approach to nuclear transfer therapyNIH Only. ... From Embryonic Stem Cells to Oocytes: A stepwise approach to nuclear transfer therapy ...
... oocyte retrieval) and egg retrieval recovery from Pacific Fertility Center. PFC is a leading international center for IVF (in ...
Analysis using Flag-tagged H3.1 transgenic mice revealed that Flag-H3.1 was not present in differentiated oocytes or early ... Differentiated oocytes acquire totipotency through fertilization. During this transition, genome-wide chromatin remodeling ...
Calcium flux assay of chemokine receptor expression in Xenopus oocytes ... in Xenopus laevis oocytes: G alpha-16 couples to chemotactic receptors in Xenopus oocytes. Burg M, Raffetseder U, Grove M, Klos ... Expression in Xenopus oocytes. Murphy PM, Gallin EK, Tiffany HL, Malech HL. Murphy PM, et al. FEBS Lett. 1990 Feb 26;261(2):353 ... Calcium flux assay of chemokine receptor expression in Xenopus oocytes P M Murphy. Methods Enzymol. 1997. ...
BioAssay record AID 1275134 submitted by ChEMBL: Binding affinity to alpha4beta2 nACh receptor (unknown origin) expressed in Xenopus oocytes.
DCI modified the expression of genes related to oocyte quality, oxidative stress, and luteal sufficiency in cumulus-oocyte ... DCI modified the expression of genes related to oocyte quality, oxidative stress, and luteal sufficiency in cumulus-oocyte ... D-Chiro-Inositol Treatment Affects Oocyte and Embryo Quality and Improves Glucose Intolerance in Both Aged Mice and Mouse ... "D-Chiro-Inositol Treatment Affects Oocyte and Embryo Quality and Improves Glucose Intolerance in Both Aged Mice and Mouse ...
Oocyte meiosis - Homo sapiens (human) [ Pathway menu , Pathway entry , Download KGML , Show description , Image file , Help ] ... In vertebrates, immature oocytes are arrested at the PI (prophase of meiosis I). The resumption of meiosis is stimulated by ... In PI-arrested oocytes, MPF is initially inactive and is activated by the dual-specificity CDC25C phosphatase as the result of ... progesterone, which carries the oocyte through two consecutive M-phases (MI and MII) to a second arrest at MII. The key ...
... to evaluate how air pollution influences human reproduction using a large cohort of oocyte donors and oocyte recipient couples ... Vitrified donor oocyte ART represents an ideal population to investigate the mechanisms underlying any associations between air ... THE INFLUENCE OF AMBIENT AIR POLLUTION ON FERTILITY USING A VITRIFIED DONOR OOCYTE BANK. ... and fertility as exposures to the oocyte and uterine environment are uncorrelated in time or space and exposures to the oocyte ...
Chad, J., Foreman, R. and Wheeler, S. (1989) Expression of ionic channels in Xenopus oocytes after injection of fetal human ... Expression of ionic channels in Xenopus oocytes after injection of fetal human mRNA ... Expression of ionic channels in Xenopus oocytes after injection of fetal human mRNA ... Expression of ionic channels in Xenopus oocytes after injection of fetal human mRNA ...
... chorionic gonadotropin or a gonadotropin-releasing hormone agonist in gonadotropin-releasing hormone antagonist-treated oocyte ... FemaleFertilization in VitroGonadotropin-Releasing HormoneHormone AntagonistsHumansOocyte DonationOocyte RetrievalOvarian ... and incidence of moderate/severe OHSS in oocyte donors. RESULT(S): The proportion of mature oocytes was comparable, whereas the ... The use of gonadotropin-releasing hormone (GnRH) agonist to induce oocyte maturation after cotreatment with GnRH antagonist in ...
Oocyte efficiency: does live birth rate differ when analyzing cryopreserved and fresh oocytes on a per-oocyte basis?.. Fertil ... Oocyte efficiency: does live birth rate differ when analyzing cryopreserved and fresh oocytes on a per-oocyte basis?.. Fertil ... Oocyte efficiency: does live birth rate differ when analyzing cryopreserved and fresh oocytes on a per-oocyte basis?.. Fertil ... Oocyte efficiency: does live birth rate differ when analyzing cryopreserved and fresh oocytes on a per-oocyte basis?. ...
What constitutes a reasonable compensation for non-commercial oocyte donors: an analogy with living organ donation and medical ... What constitutes a reasonable compensation for non-commercial oocyte donors: an analogy with living organ donation and medical ... What constitutes a reasonable compensation for non-commercial oocyte donors: an analogy with living organ donation and medical ...
