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.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
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.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
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.
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.
The outer of the three germ layers of an embryo.
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
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).
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.
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.
Members of the transforming growth factor superfamily that play a role in pattern formation and differentiation during the pregastrulation and GASTRULATION stages of chordate development. Several nodal signaling ligands are specifically involved in the genesis of left-right asymmetry during development. The protein group is named after a critical region of the vertebrate embryo PRIMITIVE STREAK referred to as HENSEN'S NODE.
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.
Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
Goosecoid protein is a homeodomain protein that was first identified in XENOPUS. It is found in the SPEMANN ORGANIZER of VERTEBRATES and plays an important role in neuronal CELL DIFFERENTIATION and ORGANOGENESIS.
A species of SEA URCHINS in the family Strongylocentrotidae found on the Pacific coastline from Alaska to Mexico. This species serves as a major research model for molecular developmental biology and other fields.
The inner of the three germ layers of an embryo.
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
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.
A genus of SEA URCHINS in the family Strongylocentrotidae with a hemicyclic apical disk and short spines.
A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)
A mature haploid female germ cell extruded from the OVARY at OVULATION.
A basic helix-loop-helix transcription factor that plays a role in determining cell fate during embryogenesis. It forms a heterodimer with TWIST TRANSCRIPTION FACTOR and ACHAETE-SCUTE GENE COMPLEX-related TRANSCRIPTION FACTORS.
Activins are produced in the pituitary, gonads, and other tissues. By acting locally, they stimulate pituitary FSH secretion and have diverse effects on cell differentiation and embryonic development. Activins are glycoproteins that are hetero- or homodimers of INHIBIN-BETA SUBUNITS.
A genus of aquatic newts belonging to the family Salamandridae and sometimes referred to as "spiny" tritons. There are two species P. waltlii and P. poireti. P. waltlii is commonly used in the laboratory. Since this genus adapts to aquarium living, it is easy to maintain in laboratories.
The founding member of the nodal signaling ligand family of proteins. Nodal protein was originally discovered in the region of the mouse embryo primitive streak referred to as HENSEN'S NODE. It is expressed asymmetrically on the left side in chordates and plays a critical role in the genesis of left-right asymmetry during vertebrate development.
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.
Proteins containing a region of conserved sequence, about 200 amino acids long, which encodes a particular sequence specific DNA binding domain (the T-box domain). These proteins are transcription factors that control developmental pathways. The prototype of this family is the mouse Brachyury (or T) gene product.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
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.
Morphological and physiological development of EMBRYOS.
A chromogenic substrate that permits direct measurement of peptide hydrolase activity, e.g., papain and trypsin, by colorimetry. The substrate liberates p-nitroaniline as a chromogenic product.
The three primary germinal layers (ECTODERM; ENDODERM; and MESODERM) developed during GASTRULATION that provide tissues and body plan of a mature organism. They derive from two early layers, hypoblast and epiblast.
A genus of SEA URCHINS in the family Echinidae found primarily on the western coasts of Ireland.
Glycoproteins that inhibit pituitary FOLLICLE STIMULATING HORMONE secretion. Inhibins are secreted by the Sertoli cells of the testes, the granulosa cells of the ovarian follicles, the placenta, and other tissues. Inhibins and ACTIVINS are modulators of FOLLICLE STIMULATING HORMONE secretions; both groups belong to the TGF-beta superfamily, as the TRANSFORMING GROWTH FACTOR BETA. Inhibins consist of a disulfide-linked heterodimer with a unique alpha linked to either a beta A or a beta B subunit to form inhibin A or inhibin B, respectively
Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.
A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.
A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.
A subclass of closely-related SOX transcription factors. Members of this subclass are expressed in VASCULAR ENDOTHELIAL CELLS and may play a role in vasculogenesis.
Proteins that are preferentially expressed or upregulated during FETAL DEVELOPMENT.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
A family of VERTEBRATE homeodomain proteins that share homology with orthodenticle protein, Drosophila. They regulate GENETIC TRANSCRIPTION and play an important role in EMBRYONIC DEVELOPMENT of the BRAIN.
A family of small polypeptide growth factors that share several common features including a strong affinity for HEPARIN, and a central barrel-shaped core region of 140 amino acids that is highly homologous between family members. Although originally studied as proteins that stimulate the growth of fibroblasts this distinction is no longer a requirement for membership in the fibroblast growth factor family.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
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.
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 family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
A bone morphogenetic protein that is a potent inducer of bone formation. It also functions as a regulator of MESODERM formation during EMBRYONIC DEVELOPMENT.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
A family of sequence-related proteins similar to HMGB1 PROTEIN that contains specific HMG-BOX DOMAINS.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A multi-functional catenin that participates in CELL ADHESION and nuclear signaling. Beta catenin binds CADHERINS and helps link their cytoplasmic tails to the ACTIN in the CYTOSKELETON via ALPHA CATENIN. It also serves as a transcriptional co-activator and downstream component of WNT PROTEIN-mediated SIGNAL TRANSDUCTION PATHWAYS.
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
A transcription factor that takes part in WNT signaling pathway where it may play a role in the differentiation of KERATINOCYTES. The transcriptional activity of this protein is regulated via its interaction with BETA CATENIN.
An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.
A factor synthesized in a wide variety of tissues. It acts synergistically with TGF-alpha in inducing phenotypic transformation and can also act as a negative autocrine growth factor. TGF-beta has a potential role in embryonal development, cellular differentiation, hormone secretion, and immune function. TGF-beta is found mostly as homodimer forms of separate gene products TGF-beta1, TGF-beta2 or TGF-beta3. Heterodimers composed of TGF-beta1 and 2 (TGF-beta1.2) or of TGF-beta2 and 3 (TGF-beta2.3) have been isolated. The TGF-beta proteins are synthesized as precursor proteins.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Wnt proteins are a large family of secreted glycoproteins that play essential roles in EMBRYONIC AND FETAL DEVELOPMENT, and tissue maintenance. They bind to FRIZZLED RECEPTORS and act as PARACRINE PROTEIN FACTORS to initiate a variety of SIGNAL TRANSDUCTION PATHWAYS. The canonical Wnt signaling pathway stabilizes the transcriptional coactivator BETA CATENIN.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.
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)
Elements of limited time intervals, contributing to particular results or situations.
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).
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
Regulatory proteins and peptides that are signaling molecules involved in the process of PARACRINE COMMUNICATION. They are generally considered factors that are expressed by one cell and are responded to by receptors on another nearby cell. They are distinguished from HORMONES in that their actions are local rather than distal.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.
The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.
ENDOPEPTIDASES which use a metal such as ZINC in the catalytic mechanism.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

Distinct roles for Fgf, Wnt and retinoic acid in posteriorizing the neural ectoderm. (1/172)

Early neural patterning in vertebrates involves signals that inhibit anterior (A) and promote posterior (P) positional values within the nascent neural plate. In this study, we have investigated the contributions of, and interactions between, retinoic acid (RA), Fgf and Wnt signals in the promotion of posterior fates in the ectoderm. We analyze expression and function of cyp26/P450RAI, a gene that encodes retinoic acid 4-hydroxylase, as a tool for investigating these events. Cyp26 is first expressed in the presumptive anterior neural ectoderm and the blastoderm margin at the late blastula. When the posterior neural gene hoxb1b is expressed during gastrulation, it shows a strikingly complementary pattern to cyp26. Using these two genes, as well as otx2 and meis3 as anterior and posterior markers, we show that Fgf and Wnt signals suppress expression of anterior genes, including cyp26. Overexpression of cyp26 suppresses posterior genes, suggesting that the anterior expression of cyp26 is important for restricting the expression of posterior genes. Consistent with this, knock-down of cyp26 by morpholino oligonucleotides leads to the anterior expansion of posterior genes. We further show that Fgf- and Wnt-dependent activation of posterior genes is mediated by RA, whereas suppression of anterior genes does not depend on RA signaling. Fgf and Wnt signals suppress cyp26 expression, while Cyp26 suppresses the RA signal. Thus, cyp26 has an important role in linking the Fgf, Wnt and RA signals to regulate AP patterning of the neural ectoderm in the late blastula to gastrula embryo in zebrafish.  (+info)

Embryogenesis and development of Epimenia babai (Mollusca Neomeniomorpha). (2/172)

Neomenioid aplacophorans (= Solenogastres) constitute one of the main lineages of molluscs. Developmental data of early embryogenesis and larval development of neomenioids are available for some species based on histological sections. I used other techniques to study the development of Epimenia babai Salvini-Plawen, 1997, and here I report new data on neomenioid development. The embryos of E. babai are lecithotrophic and cleavage is spiral, unequal, and holoblastic. Two polar lobes are formed, one at the first cleavage stage and one at the second cleavage stage. No evidence of external metameric iteration is visible through scanning electron microscopy or histology at any stage. A ciliated foot, a pedal pit, and aragonitic spicules develop from the definitive ectoderm. A spicule begins as a solid tip, continues to an open-ended hollow spicule, and finally becomes a closed-ended hollow spicule. The free-swimming trochophore larvae of E. babai have been considered unusual in lacking the characteristic neomenioid cellular test, an outer locomotory structure within which the entire definitive adult body develops. However, through the use of scanning electron and light microscopy, semithin sections, Hoechst nuclear staining, and programmed cell death staining to study the ontogeny and fate of the apical cells, I show that the entire pre-oral sphere (the apical cap) of the larvae is similar to the test of the other neomenioids. The results suggest that the test of the neomenioid larvae is an enlarged pre-oral sphere of a trochophore. The test morphologies of neomenioid larvae are compared to those of pericalymma larvae of protobranch bivalves, and the homology and evolution of molluscan larval tests is discussed.  (+info)

A prospective randomized comparison of sequential versus monoculture systems for in-vitro human blastocyst development. (3/172)

