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.
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.
A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.
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.
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.
Morphological and physiological development of EMBRYOS.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
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 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.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
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.
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).
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
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 technique of maintaining or growing mammalian EMBRYOS in vitro. This method offers an opportunity to observe EMBRYONIC DEVELOPMENT; METABOLISM; and susceptibility to TERATOGENS.
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.
Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.
A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
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).
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.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
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.
Embryonic and fetal development that takes place in an artificial environment in vitro.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
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 occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.
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.
Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.
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 unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.
The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
The cluster of cells inside a blastocyst. These cells give rise to the embryonic disc and eventual embryo proper. They are pluripotent EMBRYONIC STEM CELLS capable of yielding many but not all cell types in a developing organism.
The study of the development of an organism during the embryonic and fetal stages of life.
An order of fish with 26 families and over 3,000 species. This order includes the families CYPRINIDAE (minnows and CARPS), Cobitidae (loaches), and Catostomidae (suckers).
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
The outer of the three germ layers of an embryo.
The performance of dissections, injections, surgery, etc., by the use of micromanipulators (attachments to a microscope) that manipulate tiny instruments.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
Single cells that have the potential to form an entire organism. They have the capacity to specialize into extraembryonic membranes and tissues, the embryo, and all postembryonic tissues and organs. (Stem Cells: A Primer [Internet]. Bethesda (MD): National Institutes of Health (US); 2000 May [cited 2002 Apr 5]. Available from: http://www.nih.gov/news/stemcell/primer.htm)
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.
An individual that contains cell populations derived from different zygotes.
The inner of the three germ layers of an embryo.
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).
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 formation of one or more genetically identical organisms derived by vegetative reproduction from a single cell. The source nuclear material can be embryo-derived, fetus-derived, or taken from an adult somatic cell.
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
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.
11- to 14-membered macrocyclic lactones with a fused isoindolone. Members with INDOLES attached at the C10 position are called chaetoglobosins. They are produced by various fungi. Some members interact with ACTIN and inhibit CYTOKINESIS.
The division of a ZYGOTE into two parts, each of which is capable of further development.
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)
Damages to the EMBRYO, MAMMALIAN or the FETUS before BIRTH. Damages can be caused by any factors including biological, chemical, or physical.
A cartilaginous rod of mesodermal cells at the dorsal midline of all CHORDATE embryos. In lower vertebrates, notochord is the backbone of support. In the higher vertebrates, notochord is a transient structure, and segments of the vertebral column will develop around it. Notochord is also a source of midline signals that pattern surrounding tissues including the NEURAL TUBE development.
The only species of a cosmopolitan ascidian.
Proteins found in any species of helminth.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.

oko meduzy mutations affect neuronal patterning in the zebrafish retina and reveal cell-cell interactions of the retinal neuroepithelial sheet. (1/856)

Mutations of the oko meduzy (ome) locus cause drastic neuronal patterning defect in the zebrafish retina. The precise, stratified appearance of the wild-type retina is absent in the mutants. Despite the lack of lamination, at least seven retinal cell types differentiate in oko meduzy. The ome phenotype is already expressed in the retinal neuroepithelium affecting morphology of the neuroepithelial cells. Our experiments indicate that previously unknown cell-cell interactions are involved in development of the retinal neuroepithelial sheet. In genetically mosaic animals, cell-cell interactions are sufficient to rescue the phenotype of oko meduzy retinal neuroepithelial cells. These cell-cell interactions may play a critical role in the patterning events that lead to differentiation of distinct neuronal laminae in the vertebrate retina.  (+info)

Detection of benzo[a]pyrene diol epoxide-DNA adducts in embryos from smoking couples: evidence for transmission by spermatozoa. (2/856)

Tobacco smoking is deleterious to reproduction. Benzo[a]pyrene (B[a]P) is a potent carcinogen in cigarette smoke. Its reactive metabolite induces DNA-adducts, which can cause mutations. We investigated whether B[a]P diol epoxide (BPDE) DNA adducts are detectable in preimplantation embryos in relation to parental smoking. A total of 17 couples were classified by their smoking habits: (i) both partners smoke; (ii) wife non-smoker, husband smokes; and (iii) both partners were non-smokers. Their 27 embryos were exposed to an anti-BPDE monoclonal antibody that recognizes BPDE-DNA adducts. Immunostaining was assessed in each embryo and an intensity score was calculated for embryos in each smoking group. The proportion of blastomeres which stained was higher for embryos of smokers than for non-smokers (0.723 versus 0.310). The mean intensity score was also higher for embryos of smokers (1.40+/-0.28) than for non-smokers (0.38+/-0.14; P = 0.015), but was similar for both types of smoking couples. The mean intensity score was positively correlated with the number of cigarettes smoked by fathers (P = 0.02). Increased mean immunostaining in embryos from smokers, relative to non-smokers, indicates a relationship with parental smoking. The similar levels of immunostaining in embryos from both types of smoking couples suggest that transmission of modified DNA is mainly through spermatozoa. We confirmed paternal transmission of modified DNA by detection of DNA adducts in spermatozoa of a smoker father and his embryo.  (+info)

Cross-coupling between voltage-dependent Ca2+ channels and ryanodine receptors in developing ascidian muscle blastomeres. (3/856)

1. Ascidian blastomeres of muscle lineage express voltage-dependent calcium channels (VDCCs) despite isolation and cleavage arrest. Taking advantage of these large developing cells, developmental changes in functional relations between VDCC currents and intracellular Ca2+ stores were studied. 2. Inactivation of ascidian VDCCs is Ca2+ dependent, as demonstrated by two pieces of evidence: (1) a bell-shaped relationship between prepulse voltage and amplitude during the test pulse in Ca2+, but not in Ba2+, and (2) the decay kinetics of Ca2+ currents (ICa) obtained as the size of tail currents. 3. During replacement in the external solution of Ca2+ with Ba2+, the inward current appeared biphasic: it showed rapid decay followed by recovery and slow decay. This current profile was most evident in the mixed bath solution (2 % Ca2+ and 98 % Ba2+, abbreviated to '2Ca/98Ba'). 4. The biphasic profile of I2Ca/98Ba was significantly attenuated in caffeine and in ryanodine, indicating that Ca2+ release is involved in shaping the current kinetics of VDCCs. After washing out the caffeine, the biphasic pattern was reproducibly restored by depolarizing the membrane in calcium-rich solution, which is expected to refill the internal Ca2+ stores. 5. The inhibitors of endoplasmic reticulum (ER) Ca2+-ATPase (SERCAs) cyclopiazonic acid (CPA) and thapsigargin facilitated elimination of the biphasic profile with repetitive depolarization. 6. At a stage earlier than 36 h after fertilization, the biphasic profile of I2Ca/98Ba was not observed. However, caffeine induced a remarkable decrease in the amplitude of I2Ca/98Ba and this suppression was blocked by microinjection of the Ca2+ chelator BAPTA, showing the presence of caffeine-sensitive Ca2+ stores at this stage. 7. Electron microscopic observation shows that sarcoplasmic membranes (SR) arrange closer to the sarcolemma with maturation, suggesting that the formation of the ultrastructural machinery underlies development of the cross-coupling between VDCCs and Ca2+ stores.  (+info)

Preimplantation diagnosis by fluorescence in situ hybridization using 13-, 16-, 18-, 21-, 22-, X-, and Y-chromosome probes. (4/856)

PURPOSE: Our purpose was to select the proper chromosomes for preimplantation diagnosis based on aneuploidy distribution in abortuses and to carry out a feasibility study of preimplantation diagnosis for embryos using multiple-probe fluorescence in situ hybridization (FISH) on the selected chromosomes of biopsied blastomeres. METHODS: After determining the frequency distribution of aneuploidy found in abortuses, seven chromosomes were selected for FISH probes. Blastomeres were obtained from 33 abnormal or excess embryos. The chromosome complements of both the biopsied blastomeres and the remaining sibling blastomeres in each embryo were determined by FISH and compared to evaluate their preimplantation diagnostic potential. RESULTS: Chromosomes (16, 22, X, Y) and (13, 18, 21) were selected on the basis of the high aneuploid prevalence in abortuses for the former group and the presence of trisomy in the newborn for the latter. Thirty-six (72%) of 50 blastomeres gave signals to permit a diagnosis. Diagnoses made from biopsied blastomeres were consistent with the diagnoses made from the remaining sibling blastomeres in 18 embryos. In only 2 of 20 cases did the biopsied blastomere diagnosis and the embryo diagnosis not match. CONCLUSIONS: If FISH of biopsied blastomere was successful, a preimplantation diagnosis could be made with 10% error. When a combination of chromosome-13, -16, -18, -21, -22, -X, and -Y probes was used, up to 65% of the embryos destined to be aborted could be detected.  (+info)

Production of cloned calves following nuclear transfer with cultured adult mural granulosa cells. (5/856)