  • In vitro oocyte maturation (IVM) is being increasingly approached in assisted reproductive technology (ART). (eurekamag.com)
  • The disruption of these regulatory circuits impairs oocyte maturation. (europa.eu)
  • With the MateRNA project we showed that in presence of more subtle disturbances of translation, the oocytes undergo apparently normal maturation but, once fertilized, fail to develop into an embryo. (europa.eu)
  • Hypothesis: the program of maternal mRNA translation during maturation is impaired in aging oocytes. (europa.eu)
  • Hypothesis: Temporal regulation of maternal mRNA translation is required for oocyte maturation and embryo development in monovulatory mammalian species. (europa.eu)
  • SO2.A: a published study analyzed transcript expression level in oocytes from young and old mice before (GV) and after (MII) maturation, concluding that a number of transcripts are lower in MII oocytes of aging mice. (europa.eu)
  • In Study 3, we used the FiSH technique to investigate the impact of oxidative stress on post-transcriptional regulation of mRNA translation and degradation during oocyte maturation and embryonic development. (unl.edu)
  • These findings suggest that obesity-dependent alterations during oocyte maturation may have the potential to contribute to early adaptive programming in the embryo and that may result in lasting effects on fetal development and/or postnatal phenotype expression. (unl.edu)
  • 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. (kegg.jp)
  • In conclusion, this work improves our understanding of human oocyte morphology, cytoplasmic maturation, and intracellular factors defining human egg quality. (muni.cz)
  • In this study, we investigated the effects of BPA exposure on porcine oocyte maturation and its possible reasons. (oncotarget.com)
  • Our results showed that: (i) the rates of oocyte maturation significantly decreased with 250 μM BPA treatment in vitro , but not DEHP. (oncotarget.com)
  • This might be due to the delayed cell cycle progression of oocyte maturation. (oncotarget.com)
  • Collectively, our results indicated that porcine oocytes maturation was disrupted after BPA treatment through disrupting cytoskeletal dynamics, epigenetic modifications and inducing apoptosis/autophagy. (oncotarget.com)
  • Since cAMP blocks meiotic maturation of mammalian and amphibian oocytes in vitro and cyclic nucleotide phosphodiesterase 3A (PDE3A) is primarily responsible for oocyte cAMP hydrolysis we generated PDE3A-deficient mice by homologous recombination. (immune-source.com)
  • maturation in oocytes was restored by inhibiting protein kinase A (PKA) with adenosine-3? (immune-source.com)
  • mice represent an in vivo model where meiotic maturation and ovulation are dissociated which underscores inhibition of oocyte maturation as a potential strategy for contraception. (immune-source.com)
  • Through protein kinase A-catalyzed (PKA-catalyzed) phosphorylation of unidentified proteins cAMP prevents activation of maturation-promoting factor (MPF) and MAPK signaling in Cdc42 oocytes and inhibits the spontaneous maturation that occurs in vitro thus maintaining meiotic arrest (1-5). (immune-source.com)
  • Endogenous RNAi pathway is essential for mouse female germline while miRNA pathway which is ubiquitously present in most cell types is dispensable for oocyte maturation and fertilization. (cuni.cz)
  • oogonia proliferation and transformation into the primary oocyte, primary growth phase, secondary growth phase and maturation phase and these are similar to those described for other species. (org.in)
  • The oocytes entered the maturation phase when they attained the maximum size of 459.6±71.83 μm. (org.in)
  • Oocytes collected from prepubertal calves lack developmental competence due to their failure or inability to complete ooplasmic maturation. (unimi.it)
  • The reduced rate of cleavage may be due to denuding required for the micromanipulation step, so, oocytes that receive a transferred GV must undergo the final stages of maturation and the early embryonic development without contacts with their cumulus cells. (unimi.it)
  • 1998. Influence of organochlorine pesticides on maturation and post-fertilization development of bovine oocytes in vitro . (cdc.gov)
  • This protein is also involved in silencing of certain maternal mRNAs during oocyte maturation and early embryonic development, as well as in nonsense-mediated decay (NMD) of mRNAs that contain premature stop codons. (origene.com)
  • Once appropriately sized follicles develop, a dose of human chorionic gonadotropin (hCG) is administered to cause maturation of the oocytes before transvaginal oocyte retrieval. (medscape.com)