BACKGROUND: Extending the period of in-vitro culture to the blastocyst stage may improve implantation rates in IVF treatment. Recognition of the dynamic nature of early embryo metabolism has led to the development of commercially available sequential culture systems. However, their improved efficacy over monoculture systems remains to be demonstrated in prospective studies. METHODS: Embryos obtained from 158 women undergoing IVF treatment were randomized by sealed envelopes to culture in one of three systems: (A) culture for 5 days in our own monoculture medium (Rotterdam medium); (B) culture for 3 days in Rotterdam medium followed by 2 days in fresh Rotterdam medium; (C) culture for 5 days using the commercially available G1/G2 sequential culture system. RESULTS: There were no significant differences in blastulation, implantation or pregnancy rates between the three tested culture systems. CONCLUSION: The employed monoculture system is as effective as the G1/G2 sequential system for the culture of blastocysts for IVF.  (+info)

Establishment of the organizing activity of the lower endodermal half of the dorsal marginal zone is a primary and necessary event for dorsal axis formation in Cynops pyrrhogaster. (4/172)

The formation of the head and trunk-tail organizers in the dorsal marginal zone (DMZ) of an amphibian embryo is thought to require spatial and temporal interactions between the Nieuwkoop center and the DMZ. Recent studies of the Xenopus embryo suggested that intra-DMZ interaction is also needed to establish the regional specificity of the DMZ. However, it is not yet clarified when and how the final pattern of the head and trunk-tail organizers is established. To analyze the intra-DMZ interactions, we injected suramin into the blastocoel of the mid-blastula of the urodele, Cynops pyrrhogaster, at 6 h prior to the onset of gastrulation. The pigmented blastopore formed normally, but the convergent extension and involution of the DMZ and dorsal axis formation of the embryo were completely inhibited. Expression of gsc, chd and Lim-1 were not maintained, but noggin was unaffected in the suramin-treated embryos. Dorsal axis formation and the expression of these genes of the suramin-treated embryos were rescued by replacing the lower endodermal half of the DMZ (LDMZ) with normal LDMZ. The present results of embryological and molecular examinations indicate that organizing activity of the early Cynops gastrula DMZ is restricted to the LDMZ, and that the organizing activity of the LDMZ is established during the late blastula stages. The results also indicate that LDMZ triggers the sequential interaction within the DMZ that establishes the final pattern of the regional specificity of the DMZ, and that the formation of the LDMZ is a primary and necessary event for dorsal axis formation.  (+info)

T-brain homologue (HpTb) is involved in the archenteron induction signals of micromere descendant cells in the sea urchin embryo. (5/172)

Signals from micromere descendants play a crucial role in sea urchin development. In this study, we demonstrate that these micromere descendants express HpTb, a T-brain homolog of Hemicentrotus pulcherrimus. HpTb is expressed transiently from the hatched blastula stage through the mesenchyme blastula stage to the gastrula stage. By a combination of embryo microsurgery and antisense morpholino experiments, we show that HpTb is involved in the production of archenteron induction signals. However, HpTb is not involved in the production of signals responsible for the specification of secondary mesenchyme cells, the initial specification of primary mesenchyme cells, or the specification of endoderm. HpTb expression is controlled by nuclear localization of beta-catenin, suggesting that HpTb is in a downstream component of the Wnt signaling cascade. We also propose the possibility that HpTb is involved in the cascade responsible for the production of signals required for the spicule formation as well as signals from the vegetal hemisphere required for the differentiation of aboral ectoderm.  (+info)

Experimental analysis of gravitational effects on amphibian gastrulation. (6/172)

The effects of simulated microgravity on blastopore (Bp) formation were analysed in Xenopus laevis and Cynops pyrrhogaster embryos. Simulated microgravity produced by clinostat rotation shifted the Bp-forming region toward the vegetal pole, more markedly in Cynops embryos than in Xenopus embryos. The simulated microgravity induced aggregation of endoderm cells at the center of the embryo and separation between the endoderm and presumptive mesoderm (PM). These findings suggest that clinostat treatment disrupts cell-to-cell interaction between endoderm and PM by increasing the separation between them and, as a result, Bp formation may be shifted towards the vegetal pole.  (+info)

Beta-catenin/Tcf-regulated transcription prior to the midblastula transition. (7/172)

Following fertilization, the zygotic genome in many organisms is quiescent until the midblastula transition (MBT), when large-scale transcription begins. In Xenopus embryos, for example, transcription is believed to be repressed until the twelfth cell division. Thus, although dorsal-ventral patterning begins during the first cell cycle, little attention has been given to transcriptional regulation in pre-MBT development. We present evidence that regulated transcription begins during early cleavage stages and that the beta-catenin-Tcf complex is required for the transcription of the Xenopus nodal genes Xnr5 and Xnr6 as early as the 256-cell stage. Moreover, inhibition of beta-catenin/Tcf function can block dorsal development, but only if the inhibition begins early and is maintained throughout pre-MBT stages. Dorsal development can be rescued in ventralized embryos if Tcf-dependent transcription is activated prior to MBT, but activation of Tcf after MBT cannot rescue ventralized embryos, suggesting that beta-catenin/Tcf-dependent transcription is required prior to MBT for dorsal-ventral patterning in Xenopus.  (+info)

Activin A induces craniofacial cartilage from undifferentiated Xenopus ectoderm in vitro. (8/172)

Activin A has potent mesoderm-inducing activity in amphibian embryos and induces various mesodermal tissues in vitro from the isolated presumptive ectoderm. By using a sandwich culture method established to examine activin A activity, we previously demonstrated that activin-treated ectoderm can function as both a head and trunk-tail organizer, depending on the concentration of activin A. By using activin A and undifferentiated presumptive ectoderm, it is theoretically possible to reproduce embryonic induction. Here, we test this hypothesis by studying the induction of cartilage tissue by using the sandwich-culture method. In the sandwiched explants, the mesenchymal cell condensation expressed type II collagen and cartilage homeoprotein-1 mRNA, and subsequently, cartilage were induced as they are in vivo. goosecoid (gsc) mRNA was prominently expressed in the cartilage in the explants. Xenopus distal-less 4 (X-dll4) mRNA was expressed throughout the explants. In Xenopus embryos, gsc expression is restricted to the cartilage of the lower jaw, and X-dll4 is widely expressed in the ventral head region, including craniofacial cartilage. These finding suggest that the craniofacial cartilage, especially lower jaw cartilage, was induced in the activin-treated sandwiched explants. In addition, a normal developmental pattern was recapitulated at the histological and genetic level. This work also suggests that the craniofacial cartilage-induction pathway is downstream of activin A. This study presents a model system suitable for the in vitro analysis of craniofacial cartilage induction in vertebrates.  (+info)

