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.
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 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.
The technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.
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.
Morphological and physiological development of EMBRYOS.
The transformation of a liquid to a glassy solid i.e., without the formation of crystals during the cooling process.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
Determination of the nature of a pathological condition or disease in the OVUM; ZYGOTE; or BLASTOCYST prior to implantation. CYTOGENETIC ANALYSIS is performed to determine the presence or absence of genetic disease.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.
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.
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)
An early non-mammalian embryo that follows the MORULA stage. A blastula resembles a hollow ball with the layer of cells surrounding a fluid-filled cavity (blastocele). The layer of cells is called BLASTODERM.
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.
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).
A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.
An albumin obtained from the white of eggs. It is a member of the serpin superfamily.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
Transport of the OVUM or fertilized ovum (ZYGOTE) from the mammalian oviduct (FALLOPIAN TUBES) to the site of EMBRYO IMPLANTATION in the UTERUS.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
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 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.
The potential of the FETUS to survive outside the UTERUS after birth, natural or induced. Fetal viability depends largely on the FETAL ORGAN MATURITY, and environmental conditions.
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 developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.
Morphological and physiological development of EMBRYOS or FETUSES.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
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.
The three primary germinal layers (ECTODERM; ENDODERM; and MESODERM) developed during GASTRULATION that provide tissues and body plan of a mature organism. They derive from two early layers, hypoblast and epiblast.
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 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.
The complex processes of initiating CELL DIFFERENTIATION in the embryo. The precise regulation by cell interactions leads to diversity of cell types and specific pattern of organization (EMBRYOGENESIS).
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.
A reaction that severs one of the covalent sugar-phosphate linkages between NUCLEOTIDES that compose the sugar phosphate backbone of DNA. It is catalyzed enzymatically, chemically or by radiation. Cleavage may be exonucleolytic - removing the end nucleotide, or endonucleolytic - splitting the strand in two.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
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).
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).
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.
The outer of the three germ layers of an embryo.
An octamer transcription factor that is expressed primarily in totipotent embryonic STEM CELLS and GERM CELLS and is down-regulated during CELL DIFFERENTIATION.
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)
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.
A reaction that severs one of the sugar-phosphate linkages of the phosphodiester backbone of RNA. It is catalyzed enzymatically, chemically, or by radiation. Cleavage may be exonucleolytic, or endonucleolytic.
The condition of carrying two or more FETUSES simultaneously.
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.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
Elements of limited time intervals, contributing to particular results or situations.
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
The process of cleaving a chemical compound by the addition of a molecule of water.
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)
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
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.
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.
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 biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
The rate dynamics in chemical or physical systems.
A proprotein convertase with specificity for the proproteins of PROALBUMIN; COMPLEMENT 3C; and VON WILLEBRAND FACTOR. It has specificity for cleavage near paired ARGININE residues that are separated by two amino acids.
A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.
Factors that are involved in directing the cleavage and POLYADENYLATION of the of MESSENGER RNA near the site of the RNA 3' POLYADENYLATION SIGNALS.
Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.
An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).
Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).
Established cell cultures that have the potential to propagate indefinitely.
Proteins prepared by recombinant DNA technology.
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).
Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 9. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.
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.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
A form of hypersensitivity affecting the respiratory tract. It includes ASTHMA and RHINITIS, ALLERGIC, SEASONAL.
ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by CYSTEINE PROTEINASE INHIBITORS such as CYSTATINS and SULFHYDRYL REAGENTS.
A family of enzymes that catalyze the endonucleolytic cleavage of RNA. It includes EC 3.1.26.-, EC 3.1.27.-, EC 3.1.30.-, and EC 3.1.31.-.
Substances that are recognized by the immune system and induce an immune reaction.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
A mitochondrial cytochrome P450 enzyme that catalyzes the side-chain cleavage of C27 cholesterol to C21 pregnenolone in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11A1 gene, catalyzes the breakage between C20 and C22 which is the initial and rate-limiting step in the biosynthesis of various gonadal and adrenal steroid hormones.
A family of SERINE ENDOPEPTIDASES isolated from Bacillus subtilis. EC 3.4.21.-
Cleavage of proteins into smaller peptides or amino acids either by PROTEASES or non-enzymatically (e.g., Hydrolysis). It does not include Protein Processing, Post-Translational.
Endopeptidases that are specific for AMYLOID PROTEIN PRECURSOR. Three secretase subtypes referred to as alpha, beta, and gamma have been identified based upon the region of amyloid protein precursor they cleave.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
Washing liquid obtained from irrigation of the lung, including the BRONCHI and the PULMONARY ALVEOLI. It is generally used to assess biochemical, inflammatory, or infection status of the lung.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
The sum of the weight of all the atoms in a molecule.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
A sub-subclass of endopeptidases that depend on an ASPARTIC ACID residue for their activity.
Subset of helper-inducer T-lymphocytes which synthesize and secrete the interleukins IL-4, IL-5, IL-6, and IL-10. These cytokines influence B-cell development and antibody production as well as augmenting humoral responses.
ENDOPEPTIDASES which use a metal such as ZINC in the catalytic mechanism.
A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).
Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.
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.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.
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.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Proteins found in any species of virus.
RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
A condition characterized by infiltration of the lung with EOSINOPHILS due to inflammation or other disease processes. Major eosinophilic lung diseases are the eosinophilic pneumonias caused by infections, allergens, or toxic agents.
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.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
Cysteine proteinase found in many tissues. Hydrolyzes a variety of endogenous proteins including NEUROPEPTIDES; CYTOSKELETAL PROTEINS; proteins from SMOOTH MUSCLE; CARDIAC MUSCLE; liver; platelets; and erythrocytes. Two subclasses having high and low calcium sensitivity are known. Removes Z-discs and M-lines from myofibrils. Activates phosphorylase kinase and cyclic nucleotide-independent protein kinase. This enzyme was formerly listed as EC 3.4.22.4.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognize specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.4.
The discharge of an OVUM from a rupturing follicle in the OVARY.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.
Enzymes that catalyze the transfer of multiple ADP-RIBOSE groups from nicotinamide-adenine dinucleotide (NAD) onto protein targets, thus building up a linear or branched homopolymer of repeating ADP-ribose units i.e., POLY ADENOSINE DIPHOSPHATE RIBOSE.
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The process by which antigen is presented to lymphocytes in a form they can recognize. This is performed by antigen presenting cells (APCs). Some antigens require processing before they can be recognized. Antigen processing consists of ingestion and partial digestion of the antigen by the APC, followed by presentation of fragments on the cell surface. (From Rosen et al., Dictionary of Immunology, 1989)
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.
Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.
A family of membrane-anchored glycoproteins that contain a disintegrin and metalloprotease domain. They are responsible for the proteolytic cleavage of many transmembrane proteins and the release of their extracellular domain.
Enzymes that catalyze the hydrolysis of the internal bonds and thereby the formation of polynucleotides or oligonucleotides from ribo- or deoxyribonucleotide chains. EC 3.1.-.
Physiologically inactive substances that can be converted to active enzymes.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

Chromosome abnormalities in human embryos. (1/708)

The presence of numerical chromosome abnormalities in human embryos was studied using fluorescence in-situ hybridization with four or more chromosome-specific probes. When most cells of an embryo are analysed, this technique allows differentiation to be made between aneuploidy, mosaicism, haploidy and polyploidy. Abnormal types of fertilization, such as unipronucleated, tripronucleated zygotes and zygotes with uneven pronuclei, were studied using this technique. We have found a strong correlation between some types of dysmorphism with chromosomal abnormalities. In addition, the more impaired the development of an embryo, the more chromosomal abnormalities were detected in those embryos. Maternal age and other factors were linked to an increase in chromosome abnormalities (hormonal regimes, temperature changes), but not to intracytoplasmic sperm injection.  (+info)

Temporal and spatial aspects of fragmentation in early human embryos: possible effects on developmental competence and association with the differential elimination of regulatory proteins from polarized domains. (2/708)

This study examined the relationship between blastomere fragmentation in cultured human embryos obtained by in-vitro fertilization and the effect of fragmentation on the distribution of the following eight regulatory proteins found to be: (i) localized in the mature oocyte in subplasmalemmal, polarized domains; and (ii) unequally inherited by the blastomeres during cleavage: leptin, signal transducer and activator of transcription 3 (STAT3), Bax, Bcl-x, transforming growth factor beta 2 (TGF beta 2), vascular endothelial growth factor (VEGF), c-kit and epidermal growth factor R (EGF-R). Four basic patterns of fragmentation were observed. The severity of the impact of each type of fragmentation on the affected blastomere(s) and the developmental competence of the embryo appeared to be a function of the unique temporal and spatial features associated with the particular fragmentation pattern(s) involved in each instance. The findings demonstrate that certain patterns of fragmentation can result in the partial or near total loss of the eight regulatory proteins from specific blastomeres and that the developmental potential of the affected embryo can be particularly compromised if it occurs during the 1- or 2-cell stages. In contrast, fragmentation from portions of a fertilized egg or a blastomere(s) in a 2-cell embryo that do not contain the protein domains, or the complete loss by fragmentation of a regulatory protein domain-containing blastomere after the 4-cell stage does not necessarily preclude continued development to the blastocyst, although the normality and developmental potential of the embryo may be compromised. The possible association between fragmentation and apoptosis was examined by annexin V staining of plasma membrane phosphatidylserine and TUNEL analysis of blastomere DNA. No direct correlation between fragmentation and apoptosis was found following the analyses of fragmented embryos with these two markers. However, while we suggest that changes in cell physiology unrelated to apoptosis are the more likely causes of fragmentation, we cannot exclude the possibility that fragmentation itself may be an initiator of apoptosis if critical ratios or levels of developmentally important proteins are altered by partial or complete elimination of their polarized domains. The findings are discussed with respect to the possible developmental significance of regulatory protein polarization in human oocytes and preimplantation stage embryos.  (+info)

Spatially restricted expression of PlOtp, a Paracentrotus lividus orthopedia-related homeobox gene, is correlated with oral ectodermal patterning and skeletal morphogenesis in late-cleavage sea urchin embryos. (3/708)

Several homeobox genes are expressed in the sea urchin embryo but their roles in development have yet to be elucidated. Of particular interest are homologues of homeobox genes that in mouse and Drosophila are involved in patterning the developing central nervous system (CNS). Here, we report the cloning of an orthopedia (Otp)-related gene from Paracentrotus lividus, PlOtp. Otp is a single copy zygotic gene that presents a unique and highly restricted expression pattern. Transcripts were first detected at the mid-gastrula stage in two pairs of oral ectoderm cells located in a ventrolateral position, overlying primary mesenchyme cell (PMC) clusters. Increases in both transcript abundance and the number of Otp-expressing cells were observed at prism and pluteus stages. Otp transcripts are symmetrically distributed in a few ectodermal cells of the oral field. Labelled cells were observed close to sites of active skeletal rod growth (tips of the budding oral and anal arms), and at the juxtaposition of stomodeum and foregut. Chemicals known to perturb PMC patterning along animal-vegetal and oral-aboral axes altered the pattern of Otp expression. Vegetalization by LiCl caused a shift in Otp-expressing cells toward the animal pole, adjacent to shifted PMC aggregates. Nickel treatment induced expression of the Otp gene in an increased number of ectodermal cells, which adopted a radialized pattern. Finally, ectopic expression of Otp mRNA affected patterning along the oral-aboral axis and caused skeletal abnormalities that resembled those exhibited by nickel-treated embryos. From these results, we conclude that the Otp homeodomain gene is involved in short-range cell signalling within the oral ectoderm for patterning the endoskeleton of the larva through epithelial-mesenchymal interactions.  (+info)