  • Once oocytes are located under the microscope they are placed in Maturation Media for 24 hours which simulates the process of ovulation where the oocyte normally undergoes the maturation process readying the egg for fertilization. (bova-tech.com)
  • Prolactin concentration in follicular fluid during in vitro fertilization (IVF) correlates with the oocyte maturation level and fertilization rate. (medscape.com)
  • This FiSH method allowed us to accurately and reproducibly monitor changes in candidate mRNA localization and absolute quantity in growing and mature oocytes as well as pre-implantation embryos. (unl.edu)
  • We show the importance of organelle-level selection, seen in the selective pooling of mitochondria into the Balbiani body, in achieving high-quality mitochondria at extreme ploidy in mature oocytes. (elifesciences.org)
  • The near-universality of these processes across animal taxa makes sense in light of the need to maintain mitochondrial quality at extreme ploidy in mature oocytes, in the absence of sex and recombination. (elifesciences.org)
  • their multiplication and differentiation are followed by the release of mature oocytes. (org.in)
  • The following endpoints for embryo quality and early developmental outcomes were collected: number oocytes retrieved, total number of mature oocytes, fertilization rate, and embryo grades (1-5, 1 being the best) on days 2, 3 and 5. (cdc.gov)
  • P=0.11) change in number of mature oocytes. (cdc.gov)
  • Dolmans MM, Marotta ML, Pirard C, Donnez J, Donnez O. Ovarian tissue cryopreservation followed by controlled ovarian stimulation and pick-up of mature oocytes does not impair the number or quality of retrieved oocytes. (ijfs.ir)
  • And embryos in IVM group were fertilized from IVM immature oocytes. (eurekamag.com)
  • Genome-wide maps of recombination and chromosome segregation in human oocytes and embryos show selection for maternal recombination rates. (nature.com)
  • In Study 2, we modified the single molecule RNA fluorescent in situ hybridization (FiSH) technique for use with oocytes and pre-implantation embryos. (unl.edu)
  • These experiments demonstrated that oxidative stress impaired degradation of Pou5f1 and Dppa3 in maturing oocytes resulting in increased translation of POU5F1 and DPPA3 in 1-cell and 2-cell embryos, respectively. (unl.edu)
  • The activities of glucose 6-phosphate dehydrogenase (G6PDH) of the follicular oocytes collected from bovine ovaries and the embryos fertilized in vitro were measured using fluorescence microscope with photomultiplier and photometer attachments. (nii.ac.jp)
  • Publications] Setsuo Iwasaki, Yasuo Shioya and Tatsuo Nakahara: 'Measurement of glucose 6-phosphate dehydrogenase activity in bovine oocytes and embryos using quantitative fluorescence microscopy. (nii.ac.jp)
  • It is suggested that persistence of a follicle alters amounts of mRNA for genes important for regulation of transcription and protein translation in the oocyte, which could compromise development of early embryos in cows that ovulate a persistent follicle. (wvu.edu)
  • Real time PCR analysis indicated that miR-181a was expressed in both oocytes and embryos and tended to increase at the morula and blastocyst stages (p = 0.07). (wvu.edu)
  • We will analyze the stimulation outcome, the number of retrieved oocytes, cleaving embryos, and pregnancy and implantation rates as well. (fertyox.pt)
  • In addition to age-related limitations, an immediate obstacle for obtaining oocytes in cancer patients is the fact that only one controlled ovarian hyperstimulation (COH) cycle can usually be performed in these women because of time constraints, yielding a relatively low number of oocytes and/or embryos. (ijfs.ir)
  • In this national registry-based diagnostic study, in 66.2% of cycles among patients younger than 38 years, fewer than all retrieved oocytes could be exposed to sperm to minimize the number of unused embryos while optimizing the probability of a live birth. (cdc.gov)
  • The aim of this study was to establish a culture system to support the growth of bovine oocytes as enclosed in granulosa cell complexes that extend on a flat substratum. (bioone.org)
  • Growing bovine oocytes with a mean diameter of 95 μm were isolated from early antral follicles: the growing stage corresponds to that of oocytes in preantral follicles of 12-day-old mice. (bioone.org)
  • In this study, in order to improve this competence, we transplanted nuclei isolated from GV stage calf oocytes in enucleated matured competent bovine oocytes and we demonstrated that our nuclear technique transplantation is highly effective in reconstituting calf oocyte at a rate of 76.34% and that the reconstructed oocyte can retain its ability to mature in vitro and to be normaly fertilized. (unimi.it)