Adult somatic cell nuclear transfer was used to determine the totipotent potential of cultured mural granulosa cells, obtained from a Friesian dairy cow of high genetic merit. Nuclei were exposed to oocyte cytoplasm for prolonged periods by electrically fusing quiescent cultured cells to enucleated metaphase II cytoplasts 4-6 h before activation (fusion before activation [FBA] treatment). Additionally, some first-generation morulae were recloned by fusing blastomeres to S-phase cytoplasts. A significantly higher proportion of fused embryos developed in vitro to grade 1-2 blastocysts on Day 7 with FBA (27.5 +/- 2.5%) than with recloning (13.0 +/- 3.6%; p < 0. 05). After the transfer of 100 blastocysts from the FBA treatment, survival rates on Days 60, 100, 180, and term were 45%, 21%, 17%, and 10%, respectively. Ten heifer calves were delivered by elective cesarean section; all have survived. After the transfer of 16 recloned blastocysts, embryo survival on Day 60 was 38%; however, no fetuses survived to Day 100. DNA analyses confirmed that the calves are all genetically identical to the donor cow. It is suggested that the losses throughout gestation may in part be due to placental dysfunction at specific stages. The next advance in this technology will be to introduce specific genetic modifications of biomedical or agricultural interest.  (+info)

Morphologic evaluation and actin filament distribution in porcine embryos produced in vitro and in vivo. (6/856)

Porcine embryos produced in vitro have a small number of cells and low viability. The present study was conducted to examine the morphological characteristics and the relationship between actin filament organization and morphology of porcine embryos produced in vitro and in vivo. In vitro-derived embryos were produced by in vitro maturation, in vitro fertilization (IVF), and in vitro development. In vivo-derived embryos were collected from inseminated gilts on Days 2-6 after estrus. In experiment 1, in vitro-derived embryos (+info)

Rapid visualization of metaphase chromosomes in single human blastomeres after fusion with in-vitro matured bovine eggs. (7/856)

The present study was aimed to facilitate karyotyping of human blastomeres using the metaphase-inducing factors present in unfertilized eggs. A rapid technique for karyotyping would have wide application in the field of preimplantation genetic diagnosis. When cryopreserved in-vitro matured bovine oocytes were fused with human blastomeres, the transferred human nuclei were forced into metaphase within a few hours. Eighty-seven human blastomeres from abnormal or arrested embryos were fused with bovine oocytes in a preclinical study. Fusion efficiency was 100%. In 21 of the hybrid cells, no trace of human chromatin was found. Of the remaining 66, 64 (97%) yielded chromosomes suitable for analysis. The method was used to karyotype embryos from two patients with maternal translocations. One embryo which was judged to be karyotypically normal was replaced in the first patient, resulting in one pregnancy with a normal fetus. None of the second patient's embryos was diagnosed as normal, and hence none was transferred. The results of the present study demonstrated that the ooplasmic factors which induce and maintain metaphase in bovine oocytes can force transferred human blastomere nuclei into premature metaphase, providing the basis for a rapid method of karyotyping blastomeres from preimplantation embryos and, by implication, cells from other sources.  (+info)

Impact of blastomere biopsy and cryopreservation techniques on human embryo viability. (8/856)

The purpose of the present study was to evaluate the effect of cryopreservation on 55 embryos which had one blastomere biopsied for preimplantation genetic diagnosis of aneuploidy before freezing. The thawing outcome was compared to that obtained in 94 embryos which derived from our conventional freezing programme in patients with comparable characteristics who were treated in the same period. Their embryos were morphologically similar but the incidence of aneuploidy was 100% in the biopsy group and unknown in the controls. The percentage of embryos which survived intact after thawing was significantly lower in the biopsied group compared to the controls (9 versus 25% respectively; P < 0.025), whereas the rate of lysis was superior among biopsied embryos (34 versus 13% in the controls; P < 0.001). Similarly, the survival index was higher in the frozen-intact embryos than in the embryos which were frozen after biopsy (61 versus 38%; P < 0.001). No empty zonae resulted in the control group, while six were found after thawing biopsied embryos. In the second part of the study, blastomere biopsy was implemented on 102 thawed embryos generated by 16 patients. The chromosomal analyses revealed that 49 were normal, leading to the transfer of 2.5 +/- 0.8 embryos per patient. Only three clinical pregnancies were obtained, and are presently ongoing. In conclusion, the present findings discourage the use of conventional cryopreservation protocols in strategies involving preimplantation genetic diagnosis in human reproductive medicine. Adequate protocols are required for freezing and thawing embryos which have been subjected to biopsy procedures.  (+info)

Blastomeres are early stage embryonic cells that result from the initial rounds of cell division in a fertilized egg, also known as a zygote. These cells are typically smaller and have a more simple organization compared to more mature cells. They are important for the normal development of the embryo and contribute to the formation of the blastocyst, which is an early stage embryonic structure that will eventually give rise to the fetus. The process of cell division that produces blastomeres is called cleavage.

The cleavage stage of an ovum, also known as a fertilized egg, refers to the series of rapid cell divisions that occur after fertilization. During this stage, the single cell (zygote) divides into multiple cells, forming a blastomere. This process occurs in the fallopian tube and continues until the blastocyst reaches the uterus, typically around 5-6 days after fertilization. The cleavage stage is a critical period in early embryonic development, as any abnormalities during this time can lead to implantation failure or developmental defects.

Urochordata is a phylum in the animal kingdom that includes sessile, marine organisms commonly known as tunicates or sea squirts. The name "Urochordata" means "tail-cord animals," which refers to the notochord, a flexible, rod-like structure found in the tails of these animals during their larval stage.

Tunicates are filter feeders that draw water into their bodies through a siphon and extract plankton and other organic particles for nutrition. They have a simple body plan, consisting of a protective outer covering called a tunic, an inner body mass with a muscular pharynx, and a tail-like structure called the post-anal tail.

Urochordates are of particular interest to biologists because they are considered to be the closest living relatives to vertebrates (animals with backbones), sharing a common ancestor with them around 550 million years ago. Despite their simple appearance, tunicates have complex developmental processes that involve the formation of notochords, dorsal nerve cords, and other structures that are similar to those found in vertebrate embryos.

Overall, Urochordata is a fascinating phylum that provides important insights into the evolutionary history of animals and their diverse body plans.

A blastocyst is a stage in the early development of a fertilized egg, or embryo, in mammals. It occurs about 5-6 days after fertilization and consists of an outer layer of cells called trophoblasts, which will eventually form the placenta, and an inner cell mass, which will give rise to the fetus. The blastocyst is characterized by a fluid-filled cavity called the blastocoel. This stage is critical for the implantation of the embryo into the uterine lining.

Preimplantation Diagnosis (PID) is a genetic testing procedure performed on embryos created through in vitro fertilization (IVF), before they are implanted in the uterus. The purpose of PID is to identify genetic disorders or chromosomal abnormalities in the embryos, allowing only those free of such issues to be transferred to the uterus, thereby reducing the risk of passing on genetic diseases to offspring. It involves biopsying one or more cells from an embryo and analyzing its DNA for specific genetic disorders or chromosomal abnormalities. PID is often recommended for couples with a known history of genetic disorders or those who have experienced multiple miscarriages or failed IVF cycles.

Embryonic development is the series of growth and developmental stages that occur during the formation and early growth of the embryo. In humans, this stage begins at fertilization (when the sperm and egg cell combine) and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (now called a zygote) divides and forms a blastocyst, which then implants into the uterus. The cells in the blastocyst begin to differentiate and form the three germ layers: the ectoderm, mesoderm, and endoderm. These germ layers will eventually give rise to all of the different tissues and organs in the body.

Embryonic development is a complex and highly regulated process that involves the coordinated interaction of genetic and environmental factors. It is characterized by rapid cell division, migration, and differentiation, as well as programmed cell death (apoptosis) and tissue remodeling. Abnormalities in embryonic development can lead to birth defects or other developmental disorders.

It's important to note that the term "embryo" is used to describe the developing organism from fertilization until the end of the 8th week of pregnancy in humans, after which it is called a fetus.

A nonmammalian embryo refers to the developing organism in animals other than mammals, from the fertilized egg (zygote) stage until hatching or birth. In nonmammalian species, the developmental stages and terminology differ from those used in mammals. The term "embryo" is generally applied to the developing organism up until a specific stage of development that is characterized by the formation of major organs and structures. After this point, the developing organism is referred to as a "larva," "juvenile," or other species-specific terminology.

The study of nonmammalian embryos has played an important role in our understanding of developmental biology and evolutionary developmental biology (evo-devo). By comparing the developmental processes across different animal groups, researchers can gain insights into the evolutionary origins and diversification of body plans and structures. Additionally, nonmammalian embryos are often used as model systems for studying basic biological processes, such as cell division, gene regulation, and pattern formation.

A morula is a term used in embryology, which refers to the early stage of development in mammalian embryos. It is formed after fertilization when the zygote (a single cell resulting from the fusion of sperm and egg) undergoes several rounds of mitotic divisions to form a solid mass of 16 or more cells called blastomeres. At this stage, the cells are tightly packed together and have a compact, mulberry-like appearance, hence the name "morula" which is derived from the Latin word for "mulberry."

The morula stage typically occurs about 4-5 days after fertilization in humans and is marked by the beginning of blastulation, where the cells start to differentiate and become organized into an outer layer (trophoblast) and an inner cell mass. The trophoblast will eventually form the placenta, while the inner cell mass will give rise to the embryo proper.