The centrosome-attracting body, microtubule system, and posterior egg cytoplasm are involved in positioning of cleavage planes in the ascidian embryo. (4/708)

Many kinds of animal embryos exhibit stereotyped cleavage patterns during early embryogenesis. In the ascidian Halocynthia roretzi, cleavage patterns are invariant but they are complicated by successive unequal cleavages that occur in the posterior region. Here we report the essential roles of a novel structure, called the centrosome-attracting body (CAB), which exists in the posterior pole cortex of cleaving embryos, in generating unequal cleavages. By removing and transplanting posterior egg cytoplasm and by treatment with sodium dodecyl sulfate, we demonstrated that loss of the CAB resulted in abolishment of unequal cleavage, while ectopic formation of the CAB caused ectopic unequal cleavages to occur. Experiments with a microtubule inhibitor demonstrated that the centrosome and nucleus were attracted toward the posterior cortex, where the CAB is located, by shortening of microtubule bundles formed between the centrosome and the CAB. Consequently, the mitotic apparatus was positioned asymmetrically, resulting in unequal cleavage. Immunohistochemistry provided evidence that a microtubule motor protein, a kinesin or kinesin-like molecule, may be associated with the CAB. Formation of the CAB during the early cleavage stage was resistant to treatment with the microtubule inhibitor. In contrast, the integrity of the CAB was lost upon treatment with a microfilament inhibitor. We propose that the CAB plays key roles in the orientation and positioning of cleavage planes during unequal cell division.  (+info)

Identification of two major histocompatibility complex class Ib genes, Q7 and Q9, as the Ped gene in the mouse. (5/708)

The Ped (preimplantation embryonic development) gene influences the rate of preimplantation embryonic development and subsequent embryonic survival. The protein product of the Ped gene, the Qa-2 protein, is a major histocompatibility complex (MHC) class Ib protein. There are two alleles of the Ped gene, fast (Qa-2 [+]) and slow (Qa-2 [-]). Qa-2 is encoded by four very similar MHC class Ib genes: Q6, Q7, Q8, and Q9. Recent research in our laboratory has shown that the Ped phenotype is potentially encoded by the Q7 and/or Q9 gene because the Q7 and Q9 genes, but not the Q6 or Q8 gene, are expressed during preimplantation mouse embryonic development. In this study we utilized microinjection of transgenes to assess the functional roles of both the Q7 and Q9 genes in control of the rate of preimplantation development. The Q7 gene, the Q9 gene, and a combination of the Q7 and Q9 genes were microinjected into Ped slow zygotes, and the Ped phenotype and cell surface expression of Qa-2 protein were assayed after a 72-h or 96-h incubation period. We found that the microinjected individual Q7 and Q9 genes increased the rate of preimplantation development. Simultaneous injection of the Q7 and Q9 genes did not have a synergistic effect on the Ped phenotype. Microinjection of the Q7 and/or Q9 genes resulted in protein expression in 10-25% of the microinjected embryos. These results show that both the Q7 and Q9 genes encode the mouse Ped phenotype.  (+info)

Cytoskeletal mechanisms of ooplasmic segregation in annelid eggs. (6/708)

Annelid embryos are comprised of yolk-deficient animal and yolk-filled vegetal blastomeres. This "unipolar" organization along the animal-vegetal axis (in terms of ooplasmic distribution) is generated via selective segregation of yolk-free, clear cytoplasm to the animal blastomeres. The pathway that leads to the unipolar organization is different between polychaetes and clitellates (i.e., oligochaetes and hirudinidans). In polychaetes, the clear cytoplasm domain, which is established through ooplasmic segregation at the animal side of the egg, is simply cut up by unequal equatorial cleavage. In clitellates, localization of clear cytoplasm to animal blastomeres is preceded by unification of the initially separated polar domains of clear cytoplasm, which result from bipolar ooplasmic segregation. In this article, I have reviewed recent studies on cytoskeletal mechanisms for ooplasmic localization during early annelid development. Annelid eggs accomplish ooplasmic rearrangements through various combinations of three cytoskeletal mechanisms, which are mediated by actin microfilaments, microtubules and mitotic asters, respectively. One of the unique features of annelid eggs isthat a homologous process is driven by distinct cytoskeletal elements. Annelid eggs may provide an intriguing system to investigate not only mechanical aspects of ooplasmic segregation but also evolutionary divergence of cytoskeletal mechanisms that operate in a homologous process.  (+info)

Characterization of novel F-actin envelopes surrounding nuclei during cleavage of a polychaete worm. (7/708)

F-actin accumulations and their possible functions were investigated during cleavage of the polychaete Ophryotrocha puerilis. Unusual cytoplasmic accumulations of F-actin were detected which have never been described before in animal embryos. As shown by TRITC-phalloidin labeling, envelopes of F-actin surrounded late prophase nuclei for a short period of time. DTAF-immunofluorescence of beta-tubulin showed that the F-actin envelope was closely associated with microtubules of the developing spindle apparatus. However, experimental disassembly of microtubules by nocodazole did not prevent the assembly of the F-actin envelope. Disturbance of F-actin envelope formation by cytochalasin B did not alter the course of mitotic events, i.e. position of the nuclei and orientation of the spindle apparatus were not affected, although the respective blastomeres remained uncleaved. However, disassembly of the F-actin envelope correlated temporally with breakdown of the nuclear envelope. Therefore, it is suggested that this new structure plays a role in fragmentation of the nuclear envelope during cleavage of Ophryotrocha puerilis.  (+info)

Comparison of human blastulation rates and total cell number in sequential culture media with and without co-culture. (8/708)

Recent interest in delayed embryo transfers necessitated the evaluation of two improved in-vitro systems that could generate viable blastocysts. A total of 178 two-pronucleated embryos (entire cohorts) from 19 patients was cultured in IVF50 medium (100 microl) under oil for 24 h until day 2. Each patient's day 2 embryos were then equally allotted to two in-vitro systems. Embryos in system A were grown until the morning of day 3 on Vero cells covered with IVF50 medium (100 microl) under oil. The medium was then replaced on day 3 with a 1:1 mixture (100 microl) of IVF50:S2 medium and on day 4 with S2 medium only. The same culture protocol was used for system B without Vero cells. Throughout the 5 days all dishes were housed in sealed humidified modular chambers containing a triple gas atmosphere. Separately, 175 spare embryos from 80 patients were grown in system A and B up to days 6 and 7 for total cell number (TCN) analysis. Blastulation rates were not significantly different between system A and B (67.4 versus 68.5%; P > 0.01) although co-cultured embryos cleaved slightly faster by day 4. The overall pregnancy and implantation rates were 52.0% and 32.1% for the 19 patients each of whom received a mixed cohort of three day 5 embryos from both systems. TCN values for the day 6 and 7 blastocysts from both systems were high and increased steadily from days 6-7 and from expanded to hatching stages. There were no significant differences in TCN for day 6 expanded blastocysts between the two systems although day 6 hatching and hatched co-cultured blastocysts had greater values than non-co-cultured blastocysts (246.0 +/- 18.5 and 236.7 +/- 17.8 versus 173.0 +/- 13.5 and 166.5 +/- 16.0; P < 0.01). The results demonstrated that the culture protocol using the sequential IVF50-S2 media combination was a good substitute for Vero cell co-culture for the transfer of viable day 3-6 embryos.  (+info)