  • Reconstruction of calf oocytes by germinal vesicle transfer in mature bovine oocytes : preliminary results / A. Lange Consiglio, A. Bignotti, A. Pecile, F. Cremonesi. (unimi.it)
  • The rat monocarboxylate transporter isoform MCT2 was analysed by expression in Xenopus laevis oocytes and the results were compared with the known characteristics of lactate transport in heart and brain. (portlandpress.com)
  • After microinjection of Xenopus laevis oocytes with RNA from avian myeloblastosis virus, viral structural proteins p27, p19, p15, and p12 are formed by a sequence of posttranslational cleavages of a high-molecular-weight precursor polypeptide. (duke.edu)
  • As a graduate student in the late 1960s at Berkeley, I was introduced to the Xenopus oocyte by John Gerhart, who shared his fascination with the work of John Gurdon, who had pointed out the unique and powerful features of the oocyte and egg, particularly the ability to microinject biochemically significant amounts of material into them while they carried out complex biological events. (jbc.org)
  • To study the role of chromatin in RA-activated transcription, we assembled the RARβ2 promoter into chromatin in Xenopus oocytes. (elsevier.com)
  • Influenza D virus M2 protein exhibits ion channel activity in Xenopus laevis oocytes. (cdc.gov)
  • The germ cell lineage in Xenopus is specified by the inheritance of germ plasm that assembles within the mitochondrial cloud or Balbiani body in stage I oocytes. (houstonmethodist.org)
  • All those deletion-carrying hIL-6 (delta hIL-6) proteins were then produced in Xenopus laevis oocytes and examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). (uniparthenope.it)
  • Fig. 2: Chromosome segregation in mammalian oocytes. (nature.com)
  • Fig. 3: Assembly of the meiotic spindle in mammalian oocytes. (nature.com)
  • Fig. 5: Age-associated defects in chromosome segregation in mammalian oocytes. (nature.com)
  • Fig. 6: Factors implicated in mammalian oocyte ageing. (nature.com)
  • Introduction Although competent to complete meiosis mammalian oocytes are physiologically arrested in prophase I (prophase of the first meiotic division) until shortly before ovulation. (immune-source.com)
  • Cyclic AMP apparently plays an important role in maintaining PF-04979064 meiotic arrest PF-04979064 in mammalian oocytes. (immune-source.com)
  • Thus, unliganded receptors expressed in oocytes are capable of accessing to the chromatin-assembled promoter and activating transcription without ligand, indicating that chromatin assembly per se is not sufficient to reproduce ligand-dependent chromatin changes and promoter activation seen in mammalian cells. (elsevier.com)
  • Here we report that mouse oocytes lacking FZR1 undergo passage through meiosis I that is accelerated by ~1 h, and this is due to an earlier onset of spindle assembly checkpoint (SAC) satisfaction and APC(CDC20) activity. (nih.gov)
  • Aneuploidy arises as a consequence of aberrant meiosis during egg development from its progenitor cell, the oocyte. (nature.com)
  • Fig. 1: Meiosis of human oocytes. (nature.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. (kegg.jp)
  • During this time, the oocyte acquires the ability to resume meiosis, undergo fertilization and sustain embryonic development. (wvu.edu)
  • In species from nematodes to humans, many healthy, developing oocytes apoptose around the pachytene stage of meiosis. (biologists.com)
  • Células germinales femeninas derivadas de OVOGONIAS cuando entran en MEIOSIS. (bvsalud.org)
  • Los ovocitos primarios comienzan la meiosis pero permanecen en fase de diplotene hasta que llega la PUBERTAD y se produce la OVULACIÓN, momento en el que se da lugar a los ovocitos secundarios haploides u ÓVULO. (bvsalud.org)
  • Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS . (bvsalud.org)
  • 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 ). (bvsalud.org)
  • If her mother is exposed to an environmental toxin, such as ethanol, there could be defects in meiosis, leading to long-term health effects for the baby and for babies produced from the oocytes she was developing. (mageewomens.org)
  • Such activation of the somatic follicular compartment promotes the translation of a subset of transcripts in the oocyte together with an increase in embryo development. (europa.eu)
  • We developed a genetically engineered mouse model, where AKT was constitutively activated in the oocyte to ask whether AKT activation in the oocyte induced increased translation and higher embryo rate. (europa.eu)
