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)

In the medical field, a blastula is an early stage of embryonic development that occurs during the first few days after fertilization. It is a hollow ball of cells that is formed when the fertilized egg (zygote) begins to divide and multiply. The blastula is characterized by the presence of a fluid-filled cavity called the blastocoel, which is surrounded by a layer of cells called the blastoderm. The blastoderm is further divided into two layers: the inner cell mass, which will eventually give rise to the embryo, and the trophoblast, which will develop into the placenta. The blastula stage is a critical period of development, as it marks the beginning of gastrulation, the process by which the embryo develops into a three-dimensional structure with distinct regions. The blastula stage is also important for the formation of the primitive streak, which will eventually give rise to the embryo's primitive gut and other structures.

In the medical field, a blastocyst is an early stage of human development that occurs about 5-6 days after fertilization. It is a hollow ball of cells that is about 0.1-0.2 millimeters in diameter. The blastocyst consists of three main layers of cells: the inner cell mass, the trophoblast, and the zona pellucida. The inner cell mass is a cluster of cells that will eventually develop into the embryo and placenta. The trophoblast is a layer of cells that will develop into the placenta and nourish the developing embryo. The zona pellucida is a protective layer that surrounds the blastocyst and prevents it from being absorbed by the mother's body. The blastocyst is a critical stage in human development because it is the time when the embryo implants itself into the lining of the uterus. If the blastocyst successfully implants, it will continue to develop into a fetus. If it does not implant, it will be shed from the uterus during menstruation.

Xenopus proteins are proteins that are found in the African clawed frog, Xenopus laevis. These proteins have been widely used in the field of molecular biology and genetics as model systems for studying gene expression, development, and other biological processes. Xenopus proteins have been used in a variety of research applications, including the study of gene regulation, cell signaling, and the development of new drugs. They have also been used to study the mechanisms of diseases such as cancer, neurodegenerative disorders, and infectious diseases. In the medical field, Xenopus proteins have been used to develop new treatments for a variety of diseases, including cancer and genetic disorders. They have also been used to study the effects of drugs and other compounds on biological processes, which can help to identify potential new treatments for diseases. Overall, Xenopus proteins are important tools in the field of molecular biology and genetics, and have contributed significantly to our understanding of many biological processes and diseases.

Blastomeres are the cells that divide during early stages of embryonic development. They are the building blocks of the embryo and eventually give rise to all the different tissues and organs of the body. Blastomeres are characterized by their rapid cell division and their ability to differentiate into different cell types as the embryo develops. In medical research, blastomeres are often used to study the early stages of embryonic development and to generate stem cells for therapeutic purposes.

Nodal signaling ligands are a group of proteins that play a crucial role in embryonic development and tissue regeneration. They are also known as Nodal proteins or TGF-beta superfamily members. Nodal signaling ligands are secreted by cells and bind to specific receptors on the surface of neighboring cells, triggering a signaling cascade that regulates cell differentiation, proliferation, and migration. They are involved in a wide range of biological processes, including embryonic patterning, organogenesis, and tissue repair. In the medical field, Nodal signaling ligands have been studied for their potential therapeutic applications. For example, they have been shown to promote the regeneration of damaged tissues, such as the heart and spinal cord, and to play a role in the development of certain cancers. Additionally, Nodal signaling ligands have been used as targets for the development of new drugs to treat various diseases, including cancer and autoimmune disorders.

Goosecoid Protein is a type of transcription factor that plays a crucial role in the development of various tissues and organs in the human body. It is encoded by the "GOSE1" gene and is primarily expressed in the developing limbs, heart, and brain. In the developing limbs, Goosecoid Protein is involved in the formation of the digits and the development of the skeletal system. It also plays a role in the development of the heart, where it helps to regulate the formation of the cardiac muscle and the conduction system. Goosecoid Protein is also involved in the development of the brain, where it helps to regulate the formation of the neural tube and the development of the spinal cord. In the medical field, Goosecoid Protein is studied as a potential target for the treatment of various diseases, including cancer, cardiovascular disease, and neurological disorders. It is also being studied as a potential biomarker for the early detection of certain diseases.

Zebrafish proteins refer to proteins that are expressed in the zebrafish, a small freshwater fish that is commonly used as a model organism in biomedical research. These proteins can be studied to gain insights into the function and regulation of proteins in humans and other organisms. Zebrafish are particularly useful as a model organism because they have a similar genetic makeup to humans and other vertebrates, and they develop externally, making it easy to observe and manipulate their development. Additionally, zebrafish embryos are transparent, allowing researchers to visualize the development of their organs and tissues in real-time. Zebrafish proteins have been studied in a variety of contexts, including the development of diseases such as cancer, cardiovascular disease, and neurodegenerative disorders. By studying zebrafish proteins, researchers can identify potential therapeutic targets and develop new treatments for these diseases.