Massive zygotic transcription begins in many organisms during the midblastula transition when the cell cycle of the dividing egg slows down. A few genes are transcribed before this stage but how this differential activation is accomplished is still an open question. We have performed ChIP-seq experiments on tightly staged Drosophila embryos and show that massive recruitment of RNA polymerase II (Pol II) with widespread pausing occurs de novo during the midblastula transition. However, ∼100 genes are strongly occupied by Pol II before this timepoint and most of them do not show Pol II pausing, consistent with a requirement for rapid transcription during the fast nuclear cycles. This global change in Pol II pausing correlates with distinct core promoter elements and associates a TATA-enriched promoter with the rapid early transcription. This suggests that promoters are differentially used during the zygotic genome activation, presumably because they have distinct dynamic properties. DOI: ...
The midblastula transition (MBT) in Xenopus can be initiated prematurely by blocking the fundamental cell-cycle oscillator with cycloheximide, in which case motility and transcription are quickly initiated. Using various inhibitors of specific events of the cell cycle that do not inhibit the autonomous oscillator, we have shown that transcription is activated when DNA synthesis is interrupted and motility is activated when cell cleavage is inhibited. Furthermore, very low levels of transcription are found to occur before the MBT. These results demonstrate that the pre-MBT egg is fully competent for transcription and motility and suggest that different features of the rapid early cell cycle normally suppress these events ...
mNanog and ventx1/2 overexpression cause similar effects in Xenopus embryos.(A) Four-cell stage embryos (NF3) were injected in both dorsal blastomeres, with a 1
Blastula: Blastula,, hollow sphere of cells, or blastomeres, produced during the development of an embryo by repeated cleavage of a fertilized egg. The cells of the blastula form an
P(C1 n C2 n C3 n C4) + P(C1 n C2 n C3 n C4) + P(C1 n C2 n C3 n C4) + P(C1 n C2 n C3 n C4) + P(C1 n C2 n C3 n C4) + P(C1 n C2 n C3 n C4) + P(C1 n C2 n C3 n C4) = -p^4 + 2p^ ...
The development of multi-cellular organisms begins from a single-celled zygote, which undergoes rapid cell division to form the blastula. The rapid, multiple rounds of cell division are termed cleavage. After the cleavage has produced over 100 cells, the embryo is called a blastula. The blastula is usually a spherical layer of cells (the blastoderm) surrounding a fluid-filled or yolk-filled cavity (the blastocoel). Mammals at this stage form a structure called the blastocyst, characterized by an inner cell mass that is distinct from the surrounding blastula. During cleavage, the cells divide without an increase in mass; that is, one large single-celled zygote divides into multiple smaller cells. Each cell within the blastula is called a blastomere.. Cleavage can take place in two ways: holoblastic (total) cleavage or meroblastic (partial) cleavage. The type of cleavage depends on the amount of yolk in the eggs. In placental mammals (including humans) where nourishment is provided by the mothers ...
Mouse monoclonal antibody raised against a partial recombinant SMARCD3. SMARCD3 (NP_001003801, 385 a.a. ~ 483 a.a) partial recombinant protein with GST tag. MW of the GST tag alone is 26 KDa. (H00006604-M01A) - Products - Abnova
blastula definition: An early embryonic form created by cleavage of a fertilized ovum and comprising a spherical layer of cells surrounding a fluid-filled hole. Also called blastosphere.; An early type…
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The protein encoded by this gene is a member of the SWI/SNF family of proteins, whose members display helicase and ATPase activities and which are thought to regulate tra
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Formula: C32H41N5O5MW: 575. 71CAS: 511-09-1TNP NUMBER: TNP00320MDL NUMBER: MFCD02185004Smiles: O[[email protected]@]12N([[email protected]@H](CC(C)C)C(N3[[email protected]]1(CCC3))=O)C([C](O2)(NC(=O)[[email protected]@H]1C=C2c3c4c(C[[email protected]]2(N(C1)C))c[nH]c4ccc3)C(C)C)=OTHERAPEUTIC CATEGORY: VasoconstrictorVET THERAP CATEGORY: Has been used as an oxytoxicREFERENCE: Larson, B....
TY - JOUR. T1 - Nuclear accumulation of Smad complexes occurs only after the midblastula transition in Xenopus. AU - Saka, Yasushi. AU - Hagemann, Anja I.. AU - Piepenburg, Olaf. AU - Smith, James C.. PY - 2007/12/1. Y1 - 2007/12/1. N2 - Activin and the Nodal-related proteins induce mesendodermal tissues during Xenopus development. These signals act through specific receptors to cause the phosphorylation, at their carboxyl termini, of Smad2 and Smad3. The phosphorylated Smad proteins form heteromeric complexes with Smad4 and translocate into the nucleus to activate the transcription, after the midblastula transition, of target genes such as Xbra and goosecoid (gsc). In this paper we use bimolecular fluorescence complementation (BiFC) to study complex formation between Smad proteins both in vivo and in response to exogenous proteins. The technique has allowed us to detect Smad2-Smad4 heteromeric interactions during normal Xenopus development and Smad2 and Smad4 homo- and heteromers in isolated ...
Modified from: Kimmel et al., 1995. Developmental Dynamics 203:253-310. Copyright © 1995 Wiley-Liss, Inc. Reprinted only by permission of Wiley-Liss, a subsidiary of John Wiley & Sons, Inc. We use the term blastula to refer to the period when the blastodisc begins to look ball-like, at the 128-cell stage, or 8th zygotic cell cycle, and until the time of onset of gastrulation, ca. cycle 14. Important processes occur during this blastula period; the embryo enters midblastula transition (MBT), the yolk syncytial layer (YSL) forms, and epiboly begins. Epiboly continues during the gastrulation period. Stereoblastula would be more a appropriate term than blastula to describe the period, for it means no blastocoele is present, which is the case (Fig. 8). Only small irregular extracellular spaces exist between the deep cells of the blastodisc. The orientation of the cleavage planes is indeterminate, and they are much less regularly arranged than they were during the cleavage period. The daughter ...
In most organisms, control of the developmental program involves a regulated transition from maternally supplied mRNAs and proteins to newly synthesized zygotically encoded factors. This phenomena, known as the maternal to zygotic transition (MZT), is observed in a wide range of embryos in the animal and plant kingdoms; in chordates, the MZT typically occurs during midblastula stages, and therefore is often referred to as the midblastula transition (MBT). Early development of most organisms is exclusively maternally controlled, and the zygotic genome of the embryo remains transcriptionally silent until after the MBT, when the transition to zygotic control culminates. Recent work in a number of organisms has identified several genes that are activated prior to the MBT, but whether precocious expression of specific mRNAs is important for later development has not been examined in detail. In this work, I characterize the role of a maternal transcription factor in preMBT transcription, and identify a
Transvection. Zygotic Gene Activity in Development. The differentiation of cell types and the formation of organs depend on genes being activated in particular spatial and temporal patterns. Zygotic Gene Expression. Slideshow 6856931 by rose-dudley
mouse SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily d, member 1 SMARCD1 antibody validated for Immunoprecipitation,Microarray
Complete information for SMARCD3 gene (Protein Coding), SWI/SNF Related, Matrix Associated, Actin Dependent Regulator Of Chromatin, Subfamily D, Member 3, including: function, proteins, disorders, pathways, orthologs, and expression. GeneCards - The Human Gene Compendium
Slovenská národná knižnica si Vás dovoľuje pozvať na celoslovenský seminár Benchmarking verejných knižníc 15. októbra 2019 od 13.00 hod. v konferenčnej sále sídelnej budovy SNK Celoslovenský seminár je určený pre zriaďovateľov a riadiacich pracovníkov knižníc, pre výskumných pracovníkov, metodikov a pre širokú odbornú knihovnícku verejnosť so záujmom o vývoj slovenských verejných knižníc a aktivity Knihovníckeho institutu NK ČR na podporu knižníc. Program 13.00 Prezentácia účastníkov 13.30 - 13.40 Privítanie účastníkov Mgr. Zuzana Prachárová, riaditeľka Knižničného inštitútu SNK 13.40 - 14.40 Benchmarking knihoven a jiné aktivity Knihovnického institutu NK ČR na podporu veřejných knihoven v roku 2019PhDr. Vít Richter, riaditeľ Knihovníckeho institutu NK Praha                 14.40 - 15.50 Analýza podmienok a výkonov slovenských verejných
Coeloblastula n. pl. -lae Gr. koilos, hollow blastos, bud 1. A hollow blastula a blastula without qualification. 2. (PO-RIF Calcarea) The simple type of
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For many organisms, the first goal of embryogenesis is to accumulate a large cell population to accommodate gastrulation. To achieve this quickly, embryos employ specialized cell cycles called cleavages that consist of continuous rounds of DNA replication and division. Cell proliferation occurs rapidly because cleavage cycles lack the gap phases and cell cycle checkpoints found in canonical cell cycles. Further, the genetic materials required to sustain cleavage cycles are preloaded during oogenesis, aiding efficient cell cycle progression. After a constant, organism-specific number of cleavages, many metazoan embryos undergo the mid-blastula transition (MBT), which initiates extensive cell cycle remodeling. Cell cycles lengthen, gap phases appear and checkpoint function is acquired. At the same time, the nearly quiescent zygotic genome is activated and transcriptional activity dramatically increases. This dissertation describes how these simultaneous MBT events are regulated. Chapter 2 addresses how
goosecoid is an immediate early gene expressed at the dorsal blastoporal lip of the Xenopus gastrula. Microinjection experiments have suggested a direct role for goosecoid in organizing the dorsoventral axis of the frog embryo. Here we characterize the zebrafish homologue of goosecoid (gsc) and compare its expression to that of Brachyury or no tail (ntl), another immediate early gene required in developing mesoderm. We show that gsc exhibits two independent phases of expression: an early one in cells anterior to the presumptive notochord, but not in cells of the notochord itself, and a later one in neural crest derivatives in the larval head. Zygotic gsc transcripts are detected soon after the midblastula transition, and at the blastula stage form a gradient with a maximum at the dorsal side. Use of gsc as a dorsal marker allowed us to demonstrate that ntl expression is initially activated at the dorsal side of the blastula. At this early stage, gsc and ntl show overlapping domains of expression ...