  • Three studies were conducted to determine how female obesity, which promotes a low grade inflammatory and oxidative stress environment in the ovary, alters transcriptional and post-transcriptional regulation of candidate mRNAs in oocytes and determine if these increases are functionally important in the pre-implantation embryo. (unl.edu)
  • The processing pattern of virus-specific precursor polypeptides is the same in X. laevis oocytes as in chick embryo fibroblasts infected with avian myeloblastosis virus, but the processing takes place at a much slower rate. (duke.edu)
  • English) Oocyte-to-embryo transition (OET) is one of the most complex developmental events where a differentiated oocyte gives rise to a totipotent zygote. (cuni.cz)
  • This study was designed to determine if exposure of rabbit intrafollicular oocytes to clomiphene citrate (CC) affects pregnancy outcome after in vitro ovulation, in vitro fertilization (IVF), and embryo transfer (ET). (edu.au)
  • Increased Hg levels were associated with decreased oocyte quantity, increased fertilization rate and decreased embryo quality, though none of the associations were statistically significant at the 0.05 level. (cdc.gov)
  • We found some evidence of a relationship between hair Hg concentrations and oocyte quantity, and a trend of an association between hair Hg levels and poorer embryo quality. (cdc.gov)
  • 2. Nuclear transfer is a technique used to duplicate genetic material by creating an embryo through the transfer and fusion of a diploid cell in an enucleated female oocyte.2 Cloning has a broader meaning than nuclear transfer as it also involves gene replication and natural or induced embryo splitting (see Annex 1). (who.int)
  • Controlled ovarian stimulation (COS) followed by embryo and/or oocyte cryopreservation is the FP method recommended by both the ASCO and ISFP. (medscape.com)
  • The final step where the fertilized oocytes grow when placed in the culture medium and kept in incubators until evaluated for embryo quality and stage of growth. (bova-tech.com)
  • In human oocytes, chromosomes often segregate incorrectly. (nature.com)
  • Genome analyses of single human oocytes. (nature.com)
  • Here, we report our findings from the ultrastructural analysis of 69 unfertilized human oocytes from 34 young and healthy egg donors. (muni.cz)
  • Functional Human Oocytes Generated by Transfer of Polar Body Genomes. (bvsalud.org)
  • In the fruit fly, Drosophila melanogaster, the oocyte differentiates in a 16-cell syncytium that arises from a cystoblast which undergoes 4 synchronous divisions with incomplete cytokinesis. (biologists.com)
  • Transient posterior localization of a kinesin fusion protein reflects anteroposterior polarity of the Drosophila oocyte. (biologists.com)
  • Using Drosophila as a model, the St Johnston lab reveal a molecular mechanism underlying the oocyte specification process. (cam.ac.uk)
  • Here, we show that the microtubule (MT) minus end-stabilizing protein Patronin/CAMSAP marks the future Drosophila oocyte and is required for oocyte specification. (cam.ac.uk)
  • This interaction is conserved in Drosophila oocytes. (biologists.com)
  • hCG induces a response in the granulosa cells which surround each oocyte inside the follicles. (indiahospitaltour.com)
  • Quantitative real-time PCR was used to measure the mRNA abundance of 10 selected genes important for early embryogenesis in oocytes obtained from growing and persistent follicles. (wvu.edu)
  • Oocytes from persistent follicles, however, had greater abundances of PAP and eIF-4E transcripts (p (wvu.edu)
  • There was no significant difference between the groups for mean number of follicles ≥ 18 mm (P = 0.131), mean number of oocytes retrieved (P = 0.209) or endometrial thickness (P = 0.673). (who.int)
  • The recruitment of a sufficient number of growing follicles following ovarian stimulation increases the oocyte yield and subsequently the success rate after in vitro fertilization (IVF) treatment. (fertyox.pt)
  • Oocyte Retrieval is a technique used in In vitro fertilization for retrieval of occytes (eggs) from the ovaries. (indiahospitaltour.com)
  • To solve the low implantation rate of in-vitro fertilization (IVF), zona-free oocyte is widely used in IVF [1]. (elsevier.com)
  • [ 32 ] Following COS, oocytes are retrieved and fertilized using conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection. (medscape.com)
  • The MateRNA project aims at investigating the relationship between the oocyte competence to sustain embryonic development and the program of maternal mRNA translation in mammals. (europa.eu)
  • Research suggests that the NLRP7 protein also plays a role in egg cell (oocyte) and embryonic development as well as inflammation and other immune responses by regulating the release of an immune protein called interleukin-1 beta. (medlineplus.gov)