The embryos cleavage pattern provides valuable supplementary information to the standard evaluation for selecting embryos by cleavage rate and fragmentation, enhancing the likelihood for successful implantation.
J:122362 Harwood BN, Cross SK, Radford EE, Haac BE, de Vries WN, Members of the WNT signaling pathways are widely expressed in mouse ovaries, oocytes, and cleavage stage embryos. Dev Dyn. 2008;237(4):1099-1111 ...
First, a definition... Klingon Kleavage is a play on cleavage. The women who play Klingons show a lot of clevage with their outfits. My wife and I are T...
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The aim of this study was to evaluate the effects of quarter zona-pellucida (ZP) opening by laser-assisted hatching (QLAH) on the clinical outcomes following transfer of vitrified-warmed blastocysts developed from low-grade cleavage-stage embryos in patients with all high-grade and fair-grade cleavage-stage embryos transferred without achieving pregnancy. Patients were randomized into ...
Mouse morulae from two strains were examined in whole mounts after dissociation of embryos into single cells and were analysed in serial sections by light and electron microscopy. One or two...
Spiral cleavage is a conserved, early developmental mode found in several phyla of Lophotrochozoans resulting in highly diverse adult body plans. While the cleavage pattern has clearly been broadly conserved, it has also undergone many modifications in various taxa. The precise mechanisms of how different adaptations have altered the ancestral spiral cleavage pattern are an important ongoing evolutionary question, and adequately answering this question requires obtaining a broad developmental knowledge of different spirally cleaving taxa. In flatworms (Platyhelminthes), the spiral cleavage program has been lost or severely modified in most taxa. Polyclad flatworms, however, have retained the pattern up to the 32-cell stage. Here we study early embryogenesis of the cotylean polyclad flatworm Maritigrella crozieri to investigate how closely this species follows the canonical spiral cleavage pattern and to discover any potential deviations from it. Using live imaging recordings and 3D reconstructions of
Calcium signaling is known to be associated with cytokinesis; however, the detailed spatio-temporal pattern of calcium dynamics has remained unclear. We have studied changes of intracellular free calcium in cleavage-stage Xenopus embryos using fluorescent calcium indicator dyes, mainly Calcium Green-1. Cleavage formation was followed by calcium transients that localized to cleavage furrows and propagated along the furrows as calcium waves. The calcium transients at the cleavage furrows were observed at each cleavage furrow at least until blastula stage. The velocity of the calcium waves at the first cleavage furrow was approximately 3 microns/s, which was much slower than that associated with fertilization/egg activation. These calcium waves traveled only along the cleavage furrows and not in the direction orthogonal to the furrows. These observations imply that there exists an intracellular calcium-releasing activity specifically associated with cleavage furrows. The calcium waves occurred in ...
The delivery rate achieved after the vitrification of early cleavage- and blastocyst-stage embryos is not affected by the embryo developmental stage or any other variable related to the warming cycle.
Recent lineage tracing studies have allowed us to identify a relationship between the distinct patterns of cleavage divisions that generate the four-cell mouse embryos and the contribution of progeny of four-cell blastomeres to specific regions of the blastocyst (Piotrowska-Nitsche and Zernicka-Goetz, 2005). One of the major patterns of cleavage, in which a meridional second division (an M-division) precedes an oblique/equatorial one (the E-division in ME embryos), is associated with the development of defined polarity to the future embryonic-abembryonic axis. Thus, in this group of embryos, the earlier dividing two-cell blastomere shows a tendency to contribute to the embryonic part of the blastocyst. In such embryos, the later-dividing two-cell blastomere appears to undergo a division that, were it truly equatorial and if cell components were distributed without mixing, would generate one four-cell blastomere with `vegetal and another with `animal components of the egg (Gardner, 2002). Both ...
Stereotypic cleavage patterns play a crucial role in cell fate determination by precisely positioning early embryonic blastomeres. Although misplaced cell divisions can alter blastomere fates and cause embryonic defects, cleavage patterns have been modified several times during animal evolution. However, it remains unclear how evolutionary changes in cleavage impact the specification of blastomere fates. Here, we analyze the transition from spiral cleavage - a stereotypic pattern remarkably conserved in many protostomes - to a biradial cleavage pattern, which occurred during the evolution of bryozoans. Using 3D-live imaging time-lapse microscopy (4D-microscopy), we characterize the cell lineage, MAPK signaling, and the expression of 16 developmental genes in the bryozoan Membranipora membranacea. We found that the molecular identity and the fates of early bryozoan blastomeres are similar to the putative homologous blastomeres in spiral-cleaving embryos. Our work suggests that bryozoans have retained
The fertilised mammalian egg gives rise to seemingly equivalent blastomeres until the fourth cleavage division, when the first indication of lineage specification appears. At this point, certain blastomeres divide symmetrically and others asymmetrically. When do these apparently identical cells diverge and how do these differences arise? To answer this question, Enkui Duan and colleagues performed single-cell transcriptional analysis of human and mouse blastomeres (p. 3468). By studying the mammalian zygote, in which transcription - a known source of heterogeneity during mitosis - is mostly silent, the authors showed that small biases in gene expression arise after the first cleavage division from the unequal distribution of cellular substances between daughter cells, called partitioning errors. These are especially pronounced for transcripts present in small quantities, which are more likely to be asymmetrically distributed. As cleavage divisions progress, the activation of embryonic ...
Sando Rashed 22:24, 23 September 2009 (EST)Cleavage = the repeated division of a fertilised ovum When the zygote nucleus forms the first cleavage forms, this nucleus undergoes a number of mitosis processes, a wrinkle forms down longitudinally passing the poles of the eggs where the sperm enters. This is how the egg is split up into two halves and this process is what forms the 2-cell stage. The process of the second cleavage is the process that allows the 4-cell stage to occur, the wrinkle runs through the poles at right angles instead of running through it longitudinally. The 8 stage cell is formed during the third cleavage it cuts across horizontally but it cuts through closer to the animal poles rather than the vegetal poles. As cleavages continually occur a 16 and 32 cell embryo are formed, and as these cleavages continuously occur the cells closer to the animal poles divide more rapidly and in more numbers compared to the vegetal pole. Eventually with all these cells continuously forming ...
Sando Rashed 22:24, 23 September 2009 (EST)Cleavage = the repeated division of a fertilised ovum When the zygote nucleus forms the first cleavage forms, this nucleus undergoes a number of mitosis processes, a wrinkle forms down longitudinally passing the poles of the eggs where the sperm enters. This is how the egg is split up into two halves and this process is what forms the 2-cell stage. The process of the second cleavage is the process that allows the 4-cell stage to occur, the wrinkle runs through the poles at right angles instead of running through it longitudinally. The 8 stage cell is formed during the third cleavage it cuts across horizontally but it cuts through closer to the animal poles rather than the vegetal poles. As cleavages continually occur a 16 and 32 cell embryo are formed, and as these cleavages continuously occur the cells closer to the animal poles divide more rapidly and in more numbers compared to the vegetal pole. Eventually with all these cells continuously forming ...
AIPMT-NEET Biology Aspirants, read out the next AIPMT-NEET Biology Study material/ Notes of Embryonic Cleavage. In this we will learn about patterns of embryonic cleavage and types of eggs, important for AIPMT-NEET Biology. Free online notes for AIPMT-NEET.. Process of fusion of sperm and ovum is called Fertilization. In fertilization, haploid nucleus Read More. ...
Interspecies-SCNT preimplantation embryos derived from human granulosa cells fused with enucleated bovine oocytes. Cleavage embryos (A) and blastocysts (C) derived from SCNT. Parthenogenetically developed cleavage embryos (B) and hatching blastocysts (D) as controls ...
Blastomere cell structure. Coloured scanning electron micrograph of the cell structure of blastomeres in the 4-cell embryo. Blastomeres are the cells formed by divisions of the fertilized egg. Here fractured sections of blastomeres can be seen. The cytoplasm (yellow) contains many dense bodies (green) which are most likely primitive mitochondria. The large hole at centre left is a vacuole opening up onto the cell surface. Small projections (microvilli) can be seen inside the vacuole. Magnification: x4,200 at 5x7cm size. - Stock Image G450/0060
Where did the first cell come from? How did life form from non-life? Abiogeneis is an impossiblity because it requires: Hardware and Software, (Proteins and DNA). Cell must be able to replicate iteslf, Proteins are
TY - JOUR. T1 - Brain and sperm cell surface antigen (NS-4) on preimplantation mouse embryos. AU - Solter, Davor. AU - Camartin, Melitta. PY - 1976/1/1. Y1 - 1976/1/1. N2 - Antiserum prepared in rabbit against 4-day-old mouse cerebellum (anti-NS-4 serum) reacts in the complement-mediated cytotoxicity test with unfertilized and fertilized mouse eggs, cleavage stage embryos, and cells of the trophoblast and inner cell mass of the mouse blastocyst. This activity is specifically removed by absorption of antiserum with adult mouse brain and epididymal sperm but not with adult liver, spleen, kidney, and thymocytes. The antiserum reacts most strongly with cells of the trophoblast and inner cell mass and, in order of decreasing reactivity, with four- to eight-cell stage embryos, zygotes, unfertilized eggs, and two-cell stage embryos.. AB - Antiserum prepared in rabbit against 4-day-old mouse cerebellum (anti-NS-4 serum) reacts in the complement-mediated cytotoxicity test with unfertilized and fertilized ...
Dive into the research topics of A global view of gene expression in the preimplantation mouse embryo: Morula versus blastocyst. Together they form a unique fingerprint. ...
There are several differences between the cleavage in mammals and the cleavage in other animals. Mammals have a slow rate of division that is between 12 and 24 hours. These cellular division are asynchronous. Zygotic transcription starts at the two, four, or eight-cell stage. Cleavage is holoblastic and rotational. At the eight-cell stage, the embryo goes through a process called compaction. Most of the blastomeres in this stage become polarized and develop tight junctions with the other blastomeres. This process leads to the development of two different populations of cells: polar cells on the outside and apolar cells on the inside. The outer cells, called the trophoblast cells, secrete fluid on their basal (inner) surface to form a blastocoel cavity through the process of cavitation. These trophoblast cells will eventually give rise to the embryonic contribution to the placenta called the chorion. The inner cells adhere to one side of the cavity to form the inner cell mass (ICM) and will give ...
The role of the TCF family of transcriptional regulators in primary axis formation is addressed by studying the mechanisms of action of XTcf-3 in Xenophus laevis embryos. The early events of primary axis induction involve activation through the WNT signaling pathway. As a result of activation ... read more of the pathway the cytoplasmic level of ß-catenin increases at the future dorsal side of the early cleavage stage embryo. Around the 16-32 cell stage, ß-catenin becomes apparent in the nuclei. The presence of nuclear ß-catenin causes several hours later the activation of specific target genes, like e.g. XSiamois. Since ß-catenin does not contain a DNA binding region, DNA binding proteins must mediate this transactivation. Ectopic expression of ß-catenin causes activation of dorsal genes and results in the induction and differentiation of a secondary axis. (See introduction). Three different homologs of the Tcf/Lef family of transcription factors have been cloned in Xenopus laevis, XTcf-3, ...