Nanos is expressed in multipotent cells, stem cells, and primordial germ cells (PGCs) of organisms as diverse as jellyfish and humans. It functions together with Pumilio to translationally repress targeted mRNAs. Here we show by loss-of-function experiments that Xenopus Nanos1 is required to preserve PGC fate. Morpholino knockdown of maternal Nanos1 resulted in a striking decrease in PGCs and loss of germ cells from the gonads. Lineage tracing and TUNEL staining reveals that Nanos1 deficient PGCs fail to migrate out of the endoderm. They appear to undergo apoptosis rather than convert to normal endoderm. Whereas normal PGCs do not become transcriptionally active until neurula, Nanos1 depleted PGCs prematurely express a hyperphosphorylated RNA Pol II-CTD at the mid-blastula transition. Furthermore, they now inappropriately express somatic genes characteristic of endoderm regulated by maternal VegT including Xsox17-alpha, Bix4, Mixer, GATA4, and Edd. We further demonstrate that Pumilio specifically
Vertebrate development requires that cell proliferation be properly coordinated with morphogenesis, the process by which an embryo acquires form, and cell specification, the process by which unique cellular characteristics arise. My work has focused on the investigation of specific genetic networks that we have found to be involved in the regulation of cell proliferation during zebrafish (Danio rerio) development. We have identified two genes, wee1 and lmo4b, that are involved in two distinct, proliferative regulatory mechanisms during development. My work demonstrates that wee1 is required for the progression of the cell cycle after the midblastula transition (MBT). Loss of wee1 abolishes a temporally acquired G2/M checkpoint resulting in widespread cell death. We also found that the wee1-dependent G2/M checkpoint is required for a developmentally programmed deceleration of the cell cycle. In addition, my work shows that lmo4b functions in a spatial manner by restricting the expression of the ...
In animals, the development of the zygote into an embryo proceeds through specific recognizable stages of blastula, gastrula, and organogenesis. The blastula stage typically features a fluid-filled cavity, the blastocoel, surrounded by a sphere or sheet of cells, also called blastomeres. In a placental mammal, an ovum is fertilized in a fallopian tube through which it travels into the uterus. An embryo is called a fetus at a more advanced stage of development and up until birth or hatching. In humans, this is from the eleventh week of gestation. However, animals which develop in eggs outside the mothers body, are usually referred to as embryos throughout development; e.g. one would refer to a chick embryo, not a chick fetus, even at later stages.. During gastrulation the cells of the blastula undergo coordinated processes of cell division, invasion, and/or migration to form two (diploblastic) or three (triploblastic) tissue layers. In triploblastic organisms, the three germ layers are called ...
1. Animals are [ heterotrophs / autotrophs ]. 2. [ All / Most ] animals are multicellular.. 3. The cells in the skin of your hand are [ bigger than / the same size as ] the cells in your heart.. 4. Organisms that have 2 copies of each chromosome are [mobile / diploid ]. 5. The absence of a cell wall allows animals [ mobility / diploidy ]. 6. A hollow ball of cells that forms after fertilization is called a [ blastula / mesoderm ]. 7. In all animals except [ humans / sponges ] a zygote undergoes divisions to become a blastula.. 8. The cells of animals are organized into functional units called [ blastula / tissues ]. Match the tissue layer to the part of the body it ...
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今日は昼休み中にRDKitのMMPAスクリプトをいじってました。 kzfmさんのブログを拝見させていただいたのがきっかけです。 RDKit_2013_03_2/Contrib/mmpa配下のrfag.pyの切断ルールをRECAP風にアレンジしてみました。 209行目以降 を とします。 これでエーテル、アミド、環状アミン、エステル、芳香環−芳香環、芳香族n−芳香環、スルフォンアミド、芳香環−N−芳香環(buchwald_amination)のボンドのサーチをかけてマッチした部分の結合に関わるアトムインデックスをゲッツします。 エーテルは飽和炭素ー酸素ー飽和炭素のインデックスをとるのでインデックスは前のペアと 後ろのペアを返すようにしました。 同様に芳香環−N−芳香環も同じです。 アミドやエステルはC(=O)N, C(=O
I was reading an article (I forget where) and it stated that the BBers of old ala Schwarzenegger and Mentzer, et al.never used Clomid or Nolva or
Hi all [smile] Im learning loads from the Maybies discussions, but wanted to ask a few dim questions without taking hijacking their thread! Im 16
Mitosis Answer and Explanation: Onion root tips and whitefish blastula are commonly used to illustrate mitosis because these are tissues that are undergoing high rates of mitosis. STUDY. Why are the onion root tip and the whitefish blastula useful tissues for the study of cell division? Spell. Materials: This lab required prepared slides of whitefish blastula, onion root tips, ovary, and testis, a microscope, and chromosome kit. The cells of a developing embryo are dividing rapidly and can be used for viewing the different stages of mitosis. Whitefish blastula:. Microtubules align chromosomes along metaphase plate. Virtual Mitosis Lab: Part II - Whitefish Blastula Introduction: Mitosis is considered nuclear division, since its main stages deal strictly with the nucleus and its contents (DNA). Mitosis Whitefish Blastula. Cell Division - Mitosis - in Whitefish Blastula Cells: The arrows (A) in the photo point to a cell in the prophase stage of mitosis. A professor could ask you what are the ...
TY - JOUR. T1 - Undamaged DNA transmits and enhances DNA damage checkpoint signals in early embryos. AU - Peng, Aimin. AU - Lewellyn, Andrea L.. AU - Maller, James L.. PY - 2007/10/1. Y1 - 2007/10/1. N2 - In Xenopus laevis embryos, the midblastula transition (MBT) at the 12th cell division marks initiation of critical developmental events, including zygotic transcription and the abrupt inclusion of gap phases into the cell cycle. Interestingly, although an ionizing radiation-induced checkpoint response is absent in pre-MBT embryos, introduction of a threshold amount of undamaged plasmid or sperm DNA allows a DNA damage checkpoint response to be activated. We show here that undamaged threshold DNA directly participates in checkpoint signaling, as judged by several dynamic changes, including H2AX phosphorylation, ATM phosphorylation and loading onto chromatin, and Chk1, Chk2 phosphorylation and release from nuclear DNA. These responses on physically separate threshold DNA require γ-H2AX and are ...
Transmembrane signaling of the CXC chemokine stromal cell-derived factor-1 (SDF-1) is mediated by CXCR4, a G protein-coupled receptor initially identified in leukocytes and shown to serve as a coreceptor for the entry of HIV into lymphocytes. Characterization of SDF-1- and CXCR4-deficient mice has revealed that SDF-1 and CXCR4 are of vital developmental importance. To study the role of the SDF-1/CXCR4-chemokine/receptor system as a regulator of vertebrate development, we isolated and characterized a cDNA encoding SDF-1 of the lower vertebrate Xenopus laevis (xSDF-1). Recombinant xSDF-1 was produced in insect cells, purified, and functionally characterized. Although xSDF-1 is only 64-66% identical with its mammalian counterparts, it is indistinguishable from human (h)SDF-1alpha in terms of activating both X. laevis CXCR4 and hCXCR4. Thus, both xSDF-1 and hSDF-1alpha promoted CXCR4-mediated activation of heterotrimeric G(i2) in a cell-free system and induced release of intracellular calcium ions ...
Membrane potential and resistance were measured in eggs, cleavage stages and blastulae of the South African toad Xenopus laevis, using intracellular microelectrodes.. The membrane potential increased from −6·5 ± 2mV in eggs to −57 ± 8·0mV at the mid-blastula stage.. The input resistance of fertile eggs ranged from 0·5 MΩ to 5·0 MΩ corresponding to a specific resistance of 20-200kΩcm2. During the first two or three division cycles the input resistance usually decreased by a factor of 2-10 and then subsequently rose during the blastula stages from a mean value of 600 ± 100kΩ at stage 5 to 2·0 ± 0·5 MΩ at stage 8.. At all developmental stages examined, point polarization of a surface cell in the embryo by rectangular current pulses of 0·5−6 × 10−8 A produced voltage deflexions in other surface cells. This was seen even when several (7-8) cell junctions intervened between the current passing and voltage recording microelectrodes at distances of more than 1 mm. These ...
Taken together, these studies will reveal how the transcriptional machinery competes with chromatin assembly to regulate transcription, not only during genome activation but potentially also during differentiation and reprogramming.. 2. The role of chromatin structure and nuclear architecture in genome activation. Chromatin regulates the accessibility of the genome for DNA binding proteins. Changes in chromatin structure and nuclear organization are thus critical to understanding how regions of the genome become transcriptionally competent. We have previously shown that dramatic changes in chromatin structure accompany the onset of zygotic gene expression (Vastenhouw et al., Nature 2010 PMID: 20336069; Zhang et al., GR 2014 PMID: 24285721). Thus, the onset of transcription during genome activation provides a powerful system to study the relationship between chromatin structure and transcriptional activity.. We have recently found that transcriptional activity and accumulation of the produced RNA ...
Introduction to Animals Worksheet Circle the correct response. 1. Animals are [ heterotrophs / autotrophs ] 2. [ All / Most ] animals are multicellular. 3. The cells in the skin of your hand are [ bigger than / the same size as ] the cells in your heart. 4. Organisms that have 2 copies of each chromosome are [mobile / diploid ] 5. The absence of a cell wall allows animals [ mobility / diploidy ] 6. A hollow ball of cells that forms after fertilization is called a [ blastula / mesoderm ] 7. In all animals except [ humans / sponges ] a zygote undergoes divisions to become a blastula. 8. The cells of animals are organized into functional units called [ blastula / tissues ] Matching: ...
was studied in under laboratory conditions at a water temperature of 25-26 ℃, salinity of 30, and pH of 7.8-8.4. The embryogenesis of Portunus pelagicus was divided into six stages: cleavage, blastula, gastrula, nauplius, metanauplius, and protozoea. Embryogenesis lasted about 300 h post spawning. Eggs began superficial cleavage about 28 h after spawning when the nucleus appeared at the surface of the egg till the egg divided into 16 cells. The blastula stage was observed about 40 h post spawning and gastrula stage appeared when the presumptive endoderm and other cells near them invaginated. The fourth-stage of embryogenesis, nauplius, was characterized by three pairs of appendages appearing about 90 h post spawning, while metanauplius, the fifth-stage of embryogenesis, was characterized by five pairs of appendages, which appeared about 110 h post spawning. The sixth stage of embryogenesis was protozoea, which was characterized by seven pairs of appendages appearing about 140 h post spawning. ...
Standard protocols were used (Sambrook et al., 1989).. Hsp83-lacZ transgenes. The following approach was taken to generate the series of lacZ-Hsp83 3′‐UTR constructs that include the 5′‐Hsp83 enhancer sequences and promoter (Figure 3B). Previous reports (Kim‐Ha et al., 1993) suggested that a full‐length lacZ ORF might not be completely transcribed in vivo. Therefore, we inserted the Hsp83 3′‐UTR fragments downstream of a truncated lacZ tag. We accomplished this by constructing pB83Z, a Bluescript subclone that contains all of the Hsp83 5′ upstream region, the first exon, the intron and the first 111 codons of the ORF fused to 603 bp of lacZ sequence (Halsell, 1995). At the 3′ end of the lacZ sequence are AatII, HindIII and KpnI cloning sites for inserting the Hsp83 3′‐UTR fragments. The template for the PCR was Eco9, an 8 kb EcoRI fragment subcloned in Bluescript that contains the full‐length Hsp83 transcription unit. 5′ Fragments of the 3′‐UTR were PCR amplified ...