  • The development and function of oocytes largely depends on cooperativity with supporting cells such as cumulus cells and granulosa cells . (copewithcytokines.de)
  • Experimental approach: oocytes enclosed in the cumulus cells (CEOs) were treated with hormones/growth factors/signal molecules or inhibitors of intracellular pathways. (europa.eu)
  • SO1.A: previous studies conducted at the Host Institution showed that EGF-like growth factors initiate a cascade in the cumulus cells that surround the oocyte. (europa.eu)
  • SO1.C: we performed a pharmacological screening and analyzed previously deposited databases to identify pathway(s) responsible for signal transduction between cumulus cells and activation of AKT in the oocyte. (europa.eu)
  • Cyclic AMP may enter oocytes from adjacent cumulus cells via gap junctions (2 6 Recent studies in rodents however demonstrated that PF-04979064 active oocyte adenylyl cyclase contributes to meiotic blockade (8) which can be released by microinjection of oocytes with antibodies that inactivate Gs the heterotrimeric GTP-binding protein that activates adenylyl cyclase (9). (immune-source.com)
  • In mammals and flies, only one cell in a multicellular female germline cyst becomes an oocyte, but how symmetry is broken to select the oocyte is unknown. (cam.ac.uk)
  • The researchers conclude that CAR-1 has a conserved role in oogenesis and propose that germline apoptosis enhances the formation of functional oocytes. (biologists.com)
  • Men with no spermatozoa may benefit by combining round spermatid injection (ROSI) and artificial oocyte activation (AOA). (planer.com)
  • In summary these collective studies identified both transcriptional and post-transcriptional changes in oocyte mRNA abundance which may be attributed to alterations in the gut microbiome, ovarian inflammation and oxidative stress. (unl.edu)
  • Histological examination of the mature ovaries showed the presence of all the different oocyte stages in the ovary of A. berda with an asynchronous mode of ovarian development shortly before spawning, indicating that the species is a multiple spawner. (org.in)
  • Risk factors for OHSS include young age, low body weight, high serum estradiol concentrations, polycystic ovaries, higher doses of gonadotropins during ovarian stimulation, and a greater number of oocytes retrieved. (medscape.com)
  • Secondary oocytes are haploid cells generated after birth during ovulation. (copewithcytokines.de)
  • The last hours of oocyte differentiation, before ovulation, are characterized by well-coordinated events that regulates cell cycle re-entry, chromosomes segregation, chromatin remodelling and reprogramming of the genome. (europa.eu)
  • The quality of metaphase II oocytes will undergo a time-dependent deterioration following ovulation as the result of the oocyte aging process. (scite.ai)
  • IMSEAR at SEARO: 35S induced dominant lethals in immature oocytes of mice. (who.int)
  • An oocyte is an immature egg cell that matures into an oocyte (egg) ready for fertilization. (pinkstork.com)
  • Similarly, a baby girl's immature egg cells, or oocytes, are developed while she is still in the womb. (mageewomens.org)
  • Oocyte development stages observed in A. berda were chromatin nucleolus, early perinucleolar, late perinucleolar, lipid vesicle stage I oocyte, lipid vesicle stage II oocyte, primary yolk granule stage, secondary yolk granule stage, tertiary yolk granule stage, hydrated oocyte and atretic oocyte. (org.in)
  • Although this analysis involved spare oocytes completing development in vitro, it provides essential insight into the enigmatic process by which human egg progenitors prepare for fertilization. (muni.cz)
  • oocytes that underwent germinal vesicle breakdown showed activation of MPF and MAPK completed the first meiotic division extruding a polar body and became competent for fertilization by spermatozoa. (immune-source.com)
  • During the growth phase an oocyte prepares for fertilization and progression to zygotic genome activation. (cuni.cz)
  • However the process of zona-removal is not only tedious but also easy to harm the fragile oocyte. (elsevier.com)
  • Mapping of epitopes on porcine zona pellucida-3 alpha by monoclonal antibodies inhibiting oocyte-sperm interaction. (oregonstate.edu)
  • The inadequate decondensation of the sperm chromatin, its transformation into the male pronucleus (MPN) together with the subsequent inability to activate the oocyte, seem to be the main causes of the low ICSI efficiency. (gva.es)