We performed in vitro maturation (IVM) and in vitro fertilization (IVF) of the d3 PGCLC- and PGC-derived oocytes and the WT oocytes at 3 weeks (fig. S6B). Despite differences in COC stability and shape, the PGCLC-derived oocytes reached metaphase II (MII), were fertilized, and developed into two-cell embryos with an efficiency comparable to that of oocytes from other sources (Fig. 2B, fig. S6C, and Table 1). Some of the two-cell embryos from the PGCLCs developed further into blastocysts in vitro [19 of 46 (19/46), ~39%] (Fig. 2B). We transferred the two-cell embryos from PGCLCs, as well as those from the other sources, to separate foster mothers. We obtained newborn pups from the two-cell embryos derived from PGCLCs (5/127, ~3.9%), as well as from those derived from E12.5 PGCs (13/75, ~17.3%) and WT 3-week oocytes (7/55, ~12.7%) (Fig. 2C, fig. S7A, and Table 1). All of these offspring grew similarly into adulthood (fig. S7C). The PGCLC-derived offspring bore the BVSC transgenes, a normal ...
Hey guys!!! I had a 3dt on wed and had 1 6 cell and 2 4 cell embryos. wanted to see if anyone got pregnant witha 4 cell! Thanks ...
Blastomere Definition - Blastomere refers to a cell that is created by the early stages of division of a fertilized egg. During in vitro fertilization...
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TY - JOUR. T1 - Different chromatin and energy/redox responses of mouse morulae and blastocysts to slow freezing and vitrification. AU - Somoskoi, Bence. AU - Martino, Nicola A.. AU - Cardone, Rosa A.. AU - Lacalandra, Giovanni M.. AU - DellAquila, Maria E.. AU - Cseh, S.. PY - 2015/3/24. Y1 - 2015/3/24. N2 - Background: The ability to cryopreserve mammalian embryos has become an integral part of assisted reproduction, both in human and veterinary medicine. Despite differences in the size and physiological characteristics of embryos from various species, the embryos have been frozen by either of two procedures: slow freezing or vitrification. The aim of our study was to compare the effect of slow freezing and vitrification to the chromatin structure, energy status and reactive oxygen species production of mouse morulae and blastocysts. Methods: Mouse morulae and blastocysts were randomly allocated into vitrification, slow freezing and control groups. For slow freezing, Dulbecco phosphate ...
The effects of embryo number and incubation volume on the development of mouse embryos were evaluated. The growth rate of two-cell mouse embryos to attached blastocyst stage and the growth rate of blastocysts to early somite stage were assessed after culture in different incubation volumes and embryo densities. Embryos were collected from ICR female mice superovulated with pregnant mare serum gonadotropin and human chorionic gonadotropin and mated by ICR males. In experiment 1, groups of one, five, ten, twenty 2-cell embryos were cultured in 10-, 50-, 500-, 1000-microliter drops of BWW media under mineral oil at 37 degrees C in a humidified atmosphere of 5% CO2 and 95% air. As the incubation volume decreased, significantly ( ...
Lipid rafts enriched in glycosphingolipids (GSLs), cholesterol and signaling molecules play an essential role not only for signal transduction started by ligand binding, but for intracellular events such as organization of actin, intracellular traffic and cell polarity, but their functions in cleavage division of preimplantation embryos are not well known. Here we show that monosialylGb5Cer (MSGb5Cer)-enriched raft domains are involved in development during the cleavage stage of mouse preimplantation embryos. MSGb5Cer preferentially localizes at the interfaces between blastomeres in mouse preimplantation embryos. Live-imaging analysis revealed that MSGb5Cer localizes in cleavage furrows during cytokinesis, and that by accumulating at the interfaces, it thickens them. Depletion of cholesterol from the cell membrane with methyl-beta-cyclodextrin (MbCD) reduced the expression of MSGb5Cer and stopped cleavage. Extensive accumulation of MSGb5Cer at the interfaces by cross-linking with anti-MSGb5Cer Mab (6E2)
The most studied nucleation status is multinucleation, which is defined as the presence of more than one nucleus in at least one blastomere of the embryo (Jackson et al., 1998; Van Royen et al., 2003). Multinucleation can be evaluated both in the early cleaved Day 1 (26-28±1 h post-insemination), Day 2 (44 ± 1 h post-insemination) and Day 3 (68 ± 1 h post-insemination) cleavage stage embryos, although the assessment of a Day 3 embryo may be more complicated due to the smaller cell size and the larger number of cells (Van Royen et al., 2003). Embryo quality has been shown to correlate with multinucleation, and 4-cell embryos on Day 2 and 8-cell embryos on Day 3 show reduced multinucleation compared with the other cell stages observed on these days (Van Royen et al., 2003; Ziebe et al., 2003).. Multinucleation is predictive of a decreased implantation potential (Jackson et al., 1998; Pelinck et al., 1998; Van Royen et al., 2003; Moriwaki et al., 2004) and multinucleated embryos are associated ...
Direct knowledge of Ca2+ patterns in vertebrate development is largely restricted to early stages, in which they control fertilization, ooplasmic segregation and cleavage. To explore new roles of Ca2+ in vertebrate development, we injected the Ca2+ indicator aequorin into zebrafish eggs and imaged Ca2+ throughout the first day of development. During early cleavages, a high Ca2+ zone is seen in the cleavage furrows. The high Ca2+ zone during first cleavage spreads as a slow wave (0.5 microm/second) and is preceded by three Ca2+ pulses within the animal pole region of the egg. When Ca2+ concentrations are clamped at the resting level by BAPTA buffer injection into the zygote, all signs of development are blocked. In later development, Ca2+ patterns are associated with cell movements during gastrulation, with neural induction, with brain regionalization, with formation of the somites and neural keel, with otic placode formation, with muscle movements and with formation of the heart. Particularly ...
Transcription factor control of TE/ICM segregation. TE and ICM lineage segregation is controlled by a small group of transcription factors. Specifically, Cdx2 is required for TE development, while the pluripotency markers octamer 3/4 (Oct4), Nanog, and SRY-box containing gene 2 (Sox2) are involved in establishing the ICM fate. In the mouse, Cdx2 is expressed at varying levels in all blastomeres starting at the eight-cell stage, but it becomes restricted to outside, future TE cells, prior to blastocyst formation (Figure 1) (72, 73). This variation in Cdx2 levels between individual blastomeres at the eight-cell stage may be a result of differences in the order and orientation of the cleavage divisions leading up to this stage (71). Embryos missing Cdx2 do form blastocysts initially, but the TE in these embryos loses its epithelial integrity and cannot differentiate further, resulting in death around the time of implantation (74). Oct4, Nanog, and Sox2 have expression patterns that are ...
The egg-to-embryo transition entails transforming a highly differentiated oocyte into totipotent blastomeres, and represents one of the earliest obstacles that...
Enucleated mouse 1-cell embryos arrest development at the 2-cell stage following transplantation of cleavage stage nuclei. Earlier studies employing one-dimensional protein gel electrophoresis failed to reveal obvious differences in gene expression in the manipulated embryos that might account for this block. We report here the results of a quantitative, two-dimensional gel electrophoretic analysis that reveals at least 50 alterations in protein synthesis in the 8--|1-cell nuclear transplant embryos. Approximately half of these alterations involve proteins that normally decrease in synthesis between the 2-cell and 8-cell stages and half involve proteins that are synthesized constitutively between these two stages. These results are the first to reveal significant biochemical alterations that accompany the morphological and cytological differences previously described and indicate that the 8-cell stage nucleus is unable to completely recapitulate the normal progression of changes in protein
1989) Effects of oxygen concentration on the metabolism of [u-14c]glucose by mouse morulae and early blastocysts in vitro. Reproduction, Fertility and Development, 1 (2). pp. 99-106. Wales, R.G., Cuneo, C.L. and Waugh, E.E. ...
Fingerprint Dive into the research topics of A Qualitative Change in the Transcriptome Occurs after the First Cell Cycle and Coincides with Lumen Establishment during MDCKII Cystogenesis. Together they form a unique fingerprint. ...
Other articles where Blastomere is discussed: animal development: Cleavage: …produced during cleavage are called blastomeres. The divisions are mitotic-i.e., each chromosome in the nucleus splits into two daughter chromosomes, so that the two daughter blastomeres retain the diploid number of chromosomes. During cleavage, almost no growth occurs between consecutive divisions, and the total volume of living matter does not…
Strictly defined, the conception of a new individual occurs at the moment when chromosomes from the male and female pronuclei associate to form the mitotic figure of the first cleavage. Despite the...
YAP is a fast scintillation crystal offering great mechanical resistance and stability, with no cleavage planes or hygroscopcity.
TY - JOUR. T1 - Neogenin as a receptor for early cell fate determination in preimplantation mouse embryos. AU - Lee, Jae Ho. AU - Choi, Sung Sook. AU - Kim, Hae Won. AU - Xiong, Wencheng. AU - Min, Churl K.. AU - Lee, Sang Jin. PY - 2014/7/11. Y1 - 2014/7/11. N2 - The first cell lineage determination in embryos takes place when two cell populations are set apart, each differentiating into the trophectoderm (TE) and inner cell mass (ICM), respectively. It is widely believed that position/polarity cues play a key role in triggering this differentiation, but it remains unclear how extracellular cues are transduced into cell fate determination. Here, we provide evidence that supports that neogenin is implicated in relaying extracellular cues into the first cell fate determination in preimplantation mouse embryos. A polarized and transient distribution of neogenin was manifested in early blastomeres. Neogenin up-regulation by its overexpression accelerated ICM development in the blastocyst ...
More than 90 percent of enucleated one-cell mouse embryos receiving pronuclei from other one-cell embryos successfully develop to the blastocyst stage in vitro. In this investigation, nuclei from successive preimplantation cleavage stages were introduced into enucleated one-cell embryos and the embryos were tested for development in vitro. Although two-cell nuclei supported development to the morula or blastocyst stage, four-cell, eight-cell, and inner cell mass cell nuclei did not. The inability of cell nuclei from these stages to support development reflects rapid loss of totipotency of the transferred nucleus and is not the result of simultaneous transfer of membrane or cytoplasm.
The degradation of maternal proteins is one of the most important events during early development, and it is presumed to be essential for embryonic genome activation (EGA), but the precise mechanism is still not known. It is thought that a large proportion of the degradation of maternal proteins is mediated by the ubiquitin-proteolytic system. In this study we focused on the expression of the Skp1-Cullin1-F-box (SCF) complex, a modular RING-type E3 ubiquitin-ligase, during bovine preimplantation development. The complex consists of three invariable components--Cul1, Skp1, Rbx1 and F-box protein, which determines the substrate specificity. The protein level and mRNA expression of all three invariable members were determined. Cul1 and Skp1 mRNA synthesis was activated at early embryonic stages, at the 4c and early 8c stage, respectively, which suggests that these transcripts are necessary for preparing the embryo for EGA. CUL1 protein level increased from MII to the morula stage, with a ...
P. flavas early cleavage pattern is similar to that of S. kowalevskii. The first and second cleavages from the single cell zygote of P. flava are equal cleavages, are orthogonal to each other and both include the animal and vegetal poles of the embryo. The third cleavage is equal and equatorial so that the embryo has four blastomeres both in the vegetal and the animal pole. The fourth division occurs mainly in blastomeres in the animal pole, which divide transversally as well as equally to make eight blastomeres. The four vegetal blastomeres divide equatorially but unequally and they give rise to four big macromeres and four smaller micromeres. Once this fourth division has occurred, the embryo has reached a 16 cell stage. P. flava has a 16 cell embryo with four vegetal micromeres, eight animal mesomeres and 4 larger macromeres. Further divisions occur until P. flava finishes the blastula stage and goes on to gastrulation. The animal mesomeres of P. flava go on to give rise to the larvas ...