In the medical field, "body patterning" refers to the study of the distribution and arrangement of body structures, such as bones, muscles, and organs, within an individual's body. This can include the analysis of the shape, size, and orientation of these structures, as well as their relationships to one another. Body patterning is an important aspect of medical diagnosis and treatment, as it can provide valuable information about an individual's overall health and the potential causes of any health problems they may be experiencing. For example, a doctor may use body patterning to identify structural abnormalities or imbalances that may be contributing to a patient's pain or other symptoms. Body patterning can be studied using a variety of techniques, including medical imaging, physical examination, and anthropological analysis. It is an interdisciplinary field that draws on knowledge from a range of medical and scientific disciplines, including anatomy, physiology, genetics, and biomechanics.

Transcription factor 3 (TF3) is a protein that plays a role in regulating gene expression in the cell. It is a member of the nuclear factor-kappa B (NF-κB) family of transcription factors, which are proteins that bind to specific DNA sequences and control the transcription of genes. TF3 is involved in a variety of cellular processes, including cell growth, differentiation, and apoptosis (programmed cell death). It is also involved in the regulation of the immune response and the inflammatory response. In the medical field, TF3 is of interest because it has been implicated in the development and progression of a number of diseases, including cancer, autoimmune disorders, and inflammatory diseases. For example, TF3 has been shown to be overexpressed in certain types of cancer, and it may play a role in the development and progression of these diseases. It is also being studied as a potential therapeutic target for the treatment of these diseases.

Activins are a family of signaling proteins that play important roles in various biological processes, including embryonic development, cell differentiation, and tissue repair. They are composed of two chains, alpha and beta, that are encoded by different genes and can form either homodimers or heterodimers. Activins are secreted by cells and bind to specific receptors on the surface of target cells, triggering a signaling cascade that regulates gene expression and cellular activity. In the medical field, activins have been studied for their potential therapeutic applications in a variety of diseases, including infertility, cancer, and autoimmune disorders.

In the medical field, a nodal protein is a type of signaling protein that plays a crucial role in the development and differentiation of cells. Nodal proteins are members of the transforming growth factor-beta (TGF-beta) superfamily and are involved in the regulation of various cellular processes, including cell proliferation, migration, and differentiation. Nodal proteins are particularly important during embryonic development, where they help to establish the body plan and determine the fate of different cell types. They are also involved in the development of various organs and tissues, including the heart, lungs, and limbs. In the context of cancer, nodal proteins have been implicated in the development and progression of various types of tumors. For example, overexpression of nodal proteins has been associated with the development of breast cancer, ovarian cancer, and other types of cancer. Overall, nodal proteins are important signaling molecules that play a critical role in the development and function of various tissues and organs in the body.

T-Box Domain Proteins are a family of transcription factors that play important roles in the development and differentiation of various cell types in the body. They are characterized by the presence of a conserved T-box DNA binding domain, which allows them to interact with specific DNA sequences and regulate gene expression. T-Box Domain Proteins are involved in a wide range of biological processes, including cell proliferation, differentiation, migration, and apoptosis. They have been implicated in the development and progression of various diseases, including cancer, cardiovascular disease, and neurological disorders. In the medical field, T-Box Domain Proteins are the subject of ongoing research, with the goal of understanding their roles in disease pathogenesis and developing targeted therapies for the treatment of these conditions.

Benzoylarginine Nitroanilide (BAN) is a synthetic peptide that is used as a substrate for the measurement of angiotensin-converting enzyme (ACE) activity. ACE is an enzyme that plays a key role in the renin-angiotensin-aldosterone system (RAAS), which regulates blood pressure and fluid balance in the body. In medical research and clinical practice, BAN is often used to assess ACE activity in various tissues and fluids, including blood, urine, and tissue extracts. This information can be useful in the diagnosis and treatment of a variety of conditions, including hypertension, heart failure, and kidney disease. BAN is typically administered as a solution or suspension, and its effects are measured by monitoring changes in the absorbance of light at a specific wavelength. The rate of absorption is proportional to the amount of ACE activity present in the sample, allowing researchers and clinicians to quantify ACE activity and assess its role in various physiological and pathological processes.