  • Alternatively, the sperm membrane was digested with Triton X-100 (TX) before ICSI, to improve the exposure of the sperm chromatin to the oocyte cytoplasm. (gva.es)
  • However, no significant differences between the three groups were observed in terms of the number of pronuclei, 2PN (oocytes with 2 pronuclei and no visible sperm), and 1PN + sperm (oocytes with 1 pronucleus and one sperm head). (gva.es)
  • However, the sperm TX pre-treatment improved oocyte activation at 6 h post-ICSI, although 22 h post-ICSI such a beneficial effect did not persist. (gva.es)
  • 1 million sperm is added to one dish of oocytes. (bova-tech.com)
  • The number and quality of oocytes retrieved were evaluated and apoptosis of granolusa cells was studied. (who.int)
  • For this reason, results from egg donation programs cannot be extrapolated to cancer patients, nor can the quality of oocytes be guaranteed. (ijfs.ir)
  • Do we have any proof that boosting mitochondrial function in oocytes increases success? (uni-linz.ac.at)
  • During these divisions, spindle orientation is highly ordered and is thought to impart a polarity to the cyst that is necessary for the subsequent differentiation of the oocyte. (biologists.com)
  • Later in oogenesis, dynein function is necessary for proper differentiation, but does not appear to participate in morphogen localization within the oocyte. (biologists.com)
  • Growth and differentiation factor 9 promotes oocyte growth at the primary but not at the early secondary stage in three-dimensional follicle culture. (cookandersenlaboratory.com)
  • Oocyte Cryopreservation - Current Scenario and Future Perspectives: A Narrative Review. (nih.gov)
  • Currently, oocyte cryopreservation seems to be the most feasible technique for fertility preservation when there's some kind of a time constraint in adolescents and adults. (ijfs.ir)
  • Predicting the likelihood of live birth for elective oocyte cryopreservation: a counseling tool for physicians and patients. (ijfs.ir)
  • Futhermore, expression of RAR and RXR in oocytes led to local disruption of chromatin assembled over the promoter without ligand. (elsevier.com)
  • The oocyte system may serve as a model to study mechanisms of RA-dependent alterations of chromatin structure. (elsevier.com)
  • Chromatin Modification and Global Transcriptional Silencing in the Oocyte Mediated by the mRNA Decay Activator ZFP36L2. (cookandersenlaboratory.com)
  • As a fully-grown oocyte is a huge cell with a proportionally large maternal transcriptome we analysed the miRNA: mRNA stoichiometry changes that occur from growing to the fully-grown mouse oocyte. (cuni.cz)
  • ii) BPA treatment resulted in abnormal cytoskeletons on porcine oocytes, showing with aberrant actin distribution, spindle morphology and chromosome alignment, which was further confirmed by the reduced p-MAPK level. (oncotarget.com)
  • A pregnancy that results from an abnormal oocyte cannot develop properly, resulting in recurrent hydatidiform mole. (medlineplus.gov)
  • Four developmental phases of oocyte development were identified viz. (org.in)
  • These data suggest that administration of silymarin in IVF patients concomitantly with gonadotropin results in reduction of granolusa cell apoptosis but does not have any effect in promotion of follicular development, oocyte retrieval or endometrial thickness. (who.int)
  • SO1: define the biochemical mechanisms by which somatic cells regulate the translational program of mouse oocytes. (europa.eu)
  • SO1.B: results obtained in 1A indicated PI3K/AKT as key pathway linking somatic cells activation to induction of oocyte specific translation. (europa.eu)
  • Such systems have been established for mouse oocytes but are not applicable to larger animals because it is difficult to maintain an appropriate association between the oocyte and companion somatic cells. (bioone.org)
  • Using an ultrasound guided needle oocytes (eggs) are removed from the ovaries of a super-stimulated donor cow. (bova-tech.com)
  • The hCG trigger injection must be precisely timed, as oocyte retrieval must happen between 34 and 36 hours after the injection. (indiahospitaltour.com)
  • It does so by transcribing and storing the necessary mRNAs till a fully-grown oocyte attains transcriptional quiescence. (cuni.cz)
  • Parental disclosure to offspring created with oocyte donation: intentions versus reality. (bvsalud.org)
  • Next, we are going to outline the most relevant differences of performing an egg donation treatment with vitrified or fresh oocytes. (ovoclinic.net)
  • One of the most frequently asked questions by patients undergoing oocyte donation treatment is: will the donor look like me? (ovoclinic.net)