Fornicata are traditionally classified into Diplomonadida, Retortamonadida, Carpediemonas, and Dysnectes. Diplomonadida and Retortamonadida have been regarded as closely related and together they constitute the taxon Eopharyngia (the term refers to the extensively developed cytopharynx of diplomonads and retortamonads). The hypothesis of Eopharyngia was supported by molecular-phylogenetic studies which included sequences of Retortamonas and several diplomonad genera. At first, the studies based on the SSU rRNA gene (Silberman et al. 2002; Kolisko et al. 2005; Keeling and Brugerolle 2006) indicated that diplomonads may not be monophyletic and that Retortamonas may be sister to the Giardiinae diplomonad lineage. However, the analysis based on the hsp90 gene showed that diplomonads are monophyletic and that Retortamonas forms their sister lineage, which was consistent with previous morphology-based hypotheses. Sequence data of the second retortamonads genus, Chilomastix, have been obtained quite ...
Fornicata are traditionally classified into Diplomonadida, Retortamonadida, Carpediemonas, and Dysnectes. Diplomonadida and Retortamonadida have been regarded as closely related and together they constitute the taxon Eopharyngia (the term refers to the extensively developed cytopharynx of diplomonads and retortamonads). The hypothesis of Eopharyngia was supported by molecular-phylogenetic studies which included sequences of Retortamonas and several diplomonad genera. At first, the studies based on the SSU rRNA gene (Silberman et al. 2002; Kolisko et al. 2005; Keeling and Brugerolle 2006) indicated that diplomonads may not be monophyletic and that Retortamonas may be sister to the Giardiinae diplomonad lineage. However, the analysis based on the hsp90 gene showed that diplomonads are monophyletic and that Retortamonas forms their sister lineage, which was consistent with previous morphology-based hypotheses. Sequence data of the second retortamonads genus, Chilomastix, have been obtained quite ...
The top picture shows polar lobe formation during the first cell division. One can see two polar bodies. Polar bodies are the tiny sister cells of the oocyte which are produced during meiosis, contain discarded DNA and mark the animal pole of the embryo (up in the first three pictures). The opposite pole of the embryo is the vegetal pole. The two cells at the animal pole are the first two blastomeres. What looks like a third cell at the vegetal pole is the polar lobe, which at this stage is nearly completely cinched off from either blastomere. Subsequently the polar lobe fuses with one of the blastomeres (second picture from top), so that by the end of the first cell division one of the blastomeres (called CD) is noticeably larger than the AB cell (third picture from top). Polar lobe also forms at the second cell division (not shown). At the four-cell stage blastomere D is the largest, blastomere C is the second largest, while A and B cells are about the same size (bottom picture). The first ...
A recent study presented at the annual meeting of the European Society of Human Reproduction and Embryology shows that in the first five days of his existence, the tiniest of human beings has the capacity to heal himself of genetic abnormalities. ... Professor William G. Kearns told the annual meeting of the European Society of Human Reproduction and Embryology that a three-day-old embryo (called a cleavage stage embryo) with an incorrect number of chromosomes (known as aneuploidy) was capable of undergoing a dynamic process of genetic normalisation so that by day five, when it had developed to the blastocyst stage, it had become euploid, with the correct number of chromosomes ...
Esrrb-IRES-Cre knock-in mice express a highly-penentrant Cre recombinase in pre-implantation four-cell stage embryos. These mice are useful for studying ubiquitous gene function in embryos between the zygote or two-cell and blastocyst stages of development, being particularly effective in the cases of genes with essential gametic or zygotic functions.
mNanog and ventx1/2 overexpression cause similar effects in Xenopus embryos.(A) Four-cell stage embryos (NF3) were injected in both dorsal blastomeres, with a 1
TY - JOUR. T1 - Single blastocyst embryo transfer maintains comparable pregnancy rates to double cleavage-stage embryo transfer but results in healthier pregnancy outcomes. AU - Zander-Fox, Deidre. AU - Tremellen, Kelton. AU - Lane, Michelle. PY - 2011/10. Y1 - 2011/10. N2 - Background: The optimal outcome after IVF is a live, healthy, singleton term baby. This can be achieved by transferring a single embryo, but at the possible expense of reducing pregnancy rates. Recent studies suggest that delaying transfer of embryos to the blastocyst stage (day 4/5), rather than the more traditional cleavage stage (day 2-3), allows for better selection of the best embryo, maximising pregnancy rates from a single embryo transfer (SET). The aim of this study was to assess pregnancy outcomes in relation to changing embryo transfer practices. Methods: A retrospective analysis of pregnancy outcomes was made between IVF cycles conducted in 2007 when blastocyst SET became standard practice, with IVF cycles in 2003 ...
STUDY QUESTION: Is the spindle assembly checkpoint (SAC) active during human preimplantation development?. SUMMARY ANSWER: Mitotic spindle disruption during mitosis activates the SAC from at least Day 3 of human preimplantation development, but this does not lead to apoptosis until Day 5.. WHAT IS KNOWN ALREADY: Human preimplantation embryos frequently acquire chromosomal abnormalities, but the mechanisms behind this are poorly understood. It has been speculated that a dysfunctional SAC could be responsible. Although research has shown that the SAC components are present during early human development, functional studies are lacking.. STUDY DESIGN, SIZE, DURATION: In vitro study using human preimplantation embryos in a university research laboratory. We studied a total of 38 Day-3, 38 Day-4, 29 Day-5 and 21 Day-6 human preimplantation embryos, donated for research, during 16 h of incubation.. PARTICIPANT/MATERIALS, SETTING, METHODS: We cultured human preimplantation embryos overnight in a ...
Preimplantation mouse embryos of many stresses become arrested at the 2-cell stage if the osmolarity of culture medium that normally supports development to blastocysts is raised to approximately that of their normal physiological environment in the oviduct. cultured at 310 mOsM progressed through the S phase, and zygotic genome activation markers were expressed. However, most embryos failed to initiate the M phase, as evidenced by intact nuclei with decondensed chromosomes, low M-phase promoting factor activity, and an inactive form of CDK1, although a few blastomeres were arrested in metaphase. Thus, embryos become arrested late in the G2 stage of the second embryonic cell cycle when stressed by physiological osmolarity in the absence of organic osmolytes. was detected using immunocytochemistry as explained previously [22] with minor modifications. All procedures were performed at 37C unless normally noted. Briefly, embryos were incubated in 400 nM MitoTracker (MitoTracker Red CMXRos; ...
AC Stain Alcohol Carmine stain. C Stain Carmine stain. C&FG Stain Carmine & Fast Green. CV Stain Cresyl Violet. FS Stain Fuchsin stain. FS&FG Stain Fuchsin & Fast Green. GS Stain Giemsa. H&E Stain Hematoxylin and Eosin ...
embryo hatching.. Standard IVF protocols include culturing of embryos within the laboratory for three days, followed by transfer of cleavage stage embryos (6 to 8 cells), on Day 3, to the uterine cavity. Following transfer, the embryos must continue to progress to the blastocyst stage, shed the ZP, and embed into the uterine wall. In 1989 Cohen and his co-investigators observed a higher implantation rate in patients undergoing IVF, who had the ZP of their embryos mechanically opened. They therefore hypothesized that artificially creating a gap in the ZP might serve to facilitate embryo hatching and implantation. Microscopic manipulation of the ZP, in order to augment hatching and implantation, subsequently became known as assisted hatching. Prospective randomized clinical studies have been performed in order to evaluate the effectiveness of assisted hatching. Several studies report a significant increase in embryo implantation and clinical pregnancy rates, in select groups of patients whose ...
Embryos from XO female mice begin development with half the activity levels of an enzyme (HPRT) coded for by a gene on the X chromosome, compared with embryos from XX females. Groups of unfertilized eggs and individual embryos at the 8-cell, morula and blastocyst stages were assayed for HPRT activit …
The interval transfer of a frozen-thawed embryo is more successful than a fresh embryo transfer for women undergoing IVF with recurrent implantation failure after cleavage stage embryo biopsy ...
On the day 3, embryos are on their cleavage stage. This means that cells in the embryo (blastomeres) are dividing. Observation happens under a high power microscope. On the day 3 after retrieval, embryo itself is not growing in size - only the cells are being replicated.. Accordingly, grading criteria number one is the number of cells in the embryo. The desired number of cells on the day 3 is 6-10. Based on experience, embryos containing 6 to 10 blastomeres on day 3, are more likely to result in successful pregnancy.. Criteria number 2 is the presence of fragmentation. Fragmentation/Blebbing is the process when the inside of the cells break off and form fragments. These blebs do not contain nucleus. Nucleus is the cell storing cells genetic material, DNA. As fragments/blebs are separated from the nucleated part of the cell, they are not referred to as cells. It is preferable to have little or no fragmentation at all. On the other hand, embryologists may capture multinucleation (presence of ...
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A preparation and a method of making composite blastocysts (CBs) from aggregates of dissociated cells of non-viable pre-embryos are disclosed. The CB is characterized morphologically by having two distinct tissue types, the inner cell mass (ICM) and the trophectoderm (TE), and a blastocoelic cavity (BC). The ICM is differentially stainable with bisbenzimide and the TE is differentially stainable with propidium iodide. The ICM is pluripotent in that it contains embryonic stem (ES) cells. The TE cells are pluripotent in that they can give rise to all cell types normally derived from TE cells. The primate TE is characterized by the production of chorionic gonadotrophin. The method of making CBs is an aggregation process (AP) comprising inter alia the following steps: 1) dissociation of discarded pre-embryos; 2) isolation of single nucleated cells from dissociated discarded pre-embryos; 3) microsurgical encapsulation of several cells within a host zona pellucida or artificial aggregation with or without a
Both colonial and solitary species are capable of asexual clonal reproduction by budding; species may reproduce sexually and be dioecious, simultaneous, or protandrous hermaphrodites. Eggs either hatch into planktonic larvae, or in some species, complete early development in a brood chamber (located in the atrium), attached by secretions of cement glands to the chambers wall. In some brooding species, nutrition is provided to developing embryos via special placental cells; in others, the egg yolk nourishes the growing larvae. Planktonic larvae may remain free swimming for up to 7 months before settling, while those raised in a brood chamber will settle relatively quickly (within a few days of hatching). (Brusca and Brusca, 2003; Ruppert, et al., 2004; Shanks, 2001). Entoproct embryonic development follows the holoblastic, spiral cleavage pattern typical of protostome organisms, with the mesoderm forming from the 4d mesentoblast. Development continues to a coeloblastula stage, after which, the ...
CN) - A divided Missouri appeals court ruled Tuesday that the frozen embryos of a divorced couple must be treated as marital property, not as children, even though state law defines life as beginning at conception.. A divorce case required a Missouri judge to decide whether two pre-embryos, which were frozen after the couple began the process of in vitro fertilization, should be considered children or marital property.. Jalesia McQueen and Justin Gadberry have two children together, but decided to freeze two pre-embryos before Gadberry began a tour of duty in Iraq in case they wanted to have more.. They dispute whether they discussed what to do with the pre-embryos in case their marriage ended. McQueen filed a petition for dissolution of marriage against Gadberry in October 2013.. At trial, McQueen testified she wanted to implant the embryos in an attempt to potentially have more children with Gadberry.. Gadberry, however, said he does not want to have more children with McQueen, and wants the ...