Common Atom functions. module Language.Atom.Common ( -- * Timers Timer , timer , startTimer , startTimerIf , timerDone -- * One Shots , oneShotRise , oneShotFall -- * Debouncing , debounce -- * Lookup Tables , lookupTable -- * Hysteresis , hysteresis ) where import Data.Word import Language.Atom.Language -- , A Timer. data Timer = Timer (V Word64) -- , Creates a new timer. timer :: Name -, Atom Timer timer name = do timer ,- word64 name 0 return $ Timer timer -- , Starts a Timer. A timer can be restarted at any time. startTimer :: Timer -, E Word64 -, Atom () startTimer t = startTimerIf t true -- , Conditionally start a Timer. startTimerIf :: Timer -, E Bool -, E Word64 -, Atom () startTimerIf (Timer t) a time = t ,== mux a (clock + time) (value t) -- , True when a timer has completed. timerDone :: Timer -, E Bool timerDone (Timer t) = value t ,=. clock -- , One-shot on a rising transition. oneShotRise :: E Bool -, Atom (E Bool) oneShotRise a = do last ,- bool last False last ,== a return $ ...
Pham, M N; Kolb, H; Battelino, T; Ludvigsson, J; Pozzilli, P; Zivehe, F; Roden, M; Mandrup-Poulsen, T; Schloot, N C (2013). Fasting and meal-stimulated residual beta cell function is positively associated with serum concentrations of proinflammatory cytokines and negatively associated with anti-inflammatory and regulatory cytokines in patients with longer term type 1 diabetes. Diabetologia, 56(6):1356-1363.. Kaas, A; Pfleger, C; Hansen, L; Buschard, K; Schloot, N C; Roep, B O; Mortensen, H B; Schoenle, E J (2010). Association of adiponectin, interleukin (IL)-1ra, inducible protein 10, IL-6 and number of islet autoantibodies with progression patterns of type 1 diabetes the first year after diagnosis. Clinical and Experimental Immunology, 161(3):444-452.. Burkart, V; Siegenthaler, R K; Blasius, E; Vandenbroeck, K; Alloza, I; Fingberg, W; Schloot, N C; Christen, P; Kolb, H (2010). High affinity binding of hydrophobic and autoantigenic regions of proinsulin to the 70 kDa chaperone DnaK. BMC ...
Obtain a slide of a whitefish blastula for observation of the stages of mitosis in an animal cell. Since early embryogenesis involves rapid cellular division, the whitefish blastula has long served as a model of mitotic division in animals. It also has the advantage of demonstrating clear spindle formation in the cytoplasm. ...
Looking for endodermic? Find out information about endodermic. in biology, inner layer of tissue formed in the gastrula stage of the developing embryo. At the end of the blastula stage, cells of the embryo are arranged... Explanation of endodermic
Thông tin Thống đốc Ngân hàng Nhà nước Lê Minh Hưng đưa ra khi trả lời chất vấn của đại biểu Quốc hội cuối tuần qua cho thấy, một lượng vốn lớn của dân cư trú ẩn trong vàng, ngoại tệ trước đây quả thực đã chuyển hóa. Theo đó, không nhất thiết phải huy động nguồn lực vàng, ngoại tệ trong dân cư bằng huy động và cho vay mà có thể dẫn tới nhiều bất ổn như trước đây. Thay vào đó, với tác động của chính sách tiền tệ, thị trường chứng khoán cũng đang kích thích nguồn lực tưởng như nằm im đó.
Gastrulation: | | ||| | Gastrulation occurs when a blastula, made up of one la... World Heritage Encyclopedia, the aggregation of the largest online encyclopedias available, and the most definitive collection ever assembled.
Biology Assignment Help, Emboly - mechanism of gastrulation, EMBO L Y - The embolic morphogenetic movements are concerned with the inward migration of prospective endodermal and mesodermal blastomeres from the external surface of blastula. The movement of mesodermal and endodermal blastomers may take
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:babydust1:Why does it take 50 million sperm to fertilize one egg?:babydust1: Because they wont ask for directions either! August 1st - AnnieJ 2nd - page 76
The gastric avoid is actually completed through separating the actual belly right into a scaled-down top part along with a bigger reduce part as well as
Blastula cell implantation could serve to eliminate infertility. The blastula stage of early embryo development begins with the ... Only when the blastocoel is formed does the early embryo become a blastula. The blastula precedes the formation of the gastrula ... Blastulation is the stage in early animal embryonic development that produces the blastula. The blastula (from Greek βλαστός ( ... In mammals, the blastula is referred to as a blastocyst. The blastocyst contains an embryoblast (or inner cell mass) that will ...
After the 7th cleavage has produced 128 cells, the morula becomes a blastula. The blastula is usually a spherical layer of ... "Blastula". Encyclopedia Britannica. Retrieved 5 October 2020. Hackett JA, Sengupta R, Zylicz JJ, Murakami K, Lee C, Down TA, ... The different cells derived from cleavage, up to the blastula stage, are called blastomeres. Depending mostly on the amount of ... The blastocyst must not be confused with the blastula; even though they are similar in structure, their cells have different ...
Cleavage ends with the formation of the blastula. Depending mostly on the amount of yolk in the egg, the cleavage can be ... Forgács, G.; Newman, Stuart A. (2005). "Cleavage and blastula formation". Biological physics of the developing embryo. ...
Patterning the Xenopus blastula. Development 124:4179-91. 4. Heasman J. 2006. Patterning the early Xenopus embryo. Development ... During the blastula and gastrula stages, vegetal cells (the presumptive endoderm), release signals to marginal zone cells ...
In animals other than mammals, this is called the blastula.) The trophoblasts secrete fluid into the blastocoel. The resulting ... Forgács, G.; Newman, Stuart A. (2005). "Cleavage and blastula formation". Biological physics of the developing embryo. ...
Note that the blastopore is not an opening into the blastocoel, the space within the blastula, but represents a new inpocketing ... In developmental biology, gastrulation is a phase early in the embryonic development of most animals, during which the blastula ... Gastrulation takes place after cleavage and the formation of the blastula. Gastrulation is followed by organogenesis, when ... ISBN 978-0-8160-7008-4. Forgács, G. & Newman, Stuart A. (2005). "Cleavage and blastula formation". Biological physics of the ...
Cleavage results in a blastula. Depending on the species, a blastula stage embryo can appear as a ball of cells on top of yolk ... to form a blastula, which looks similar to a ball of cells. Next, the cells in a blastula-stage embryo start rearranging ... blastula, gastrulation, and organogenesis. Cleavage is the period of rapid mitotic cell divisions that occur after ...
Cleavage (embryo) Blastula Boklage, Charles E. (2009). How New Humans Are Made: Cells and Embryos, Twins and Chimeras, Left and ...
After the blastula hatches from the fertilization envelope, the vegetal side of the blastula begins to flatten and thicken as a ... Even as the blastomeres continue to divide, the blastula remains one-cell thick and thins out as the embryo expands outward. ... An amphibian embryo in the 128- cell stage is considered a blastula as the blastocoel in the embryo becomes apparent during ... At the 120- cell stage, the sea urchin embryo is considered a blastula because of its developed blastocoel, which every ...
Most starfish embryos hatch at the blastula stage. The original ball of cells develops a lateral pouch, the archenteron. The ...
Invagination of the blastula occurs when the endoderm loses its affinity towards hyalin, while the ectoderm retains it. This ... Zinc, then, causes an animalizing effect since the binding of the blastula cells would be stronger, while the weaker attachment ... Timourian, H; Watchmaker, G (1975). "The Sea-Urchin Blastula: Extent of Cellular Determination". American Zoologist. 15 (3): ...
In many animals, the morula then develops by cavitation to become the blastula. Cellular differentiation then develops the ... In other animals this is called a blastula. In humans, blastocyst formation begins about 5 days after fertilization when a ... blastula's cells into two types: trophoblast cells that surround the blastocoel and an inner mass of cells (the embryoblast). ...
Clonal analyses of the blastula and gastrula stages". Developmental Biology. 108 (1): 94-101. doi:10.1016/0012-1606(85)90012-0 ...
In the early blastula stage of the embryo, Ectodermin mRNA and protein forms a gradient that goes from the animal pole (highest ... The mRNA was then injected into several Xenopus embryos at a four-cell stage and looked in early blastula embryos for an ... A cDNA library from the blastula stage of a frog embryo was cloned into RNA expression plasmids to generate synthetic mRNA. ... It has been proposed that Notch and/or NODAL, expressed in the vegetal/mesoderm region of the early blastula embryo, could ...
Twenty hours after fertilization, a blastula with an invaginated pore at the vegetal pole forms. The blastula then rotates ... Fourteen hours after fertilization, a wrinkled blastula is formed. ...
A fourth "layer" consists of the germ cells that are set aside in the embryo at the blastula stage, which are incorporated into ... The germ layers form during gastrulation of the blastula. Additionally, the term may refer to any ovum in which the blastoderm ...
The blastula is polar, and its two halves are called the animal hemisphere and vegetal hemisphere. It is the animal hemisphere ... The cells continue to extend inward and migrate along the inner wall of the blastula to form a fluid-filled cavity called the ... At the start of this process, the developing embryo has divided into many cells, forming a hollow ball called the blastula. ... Baer also received credit for the discovery of the blastula. Baer published his findings, including his germ layer theory, in a ...
The blastula of the tunicates is a little flattened in the vegetal pole making a change of shape from a columnar to a wedge ... During gastrulation, the blastula will be transformed by the invagination. The endoderm will fold towards the inner part and ... Invagination consists of the folding of an area of the exterior sheet of cells towards the inside of the blastula. In each ... the blastula, into a multi-layered organism, with differentiated germ layers: endoderm, mesoderm, and ectoderm. More localized ...
It is specifically expressed during late blastula and gastrula stages. During gastrulation, it is critical in promoting the ...
These fuse to form zygotes, which develop via mitosis into a hollow sphere, called a blastula. In sponges, blastula larvae swim ... The blastula is a stage in embryonic development that is unique to most animals, allowing cells to be differentiated into ... In most other groups, the blastula undergoes more complicated rearrangement. It first invaginates to form a gastrula with a ... the blastula, during embryonic development. Over 1.5 million living animal species have been described-of which around 1 ...
Formation of the blastulaEdit. After the 7th cleavage has produced 128 cells, the embryo is called a blastula.[2] The blastula ... The different cells derived from cleavage, up to the blastula stage, are called blastomeres. Depending mostly on the amount of ... The blastocyst must not be confused with the blastula; even though they are similar in structure, their cells have different ... During gastrulation cells migrate to the interior of the blastula, subsequently forming two (in diploblastic animals) or three ...