It's important to note that the morula stage is a transient phase in embryonic development, and it represents a critical period of growth and differentiation as the embryo prepares for implantation into the uterine wall.

Embryo transfer is a medical procedure that involves the transfer of an embryo, which is typically created through in vitro fertilization (IVF), into the uterus of a woman with the aim of establishing a pregnancy. The embryo may be created using the intended parent's own sperm and eggs or those from donors. After fertilization and early cell division, the resulting embryo is transferred into the uterus of the recipient mother through a thin catheter that is inserted through the cervix. This procedure is typically performed under ultrasound guidance to ensure proper placement of the embryo. Embryo transfer is a key step in assisted reproductive technology (ART) and is often used as a treatment for infertility.

A zygote is the initial cell formed when a sperm fertilizes an egg, also known as an oocyte. This occurs in the process of human reproduction and marks the beginning of a new genetic identity, containing 46 chromosomes - 23 from the sperm and 23 from the egg. The zygote starts the journey of cell division and growth, eventually developing into a blastocyst, then an embryo, and finally a fetus over the course of pregnancy.

A mammalian embryo is the developing offspring of a mammal, from the time of implantation of the fertilized egg (blastocyst) in the uterus until the end of the eighth week of gestation. During this period, the embryo undergoes rapid cell division and organ differentiation to form a complex structure with all the major organs and systems in place. This stage is followed by fetal development, which continues until birth. The study of mammalian embryos is important for understanding human development, evolution, and reproductive biology.

Embryonic induction is a process that occurs during the development of a multicellular organism, where one group of cells in the embryo signals and influences the developmental fate of another group of cells. This interaction leads to the formation of specific structures or organs in the developing embryo. The signaling cells that initiate the process are called organizers, and they release signaling molecules known as morphogens that bind to receptors on the target cells and trigger a cascade of intracellular signals that ultimately lead to changes in gene expression and cell fate. Embryonic induction is a crucial step in the development of complex organisms and plays a key role in establishing the body plan and organizing the different tissues and organs in the developing embryo.

Fertilization in vitro, also known as in-vitro fertilization (IVF), is a medical procedure where an egg (oocyte) and sperm are combined in a laboratory dish to facilitate fertilization. The fertilized egg (embryo) is then transferred to a uterus with the hope of establishing a successful pregnancy. This procedure is often used when other assisted reproductive technologies have been unsuccessful or are not applicable, such as in cases of blocked fallopian tubes, severe male factor infertility, and unexplained infertility. The process involves ovarian stimulation, egg retrieval, fertilization, embryo culture, and embryo transfer. In some cases, additional techniques such as intracytoplasmic sperm injection (ICSI) or preimplantation genetic testing (PGT) may be used to increase the chances of success.

A gastrula is a stage in the early development of many animals, including humans, that occurs following fertilization and cleavage of the zygote. During this stage, the embryo undergoes a process called gastrulation, which involves a series of cell movements that reorganize the embryo into three distinct layers: the ectoderm, mesoderm, and endoderm. These germ layers give rise to all the different tissues and organs in the developing organism.

The gastrula is characterized by the presence of a central cavity called the archenteron, which will eventually become the gut or gastrointestinal tract. The opening of the archenteron is called the blastopore, which will give rise to either the mouth or anus, depending on the animal group.

In summary, a gastrula is a developmental stage in which an embryo undergoes gastrulation to form three germ layers and a central cavity, which will eventually develop into various organs and tissues of the body.

Embryonic and fetal development is the process of growth and development that occurs from fertilization of the egg (conception) to birth. The terms "embryo" and "fetus" are used to describe different stages of this development:

* Embryonic development: This stage begins at fertilization and continues until the end of the 8th week of pregnancy. During this time, the fertilized egg (zygote) divides and forms a blastocyst, which implants in the uterus and begins to develop into a complex structure called an embryo. The embryo consists of three layers of cells that will eventually form all of the organs and tissues of the body. During this stage, the basic structures of the body, including the nervous system, heart, and gastrointestinal tract, begin to form.
* Fetal development: This stage begins at the end of the 8th week of pregnancy and continues until birth. During this time, the embryo is called a fetus, and it grows and develops rapidly. The organs and tissues that were formed during the embryonic stage continue to mature and become more complex. The fetus also begins to move and kick, and it can hear and respond to sounds from outside the womb.

Overall, embryonic and fetal development is a complex and highly regulated process that involves the coordinated growth and differentiation of cells and tissues. It is a critical period of development that lays the foundation for the health and well-being of the individual throughout their life.

Embryo culture techniques refer to the methods and procedures used to maintain and support the growth and development of an embryo outside of the womb, typically in a laboratory setting. These techniques are often used in the context of assisted reproductive technologies (ART), such as in vitro fertilization (IVF).

The process typically involves fertilizing an egg with sperm in a laboratory dish and then carefully monitoring and maintaining the resulting embryo in a specialized culture medium that provides the necessary nutrients, hormones, and other factors to support its development. The culture medium is usually contained within an incubator that maintains optimal temperature, humidity, and gas concentrations to mimic the environment inside the body.

Embryologists may use various embryo culture techniques depending on the stage of development and the specific needs of the embryo. For example, some techniques involve culturing the embryo in a single layer, while others may use a technique called "co-culture" that involves growing the embryo on a layer of cells to provide additional support and nutrients.

The goal of embryo culture techniques is to promote the healthy growth and development of the embryo, increasing the chances of a successful pregnancy and live birth. However, it's important to note that these techniques are not without risk, and there are potential ethical considerations surrounding the use of ART and embryo culture.

Developmental gene expression regulation refers to the processes that control the activation or repression of specific genes during embryonic and fetal development. These regulatory mechanisms ensure that genes are expressed at the right time, in the right cells, and at appropriate levels to guide proper growth, differentiation, and morphogenesis of an organism.

Developmental gene expression regulation is a complex and dynamic process involving various molecular players, such as transcription factors, chromatin modifiers, non-coding RNAs, and signaling molecules. These regulators can interact with cis-regulatory elements, like enhancers and promoters, to fine-tune the spatiotemporal patterns of gene expression during development.

Dysregulation of developmental gene expression can lead to various congenital disorders and developmental abnormalities. Therefore, understanding the principles and mechanisms governing developmental gene expression regulation is crucial for uncovering the etiology of developmental diseases and devising potential therapeutic strategies.

Embryo implantation is the process by which a fertilized egg, or embryo, becomes attached to the wall of the uterus (endometrium) and begins to receive nutrients from the mother's blood supply. This process typically occurs about 6-10 days after fertilization and is a critical step in the establishment of a successful pregnancy.

During implantation, the embryo secretes enzymes that help it to burrow into the endometrium, while the endometrium responds by producing receptors for the embryo's enzymes and increasing blood flow to the area. The embryo then begins to grow and develop, eventually forming the placenta, which will provide nutrients and oxygen to the developing fetus throughout pregnancy.

Implantation is a complex process that requires precise timing and coordination between the embryo and the mother's body. Factors such as age, hormonal imbalances, and uterine abnormalities can affect implantation and increase the risk of miscarriage or difficulty becoming pregnant.

Zona pellucida is a term used in the field of reproductive biology and it refers to the glycoprotein membrane that surrounds mammalian oocytes (immature egg cells). This membrane plays a crucial role in the fertilization process. It has receptors for sperm, and upon binding with the sperm, it undergoes changes that prevent other sperm from entering, a process known as the zona reaction. This membrane is also involved in the early development of the embryo.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

An oocyte, also known as an egg cell or female gamete, is a large specialized cell found in the ovary of female organisms. It contains half the number of chromosomes as a normal diploid cell, as it is the product of meiotic division. Oocytes are surrounded by follicle cells and are responsible for the production of female offspring upon fertilization with sperm. The term "oocyte" specifically refers to the immature egg cell before it reaches full maturity and is ready for fertilization, at which point it is referred to as an ovum or egg.

Cryopreservation is a medical procedure that involves the preservation of cells, tissues, or organs by cooling them to very low temperatures, typically below -150°C. This is usually achieved using liquid nitrogen. The low temperature slows down or stops biological activity, including chemical reactions and cellular metabolism, which helps to prevent damage and decay.

The cells, tissues, or organs that are being cryopreserved must be treated with a cryoprotectant solution before cooling to prevent the formation of ice crystals, which can cause significant damage. Once cooled, the samples are stored in specialized containers or tanks until they are needed for use.

Cryopreservation is commonly used in assisted reproductive technologies, such as the preservation of sperm, eggs, and embryos for fertility treatments. It is also used in research, including the storage of cell lines and stem cells, and in clinical settings, such as the preservation of skin grafts and corneas for transplantation.

I'm happy to help! However, it seems there might be a bit of confusion here. "Sea urchins" is a common name that refers to a type of marine invertebrate animal, typically characterized by their round, spiny shells. They belong to the class Echinoidea within the phylum Echinodermata.

Medically speaking, there isn't a specific definition for "sea urchins." However, if you come into contact with sea urchins while swimming or diving and accidentally step on them, their spines can puncture your skin and potentially cause an infection. In this case, medical attention may be necessary to remove the embedded spines and treat any resulting infection.

If you were referring to a specific medical term related to sea urchins, could you please clarify? I'm here to help!