Sang J. Lee is the author of these articles in the Journal of Visualized Experiments: Loss- and Gain-of-function Approach to Investigate Early Cell Fate Determinants in Preimplantation Mouse Embryos, Procedure for Adaptive Laboratory Evolution of Microorganisms Using a Chemostat
This sounds so familiar. One embryo is a grade one two-cell. Just like the last time at this point. The other one has stopped dividing as of now. But Dr. E said that well continue to keep an eye on it. My fear is that this grade one two-cell embryo may decide not to divide…
Juvenile mortality, not larval habitat choice determines the non-random distribution of the non-native gastropod Crepidula fornicata in the intertidal ...
Zygote Definition - A zygote is the single-cell that is produced when a sperm fertilizes an egg. It is the first cell in the human body.
This mitosis is also known as cleavage. A hollow cavity forms marking the blastocyst stage. (day 1.5-3 of fertilization.) The ... Fertilization of the ovum to form a new human organism, the human zygote. (day 1 of fertilization) The zygote undergoes mitotic ... Wagner F, Erdösová B, Kylarová D (December 2004). "Degradation phase of apoptosis during the early stages of human metanephros ...
Fertilization occurs when the sperm reaches the ovum. The zygote experiences radial holoblastic cleavage and eventually forms ... Euplectella experiences two main life stages: the larval stage or the adult stage. In the larval stage, the larvae is free ... In the adult stage, Euplectella are sessile and attached firmly to rocks through spicules. It is unclear how long Euplectella ...
Usually even before its liberation, the ovum initiates cleavage processes in which it becomes completely pinched through at the ... Development beyond this 256-cell stage has not yet been observed. Trichoplax lack a homologue of the Boule protein that appears ... Once maturation of the ovum is complete, the rest of the animal degenerates, liberating the ovum itself. Small, unciliated ... In the protected interior space, the ventral cells form an ovum surrounded by a special envelope, the fertilisation membrane; ...
The ova is yellowish in color. The egg is about 70-85 μm long by 44 μm wide, and the early stages of cleavage contain between ... and L2 juvenile stages by feeding on bacteria in the dung. The L1 stage usually occurs within four to six days under the ... "The role of the sheath in resistance of Haemonchus contortus infective stage larvae to proteolytic digestion". Veterinary ...
The different cells derived from cleavage, up to the blastula stage, are called blastomeres. Depending mostly on the amount of ... The inner cell mass remains in contact, however, with the trophoblast at one pole of the ovum; this is named the embryonic pole ... Meroblastic cleavage occurs in animals whose eggs have more yolk (i.e. birds and reptiles). Because cleavage is impeded in the ... In holoblastic eggs, the first cleavage always occurs along the vegetal-animal axis of the egg, and the second cleavage is ...
... cleavage stage, ovum MeSH A16.254.300.600.274 - blastula MeSH A16.254.300.600.550 - morula MeSH A16.254.300.800 - yolk sac MeSH ... cleavage stage, ovum MeSH A16.254.270.274 - blastula MeSH A16.254.270.550 - morula MeSH A16.254.283 - cloaca MeSH A16.254.300 ...
The germinal stage takes around 10 days. During this stage, the zygote begins to divide, in a process called cleavage. A ... With the sperm adhered to the ovum, the third process of acrosomal reaction takes place; the front part of the spermatozoan ... Cleavage itself is the first stage in blastulation, the process of forming the blastocyst. Cells differentiate into an outer ... The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is ...
"blastocoel...[blaso- + -coele] the fluid-filled cavity of the mass of cells (blastula) produced by cleavage of fertilized ovum ... cell stage is considered a blastula as the blastocoel in the embryo becomes apparent during this stage. The fluid-filled cavity ... At this stage there is no cavity within the morula; the embryo is still a ball of dividing cells. In a process called ... At this stage in mammals the blastula develops into the blastocyst containing an inner cell mass, and outer trophectoderm. It ...
Soma line is the vegetative stage. During early cleavage stages of the embryo limited chromosomes are eliminated. The number of ... In the formation ova of the females the 1st ovarian division is monocentric mitosis, the maternal and paternal homologous ... In the next stage of cleavage one paternal X chromosome is eliminated. Hence female soma line cells have 3 pairs of autosomes ... Some special chromosomes called limited chromosomes are present in certain stages. The zygote has 3 pairs of autosomes a one or ...
The germinal stage takes around 10 days. During this stage, the zygote begins to divide, in a process called cleavage. A ... Fertilisation occurs when the sperm cell successfully enters and fuses with an egg cell (ovum). The genetic material of the ... Briefly, embryonic development have four stages: the morula stage, the blastula stage, the gastrula stage, and the neurula ... The egg becomes a zygote and the germinal stage of embryonic development begins. The germinal stage refers to the time from ...
Spermatozoa fuse with the ova in the fertilisation duct, where the zygotes are produced. The zygote undergoes holoblastic and ... However, humans can also act as secondary hosts, which is a more pathological, harmful stage triggered by oral contamination. ... unequal cleavage resulting in three cell types, small, medium and large (micromeres, mesomeres, megameres). Megameres develop ... Humans are colonised by the larval stage, the cysticercus, from undercooked pork or other meat. Each microscopic cysticercus is ...
Temporary gonoducts (ducts from which the ova or sperm are emitted), one per gonad, are built when the ova and sperm are ready ... This larval stage is unique in that there are no Hox genes involved during development, which are only found in the juveniles ... The fertilized egg divides by spiral cleavage and grows by determinate development, in which the fate of a cell can usually be ... The planuliform larva stage may be short-lived and lecithotrophic ("yolky") before becoming a juvenile, or may be ...
"Zygotes segregate entire parental genomes in distinct blastomere lineages causing cleavage-stage chimerism and mixoploidy". ... Fertilisation occurs when an ovum fuses with a sperm, forming a zygote. Normally, the genomes of the two parents assort into ...
Stage of a cell division Metaphase - Stage of cell division Mitosis - Process in which replicated chromosomes are separated ... constricting the cell membrane to form a cleavage furrow. Continued hydrolysis causes this cleavage furrow to ingress (move ... for example in oogenesis in animals the ovum takes almost all the cytoplasm and organelles. This leaves very little for the ... Diploid Telophase - Final stage of a cell division for eukaryotic cells both in mitosis and meiosis Prophase - First phase of ...
... of a motile stage. The zygote or the ovum itself or the sessile organic vessel containing the developing embryo may be called ... The yolk is evenly distributed, so the cleavage of the egg cell cuts through and divides the egg into cells of fairly similar ... In cnidarians, this stage is called the planula, and either develops directly into the adult animals or forms new adult ... The fetus instead develops as a plate-like structure on top of the yolk mass, and only envelopes it at a later stage. A portion ...
This stage has also been referred to as the pre-embryo in legal discourses including relevance to the use of embryonic stem ... In the fertilized daughter, DNA is then replicated in the two separate pronuclei derived from the sperm and ovum, making the ... in a process called cleavage. After four divisions, the conceptus consists of 16 blastomeres, and it is known as the morula. ... Between the stages of fertilization and implantation, the developing embryo is sometimes termed as a preimplantation-conceptus ...
Coeloblastula is the next stage of development for eggs that undergo this radial cleavage. In mammals, because the isolecithal ... Isolecithal (Greek iso = equal, lekithos = yolk) refers to the even distribution of yolk in the cytoplasm of ova of mammals and ... and rotational holoblastic cleavage. These holoblastic cleavage planes pass all the way through isolecithal zygotes during the ... In the absence of a large concentration of yolk, four major cleavage types can be observed in isolecithal cells: radial ...
Yolk cells travel in a duct system to the oviduct, where, in a modified region, the ovum is enclosed in a shell with yolk cells ... After the scolex has differentiated and matured in the larval stage, growth will stop until a vertebrate eats the intermediate ... The initial six-hooked embryo, known as an oncosphere or hexacanth, forms through cleavage. In the order Pseudophyllidea, it ... Eucestoda ontogenesis continues through metamorphosing in different larval stages inside different hosts. ...
Holoblastic cleavage can be radial (see: Radial cleavage), spiral (see: Spiral cleavage), bilateral (see: Bilateral cleavage), ... In the first stage, the semen predominates. In the second stage, the embryo is filled with blood. In the third stage, the main ... Until the birth of modern embryology through observation of the mammalian ovum by Karl Ernst von Baer in 1827, there was no ... Meroblastic cleavage can be bilateral (see: Bilateral cleavage), discoidal (see: Discoidal cleavage), or centrolecithal (see: ...
... stages of meiosis. The long period of meiotic arrest at the four chromatid dictyate stage of meiosis may facilitate ... Germ cell specification begins during cleavage in many animals or in the epiblast during gastrulation in birds and mammals. ... ovum). The unfertilized egg of most animals is asymmetrical: different regions of the cytoplasm contain different amounts of ... The mouse oocyte in the dictyate (prolonged diplotene) stage of meiosis actively repairs DNA damage, whereas DNA repair was not ...
... cleavage) (photograph). By 8-9 hours, it has reached the 64-cell stage. Some molecular and histological evidence suggests the ... In section, they are very different, with the ovaries densely filled with nutrient-packed ova (see ovum and photograph) and the ... To this stage ,the larva has been virtually transparent, but the posterior section is now opaque with the initial development ... Juveniles of A. planci that had reached the stage of feeding on coral were then reared for some years in the same large closed- ...
It is optimally performed at the 6- to 8-cell stage, where it can be used as an expansion of IVF to increase the number of ... Dolly's embryo was created by taking the cell and inserting it into a sheep ovum. It took 435 attempts before an embryo was ... and Parton is known for her ample cleavage. The modern cloning techniques involving nuclear transfer have been successfully ... At an early growth stage when colonies consist of only a few cells, sterile polystyrene rings (cloning rings), which have been ...
The main durations of embryo culture are until cleavage stage (day two to four after co-incubation) or the blastocyst stage ( ... removing an ovum or ova (egg or eggs) from their ovaries and letting sperm fertilise them in a culture medium in a laboratory. ... among births having from embryos cultured until the blastocyst stage compared with cleavage stage. Laboratories have developed ... On the contrary, for women of advanced maternal age, PGS with cleavage-stage biopsy significantly lowers the live birth rate. ...
The first stage of prophase I is the leptotene stage, also known as leptonema, from Greek words meaning "thin threads".: 27 In ... which enlarges to become an ovum. Therefore, in females each primary oocyte that undergoes meiosis results in one mature ovum ... Nuclear envelopes re-form and cleavage or cell plate formation eventually produces a total of four daughter cells, each with a ... 27 is the stage at which all autosomal chromosomes have synapsed. In this stage homologous recombination, including chromosomal ...
After the fertilization, the cleavage of the embryo leads to the formation of the germinal disc. As food, the chicken egg yolk ... All bony fish, some sharks and rays have yolk sacs at some stage of development, with all oviparous fish retaining the sac ... The yolk mass, together with the ovum proper (after fertilization, the embryo) are enclosed by the vitelline membrane, whose ... contrary to the claim that the avian ovum (in strict sense) and its yolk are a single giant cell. ...
The oral-aboral axis is specified early in cleavage, and the left-right axis appears at the late gastrula stage. In most cases ... The transparency of the urchin's eggs enabled them to be used to observe that sperm cells actually fertilize ova. They continue ... In the larval stages, the adult rudiment grows from the left coelomic pouch; after metamorphosis, that rudiment grows to become ... During cleavage, mesoderm and small micromeres are specified. At the end of gastrulation, cells of these two types form ...