During this stage, the embryo is referred to as a blastula. The series of changes to the blastula that characterize the ... In developmental biology, midblastula or midblastula transition (MBT) occurs during the blastula stage of embryonic development ...
This was an important extension of work of Briggs and King in 1952 on transplanting nuclei from embryonic blastula cells. Five ... Robert Briggs & Thomas J. King (May 1952). "Transplantation of Living Nuclei From Blastula Cells into Enucleated Frogs' Eggs". ...
This work was an important extension of work of Briggs and King in 1952 on transplanting nuclei from embryonic blastula cells ... Robert Briggs and Thomas J. King (May 1952). "Transplantation of Living Nuclei From Blastula Cells into Enucleated Frogs' Eggs ...
The BCNE center is the Blastula Chordin and Noggin Expressing center. The BCNE center is located in the dorsal region of the ... This center predisposes cells in the blastula stage to become neural tissue. The cells of the BCNE region give rise to the ... Even with the BCNE center removed from the blastula, the Nieuwkoop Center is able to induce formation of the Spemann-Mangold ... It appears after the mid-blastula stage and is triggered by the expression of beta-catenin like the Nieuwkoop center. This ...
... during late blastula and enriched in the presumptive endodermal cells in late blastula. Notch is both necessary and sufficient ... By the late blastula stage, the Xenopus embryos have a clear dorsal/ventral axis. In the early gastrula, most of the tissue in ... It was observed that β-catenin was present in the nuclei at the vegetal pole of the blastula. Through a series of experiments, ... There are many different developmental potentials throughout the blastula stage embryos. The vegetal cap can give rise to only ...
Briggs, R.; King, T. J. (1952). "Transplantation of Living Nuclei from Blastula Cells into Enucleated Frogs' Eggs". Proceedings ...
... normal segmentation occurs in the blastula but gastrulation fails. Finally, in other crosses, the initial stages are normal but ...
After cleavage, the dividing cells, or morula, becomes a hollow ball, or blastula, which develops a hole or pore at one end. ... In bilateral animals, the blastula develops in one of two ways that divide the whole animal kingdom into two halves (see: ... In due course, the blastula changes into a more differentiated structure called the gastrula. ... Embryological origins of the mouth and anus). If in the blastula the first pore (blastopore) becomes the mouth of the animal, ...
"Coupling of zygotic transcription to mitotic control at the Drosophila mid-blastula transition". Development. 136 (12): 2101- ...
Blastula,, hollow sphere of cells, or blastomeres, produced during the development of an embryo by repeated cleavage of a ... a hollow ball called a blastula. In most mammals the blastula attaches itself to the uterine lining, thus stimulating the ... More About Blastula. 4 references found in Britannica articles. Assorted References. *embryonic development* In embryo ... Blastula, hollow sphere of cells, or blastomeres, produced during the development of an embryo by repeated cleavage of a ...
Some of these blastulae were fixed. The remainder developed as shown in table 2. Of the complete blastulae the majority (74%) ... Development of Blastulae Derived from Enucleated Eggs Injected with Blastula Cell Nuclei ... A blastula or early gastrula (St. 8 to 10, Shumway11), placed in the same dish, is then opened up and one of the subsurface ... The total volume of the donor blastula cell is about 2 ×10−4 cu. mm., while the average volume of the pipiens egg is about 3.4 ...
1995) Expression cloning of siamois, a Xenopus homeobox gene expressed in dorsal-vegetal cells of blastulae and able to induce ... 1994) A functional test for maternally inherited cadherin in Xenopus shows its importance in cell adhesion at the blastula ...
This review starts from the classical standpoint that there are at least two separable processes acting with respect to axis formation and tissue specification in the early Xenopus embryo: a UV-insensitive event establishing a postgastrula embryo consisting of three concentric germ layers, ectoderm, mesoderm and endoderm, all of a ventral character; and a UV-sensitive event producing tissue of a dorsal type, including somites, notochord and neural tissue, and concomitantly establishing the dorsoventral and anteroposterior axes. The experimental evidence suggesting the molecular basis of the dorsal and ventral pathways is reviewed.. ...
From blastula to neural crest, do not pass go. During vertebrate development, neural crest cells give rise to an unusual ... We suggest that neural crest cells may have evolved as a consequence of a subset of blastula cells retaining activity of the ... Here, we describe shared molecular underpinnings of potency in neural crest and blastula cells. We show that in Xenopus, key ... Buitrago-Delgado et al. now show that neural crest cells have components of the molecular programs characteristic of blastula ...
Name: blastula stage XAO Id: 1000003 Definition: Embryonic stage during which the solid morula acquires an internal cavity, ...
blastula definition: An early embryonic form created by cleavage of a fertilized ovum and comprising a spherical layer of cells ... Definition for "blastula"*An early embryonic form created by cleavage of… ... How would you define blastula?. All the definitions on AZdictionary were written by people just like you. Nows your chance to ... Urban Dictionary for "blastula"*Early phase of fetal development composed… ...
... cells of the early blastula animal pole are all equivalent and are fully pluripotent until the midblastula transition that ... Morphogen Gradient Zebrafish Blastula Injection Cell transplantation Bead implantation Embryoid bodies This is a preview of ... Fauny JD, Thisse B, Thisse C (2009) The entire zebrafish blastula-gastrula margin acts as an organizer dependent on the ratio ... In the zebrafish embryo, cells of the early blastula animal pole are all equivalent and are fully pluripotent until the ...
Expression cloning of Siamois, a Xenopus homeobox gene expressed in dorsal-vegetal cells of blastulae and able to induce a ...
BLASTULA PERIOD (2 1/4 - 5 1/4 h). Modified from: Kimmel et al., 1995. Developmental Dynamics 203:253-310. Copyright © 1995 ... By the late blastula period, EVL cell cycles are longer and less synchronous than deep cell cycles (Kane et al., 1992). At the ... We use the term blastula to refer to the period when the blastodisc begins to look ball-like, at the 128-cell stage, or 8th ... Early on, the cells of the blastula continue to divide synchronously, at the same rhythm as before (Fig. 5 and Fig. 9). More ...
A blastula or early gastrula was opened and a single animal pole cell was obtained with a micropipette. The cell surface was ... This part of the experiment was performed by inseminating R. pipiens eggs with R. catesbeiana sperm to create donor blastulae. ... When Briggs and King punctured eggs of Rana pipiens, they observed rotation and abnormal cleavage or blastula formation. When ... Transplantation of Living Nuclei from Blastula Cells into Enucleated Frogs Eggs (1952), by Robert Briggs and Thomas J. King. ...
... - blȁstula ž DEFINICIJA zool. rani oblik brazdanja jajeta mnogih mnogostaničnih životinja ETIMOLOGIJA nlat. blastula: ... blastula - blastula. См. бластула. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л ... Blastula - Blastula, Embryonalstadium der Metazoen; entsteht bei der ⇒ Furchung aus der ⇒ Morula. Die Blastomeren formieren ... Blastula - Blas tu*la, n. [NL., dim. of Gr. blasto s a sprout.] (Biol.) That stage in the development of the ovum in which the ...
... the early developmental stage of an animal, following the morula stage and consisting of a single, ... blastula. (blāschə-lə). Plural blastulas or blastulae (blāschə-lē). An animal embryo at the stage immediately following the ... Definithing > Dictionary > b > Blastula. Blastula. the early developmental stage of an animal, following the morula stage and ... blastula [(blas-chuh-luh)]. Note: This is the stage of development where embryonic stems cells can be harvested for medical ...
Whitefish blastula. Metaphase. Test. Anaphase. Mitosis occurs in whitefish blastula and onion root tip, and it is easily ... Whitefish blastula:. Microtubules align chromosomes along metaphase plate. Virtual Mitosis Lab: Part II - Whitefish Blastula ... Mitosis Whitefish Blastula. Cell Division - Mitosis - in Whitefish Blastula Cells: The arrows (A) in the photo point to a cell ... Explain why whitefish blastula and onion root tips are selected for a study of mitosis. Onion root tips are used because the ...
formation of blastula. *. In morula. blastomeres resulting from a number of cleavages of a zygote, or fertilized egg. Its name ...
Blastula and gastrula represent the important stages of the embryonic development in animals. Blastula, in particular, occurs ... Key Differences between Blastula and Gastrula. Formation. *Blastula is formed from morola and it is the first stage in the ... The cells in blastula are referred to as undifferentiated, and there is no movement of cells during the formation of blastula. ... Home Science & Tech Biology Difference between Blastula and Gastrula. Difference between Blastula and Gastrula. November 6, ...
Furthermore, inner cell mass is another difference between blastula and blastocyst. Blastula does not contain inner cell mass ... and blastocyst is that blastula is the early form of the embryonic development of animals whereas blastocyst is the blastula of ... What is Blastula. Blastula is a stage of early embryonic development of animals. It develops from the morula, which is a solid ... Blastula undergoes gastrulation, developing into the gastrula.. Key Areas Covered. 1. What is Blastula. - Definition, Structure ...
It discusses the various stages of embryonic development (meiosis, fertilization, blastula development, and gastrulation, and ... The Blastula; Gastrulation; Morphogenesis; Biological Fields; Chaos, Fractals, and Deep Structure; Ontogeny and Phylogeny; and ...
Revision history of "Paper - On a human blastula recovered from the uterine cavity 4 days after ovulation (1946)". From ... Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Paper_-_On_a_human_blastula_recovered_from_the_uterine_ ...
Researching How Cells Divide : from Zygote to Blastula. Posted on 2015-09-03. by g2 ...
Results showed that after the lowest DNA methylation level at day 3 (early embryonic stage, blastula) there was an increase by ... Developing an epigenetics model species - From blastula to mature adult, life cycle methylation profile of Enchytraeus ... Developing an epigenetics model species - From blastula to mature adult, life cycle methyl ...
Formation of the blastulaEdit. After the 7th cleavage has produced 128 cells, the embryo is called a blastula.[2] The blastula ... The different cells derived from cleavage, up to the blastula stage, are called blastomeres. Depending mostly on the amount of ... The blastocyst must not be confused with the blastula; even though they are similar in structure, their cells have different ... During gastrulation cells migrate to the interior of the blastula, subsequently forming two (in diploblastic animals) or three ...
The development of A. japonicus includes six major phases: fertilized oocytes, early development (including cleavage, blastula ... The blastula is ciliated and rotates actively. After about 2 to 3 h, the hatched embryo gradually elongates and moves to the ... C the fertilized eggs require about 45 minutes to begin to divide themselves and finally develop into a blastula (Table 1). ...