A blastula is a stage in the early development of many animals, including mammals. It is a hollow ball of cells that forms as a result of cleavage, which is the process of cell division during embryonic development. The blastula is typically characterized by the presence of a fluid-filled cavity called the blastocoel, which is surrounded by a single layer of cells known as the blastoderm.

In mammals, the blastula stage follows the morula stage, which is a solid mass of cells that results from cleavage of the fertilized egg. During further cell division and rearrangement, the cells in the morula become organized into an inner cell mass and an outer layer of cells, called the trophoblast. The inner cell mass will eventually give rise to the embryo proper, while the trophoblast will contribute to the formation of the placenta.

As the morula continues to divide and expand, it forms a cavity within the inner cell mass, which becomes the blastocoel. The single layer of cells surrounding the blastocoel is called the blastoderm. At this stage, the blastula is capable of further development through a process called gastrulation, during which the three germ layers of the embryo (ectoderm, mesoderm, and endoderm) are formed.

It's important to note that not all animals go through a blastula stage in their development. Some animals, such as insects and nematodes, have different patterns of early development that do not include a blastula stage.

Ectogenesis is a theoretical concept in medical and reproductive biology that refers to the development of an organism outside of the body, typically referring to the growth and development of a fetus or embryo in an artificial environment, such as an external womb or an artificial uterus. This concept is still largely speculative and not currently possible with existing technology. It raises various ethical, legal, and social questions related to pregnancy, reproduction, and the nature of parenthood.

'Caenorhabditis elegans' is a species of free-living, transparent nematode (roundworm) that is widely used as a model organism in scientific research, particularly in the fields of biology and genetics. It has a simple anatomy, short lifespan, and fully sequenced genome, making it an ideal subject for studying various biological processes and diseases.

Some notable features of C. elegans include:

* Small size: Adult hermaphrodites are about 1 mm in length.
* Short lifespan: The average lifespan of C. elegans is around 2-3 weeks, although some strains can live up to 4 weeks under laboratory conditions.
* Development: C. elegans has a well-characterized developmental process, with adults developing from eggs in just 3 days at 20°C.
* Transparency: The transparent body of C. elegans allows researchers to observe its internal structures and processes easily.
* Genetics: C. elegans has a fully sequenced genome, which contains approximately 20,000 genes. Many of these genes have human homologs, making it an excellent model for studying human diseases.
* Neurobiology: C. elegans has a simple nervous system, with only 302 neurons in the hermaphrodite and 383 in the male. This simplicity makes it an ideal organism for studying neural development, function, and behavior.

Research using C. elegans has contributed significantly to our understanding of various biological processes, including cell division, apoptosis, aging, learning, and memory. Additionally, studies on C. elegans have led to the discovery of many genes associated with human diseases such as cancer, neurodegenerative disorders, and metabolic conditions.

"Body patterning" is a general term that refers to the process of forming and organizing various tissues and structures into specific patterns during embryonic development. This complex process involves a variety of molecular mechanisms, including gene expression, cell signaling, and cell-cell interactions. It results in the creation of distinct body regions, such as the head, trunk, and limbs, as well as the organization of internal organs and systems.

In medical terminology, "body patterning" may refer to specific developmental processes or abnormalities related to embryonic development. For example, in genetic disorders such as Poland syndrome or Holt-Oram syndrome, mutations in certain genes can lead to abnormal body patterning, resulting in the absence or underdevelopment of certain muscles, bones, or other structures.

It's important to note that "body patterning" is not a formal medical term with a specific definition, but rather a general concept used in developmental biology and genetics.

Mosaicism, in the context of genetics and medicine, refers to the presence of two or more cell lines with different genetic compositions in an individual who has developed from a single fertilized egg. This means that some cells have one genetic makeup, while others have a different genetic makeup. This condition can occur due to various reasons such as errors during cell division after fertilization.

Mosaicism can involve chromosomes (where whole or parts of chromosomes are present in some cells but not in others) or it can involve single genes (where a particular gene is present in one form in some cells and a different form in others). The symptoms and severity of mosaicism can vary widely, depending on the type and location of the genetic difference and the proportion of cells that are affected. Some individuals with mosaicism may not experience any noticeable effects, while others may have significant health problems.

"Xenopus laevis" is not a medical term itself, but it refers to a specific species of African clawed frog that is often used in scientific research, including biomedical and developmental studies. Therefore, its relevance to medicine comes from its role as a model organism in laboratories.

In a broader sense, Xenopus laevis has contributed significantly to various medical discoveries, such as the understanding of embryonic development, cell cycle regulation, and genetic research. For instance, the Nobel Prize in Physiology or Medicine was awarded in 1963 to John R. B. Gurdon and Sir Michael J. Bishop for their discoveries concerning the genetic mechanisms of organism development using Xenopus laevis as a model system.

Nuclear transfer techniques are scientific procedures that involve the transfer of the nucleus of a cell, containing its genetic material, from one cell to another. The most well-known type of nuclear transfer is somatic cell nuclear transfer (SCNT), which is used in therapeutic cloning and reproductive cloning.

In SCNT, the nucleus of a somatic cell (a body cell, not an egg or sperm cell) is transferred into an enucleated egg cell (an egg cell from which the nucleus has been removed). The egg cell with the new nucleus is then stimulated to divide and grow, creating an embryo that is genetically identical to the donor of the somatic cell.

Nuclear transfer techniques have various potential applications in medicine, including the creation of patient-specific stem cells for use in regenerative medicine, drug development and testing, and the study of genetic diseases. However, these procedures are also associated with ethical concerns, particularly in relation to reproductive cloning and the creation of human embryos for research purposes.

"Xenopus proteins" refer to the proteins that are expressed or isolated from the Xenopus species, which are primarily used as model organisms in biological and biomedical research. The most commonly used Xenopus species for research are the African clawed frogs, Xenopus laevis and Xenopus tropicalis. These proteins play crucial roles in various cellular processes and functions, and they serve as valuable tools to study different aspects of molecular biology, developmental biology, genetics, and biochemistry.

Some examples of Xenopus proteins that are widely studied include:

1. Xenopus Histones: These are the proteins that package DNA into nucleosomes, which are the fundamental units of chromatin in eukaryotic cells. They play a significant role in gene regulation and epigenetic modifications.
2. Xenopus Cyclins and Cyclin-dependent kinases (CDKs): These proteins regulate the cell cycle and control cell division, differentiation, and apoptosis.
3. Xenopus Transcription factors: These proteins bind to specific DNA sequences and regulate gene expression during development and in response to various stimuli.
4. Xenopus Signaling molecules: These proteins are involved in intracellular signaling pathways that control various cellular processes, such as cell growth, differentiation, migration, and survival.
5. Xenopus Cytoskeletal proteins: These proteins provide structural support to the cells and regulate their shape, motility, and organization.
6. Xenopus Enzymes: These proteins catalyze various biochemical reactions in the cell, such as metabolic pathways, DNA replication, transcription, and translation.

Overall, Xenopus proteins are essential tools for understanding fundamental biological processes and have contributed significantly to our current knowledge of molecular biology, genetics, and developmental biology.

Parthenogenesis is a form of asexual reproduction in which offspring develop from unfertilized eggs or ovums. It occurs naturally in some plant and insect species, as well as a few vertebrates such as reptiles and fish. Parthenogenesis does not involve the fusion of sperm and egg cells; instead, the development of offspring is initiated by some other trigger, such as a chemical or physical stimulus. This type of reproduction results in offspring that are genetically identical to the parent organism. In humans and other mammals, parthenogenesis is not a natural occurrence and would require scientific intervention to induce.

Aneuploidy is a medical term that refers to an abnormal number of chromosomes in a cell. Chromosomes are thread-like structures located inside the nucleus of cells that contain genetic information in the form of genes.

In humans, the normal number of chromosomes in a cell is 46, arranged in 23 pairs. Aneuploidy occurs when there is an extra or missing chromosome in one or more of these pairs. For example, Down syndrome is a condition that results from an extra copy of chromosome 21, also known as trisomy 21.

Aneuploidy can arise during the formation of gametes (sperm or egg cells) due to errors in the process of cell division called meiosis. These errors can result in eggs or sperm with an abnormal number of chromosomes, which can then lead to aneuploidy in the resulting embryo.

Aneuploidy is a significant cause of birth defects and miscarriages. The severity of the condition depends on which chromosomes are affected and the extent of the abnormality. In some cases, aneuploidy may have no noticeable effects, while in others it can lead to serious health problems or developmental delays.

'Cell lineage' is a term used in biology and medicine to describe the developmental history or relationship of a cell or group of cells to other cells, tracing back to the original progenitor or stem cell. It refers to the series of cell divisions and differentiation events that give rise to specific types of cells in an organism over time.

In simpler terms, cell lineage is like a family tree for cells, showing how they are related to each other through a chain of cell division and specialization events. This concept is important in understanding the development, growth, and maintenance of tissues and organs in living beings.

"Xenopus" is not a medical term, but it is a genus of highly invasive aquatic frogs native to sub-Saharan Africa. They are often used in scientific research, particularly in developmental biology and genetics. The most commonly studied species is Xenopus laevis, also known as the African clawed frog.