Both of these systems use a two-stage filtration process, in which fluid and waste products are first extracted and these are ... Most polychaetes whose reproduction has been studied lack permanent gonads, and it is uncertain how they produce ova and sperm ... Hence this development pattern is often described as "spiral determinate cleavage". The term originated from Jean-Baptiste ... When their cells divide after the 4-cell stage, descendants of these four cells form a spiral pattern. In these phyla the " ...
The Spiralia are a large group of protostomes that develop by spiral cleavage in the early embryo. The Spiralia's phylogeny has ... The blastula is a stage in embryonic development that is unique to animals, allowing cells to be differentiated into ... non-motile gametes are ova. These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In ... Valentine, James W. (July 1997). "Cleavage patterns and the topology of the metazoan tree of life". PNAS. 94 (15): 8001-8005. ...
After the stages of resection, strand invasion and DNA synthesis, the DSBR and SDSA pathways become distinct. The DSBR pathway ... This cleavage is done by RuvAB complex interacting with RuvC, which together form the RuvABC complex. RuvC is an endonuclease ... In turn, nondisjunction can cause sperm and ova to have too few or too many chromosomes. Down's syndrome, which is caused by an ... Mimitou EP, Symington LS (May 2009). "Nucleases and helicases take center stage in homologous recombination". Trends in ...
Errors in maternal ovum also occur, but at a lower rate than in paternal sperm. The types of mutations that occur also tend to ... The ZFN editing complex consists of a zinc finger protein (ZFP) and a restriction enzyme cleavage domain. The ZNP domain can be ... Germline mutations can occur before fertilization and during various stages of zygote development. When the mutation arises ... Endogenous mutations are more prominent in sperm than in ova. This is because spermatocytes go through a larger number of cell ...
Most species use sexual reproduction, releasing sperm cells into the water to fertilize ova that in some species are released ... ISBN 978-1-84407-527-0. Jacobson N (2000). Cleavage. Rutgers University Press. p. 62. ISBN 978-0-8135-2715-4. "Sponges". ... while in larval stage of life they are motile . Although there are freshwater species, the great majority are marine (salt- ...
She is the director of the drama club and during times on stage she has to be very forceful in order to get a good response out ... Yuu Kashiwagi (栢木 優雨, Kashiwagi Yū) Voiced by: Shion Hondaeri (PC), Ai Shimizu (PSP), Mana Hirata (OVA) Yuu is a new student in ... Throughout the anime, willing suspension of disbelief is employed, as there are severally scenes where Mizuho shows cleavage ( ... Despite being very nervous on the stage, but she is selected for the leading role at the school festival by Kei, who is the ...
Full-length OPN (OPN-FL) can be modified by thrombin cleavage, which exposes a cryptic sequence, SVVYGLR on the cleaved form of ... The secreted form of Opn (Opn-s) plays a proinflammatory role during allergen sensitization (OVA/Alum), as neutralization of ... and disease stage-specific targeting. Although the exact mechanisms of osteopontin signaling in PDAC are unknown, it binds to ... an inhibition regulated by PHEX cleavage of ASARM". Journal of Bone and Mineral Research. 23 (10): 1638-1649. doi:10.1359/jbmr. ...
At this stage the pentaradial symmetry develops. A plankton-eating larva, living and feeding in the water column, is considered ... The large size and the transparency of the eggs enables the observation of sperm cells in the process of fertilising ova. The ... On fracturing such rock, paleontologists can observe distinctive cleavage patterns and sometimes even the intricate internal ... Echinoderms have secondary radial symmetry in portions of their body at some stage of life, most likely an adaptation to a ...
The authors found this surprising, since nemertines have spiral cleavage in the early stages of cell division and form a ... Ripe gametes (ova or sperm) float from the gonads into the main coelom and then exit into the mantle cavity. The larvae of ... Hence radial cleavage does not imply that brachiopods are affiliated with deuterostomes. The traditional view is that the ... The gonads are masses of developing gametes (ova or sperm), and most species have four gonads, two in each valve. Those of ...
The different stages of mitosis all together define the mitotic phase of an animal cell cycle-the division of the mother cell ... The zygote undergoes a rapid multiple rounds of mitotic cell period of cell divisions called cleavage, which forms a ball of ... The smaller, motile gametes are spermatozoa and the larger, non-motile gametes are ova. These fuse to form zygotes, which ... During the third stage of photosynthesis, the movement of protons down their concentration gradients from the thylakoid lumen ...
It has reached the blastocyst stage at the time of implantation: this is when pregnancy begins. The loss of the corpus luteum ... The follicle that reaches maturity is called an antral follicle, and it contains the ovum (egg cell). The theca cells develop ... In the corpus luteum, cholesterol side-chain cleavage enzyme converts cholesterol to pregnenolone, which is converted to ... Menopause is preceded by a stage of hormonal changes called perimenopause. Eumenorrhea denotes normal, regular menstruation ...
The space within an ovum or immature ovum is located is the cell-nest. The cumulus-oocyte complex contains layers of tightly ... The oocyte is arrested in Meiosis II at the stage of metaphase II and is considered a secondary oocyte. Before ovulation, the ... "XPACE4 is a localized pro-protein convertase required for mesoderm induction and the cleavage of specific TGFbeta proteins in ... In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female ...
The corpus luteum is the last stage of the ovarian follicles' lifecycle. It has an important role in secreting estrogen and ... the ovum is not released from the ovary during menstrual cycle), hyperandrogenism (increased levels of androgen hormones, such ... "cFLIP regulates death receptor-mediated apoptosis in an ovarian granulosa cell line by inhibiting procaspase-8 cleavage". The ... Follicular atresia occurs throughout all stages of follicular development, until the follicular reserve is completely exhausted ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
The zygote is the new cell, which is referred to as the fertilized ovum. Following the fertilization ... cleavage, gastrulation and organogenesis. The process of fertilization involves the fusion of a haploid female and male gamete ... the process of embryogenesis has four stages: fertilization, ... Embryo at stage after the Blastula. Stage in Embryogenesis. ... In every coelomate that sexually reproduces, the process of embryogenesis has four stages: fertilization, cleavage, ...
Note the smaller polar body between the two blastomeres at the upper margin of the cleavage plane. The larger polar body below ... Stage 1 / 1 day Stage 2 / 2-3 days Stage 3-1 / 4 days Stage 3-2 / 4-5 days Stage 4 / 6 days Stage 5a-1 / 7 days Stage 5a-2 / 8 ... Stage 5c / 12 days Stage 6 / 13-17 days Stage 7 / 16-19 days Stage 8 / 23 days Stage 9 / 25 days Stage 10 / 28 days Stage 11 / ... Stage 13 / 32 days Stage 14 / 33 days Stage 15 / 36 days Stage 16 / 39 days Stage 17 / 41 days Stage 18 / 44 days Stage 19 / 45 ...
Cleavage Stage, Ovum. J. S. Kanodia, Kim, Y., Tomer, R., Khan, Z., Chung, K., Storey, J. D., Lu, H., Keller, P. J., and ...
the two combined ova will act as a single zygote that has already achieved the first cleavage division or 2-cell stage of ... This allows the unfertilized ovum to exit the vagina before menstruation it is, therefore, possible for an ovum collision to ... 2 ova squishing together. Ive met the anon who commissioned these on /d/. I dont get it, but you get used to that on /d/.. ... Are those supposed to be clits or ovaries or what? A cross section of the anus and vagina? A zygote in its 2 cell stage? I do ...
Cleavage Stage, Ovum Entry term(s). Cleavage Stages, Ovum Ovum Cleavage Stage Ovum Cleavage Stages Ovum Segmentation Stage Ovum ... Cleavage Stages, Ovum. Ovum Cleavage Stage. Ovum Cleavage Stages. Ovum Segmentation Stage. Ovum Segmentation Stages. ... Cleavage Stage, Ovum - Preferred Concept UI. M0004547. Scope note. The earliest developmental stage of a fertilized ovum ( ... Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
Cleavage Stage, Ovum A16.254.270 A16.166. A16.254.300.600. Cloaca A16.254.283 A16.178. Cloxacillin D2.886.675.966.500.750. ... Ovum A16.631 A16.690. Oxacillin D2.886.675.966.500.750.625 D2.886.108.750.625. D4.75.80.875.99.221.750.625. Papillary Muscles ...
2. An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a ... 3. An animal embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped ... 1. An embryo at an early stage of development, consisting of a hollow ball of cells.. ...
of uteri showing early cleavage stages (mitosis). Ascaris megalocephala embryology. Sec. of uteri showing later cleavage stages ... of uteri showing entrance and modification of sperm in ova Ascaris megalocephala embryology. Sec. of uteri showing maturation ... Mitotic stages in smear of red bone marrow of mammal * Meiotic (maturation) stages in testis of mouse, sec. iron hematoxyline ... stages (meiosis). Polar bodies can be seen. Ascaris megalocephala embryology. Sec. of uteri showing ova with male and female ...
Cleavage Stage, Ovum. *Cloaca. *Embryo, Mammalian. *Embryo, Nonmammalian. *Fetus. *Germ Layers. *Gestational Sac ...
Cleavage Stage, Ovum Female Fertilization Fertilization in Vitro Follicular Fluid - metabolism Growth Hormone - therapeutic use ... The review presents the main stages in the development of hepatitis C antiviral therapy, the efficacy of various treatment ... and cleavage in vitro. Further, the quality of embryos, development of the endometrium, rate of clinical pregnancy, and serum ...
... the cavity formed by the arrangement of the cells in segmentation or cleavage of the ovum; the cavity of the blastosphere. In ... the gastrula stage, the segmentation cavity in which the mesoblast is ... cell cleavage; cell multiplication; endogenous cell formation. [1913 Webster] {Segmentation cavity} (Biol.), ... Segmentation of the ovum, or Egg cleavage (Biol.), the process by which the embryos of all the higher plants and animals are ...
Outcomes of vitrified early cleavage-stage and blastocyst-stage embryos in a cryopreservation program: evaluation of 3,150 ... The linear regression model considering embryo developmental stage, ovum donation or patients own oocytes, and hormonal ... OBJECTIVE: To assess the outcomes achieved after Cryotop vitrification of both early cleavage and blastocyst-stage embryos and ... to determine whether the embryo developmental stage and embryo quality as well as the origin of the embryos (ovum donation ...
These stages are depicted in Fig. 35.1. Basically, the earlier the fertilized ovum divides, the more separate the twins. ... Cleavage prior to development of an inner cell mass will result in two placentas, two sets of membranes and two fetuses, ... However, it is clear that division of the fertilized ovum at specific early stages of development is responsible for the ... Twins may arise from one of two mechanisms: division of a single fertilized ovum into two embryos ("identical" or monozygotic ...
It is produced by cleavage of a fertilized ovum and consists of a spherical layer of around 128 cells with a large fluid-filled ... The blastula (from Greek βλαστός (blastos), meaning "sprout") is an early stage of embryonic development in animals. It is also ...
The zygote begins a process of cleavage that yields a growing and developing embryo, which progresses through th stages of ... One: The ,inception of life pccurs with the union of a sperm and an ovum, forming a zygote which carries the full genetic code ... has reached the stage of brain stem death, he is considered to have withdrawn from life, and certain rulings of the dead are ... Three: When it arrives at the spirit-breathing stage, the time of which is subject to controversy, being either forty or 120 ...
The ovum Buy Valium Europe contains one or if this lip possessed a hypoblast, though somites, and 24th 981. Buy Diazepam With ... The absorption spectrum is for the area thirteen or cleavage. This Order Alprazolam manner, or decreased because the forces of ... Extremity, and 32 -cell stage front there is also seems, made the foot growths and ctphonantes. Or smaller fragments the pars ... From a spherical to be they polzl, and separated by the ovum of two tail regions of cells. That they also ex- large extent at ...
  • The zygote is the new cell, which is referred to as the fertilized ovum. (differencebetween.net)
  • Following the fertilization event, the cleavage process involves the rapid division of the zygote, into many cells. (differencebetween.net)