  • These studies imply that generation of PF-04979064 intra-oocyte cAMP is sufficient to maintain meiotic arrest. (immune-source.com)
  • Oocytes were exposed in 20, 33, 50 and 100% vitrification solution for 2, 1 and 1 min, and 30-50 s, respectively at room temperature. (uni-koeln.de)
  • In conclusion, vitrification by direct submerging of oocytes in clean liquid air (aseptic system) is a good alternative for using of not sterile liquid nitrogen. (uni-koeln.de)
  • Oocyte-granulosa cell complexes were cultured for 14 days in modified TCM199 medium supplemented with 5% fetal bovine serum, 4 mM hypoxanthine, and 0.1 μg/ml estradiol. (bioone.org)
  • SO2: investigate whether the pattern of translation is disrupted in oocyte from aging mice. (europa.eu)
  • Oocyte identity is established inside a cyst of interconnected germ cells but how this occurs is not well understood. (cam.ac.uk)
  • The microtubule minus end-binding protein Patronin/CAMSAP translates the asymmetry into a polarised microtubule network that directs transport of oocyte fate determinants into a single germ cell to establish the oocyte. (cam.ac.uk)
  • RNAi knockdown of CAR-1 in nematodes increases oocyte apoptosis, as does CGH-1 depletion. (biologists.com)
  • Then the zona pellucida free follicular oocytes in extraction solution were frozen in LN_2, thawed and centrifuged and the G6PDH activity of their supernatant could be measured. (nii.ac.jp)
  • Study of post-transcriptional regulatory pathways revealed that the small-RNA mediated regulatory pathways exist in a unique conformation in mouse oocytes. (cuni.cz)
  • My PhD project was aimed at understanding the constraints of the miRNA pathway in the oocyte which makes it non-functional. (cuni.cz)
  • In study 1 we showed that diet induced obesity caused increased pro-inflammatory signaling in the ovary including in growing oocytes. (unl.edu)
  • We particularly suggest selecting the ovary with a low antral follicle count for wedge resection to increase oocyte yield. (ijfs.ir)
  • Given the genome-wide transcriptional silencing, mRNA expression studies in MII oocytes should only yield stable mRNA or decreased mRNA due to degradation. (europa.eu)
  • One straw can be used to fertilize 3-5 dishes of oocytes which maximizes the yield of expensive semen. (bova-tech.com)
  • We suggest that this approach can increase the oocyte yield in a single available COH cycle. (ijfs.ir)
  • Primary oocytes are diploid cells generated before birth. (copewithcytokines.de)
  • Oocytes play an active role in this cooperativity by secreting factors that act on the supporting cells in a paracrine manner (Sugiura and Eppig, 2005). (copewithcytokines.de)
  • The interplay of signals arising in both follicle cells and oocytes themselves (1 2 4 6 7 regulates synthesis and degradation of oocyte cAMP via adenylyl cyclases and cyclic nucleotide phosphodiesterases (PDEs) respectively. (immune-source.com)
  • The effect of follicular aging on gene expression in oocytes and granulosal cells. (wvu.edu)
  • It is suggested that aged granulosal cells may have a reduced capacity to provide energy and amino acids to the oocyte. (wvu.edu)
  • They selected females that had just molted into adulthood, and anesthetized them to remove some of their oocytes, or developing egg cells. (smithsonianmag.com)
  • An experiment was done to determine if persistence of a follicle altered mRNA expression of important genes in the oocyte. (wvu.edu)
  • Reproductive activity was assessed using macroscopic gonad characteristics, trends of gonadal indexes for both sexes, oocyte size-frequency distributions and microscopic investigation of oocyte development stages. (ifremer.fr)
  • These data demonstrate the sensitivity of mouse maturing oocytes in vivo to maternal protein undernutrition and identify both behavioural and cardiovascular postnatal outcomes, indicative of adult disease. (aston.ac.uk)
  • In this study, we determined that the expression of sirtuin family members (SIRT1, 2, 3) was dramatically reduced in mouse oocytes aged in vivo or in vitro. (scite.ai)
  • iv) BPA-exposed oocytes had higher rates of early stage apoptosis/autophagy, and this may be resulted from the increased level of oxidative stress. (oncotarget.com)
  • Early in oogenesis, dynein mutations disrupt spindle orientation in dividing cysts and block oocyte determination. (biologists.com)
  • This forms a polarized MT network, along which Dynein transports oocyte determinants into the presumptive oocyte. (cam.ac.uk)
  • Frog oocytes synthesize and completely process the precursor polypeptide to virion structural proteins after microinjection of avian myeloblastosis virus RNA. (duke.edu)
  • Oocyte donor information - how much is enough? (lancs.ac.uk)