In a medical context, Xenopus might be mentioned when discussing their use in research or as a model organism to study various biological processes or diseases.

A Blastocyst Inner Cell Mass (ICM) is a group of cells within a blastocyst, which is an early-stage preimplantation embryo that develops in mammals. The blastocyst consists of two main components: the trophectoderm, which forms the outer layer and eventually gives rise to the placenta, and the inner cell mass (ICM), which is a cluster of cells located inside the blastocyst.

The ICM is composed of pluripotent cells that have the ability to differentiate into any of the three primary germ layers: ectoderm, mesoderm, or endoderm. These cells will eventually give rise to the fetus and some extraembryonic structures such as the yolk sac and allantois.

The ICM is an essential part of the blastocyst, and its development and quality are critical factors in the success of assisted reproductive technologies (ART) like in vitro fertilization (IVF). The assessment of the ICM's morphology and cell count can help embryologists evaluate the potential of an embryo to develop into a viable pregnancy.

Embryology is the branch of biology that deals with the formation, growth, and development of an embryo. It is a scientific study that focuses on the structural and functional changes that occur during the development of a fertilized egg or zygote into a mature organism. Embryologists study the various stages of embryonic development, including gametogenesis (the formation of sperm and eggs), fertilization, cleavage, gastrulation, neurulation, and organogenesis. They also investigate the genetic and environmental factors that influence embryonic development and may use this information to understand and prevent birth defects and other developmental abnormalities.

Cypriniformes is an order of freshwater fish that includes carps, minnows, and loaches. These fish are characterized by the presence of a single pair of barbels near their mouths and the absence of teeth on their jaws. They are found primarily in North America, Europe, and Asia. Some well-known examples of Cypriniformes include the common carp, goldfish, and zebrafish. These fish are often used as model organisms in scientific research due to their relatively small size, ease of breeding, and genetic similarity to humans.

In medical and embryological terms, the mesoderm is one of the three primary germ layers in the very early stages of embryonic development. It forms between the ectoderm and endoderm during gastrulation, and it gives rise to a wide variety of cell types, tissues, and organs in the developing embryo.

The mesoderm contributes to the formation of structures such as:

1. The connective tissues (including tendons, ligaments, and most of the bones)
2. Muscular system (skeletal, smooth, and cardiac muscles)
3. Circulatory system (heart, blood vessels, and blood cells)
4. Excretory system (kidneys and associated structures)
5. Reproductive system (gonads, including ovaries and testes)
6. Dermis of the skin
7. Parts of the eye and inner ear
8. Several organs in the urogenital system

Dysfunctions or abnormalities in mesoderm development can lead to various congenital disorders and birth defects, highlighting its importance during embryogenesis.

Ectoderm is the outermost of the three primary germ layers in a developing embryo, along with the endoderm and mesoderm. The ectoderm gives rise to the outer covering of the body, including the skin, hair, nails, glands, and the nervous system, which includes the brain, spinal cord, and peripheral nerves. It also forms the lining of the mouth, anus, nose, and ears. Essentially, the ectoderm is responsible for producing all the epidermal structures and the neural crest cells that contribute to various derivatives such as melanocytes, adrenal medulla, smooth muscle, and peripheral nervous system components.

Micromanipulation is a term used in the field of medicine, specifically in assisted reproductive technologies (ARTs) such as in vitro fertilization (IVF). It refers to a technique that involves the manipulation of oocytes (human eggs), sperm, and/or embryos under a microscope using micromanipulative tools and equipment.

The most common form of micromanipulation is intracytoplasmic sperm injection (ICSI), where a single sperm is selected and injected directly into the cytoplasm of an oocyte to facilitate fertilization. Other forms of micromanipulation include assisted hatching (AH), where a small opening is made in the zona pellucida (the protective layer surrounding the embryo) to help the embryo hatch and implant into the uterus, and embryo biopsy, which involves removing one or more cells from an embryo for genetic testing.

Micromanipulation requires specialized training and equipment and is typically performed in IVF laboratories by experienced embryologists. The goal of micromanipulation is to improve the chances of successful fertilization, implantation, and pregnancy, particularly in cases where conventional methods have been unsuccessful or when there are specific fertility issues, such as male factor infertility or genetic disorders.

An ovum is the female reproductive cell, or gamete, produced in the ovaries. It is also known as an egg cell and is released from the ovary during ovulation. When fertilized by a sperm, it becomes a zygote, which can develop into a fetus. The ovum contains half the genetic material necessary to create a new individual.

Totipotent stem cells are a type of stem cell that have the greatest developmental potential and can differentiate into any cell type in the body, including extra-embryonic tissues such as the placenta. These stem cells are derived from the fertilized egg (zygote) and are capable of forming a complete organism. As development progresses, totipotent stem cells become more restricted in their differentiation potential, giving rise to pluripotent stem cells, which can differentiate into any cell type in the body but not extra-embryonic tissues. Totipotent stem cells are rarely found in adults and are primarily studied in the context of embryonic development and regenerative medicine.

'Caenorhabditis elegans' (C. elegans) is a type of free-living, transparent nematode (roundworm) that is often used as a model organism in scientific research. C. elegans proteins refer to the various types of protein molecules that are produced by the organism's genes and play crucial roles in maintaining its biological functions.

Proteins are complex molecules made up of long chains of amino acids, and they are involved in virtually every cellular process, including metabolism, DNA replication, signal transduction, and transportation of molecules within the cell. In C. elegans, proteins are encoded by genes, which are transcribed into messenger RNA (mRNA) molecules that are then translated into protein sequences by ribosomes.

Studying C. elegans proteins is important for understanding the basic biology of this organism and can provide insights into more complex biological systems, including humans. Because C. elegans has a relatively simple nervous system and a short lifespan, it is often used to study neurobiology, aging, and development. Additionally, because many of the genes and proteins in C. elegans have counterparts in other organisms, including humans, studying them can provide insights into human disease processes and potential therapeutic targets.

A chimera, in the context of medicine and biology, is a single organism that is composed of cells with different genetics. This can occur naturally in some situations, such as when fraternal twins do not fully separate in utero and end up sharing some organs or tissues. The term "chimera" can also refer to an organism that contains cells from two different species, which can happen in certain types of genetic research or medical treatments. For example, a patient's cells might be genetically modified in a lab and then introduced into their body to treat a disease; if some of these modified cells mix with the patient's original cells, the result could be a chimera.

It's worth noting that the term "chimera" comes from Greek mythology, where it referred to a fire-breathing monster that was part lion, part goat, and part snake. In modern scientific usage, the term has a specific technical meaning related to genetics and organisms, but it may still evoke images of fantastical creatures for some people.

Endoderm is the innermost of the three primary germ layers in a developing embryo, along with the ectoderm and mesoderm. The endoderm gives rise to several internal tissues and organs, most notably those found in the digestive system and respiratory system. Specifically, it forms the lining of the gut tube, which eventually becomes the epithelial lining of the gastrointestinal tract, liver, pancreas, lungs, and other associated structures.

During embryonic development, the endoderm arises from the inner cell mass of the blastocyst, following a series of cell divisions and migrations that help to establish the basic body plan of the organism. As the embryo grows and develops, the endoderm continues to differentiate into more specialized tissues and structures, playing a critical role in the formation of many essential bodily functions.

Intracytoplasmic Sperm Injection (ICSI) is a specialized form of assisted reproductive technology (ART), specifically used in the context of in vitro fertilization (IVF). It involves the direct injection of a single sperm into the cytoplasm of a mature egg (oocyte) to facilitate fertilization. This technique is often used when there are issues with male infertility, such as low sperm count or poor sperm motility, to increase the chances of successful fertilization. The resulting embryos can then be transferred to the uterus in hopes of achieving a pregnancy.

In situ hybridization, fluorescence (FISH) is a type of molecular cytogenetic technique used to detect and localize the presence or absence of specific DNA sequences on chromosomes through the use of fluorescent probes. This technique allows for the direct visualization of genetic material at a cellular level, making it possible to identify chromosomal abnormalities such as deletions, duplications, translocations, and other rearrangements.

The process involves denaturing the DNA in the sample to separate the double-stranded molecules into single strands, then adding fluorescently labeled probes that are complementary to the target DNA sequence. The probe hybridizes to the complementary sequence in the sample, and the location of the probe is detected by fluorescence microscopy.

FISH has a wide range of applications in both clinical and research settings, including prenatal diagnosis, cancer diagnosis and monitoring, and the study of gene expression and regulation. It is a powerful tool for identifying genetic abnormalities and understanding their role in human disease.

Cloning of an organism is the process of creating a genetically identical copy of an entire living organism, including all of its DNA. This is achieved through a variety of laboratory techniques that can vary depending on the type of organism being cloned. In the case of animals, one common method is called somatic cell nuclear transfer (SCNT).

In SCNT, the nucleus of a donor animal's cell (which contains its DNA) is removed and transferred into an egg cell that has had its own nucleus removed. The egg cell is then stimulated to divide and grow, resulting in an embryo that is genetically identical to the donor animal. This embryo can be implanted into a surrogate mother, where it will continue to develop until birth.