Inhibins are a group of hormones produced by the ovaries and testes in humans and other animals. They play a role in regulating the production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by the pituitary gland. Inhibins are primarily produced by the granulosa cells of the ovarian follicles and the Sertoli cells of the testes. Inhibins act as negative feedback regulators of FSH and LH production. When the levels of FSH and LH are high, inhibins are produced and released into the bloodstream, which then inhibits the production of FSH and LH by the pituitary gland. This feedback mechanism helps to maintain a balance between the production of FSH and LH and the development of ovarian follicles and sperm production. Inhibins are also involved in the regulation of pregnancy and lactation. During pregnancy, the levels of inhibins increase, which helps to suppress the production of FSH and LH, preventing the development of additional ovarian follicles and ovulation. In lactating women, inhibins help to suppress the production of FSH and LH, preventing the return of the menstrual cycle until after lactation has ended. Abnormal levels of inhibins can be associated with various medical conditions, including polycystic ovary syndrome (PCOS), premature ovarian failure, and testicular cancer.

Bone morphogenetic proteins (BMPs) are a group of signaling proteins that play a crucial role in the development and maintenance of bone tissue. They are secreted by various cells in the body, including bone-forming cells called osteoblasts, and are involved in processes such as bone growth, repair, and remodeling. BMPs are also used in medical treatments to promote bone growth and healing. For example, they are sometimes used in orthopedic surgeries to help repair fractures or to stimulate the growth of new bone in areas where bone has been lost, such as in spinal fusion procedures. They may also be used in dental procedures to help promote the growth of new bone in areas where teeth have been lost. BMPs are also being studied for their potential use in other medical applications, such as in the treatment of osteoporosis, a condition characterized by weak and brittle bones, and in the repair of damaged or diseased tissues in other parts of the body.

In the medical field, blastoderm refers to the early stage of development of an embryo in which the cells are arranged in a single layer and are undergoing rapid cell division. The blastoderm is the first visible structure that forms after fertilization and is composed of two distinct layers: the inner cell mass (ICM) and the trophectoderm. The ICM is the layer of cells that will eventually give rise to all the internal organs and tissues of the developing embryo, while the trophectoderm will develop into the placenta and other structures that support the growth and development of the embryo. The blastoderm stage is a critical period of development, as it sets the stage for the formation of all the major organs and tissues of the body. Any abnormalities or disruptions during this stage can have serious consequences for the health and development of the embryo.

SOXF transcription factors are a family of transcription factors that play a crucial role in the development and differentiation of various tissues and organs in the body. The SOXF transcription factors include SOX9, SOX10, and SOX11, which are encoded by the SOX9, SOX10, and SOX11 genes, respectively. SOXF transcription factors are involved in a wide range of biological processes, including cell proliferation, differentiation, and apoptosis. They are particularly important in the development of the nervous system, where they regulate the differentiation of neural crest cells, which give rise to many different cell types, including neurons, glia, and Schwann cells. In addition to their role in development, SOXF transcription factors have also been implicated in various diseases and disorders, including cancer, neurodegenerative diseases, and developmental disorders such as congenital heart defects and cleft palate. Overall, SOXF transcription factors are an important class of transcription factors that play a critical role in the development and function of many different tissues and organs in the body.

Fetal proteins are proteins that are produced by the developing fetus and are present in the mother's blood during pregnancy. These proteins are not normally present in the mother's blood before pregnancy and are not produced by the mother's body. They are produced by the fetus as it grows and develops, and they can be used to monitor the health and development of the fetus. There are several different types of fetal proteins, including alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3). These proteins are typically measured in the mother's blood through a blood test called a pregnancy test or a pregnancy screening test. The levels of these proteins can provide information about the health of the fetus and can be used to detect certain conditions, such as neural tube defects, chromosomal abnormalities, and fetal tumors. It is important to note that the levels of fetal proteins in the mother's blood can also be affected by other factors, such as the mother's age, weight, and medical history. Therefore, the results of a pregnancy test or pregnancy screening test should be interpreted in the context of the mother's overall health and medical history.

In the medical field, a base sequence refers to the specific order of nucleotides (adenine, thymine, cytosine, and guanine) that make up the genetic material (DNA or RNA) of an organism. The base sequence determines the genetic information encoded within the DNA molecule and ultimately determines the traits and characteristics of an individual. The base sequence can be analyzed using various techniques, such as DNA sequencing, to identify genetic variations or mutations that may be associated with certain diseases or conditions.

Homeodomain proteins are a class of transcription factors that play a crucial role in the development and differentiation of cells and tissues in animals. They are characterized by a highly conserved DNA-binding domain called the homeodomain, which allows them to recognize and bind to specific DNA sequences. Homeodomain proteins are involved in a wide range of biological processes, including embryonic development, tissue differentiation, and organogenesis. They regulate the expression of genes that are essential for these processes by binding to specific DNA sequences and either activating or repressing the transcription of target genes. There are many different types of homeodomain proteins, each with its own unique function and target genes. Some examples of homeodomain proteins include the Hox genes, which are involved in the development of the body plan in animals, and the Pax genes, which are involved in the development of the nervous system. Mutations in homeodomain proteins can lead to a variety of developmental disorders, including congenital malformations and intellectual disabilities. Understanding the function and regulation of homeodomain proteins is therefore important for the development of new treatments for these conditions.