  • A zygote in its 2 cell stage? (4chan.org)
  • The earliest developmental stage of a fertilized ovum ( ZYGOTE ) during which there are several mitotic divisions within the ZONA PELLUCIDA . (bvsalud.org)
  • One: The ,inception of life pccurs with the union of a sperm and an ovum, forming a zygote which carries the full genetic code of the human ace in general and of the particular individual, who is differerent from all others throughout the ages. (islamstickers.uk)
  • The zygote begins a process of cleavage that yields a growing and developing embryo, which progresses through th stages of gestation towards birth. (islamstickers.uk)
  • During cleavage, the zygote rapidly divides into multiple cells without increasing in size. (umn.edu)
  • The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. (musc.edu)
  • The egg is now referred to as a zygote as the cells split in a process known as cleavage and the start of embryonic development. (socialbaby.com)
  • Twins may arise from one of two mechanisms: division of a single fertilized ovum into two embryos ( "identical" or monozygotic twins ) or fertilization of two separate ova ( "fraternal" or dizygotic twins ). (pediagenosis.com)
  • We compared the pregnancy and live birth rates following transfer of early-stage embryos or blastocysts produced by somatic cell nuclear transfer using in vitro -matured oocytes. (cambridge.org)
  • Next, 71 early-stage embryos were surgically transferred to the left fallopian tube of 28 recipients and 47 blastocysts were transferred to the left uterine horn of 26 recipients. (cambridge.org)
  • Development of the human heart from its first appearance to the stage found in embryos of twenty somites. (ehd.org)
  • Two human embryos showing early stages of the definitive yolk sac. (ehd.org)
  • Results: Temperature had an effect on the cleavage rates of developing sea urchin embryos. (orcaeyes.com)
  • The fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. (umn.edu)
  • When the ovum is fertilized by a sperm cell (up to 72 hours later) their genetic material combines. (socialbaby.com)
  • The blastula (from Greek βλαστός (blastos), meaning "sprout") is an early stage of embryonic development in animals. (rulesareforrobots.com)
  • The early stages of embryonic development are also crucial for ensuring the fitness of the organism. (umn.edu)
  • The next stage in embryonic development is the formation of the body plan. (umn.edu)
  • What's the importance of cleavage in embryonic development? (orcaeyes.com)
  • germ layer, any of three primary cell layers, formed in the earliest stages of embryonic development, consisting of the endoderm (inner layer), the ectoderm (outer layer), and the mesoderm (middle layer). (orcaeyes.com)
  • In the simplest case, that of small ova destitute of food yolk, the ovum or egg divides into two similar halves or segments (blastomeres), each of these again divides into two, and so on, thus giving rise to a mass of cells (mulberry mass, or morula), all equal and similar, from the growth and development of which the future animal is to be formed. (landak.com)
  • Basically, the earlier the fertilized ovum divides, the more separate the twins. (pediagenosis.com)
  • 2. An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity. (wordinfo.info)
  • 3. An animal embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped layer of cells around a fluid-filled cavity known as a blastocoel. (wordinfo.info)
  • In the gastrula stage, the segmentation cavity in which the mesoblast is formed lies between the entoblast and ectoblast. (landak.com)
  • Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. (bvsalud.org)
  • Segmentation of the ovum , or Egg cleavage (Biol. (landak.com)
  • Quite frequently, however, the equality and regularity of cleavage is interfered with by the presence of food yolk, from which results unequal segmentation. (landak.com)
  • a process of cleavage or segmentation, by which the egg undergoes endogenous division with formation of a mass of nearly similar cells, from the growth and differentiation of which the new organism is ultimately formed. (sabda.org)
  • See Segmentation of the ovum , under Segmentation . (sabda.org)
  • Both meroblatic and holoblastic cleavages can give rise to the blastula. (differencebetween.net)
  • In holoblastic eggs, the first cleavage always occurs along the vegetal-animal axis of the egg, the second cleavage is perpendicular to the first. (orcaeyes.com)
  • The gastrula has three germ layers, that interact in a variety of ways in order to form organs, representing the final stage of embryogenesis - organogenesis. (differencebetween.net)
  • In every coelomate that sexually reproduces, the process of embryogenesis has four stages: fertilization, cleavage, gastrulation and organogenesis. (differencebetween.net)
  • The blastula is the first important stage following fertilization, playing a very important role in organism development. (differencebetween.net)
  • MAIN OUTCOME MEASURES: Number of oocytes retrieved after stimulation, total amount of gonadotropin used, time required for stimulation, number of follicles developing, rate of fertilization, and cleavage in vitro. (arctichealth.org)
  • Cleavage: rapid, multiple Another effect of fertilization on the plasma membrane of the egg is a several-fold increase in its permeability to various molecules. (grupoelchele.com)
  • The resulting cell is then called the Implantation may have other related symptoms but implantation bleeding usually has only one symptom January 23rd i started spotting This type of spotting should occur about 7 days after the period Implantation bleeding is a completely normal phenomenon and occurs Fertilization Following ovulation, the ovum with its cumulus oophorus cells are picked up by the fimbria of the fallopian tube. (grupoelchele.com)
  • Where does cleavage start after fertilization? (orcaeyes.com)
  • Around 24 hours after fertilization occurs, the first cleavage division occurs. (orcaeyes.com)
  • Note the smaller polar body between the two blastomeres at the upper margin of the cleavage plane. (ehd.org)
  • The individual cells that are generated as a result of the cleavage are termed blastomeres and the cleavage phase ends when a hollow sphere of blastomeres called the blastula has formed. (orcaeyes.com)
  • From here, the spatial arrangement of blastomeres can follow various patterns, due to different planes of cleavage, in various organisms. (orcaeyes.com)
  • Pregnancy rate based on P 4 level was 17.86% (5/28) and 11.54% (3/26) for early-stage embryo and blastocyst transfer, respectively. (cambridge.org)
  • Mammals at this stage form a structure called the blastocyst, characterized by an inner cell mass that is distinct from the surrounding blastula, shown in Figure 2b . (umn.edu)
  • In mammals, the blastula forms the blastocyst in the next stage of development. (umn.edu)
  • Morula is the stage before BLASTULA in non-mammalian animals or a BLASTOCYST in mammals. (childrensmercy.org)
  • Dr. Behr developed a culture medium for embryo culture to the blastocyst stage, which improved pregnancy rates, implantation rates and reduced the risks of multiple gestation in IVF. (stanford.edu)
  • any small hymenopterous insect, which, in the larval stage, lives within the eggs of other insects. (sabda.org)
  • Meiosis, in contrast, is a specialized kind of cell cycle that reduces the chromosome number by Oogenesis is the process of development of female gametes (also called ova or eggs), that takes place in ovaries. (grupoelchele.com)
  • Eggs are often in a later stage of cleavage than hookworm species when shed in feces. (cdc.gov)
  • It is produced by cleavage of a fertilized ovum and consists of a spherical layer of around 128 cells with a large fluid-filled space called the blastocoel in the animal pole of the embryo. (rulesareforrobots.com)
  • From a spherical to be they polzl, and separated by the ovum of two tail regions of cells. (goldenowlhunt.com)
  • As the blastula and gastrula are different structures, present at different stages in the embryogenesis process, there are several differences that exist between the two structures. (differencebetween.net)
  • During the process of embryogenesis, blastula formation is followed by the gastrula, thus both represents a different stage of embryo formation. (differencebetween.net)
  • The gastrula has more cells present, than in the earlier blastula stage. (differencebetween.net)
  • A gastrula contains differentiated cells, while the earlier blastula stage only has undifferentiated cells. (differencebetween.net)
  • There are a number of differences between the two structures, given that each occurs at a different stage of the embryogenesis process. (differencebetween.net)
  • The placen The stage that the fertilized egg is termed an embryo occurs about 1 day after conception. (grupoelchele.com)
  • 1. An embryo at an early stage of development, consisting of a hollow ball of cells. (wordinfo.info)
  • After the cleavage has produced over 100 cells, the embryo is called a blastula. (umn.edu)
  • At this stage of development, illustrated in Figure 3 the inner cell mass consists of embryonic stem cells that will differentiate into the different cell types needed by the organism. (umn.edu)
  • In humans, lymphocytes are small cells (6 µm in diameter), columnar epithelial cells (10 µm x 20 µm) are medium-size cells, and mature ova (120 to 150 µm) are some of the largest cells. (unboundmedicine.com)
  • However, it is clear that division of the fertilized ovum at specific early stages of development is responsible for the spectrum of clinical presentations with monozygotic twinning. (pediagenosis.com)
  • Cleavage prior to development of an inner cell mass will result in two placentas, two sets of membranes and two fetuses, whereas division after the embryonic disc has formed results in conjoined twins. (pediagenosis.com)
  • Visit the Virtual Human Embryo project at the Endowment for Human Development site to step through an interactive that shows the stages of embryo development, including micrographs and rotating 3-D images. (umn.edu)
  • For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS. (musc.edu)
  • Biologic and morphologic development of donated human ova recovered by nonsurgical uterine lavage. (ehd.org)
  • Two human ova of the pre-villous stage, having a development age of about eight and nine days respectively. (ehd.org)
  • On the preimplantation stages of the human ovum: A description of four normal and four abnormal specimens ranging from the second to the fifth day of development. (ehd.org)
  • These creations are the first stages in the development of the nervous system. (socialbaby.com)
  • Cleavage serves two important functions in early development. (orcaeyes.com)
  • The miRNA profile of a given cell thus provides a signature of its phenotype and/or stage of development. (justia.com)
  • This cleavage stage generally covers the period up to 16-cell MORULA . (bvsalud.org)
  • Three: When it arrives at the spirit-breathing stage, the time of which is subject to controversy, being either forty or 120 days, the fetus acquires greater sanctity, as all scholars agree, and additional legal stipulations apply to it. (islamstickers.uk)
  • Beginning with Aristotle, quickening divided the developmental stages of embryo and fetus. (asu.edu)
  • We show that the role for PARP-1 in expression of IL-4-induced genes (e.g. gata-3 ) in splenocytes did not involve effects on STAT6 phosphorylation or its subcellular trafficking, rather, it influenced its occupancy of gata-3 proximal and distal promoters in the early stages of IL-4 stimulation. (biomedcentral.com)
  • The rapid, multiple rounds of cell division are termed cleavage. (umn.edu)
  • What is the significance of the early cell division called cleavage? (orcaeyes.com)
  • the body formed by fusion of the male and female pronucleus in an impregnated ovum. (landak.com)
  • At the time of sexual intercourse the egg or ovum is a single cell and is just 0.13mm (0.005in) in diameter. (socialbaby.com)
  • Siamese or conjoined twins are the rarest and arise from cleavage of the differentiating embryonic disc 13-16 days post-conception. (pediagenosis.com)
  • Two human ova of the pre-villous stage, having an ovulation age of about eleven and twelve days respectively. (ehd.org)
  • At later stages, PARP-1 was crucial for STAT6 integrity as its inhibition, pharmacologically or by gene knockout, compromised the fate of the transcription factor. (biomedcentral.com)
  • [ 100 ] Allergens with protease activity may also exert their effect in a protease-independent manner by sensitizing to a non-protease protein like OVA. (medscape.com)
  • Effect of temperature on sea urchin cleavage. (orcaeyes.com)
  • Extremity, and 32 -cell stage front there is also seems, made the foot growths and ctphonantes. (goldenowlhunt.com)
  • Non-surgical transfer of in vivo fertilised donated ova to five infertile women: report of two pregnancies. (medscape.com)
  • Cleavage is illustrated in Figure 2a . (umn.edu)