Cloning of organisms has raised ethical concerns and debates, particularly in the case of animals, due to questions about the welfare of cloned animals and the potential implications for human cloning. However, cloning is also seen as having potential benefits, such as the ability to produce genetically identical animals for research or agricultural purposes.

It's important to note that while cloning can create genetically identical organisms, it does not necessarily mean that they will be identical in every way, as environmental factors and random genetic mutations can still result in differences between clones.

Microinjection is a medical technique that involves the use of a fine, precise needle to inject small amounts of liquid or chemicals into microscopic structures, cells, or tissues. This procedure is often used in research settings to introduce specific substances into individual cells for study purposes, such as introducing DNA or RNA into cell nuclei to manipulate gene expression.

In clinical settings, microinjections may be used in various medical and cosmetic procedures, including:

1. Intracytoplasmic Sperm Injection (ICSI): A type of assisted reproductive technology where a single sperm is injected directly into an egg to increase the chances of fertilization during in vitro fertilization (IVF) treatments.
2. Botulinum Toxin Injections: Microinjections of botulinum toxin (Botox, Dysport, or Xeomin) are used for cosmetic purposes to reduce wrinkles and fine lines by temporarily paralyzing the muscles responsible for their formation. They can also be used medically to treat various neuromuscular disorders, such as migraines, muscle spasticity, and excessive sweating (hyperhidrosis).
3. Drug Delivery: Microinjections may be used to deliver drugs directly into specific tissues or organs, bypassing the systemic circulation and potentially reducing side effects. This technique can be particularly useful in treating localized pain, delivering growth factors for tissue regeneration, or administering chemotherapy agents directly into tumors.
4. Gene Therapy: Microinjections of genetic material (DNA or RNA) can be used to introduce therapeutic genes into cells to treat various genetic disorders or diseases, such as cystic fibrosis, hemophilia, or cancer.

Overall, microinjection is a highly specialized and precise technique that allows for the targeted delivery of substances into small structures, cells, or tissues, with potential applications in research, medical diagnostics, and therapeutic interventions.

I believe you may be mistakenly using the term "starfish" to refer to a medical condition. If so, the correct term is likely " asterixis," which is a medical sign characterized by rapid, rhythmic flapping or tremulous movements of the hands when they are extended and the wrist is dorsiflexed (held with the back of the hand facing upwards). This is often seen in people with certain neurological conditions such as liver failure or certain types of poisoning.

However, if you are indeed referring to the marine animal commonly known as a "starfish," there isn't a specific medical definition for it. Starfish, also known as sea stars, are marine animals belonging to the class Asteroidea in the phylum Echinodermata. They have a distinctive shape with five or more arms radiating from a central disc, and they move slowly along the ocean floor using their tube feet. Some species of starfish have the ability to regenerate lost body parts, including entire limbs or even their central disc.

Cell differentiation is the process by which a less specialized cell, or stem cell, becomes a more specialized cell type with specific functions and structures. This process involves changes in gene expression, which are regulated by various intracellular signaling pathways and transcription factors. Differentiation results in the development of distinct cell types that make up tissues and organs in multicellular organisms. It is a crucial aspect of embryonic development, tissue repair, and maintenance of homeostasis in the body.

Morphogenesis is a term used in developmental biology and refers to the process by which cells give rise to tissues and organs with specific shapes, structures, and patterns during embryonic development. This process involves complex interactions between genes, cells, and the extracellular environment that result in the coordinated movement and differentiation of cells into specialized functional units.

Morphogenesis is a dynamic and highly regulated process that involves several mechanisms, including cell proliferation, death, migration, adhesion, and differentiation. These processes are controlled by genetic programs and signaling pathways that respond to environmental cues and regulate the behavior of individual cells within a developing tissue or organ.

The study of morphogenesis is important for understanding how complex biological structures form during development and how these processes can go awry in disease states such as cancer, birth defects, and degenerative disorders.

Cytochalasins are a group of fungal metabolites that have the ability to disrupt the organization and dynamics of the cytoskeleton in eukaryotic cells. They bind to the barbed end of actin filaments, preventing the addition or loss of actin subunits, which results in the inhibition of actin polymerization and depolymerization. This can lead to changes in cell shape, motility, and cytokinesis (the process by which a cell divides into two daughter cells).

There are several different types of cytochalasins, including cytochalasin A, B, C, D, and E, among others. Each type has slightly different effects on the actin cytoskeleton and may also have other cellular targets. Cytochalasins have been widely used in research to study the role of the actin cytoskeleton in various cellular processes.

In addition to their use in research, cytochalasins have also been investigated for their potential therapeutic applications. For example, some studies have suggested that cytochalasins may have anti-cancer properties by inhibiting the proliferation and migration of cancer cells. However, more research is needed before these compounds can be developed into effective treatments for human diseases.

Monozygotic twinning, also known as identical twinning, is a type of twin pregnancy that occurs when a single fertilized egg (ovum) splits into two embryos during the early stages of development. This results in the formation of two genetically identical individuals who share the same set of DNA and are therefore considered to be genetic clones of each other.

Monozygotic twinning is thought to occur in about 1 in every 250 pregnancies, making it less common than dizygotic (fraternal) twinning, which occurs when two separate eggs are fertilized by two different sperm. In monozygotic twinning, the timing of the split determines the type of placenta and amniotic sac each twin will have.

If the split occurs within the first few days after fertilization, the twins will typically develop in separate amniotic sacs and have their own individual placentas. If the split occurs later, the twins may share an amniotic sac (monoamniotic) or a placenta (monochorionic), or both (monochorionic-monoamniotic).

Monozygotic twinning is associated with some increased risks for pregnancy complications, such as preterm labor and delivery, low birth weight, and twin-to-twin transfusion syndrome, a rare condition in which blood flows unevenly between the twins through shared placental blood vessels. However, most monozygotic twins are born healthy and develop normally.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Prenatal injuries, also known as antenatal injuries, refer to damages or harm that occur to a fetus during pregnancy. These injuries can result from various factors such as maternal infections, exposure to toxic substances, genetic disorders, or physical trauma. Some common examples of prenatal injuries include cerebral palsy, intellectual disabilities, blindness, deafness, and limb deformities. It is essential to monitor and manage the health of both the mother and fetus during pregnancy to reduce the risk of prenatal injuries.

The notochord is a flexible, rod-shaped structure that is present in the embryos of chordates, including humans. It is composed of cells called chordocytes and is surrounded by a sheath. The notochord runs along the length of the body, providing support and flexibility. In human embryos, the notochord eventually becomes part of the discs between the vertebrae in the spine. An abnormal or absent notochord can lead to developmental problems with the spine and nervous system.

'Ciona intestinalis' is a species of tunicate, also known as sea squirts. They are marine invertebrate animals that are characterized by their sac-like bodies and filter-feeding habits. Tunicates are members of the phylum Chordata, which includes all animals with dorsal, hollow nerve cords – a category that also contains vertebrates (animals with backbones).

'Ciona intestinalis' is often used as a model organism in biological research due to its simple anatomy and relatively small genome. It has been studied in various fields such as developmental biology, evolution, and biomedical research. The species is native to the waters of the North Atlantic Ocean but has been introduced to many other regions around the world.

Helminth proteins refer to the proteins that are produced and expressed by helminths, which are parasitic worms that cause diseases in humans and animals. These proteins can be found on the surface or inside the helminths and play various roles in their biology, such as in development, reproduction, and immune evasion. Some helminth proteins have been identified as potential targets for vaccines or drug development, as blocking their function may help to control or eliminate helminth infections. Examples of helminth proteins that have been studied include the antigen Bm86 from the cattle tick Boophilus microplus, and the tetraspanin protein Sm22.6 from the blood fluke Schistosoma mansoni.

Cell division is the process by which a single eukaryotic cell (a cell with a true nucleus) divides into two identical daughter cells. This complex process involves several stages, including replication of DNA, separation of chromosomes, and division of the cytoplasm. There are two main types of cell division: mitosis and meiosis.

Mitosis is the type of cell division that results in two genetically identical daughter cells. It is a fundamental process for growth, development, and tissue repair in multicellular organisms. The stages of mitosis include prophase, prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis, which divides the cytoplasm.

Meiosis, on the other hand, is a type of cell division that occurs in the gonads (ovaries and testes) during the production of gametes (sex cells). Meiosis results in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction and genetic diversity. The stages of meiosis include meiosis I and meiosis II, which are further divided into prophase, prometaphase, metaphase, anaphase, and telophase.

In summary, cell division is the process by which a single cell divides into two daughter cells, either through mitosis or meiosis. This process is critical for growth, development, tissue repair, and sexual reproduction in multicellular organisms.