blastula. the stage of animal embryo development that consists of a hollow ball of cells surrounding a central cavity ... the structure formed from the blastula that has three distinct layers of cells and body axes ...
D) Early blastula. (E) Blastula. Gcm is not expressed within the vegetal plate, but rather in cells scattered within the ... A-C) delta. (A) Blastula stage. (B) Early gastrula stage. (C) Larval stage. Delta is expressed in the central vegetal plate in ... C) Vegetal pole view of foxa expression in a blastula-stage embryo in which one of two blastomeres of the two-cell embryo was ... A and B) Vegetal views of blastula-stage embryos in which one of the first two blastomeres had been injected with a MASO ...
At a minimum, this needs to be provided for the blastula transplant experiments, which are often somewhat noisy, yet many of ... differentiation defect? Were the chimeric transplants (i.e. nac;pfe;leo-tk3) done with GFP labelled blastula cells, which could ... differentiation defect? Were the chimeric transplants (i.e. nac;pfe;leo-tk3) done with GFP labelled blastula cells, which could ... Blastula transplantations. Request a detailed protocol Chimeric animals were generated by transplantations of cells during ...
After cleavage, the dividing cells, or morula, becomes a hollow ball, or blastula, which develops a hole or pore at one end. ... In bilateral animals, the blastula develops in one of two ways that divide the whole animal kingdom into two halves (see: ... In due course, the blastula changes into a more differentiated structure called the gastrula. ... Embryological origins of the mouth and anus). If in the blastula the first pore (blastopore) becomes the mouth of the animal, ...
Blastocyst (also Blastula): A hollow ball of cells that forms early in the development of an animal embryo-about four days ...
mid-blastula transition E??J ځAMBT midkine ~ b h J C Miller-Dieker syndrome ~ [ f B [ J [ nj Q ...
This sheet of cells folds and forms a hollow sphere resembling a normal blastula at the 29-210-cell stage (closing movement ... Kadokawa, Y. ; Dan-Sohkawa, M. ; Eguchi, G. / Studies on the mechanism of blastula formation in starfish embryos denuded of ... Kadokawa, Y, Dan-Sohkawa, M & Eguchi, G 1986, Studies on the mechanism of blastula formation in starfish embryos denuded of ... Studies on the mechanism of blastula formation in starfish embryos denuded of fertilization membrane. / Kadokawa, Y.; Dan- ...
  • Blastula , hollow sphere of cells, or blastomeres, produced during the development of an embryo by repeated cleavage of a fertilized egg. (britannica.com)
  • When Briggs and King punctured eggs of Rana pipiens , they observed rotation and abnormal cleavage or blastula formation. (asu.edu)
  • During cleavage process, this newly formed fertilized ovum will divide rapidly into many cells and lead to blastula, which in mammals is called the blastocyst. (knowswhy.com)
  • The different cells derived from cleavage, up to the blastula stage , are called blastomeres . (wikipedia.org)
  • The development of A. japonicus includes six major phases: fertilized oocytes, early development (including cleavage, blastula and gastrula), auricularia (including early auricularia, middle auricularia and late auricularia), metamorphosis (including doliolaria and pentactula), juvenile, young sea cucumber and adult (Figure 1). (fao.org)
  • After cleavage , the dividing cells, or morula , becomes a hollow ball, or blastula , which develops a hole or pore at one end. (wikipedia.org)
  • After the 7th cleavage has produced 128 cells, the morula becomes a blastula. (wikipedia.org)
  • The zygote undergoes cleavage to form the blastula. (bartleby.com)
  • In organisms such as mammals, the earlier morula ( q.v. ), a berrylike cluster of cells, develops into a somewhat different form of blastula, the blastocyst ( q.v. ). (britannica.com)
  • Blastula is actualy formed from morula which produces hundreds of cells. (knowswhy.com)
  • or blastula) A hollow ball of cells formed from a morula about five days after fertilization. (thefreedictionary.com)
  • The main difference between blastula and blastocyst is that blastula is the early form of the embryonic development of animals whereas blastocyst is the blastula of mammals . (pediaa.com)
  • Furthermore, blastula is characterized by the presence of a spherical layer of cells filled with fluid while blastocyst is lined by a layer of trophoblast cells and it contains an inner cell mass at one end and the fluid-filled cavity is known as blastocoel . (pediaa.com)
  • Blastula and blastocyst are two types of early stages of embryonic development of animals. (pediaa.com)
  • Moreover, blastocyst undergoes its further developing process known as gastrulation in which the single-layered blastula reorganizes into a multilayered structure. (pediaa.com)
  • Blastula refers to an animal embryo at the early stage of development when it is a hollow ball of cells whereas blastocyst refers to mammalian blastula in which some differentiation of cells has occurred. (pediaa.com)
  • Thus, this is the main difference between blastula and blastocyst. (pediaa.com)
  • Also, another difference between blastula and blastocyst is that bastula occurs in animals while blastocyst occurs in mammals. (pediaa.com)
  • The outer cell layer of the blastula is known as blastomeres while the outer cell layer of the blastocyst is known as the trophoblast. (pediaa.com)
  • Furthermore, inner cell mass is another difference between blastula and blastocyst. (pediaa.com)
  • Blastula does not contain an inner cell mass while blastocyst contains an inner cell mass. (pediaa.com)
  • Moreover, blastomere or blastoderm is pluripotent in the blastula while the inner cell mass is pluripotent in the blastocyst. (pediaa.com)
  • Hence, this is another difference between blastula and blastocyst. (pediaa.com)
  • In mammals, the blastula is referred to as a blastocyst. (wikipedia.org)
  • In the mammalian blastocyst (term for mammalian blastula) there are three lineages that give rise to later tissue development. (wikipedia.org)
  • The blastula is usually a spherical layer of cells (the blastoderm) surrounding a fluid-filled or yolk-filled cavity (the blastocoel or blastocyst). (wikipedia.org)
  • Mammals at this stage form a structure called the blastocyst,[1] characterized by an inner cell mass that is distinct from the surrounding blastula. (wikipedia.org)
  • After the blastula develops, it undergoes transition to the gastrula ( q.v. ), a process called gastrulation. (britannica.com)
  • We use the term blastula to refer to the period when the blastodisc begins to look ball-like, at the 128-cell stage, or 8th zygotic cell cycle, and until the time of onset of gastrulation, ca. cycle 14. (zfin.org)
  • Gastrula is formed just after the blastula during the process termed gastrulation. (knowswhy.com)
  • Blastula undergoes gastrulation, developing into the gastrula . (pediaa.com)
  • It discusses the various stages of embryonic development (meiosis, fertilization, blastula development, and gastrulation, and then the embryology of each of the human organs and organ systems in detail). (northatlanticbooks.com)
  • The blastula undergoes gastrulation to form the gastrula. (bartleby.com)
  • 2. The first thing that forms during gastrulation is a(n) _____ in the side of the blastula. (study.com)
  • The outer layer of a blastula that gives rise to the ectoderm after gastrulation. (dictionary.com)
  • The cells of the blastula form an epithelial (covering) layer, called the blastoderm , enclosing a fluid-filled cavity, the blastocoel . (britannica.com)
  • The inside of the blastula is a fluid-filled cavity known as blastocoel. (pediaa.com)
  • The blastula and blastocoel develop into the gastrula, which contains the three germ layers in a process. (pediaa.com)
  • The blastula (from Greek βλαστός (blastos meaning sprout) is a hollow sphere of cells (blastomeres) surrounding an inner fluid-filled cavity (the blastocoel). (wikipedia.org)
  • Only when the blastocoel is formed does the early embryo become a blastula. (wikipedia.org)
  • A common feature of a vertebrate blastula is that it consists of a layer of blastomeres, known as the blastoderm, which surrounds the blastocoel. (wikipedia.org)
  • The blastula stage of early embryo development begins with the appearance of the blastocoel. (wikipedia.org)
  • A blastula is a sphere of cells surrounding a blastocoel. (wikipedia.org)
  • Briggs and King used amphibian cells from the late blastula , which are similar in size to differentiated cells of embryos that are a little older. (asu.edu)
  • Kadokawa, Y , Dan-Sohkawa, M & Eguchi, G 1986, ' Studies on the mechanism of blastula formation in starfish embryos denuded of fertilization membrane ', Cell Differentiation , vol. 19, no. 2, pp. 79-88. (fujita-hu.ac.jp)
  • In Xenopus embryos, the blastula is composed of three different regions. (wikipedia.org)
  • A) In situ hybridization examining Sox2 and Sox3 expression in wildtype Xenopus embryos collected between blastula and late neurula stages. (biologists.com)
  • Furthermore, the cost of synthesis in the larval stages was also similar to costs measured for blastula and gastrula embryos of 8.4±0.99 J mg -1 protein synthesized. (biologists.org)
  • In most animals, embryos pass through a blastula stage , [11] which is a characteristic exclusive to animals, and which allows for differentiation into specialized tissues and organs. (wikipedia.org)
  • We show that in Xenopus , key neural crest regulatory factors are also expressed in blastula animal pole cells and promote pluripotency in both cell types. (sciencemag.org)
  • In many animals, such as Drosophila and Xenopus, the mid blastula transition (MBT) is a crucial step in development during which the maternal mRNA is degraded and control over development is passed to the embryo. (wikipedia.org)
  • In many organisms including Xenopus and Drosophila, the midblastula transition usually occurs after a particular number of cell divisions for a given species, and is defined by the ending of the synchronous cell division cycles of the early blastula development, and the lengthening of the cell cycles by the addition of the G1 and G2 phases. (wikipedia.org)
  • A photograph of an early stage blastula from the Xenopus laevis frog. (learner.org)
  • Heasman, J. (1997) Patterning the Xenopus blastula. (springer.com)
  • A blastula is a spherical arrangement of cells, like a zygote, that results from fertilization. (ecophoto.de)
  • Blastula results from zygote rapid mitotic divisions whereas gastrula results from blastula slow mitotic divisions. (knowswhy.com)
  • Mitosis Answer and Explanation: Onion root tips and whitefish blastula are commonly used to illustrate mitosis because these are tissues that are undergoing high rates of mitosis. (ecophoto.de)
  • Virtual Mitosis Lab: Part II - Whitefish Blastula Introduction: Mitosis is considered nuclear division, since its main stages deal strictly with the nucleus and its contents (DNA). (ecophoto.de)
  • Cell Division - Mitosis - in Whitefish Blastula Cells: The arrows (A) in the photo point to a cell in the prophase stage of mitosis. (ecophoto.de)
  • Two specimens are commonly used by biologists to study mitosis: the blastula of a whitefish and the root tip of an onion. (ecophoto.de)