... size is typically considered uneven when one blastomere has a diameter over 25% larger than that of the other being ... In biology, a blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres ... The blastomere is considered totipotent; that is, blastomeres are capable of developing from a single cell into a fully fertile ... The other blastomeres that differentiate, then, will become apolar. Polar blastomere cells that differentiate will move to an ...
He investigated frog blastomeres. During this time (in 1911), he married and began a family. He and his wife ultimately had two ...
For example, subsets of blastomeres can be used to give rise to chimera with specified cell lineage from one embryo. The Inner ... Rossant, J. (1976). "Postimplantation development of blastomeres isolated from 4- and 8-cell mouse eggs". J. Embryol. Exp. ... Kubiak, J; Tarkowski, A. (1985). "Electrofusion of mouse blastomeres. Exp". Cell Res. 157 (2): 561-566. doi:10.1016/0014-4827( ...
Kimmel CB, Law RD (March 1985). "Cell lineage of zebrafish blastomeres. III. Clonal analyses of the blastula and gastrula ... Kimmel CB, Law RD (March 1985). "Cell lineage of zebrafish blastomeres. I. Cleavage pattern and cytoplasmic bridges between ...
... then the four vegetal pole blastomeres divide to make a level of four large blastomeres (macromeres) and four very small ... which divide transversally as well as equally to make eight blastomeres. The four vegetal blastomeres divide equatorially but ... The animal mesomeres of P. flava go on to give rise to the larva's ectoderm, animal blastomeres also appear to give rise to ... The third cleavage is equal and equatorial so that the embryo has four blastomeres both in the vegetal and the animal pole. The ...
On the existence of cell communications between blastomeres. Proc. Roy. Soc. B, 77, 498. ------ Studies on the development of ...
2001) Mouse singletons and twins developed from isolated diploid blastomeres supported with tetraploid blastomeres. Int. J. Dev ... 2010) Individual blastomeres of 16- and 32- cell mouse embryos are able to develop into foetuses and mice. Dev. Biol. 348, 190- ... In 1959 Tarkowski showed that a single blastomere isolated from a 2-cell stage mouse embryo is fully able to develop and the ... Tarkowski, A.K. and Wroblewska, J. (1967) Development of blastomeres of mouse eggs isolated at the 4- and 8-cell stage. J. ...
Meshcheryakov, V. N.; Beloussov, L. V. (1975). "Asymmetrical rotations of blastomeres in early cleavage of gastropoda". Wilhelm ...
Piotrowska-Nitsche K, Perea-Gomez A, Haraguchi S, Zernicka-Goetz M (February 2005). "Four-cell stage mouse blastomeres have ...
Each of the blastomeres that form is also spherical. On approximately day 3, at the eight-cell stage, compaction usually begins ... And the fate of the blastomeres is not yet determined. The two-cell embryo is spherical and surrounded by the transparent zona ...
Klimanskaya I, Chung Y, Becker S, Lu SJ, Lanza R (2006). "Human embryonic stem cell lines derived from single blastomeres". ...
... in which a single blastomere is extracted from a blastocyst. At the 2007 meeting of the International Society for Stem Cell ... "Human embryonic stem cell lines derived from single blastomeres". Nature. 444 (7118): 481-485. Bibcode:2006Natur.444..481K. doi ... "Human embryonic stem cell lines derived from single blastomeres". Nature. 444 (7118): 481-485. Bibcode:2006Natur.444..481K. doi ... "Human embryonic stem cell lines derived from single blastomeres". Nature. 444 (7118): 481-485. Bibcode:2006Natur.444..481K. doi ...
The absence of Oct-3/4 in Oct-3/4+ cells, such as blastomeres and embryonic stem cells, leads to spontaneous trophoblast ... "Human embryonic stem cell lines derived from single blastomeres". Nature. 444 (7118): 481-5. Bibcode:2006Natur.444..481K. doi: ...
When eight blastomeres have formed, they start to compact. They begin to develop gap junctions, enabling them to develop in an ... The blastomeres in the blastocyst are arranged into an outer layer called the trophoblast. The trophoblast then differentiates ... Initially, the dividing cells, called blastomeres (blastos Greek for sprout), are undifferentiated and aggregated into a sphere ... With further compaction the individual outer blastomeres, the trophoblasts, become indistinguishable. They are still enclosed ...
... after the analysis of one or two blastomeres, and when two blastomeres are analysed, the results should be concordant. Other ... Not all methods of opening the zona pellucida have the same success rate because the well-being of the embryo and/or blastomere ... In contrast to karyotyping, it can be used on interphase chromosomes, so that it can be used on PBs, blastomeres and TE samples ... A hole is made in the zona pellucida and one or two blastomeres containing a nucleus are gently aspirated or extruded through ...
Destouni, Aspasia; Vermeesch, Joris (2017). "How can zygotes segregate entire parental genomes into distinct blastomeres? The ... "Zygotes segregate entire parental genomes in distinct blastomere lineages causing cleavage-stage chimerism and mixoploidy". ...
... and finally heals the membrane after separation of blastomeres. The fate of the first cells, called blastomeres, is determined ... This contrasts with the situation in some other animals, such as mammals, in which each blastomere can develop into any part of ... Finally, the third set of blastomeres are the deep cells. These deep cells are located between the enveloping layer and the ...
2006). "Human embryonic stem cell lines derived from single blastomeres". Nature. 444 (7118): 481-485. Bibcode:2006Natur.444.. ...
This means that the daughter blastomeres are at a 45° angle. Like other gastropods, Elysia pusilla uses their ventral foot to ...
Blastomeres isolated from the ICM of mammalian embryos and grown in culture are known as embryonic stem (ES) cells. These ... Blastomeres are dissociated from an isolated ICM in an early blastocyst, and their transcriptional code governed by Oct4, Sox2 ... Initial polarization of blastomeres occurs at the 8-16 cell stage. An apical-basolateral polarity is visible through the ... Blastomeres of the mouse embryo lose totipotency after the fifth cleavage division: Expression of Cdx2 and Oct4 and ...
An embryo counting 16 to 64 blastomeres is called a morula. From the stage of having 128 cells, the embryo develops a cavity, ... When the embryo is composed of over 10.000 blastomeres (R.pipiens - after 25 or 26 hours), the next stage of embryonic ... This results in the creation of four identical blastomeres - separate cells now forming the embryo. The third cleavage runs ... equatorially and closer to the animal pole, thus creating blastomeres of unequal size (micromeres in the animal region and ...
This may also happen by the fusion of the first two blastomeres. Other species restore their ploidy by the fusion of the ...
In holoblastic cleavage, the zygote and blastomeres are completely divided during the cleavage, so the number of blastomeres ... when contact with the micromeres dictates one cell to become the future D blastomere. Once specified, the D blastomere signals ... Each blastomere produced by early embryonic cleavage does not have the capacity to develop into a complete embryo. A cell can ... This polar lobe forms at the vegetal pole during cleavage, and then gets shunted to the D blastomere. The polar lobe contains ...
Once in the parent, the larva blastomeres will migrate into the blastocoel. In order for this calcareous sponge species to ...
In Xenopus, blastomeres behave as pluripotent stem cells which can migrate down several pathways, depending on cell signaling. ... A common feature of a vertebrate blastula is that it consists of a layer of blastomeres, known as the blastoderm, which ... Amphibian EP-cadherin and XB/U cadherin perform a similar role as E-cadherin in mammals establishing blastomere polarity and ... The blastula (from Greek βλαστός (blastos meaning sprout)) is a hollow sphere of cells known as blastomeres surrounding an ...
This may also happen by the fusion of the first two blastomeres. Other species restore their ploidy by the fusion of the ...
This first division produces two distinctly different blastomeres, termed AB and P1. When the sperm cell fertilizes the egg ...
Embryos are generally obtained through blastomere or blastocyst biopsy. The latter technique has proved to be less deleterious ...
Blastomere biopsy is a technique in which blastomeres are removed from the zona pellucida. It is commonly used to detect ... Yu, Y; Zhao, Y; Li, R; Li, L; Zhao, H; Li, M; Sha, J; Zhou, Q; Qiao, J (Dec 6, 2013). "Assessment of the risk of blastomere ...
The different cells derived from cleavage, up to the blastula stage, are called blastomeres. Depending mostly on the amount of ... From here the spatial arrangement of blastomeres can follow various patterns, due to different planes of cleavage, in various ...
Blastomere size is typically considered uneven when one blastomere has a diameter over 25% larger than that of the other being ... In biology, a blastomere is a type of cell produced by cell division (cleavage) of the zygote after fertilization; blastomeres ... The blastomere is considered totipotent; that is, blastomeres are capable of developing from a single cell into a fully fertile ... The other blastomeres that differentiate, then, will become apolar. Polar blastomere cells that differentiate will move to an ...
He investigated frog blastomeres. During this time (in 1911), he married and began a family. He and his wife ultimately had two ...
Another approach for PGT is to biopsy a single blastomere from day 3 embryos; this allows extraction of a single blastomere ... and magnesium-free medium for approximately 20 minutes in order to reduce blastomere-to-blastomere adherence. ... After the small opening is made, a pipette is placed through the opening and focused on the blastomere of choice, containing a ... Removal of blastomere from an 8-cell embryo (cleavage-stage embryo). View Media Gallery ...
Performing PCR on single blastomeres from early cleavage stage (six- to eight-cell) human embryos should, in principle, enable ... Performing PCR on single blastomeres from early cleavage stage (six- to eight-cell) human embryos should, in principle, enable ... Performing PCR on single blastomeres from early cleavage stage (six- to eight-cell) human embryos should, in principle, enable ... Performing PCR on single blastomeres from early cleavage stage (six- to eight-cell) human embryos should, in principle, enable ...