  • Cell Division - Mitosis - in Whitefish Blastula Cells: This cell is in the interphase stage of the cell cycle. (ecophoto.de)
  • Mitosis occurs in whitefish blastula and onion root tip, and it is easily observable. (ecophoto.de)
  • Explain why whitefish blastula and onion root tips are selected for a study of mitosis. (ecophoto.de)
  • Blastula continues to grow, cells continue reproducing using mitosis . (wikipedia.org)
  • Obtain a slide of a whitefish blastula for observation of the stages of mitosis in an animal cell. (gac.edu)
  • Using Figure 11.3A as a guide, draw and label all stages of mitosis, including spindle formation, in the whitefish blastula. (gac.edu)
  • The marginal tier of blastomeres in the early blastula have a unique fate. (zfin.org)
  • Generally, blastula consists of an outer layer of cells known as blastomeres. (pediaa.com)
  • Furthermore, one of the main characteristic features of the blastula of vertebrates is the presence of a layer of blastomeres known as the blastoderm. (pediaa.com)
  • Why are the onion root tip and the whitefish blastula useful tissues for the study of cell division? (ecophoto.de)
  • Whitefish Blastula, when dyed properly, clearly shows the spindle. (wikibooks.org)
  • Since early embryogenesis involves rapid cellular division, the whitefish blastula has long served as a model of mitotic division in animals. (gac.edu)
  • However, the study of the blastula stage is important in stem cell techniques and fertility treatments. (pediaa.com)
  • The study of the blastula and of cell specification has many implications in stem cell research and assisted reproductive technology. (wikipedia.org)
  • A blastula is a hollow and spherically-shaped structure with a single cell layer called the blastoderm. (knowswhy.com)
  • As highlighted already, gastrula is the embryonic development stage preceded by blastula. (knowswhy.com)
  • Blastula is formed from morola and it is the first stage in the embryogenesis formed from blastulation. (knowswhy.com)
  • Blastula is basically referred to as the pre-embryo stage and the gastrula as the mature stage. (knowswhy.com)
  • Blastula is a stage of early embryonic development of animals. (pediaa.com)
  • Moreover, several activities occur in the blastula stage of the embryo including the establishment of cell polarity, regulation of gene expression , cell specification, axis formation, etc. (pediaa.com)
  • Results showed that after the lowest DNA methylation level at day 3 (early embryonic stage, blastula ) there was an increase by day 7 ( organogenesis ) after which levels were maintained at days 11, 18 and 25. (bvsalud.org)
  • Blastulation is the stage in early animal embryonic development that produces the blastula. (wikipedia.org)
  • By manipulating the cell signals during the blastula stage of development, various tissues can be formed. (wikipedia.org)
  • In many organisms the development of the embryo up to this point and for the early part of the blastula stage is controlled by maternal mRNA, so called because it was produced in the egg prior to fertilization and is therefore exclusively from the mother. (wikipedia.org)
  • In the following slides, we'll explore the basic characteristics shared by all (or at least most) animals, from snails and zebras to mongooses and sea anemones: multicellularity, eukaryotic cell structure, specialized tissues, sexual reproduction, a blastula stage of development, motility, heterotrophy and possession of an advanced nervous system. (thoughtco.com)
  • Only true animals experience the next stage: the formation of a blastula, a hollow sphere of multiple cells surrounding an inner fluid cavity. (thoughtco.com)
  • With few exceptions, animals are motile (able to move), heterotrophic (consume organic material), reproduce sexually , and their embryonic development includes a blastula stage. (wikipedia.org)
  • Agrican clawed frog embryo was cut in halves at blastula stage. (flashcardmachine.com)
  • At this stage it is called a blastula. (earthlife.net)
  • The msp130 transcripts are first detected at the blastula stage, in micromere-lineage cells just prior to ingression. (davidson.edu)
  • Animals are generally considered to be multicellular organisms that are capable of locomotion in response to their environment (motile), are required to ingest or eat and swallow other organisms to gain proper nutrition (heterotropic), contain within each cell genetic material organized as two sets of chromosomes within a membrane-bound nucleus ( eukaryotic ), develop through a blastula (hollow ball) stage, and integrate muscle tissue, nervous tissue, and collagen into their body. (newworldencyclopedia.org)
  • now show that neural crest cells have components of the molecular programs characteristic of blastula cells from earlier in development (see the Perspective by Hoppler and Wheeler). (sciencemag.org)
  • We suggest that neural crest cells may have evolved as a consequence of a subset of blastula cells retaining activity of the regulatory network underlying pluripotency. (sciencemag.org)
  • Though neural crest cells and blastula cells have many similarities, they express different Sox transcription factors, with the neural crest transitioning to expressing SoxE factors (Sox8-10). (biologists.com)
  • It is present at the mesenchyme blastula, gastrula and pluteus stages (Leaf et al. (davidson.edu)
  • Disclaimer: Blastula definition / meaning should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional. (definithing.com)
  • In the zebrafish embryo, cells of the early blastula animal pole are all equivalent and are fully pluripotent until the midblastula transition that occurs at the tenth cell cycle (512 to 1K cells). (springer.com)
  • First, early expression of SoxE in the blastula inhibits expression of pluripotent cell markers. (biologists.com)
  • We show that FGF signaling controls a subset of genes expressed by pluripotent blastula cells, and find a striking switch in the signaling cascades activated by FGF signaling as cells lose pluripotency and commence lineage restriction. (elifesciences.org)
  • In the Amphibia the cells of choice for this purpose are those of the late blastula. (pnas.org)
  • A blastula or early gastrula (St. 8 to 10, Shumway 11 ), placed in the same dish, is then opened up and one of the subsurface animal pole cells is dissected free from its neighbors. (pnas.org)
  • Blastula cells have the broad range of developmental potentials necessary to build the embryo. (sciencemag.org)
  • Here, we describe shared molecular underpinnings of potency in neural crest and blastula cells. (sciencemag.org)
  • Early on, the cells of the blastula continue to divide synchronously, at the same rhythm as before ( Fig. 5 and Fig. 9 ). (zfin.org)
  • In 1952 Robert Briggs and Thomas J. King published their article, "Transplantation of Living Nuclei from Blastula Cells into Enucleated Frogs' Eggs," in the Proceedings of the National Academy of Sciences , the culmination of a series of experiments conducted at the Institute for Cancer Research and Lankenau Hospital Research Institute in Philadelphia, Pennsylvania. (asu.edu)
  • Therefore, their experiment showed that living nuclei could be transplanted from blastula or early gastrula cells into enucleated eggs. (asu.edu)
  • The cells in blastula are referred to as undifferentiated, and there is no movement of cells during the formation of blastula. (knowswhy.com)
  • There are most differentiated cells in gastrula, whereas the blastula has 128 undifferentiated cells. (knowswhy.com)
  • There is no observed movement of cells during the formation of blastula. (knowswhy.com)
  • The cells in blastula are few and are referred to as undifferentiated, whereas those in the gastrula are many and are referred to as differentiated cells. (knowswhy.com)
  • Blastula cells are undifferentiated while gastrula cells are differentiated are more than the ones in blastula. (knowswhy.com)
  • It's only when cells are enclosed in a blastula that they start differentiating into different tissue types, as described in slide #4. (thoughtco.com)
  • SoxB1 transcription factors (Sox1-3) maintain the stem cell state in the early blastula and in embryonic stem cells. (biologists.com)
  • Here, they used explant cultures of blastula cells and measured the induction of mesoderm markers over time. (biologists.com)
  • What are the individual cells of the blastula called? (studystack.com)
  • Indeed, we found that factors that have long been considered neural crest potency factors, such as Snail1 ( Taylor and LaBonne, 2007 ) and Sox5 ( Nordin and LaBonne, 2014 ), are expressed earlier, in blastula animal pole cells, and are required for their pluripotency. (elifesciences.org)
  • The relative abundance of msp130 transcripts is uniform among the 32 cells of this lineage in secondary mesenchyme blastulae and in gastrulae. (davidson.edu)
  • The formation of blastula is as a result of the process called blastulation. (knowswhy.com)
  • Blastula and gastrula represent the important stages of the embryonic development in animals. (knowswhy.com)
  • More accurately, the cleavages during the early blastula period are "metasynchronous" because the mitoses do not all occur at quite the same time. (zfin.org)
  • A blastula or early gastrula was opened and a single animal pole cell was obtained with a micropipette. (asu.edu)
  • URD identified the trajectories of 25 cell types through early somitogenesis, gene expression along them, and their spatial origin in the blastula. (nih.gov)
  • Blastula, in particular, occurs prematurely in embryonic development whereas gastrula happens later after the formation of blastula. (knowswhy.com)
  • Following the formation of blastula is the formation of gastrula at an advanced embryonic development. (knowswhy.com)
  • Furthermore, there are rapid mitotic divisions in the formation of blastula while there are slow mitotic divisions in the formation of gastrula. (knowswhy.com)
  • There are cell movements in the formation of gastrula while there are no observed movements in the formation of blastula. (knowswhy.com)
  • The blastula precedes the formation of the gastrula in which the germ layers of the embryo form. (wikipedia.org)
  • The cortical nuclear divisions continue until the mid‐blastula transition (MBT), at which time cellularisation results in the formation of a multicellular embryo. (els.net)
  • The blastula develops into gastrula. (bartleby.com)
  • This ball grows into a blastula which later develops into a baby. (wikibooks.org)
  • The series of mitotic cell divisions that produces a blastula from a fertilized ovum. (thefreedictionary.com)
  • Cellularisation, a key feature of the mid‐blastula transition, marks the time at which zygotic transcription occurs and maternal products are degraded. (els.net)
  • any cell that occurs in the BLASTULA . (thefreedictionary.com)
  • The blastula implants on what day after fertilization? (studystack.com)
  • lo mesodèrma de la neurula que's divisa en segment regulars qui balharàn los somits e las vertèbras . (wikipedia.org)
  • When the water temperature ranges from 21 to 24 °C the fertilized eggs require about 45 minutes to begin to divide themselves and finally develop into a blastula (Table 1). (fao.org)
  • The mid-blastula transition is also characterized by a marked increase in transcription of new, non-maternal mRNA transcribed from the genome of the organism. (wikipedia.org)
  • In vitro fertilisation involves implantation of a blastula into a mother's uterus. (wikipedia.org)