Definition: Small blastomere of the vegetal hemisphere of the cleaving embryo located at to the vegetal pole ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
Blastomeres A16.254.90 A16.94. Blastula A16.254.270.274 A16.331.99. A16.254.300.600.274. Blood Flow Velocity G9.330.553.400.95 ...
is done; polar bodies from oocytes, blastomeres from 6- to 8-cell embryos, or a trophectoderm sample from the blastocyst is ...
In six blastomeres, from five embryos an incomplete haplotype was observed with loss of all alleles telomeric to the CGG repeat ... A blastomere from another embryo showed the complementary duplication. We conclude that a CGG repeat expansion at FRAXA causes ... We performed preimplantation genetic diagnosis (PGD) on 595 blastomeres biopsied from 442 cleavage stage embryos at risk for ... Subsequent analysis of additional blastomeres from three embryos by array comparative genomic hybridization (aCGH) confirmed ...
Laufer 1993 Antinori 1994 Liow 1996 Kaneko 2006 2009 LZD in addition has been utilized to biopsy the polar body and blastomere ...
At the 8-cell stage of the embryo, a single cell is removed and analyzed (blastomere biopsy) for X-linked recessive diseases. ...
  • To gain insights into lineage allocation in humans, we derived ten human embryonic stem cell lines (designated UCSFB1-10) from single blastomeres of four 8-cell embryos and one 12-cell embryo from a single couple. (escholarship.org)
  • As predicted by the transcriptomic data, immunolocalization of EOMES, T brachyury, GDF15 and active β-catenin revealed differential expression among blastomeres of 8- to 10-cell human embryos. (escholarship.org)
  • Early studies on cloning of non-human primates by nuclear transfer utilized embryonic blastomeres from preimplantation embryos which resulted in the reproducible birth of live offspring. (nih.gov)
  • polar bodies from oocytes, blastomeres from 6- to 8-cell embryos, or a trophectoderm sample from the blastocyst is used. (msdmanuals.com)
  • blastomeres are an essential part of blastula formation, and blastocyst formation in mammals. (wikipedia.org)
  • The division of blastomeres from the zygote allows a single fertile cell to continue to cleave and differentiate until a blastocyst forms. (wikipedia.org)
  • Polar blastomere cells that differentiate will move to an outer position in the developing blastocyst and show precursors for the trophectoderm, while the apolar cells will move to an inner position and begin developing into the embryo. (wikipedia.org)
  • The morula is a solid ball of blastomeres, while the blastocyst has a fluid-filled cavity, the blastocoel, and distinct cell layers - the inner cell mass and the trophoblast cells. (reproduction-online.org)
  • In humans, blastomere formation begins immediately following fertilization and continues through the first week of embryonic development. (wikipedia.org)
  • The moral issue applies at every point in embryonic development after the initial blastomere stage. (blogs.com)
  • MNB stands for multinucleated blastomere and refers to the presence of more than one nucleus in one or more of the embryonic cells (i.e. the cell is genetically abnormal). (sharedjourney.com)
  • This has been demonstrated through studies and conjectures made with mouse blastomeres, which have been accepted as true for most mammalian blastomeres as well. (wikipedia.org)
  • Centre for Preimplantation Genetic Diagnosis This article describes the selection of suitable probes for single-cell FISH, spreading techniques for blastomere nuclei, and in situ hybridization and signal scoring, applied to pre-implantation genetic diagnosis (PGD) in a clinical setting. (jove.com)
  • Cortical granule breakdown also occurred in maturing oocytes (after germinal vesicle breakdown but before second meiotic metaphase), but only in the blastomere containing the infected Ca2+. (rupress.org)
  • As expected, in mature oocytes (at second meiotic metaphase) cortical granule breakdown occurred over the entire oocyte surface, including both blastomeres. (rupress.org)
  • The other blastomeres that differentiate, then, will become apolar. (wikipedia.org)
  • This means that, under this model, blastomere cells do not differentiate based on cellular differences, but rather they do so because of mechanical and chemical stimuli based on where they are positioned at that time. (wikipedia.org)
  • During the morula stage, the blastomeres begin to differentiate, setting the stage for the development of specialized cell types. (reproduction-online.org)
  • Initially, all the blastomeres are totipotent, meaning they have the potential to develop into any cell type in the body. (reproduction-online.org)
  • The blastomeres in the morula are totipotent, meaning each cell has the potential to develop into a complete organism. (reproduction-online.org)
  • This allows for approximately half of the blastomeres to inherit polar regions that can rebuild the apical cortical domain. (wikipedia.org)
  • When the zygote contains 16 to 32 blastomeres it is referred to as a morula. (wikipedia.org)
  • The cells that make up the morula are known as blastomeres. (reproduction-online.org)
  • In the morula stage, the zygote undergoes multiple rounds of cleavage divisions, resulting in the formation of many blastomeres. (reproduction-online.org)
  • Relative blastomere size within the embryo is dependent not only on the stage of the cleavage, but also on the regularity of the cleavage amongst the cells. (wikipedia.org)
  • that is, blastomeres are capable of developing from a single cell into a fully fertile adult organism. (wikipedia.org)
  • How to analyze a single blastomere? (cambridge.org)
  • A single cell or blastomere removed from each embryo is then tested to detect X and Y chromosome material. (scrcivf.com)
  • However, if the number of blastomeres in the cellular mass is not even, then the division should be asynchronous such that the sizes of the cells best support the mass's specific stage of differentiation. (wikipedia.org)
  • Our data suggest heterogeneity among early-stage blastomeres and that the UCSFB lines have unique properties, indicative of a more immature state than conventional lines. (escholarship.org)
  • Adolph Eduard Driesch allowed the eggs of a sea urchin develop into the two-blastomere stage. (benjaminbarber.org)
  • These mitotic divisions continue and result in a grouping of cells called blastomeres. (wikipedia.org)
  • Once this begins, microtubules within the morula's cytosolic material in the blastomere cells can develop into important membrane functions, such as sodium pumps. (wikipedia.org)
  • If the number of blastomeres in the cellular mass is even, then the sizes of the cells should be congruent. (wikipedia.org)
  • There are two main models for differentiation that determine which blastomere cells will divide into either the inner cell mass or the trophectoderm. (wikipedia.org)
  • The blastomeres start to organize themselves into distinct layers, known as the inner cell mass and the outer layer of trophoblast cells. (reproduction-online.org)
  • smaller amounts of Ca2+ produced either a local cortical granule reaction of the formation of one large and one small "blastomere. (rupress.org)
  • The differentiation of the blastomere allows for the development of two distinct cell populations: the inner cell mass, which becomes the precursor to the embryo, and the trophectoderm, which becomes the precursor to the placenta. (wikipedia.org)
  • Post-thawing blastomere survival rate and type of endometrial preparation for FET did not affect the success rate. (tau.ac.il)
  • Studies have analyzed monozygotic twin mouse blastomeres in their two-cell state, and have found that when one of the twin blastomeres is destroyed, a fully fertile adult mouse can still develop. (wikipedia.org)
  • After this, the 8-cell blastomere mass begins to compact by forming tight junctions between themselves, and cytosolic components of the cell accumulate in the apical region while the nucleus of each cell moves to the basal region. (wikipedia.org)
  • During the 8-cell differentiation period, the blastomeres form adheren junctions, and subsequently polarize along the apical-basal axis. (wikipedia.org)
  • RÉSUMÉ La présente étude menée en Turquie a évalué l'impact de la loi rendant obligatoire le transfert d'un embryon unique en fonction de l'âge et de l'augmentation consécutive des transferts d'embryons congelés- décongelés sur l'issue de la grossesse des patientes bénéficiant d'une fécondation in vitro. (who.int)
  • Le transfert d'un embryon unique, le transfert d'embryons congelés-décongelés et le transfert de deux embryons ont été réalisés chez 5632 patientes après l'entrée en vigueur de la loi, tandis que l'approche traditionnelle par fécondation in vitro et par transferts d'embryons congelés-décongelés a été utilisée chez 6029 patientes avant le vote de cette loi. (who.int)
  • PGT as offered for these indications (PGT-M/SR) comprises an in vitro fertilization (IVF)-treatment combined with a blastomere biopsy at the cleavage stage or trophectoderm (TE) biopsy at the blastocyst stage of the in vitro embryo. (medscape.com)
  • 29. Development of single mouse blastomeres into blastocysts, outgrowths and the establishment of embryonic stem cells. (nih.gov)
  • Zebrafish blastomere screen identifies retinoic acid suppression of MYB in adenoid cystic carcinoma. (accrf.org)
  • Asymmetric transcript discovery by RNA-seq in C. elegans blastomeres identifies neg-1, a gene important for anterior morphogenesis. (uchicago.edu)
  • 22. Efficient establishment of mouse embryonic stem cell lines from single blastomeres and polar bodies. (nih.gov)
  • 23. Derivation of the first Swiss human embryonic stem cell line from a single blastomere of an arrested four-cell stage embryo. (nih.gov)
  • Myosin rings and spreading in mouse blastomeres. (rupress.org)
  • 33. Unsuccessful derivation of human embryonic stem cell lines from pairs of human blastomeres. (nih.gov)
  • Inside the intact ZONA PELLUCIDA , each cleavage yields two blastomeres of about half size of the parent cell. (nih.gov)