In the medical field, RNA, Messenger (mRNA) refers to a type of RNA molecule that carries genetic information from DNA in the nucleus of a cell to the ribosomes, where proteins are synthesized. During the process of transcription, the DNA sequence of a gene is copied into a complementary RNA sequence called messenger RNA (mRNA). This mRNA molecule then leaves the nucleus and travels to the cytoplasm of the cell, where it binds to ribosomes and serves as a template for the synthesis of a specific protein. The sequence of nucleotides in the mRNA molecule determines the sequence of amino acids in the protein that is synthesized. Therefore, changes in the sequence of nucleotides in the mRNA molecule can result in changes in the amino acid sequence of the protein, which can affect the function of the protein and potentially lead to disease. mRNA molecules are often used in medical research and therapy as a way to introduce new genetic information into cells. For example, mRNA vaccines work by introducing a small piece of mRNA that encodes for a specific protein, which triggers an immune response in the body.

In the medical field, an amino acid sequence refers to the linear order of amino acids in a protein molecule. Proteins are made up of chains of amino acids, and the specific sequence of these amino acids determines the protein's structure and function. The amino acid sequence is determined by the genetic code, which is a set of rules that specifies how the sequence of nucleotides in DNA is translated into the sequence of amino acids in a protein. Each amino acid is represented by a three-letter code, and the sequence of these codes is the amino acid sequence of the protein. The amino acid sequence is important because it determines the protein's three-dimensional structure, which in turn determines its function. Small changes in the amino acid sequence can have significant effects on the protein's structure and function, and this can lead to diseases or disorders. For example, mutations in the amino acid sequence of a protein involved in blood clotting can lead to bleeding disorders.

Transcription factors are proteins that regulate gene expression by binding to specific DNA sequences and controlling the transcription of genetic information from DNA to RNA. They play a crucial role in the development and function of cells and tissues in the body. In the medical field, transcription factors are often studied as potential targets for the treatment of diseases such as cancer, where their activity is often dysregulated. For example, some transcription factors are overexpressed in certain types of cancer cells, and inhibiting their activity may help to slow or stop the growth of these cells. Transcription factors are also important in the development of stem cells, which have the ability to differentiate into a wide variety of cell types. By understanding how transcription factors regulate gene expression in stem cells, researchers may be able to develop new therapies for diseases such as diabetes and heart disease. Overall, transcription factors are a critical component of gene regulation and have important implications for the development and treatment of many diseases.

OTX transcription factors are a family of transcription factors that play important roles in the development of the nervous system, eye, and other organs in vertebrates. They are named after the "otx" gene, which was first identified in the fruit fly Drosophila melanogaster. OTX transcription factors are characterized by a conserved DNA-binding domain called the OTX domain, which is responsible for recognizing specific DNA sequences. In vertebrates, there are three OTX genes: OTX1, OTX2, and OTX3. These genes are expressed in specific regions of the developing embryo and are involved in regulating the differentiation and development of various cell types. In the nervous system, OTX transcription factors are involved in the development of the retina, optic nerve, and brain. They are also involved in the development of the ear and other sensory organs. In the eye, OTX transcription factors are involved in the development of the retina and the lens. In addition to their roles in development, OTX transcription factors have also been implicated in various diseases, including cancer. For example, overexpression of OTX2 has been associated with the development of certain types of brain tumors, while mutations in the OTX1 gene have been linked to a rare form of eye cancer called retinoblastoma. Overall, OTX transcription factors are important regulators of development and have important roles in the formation and function of various organs and tissues in vertebrates.

Fibroblast Growth Factors (FGFs) are a family of proteins that play important roles in cell growth, differentiation, and tissue repair. They are produced by a variety of cells, including fibroblasts, endothelial cells, and neurons, and act on a wide range of cell types, including epithelial cells, muscle cells, and bone cells. FGFs are involved in many physiological processes, including embryonic development, wound healing, and tissue regeneration. They also play a role in the development of certain diseases, such as cancer and fibrosis. There are 23 known members of the FGF family, and they act by binding to specific receptors on the surface of cells, which then activate intracellular signaling pathways that regulate cell growth and other cellular processes. FGFs are often used as therapeutic agents in clinical trials for the treatment of various diseases, including cancer, heart disease, and neurological disorders.

In the medical field, the cleavage stage of the ovum refers to the early stages of development of an egg cell (ovum) after fertilization by a sperm cell. During this stage, the single cell of the ovum undergoes multiple rounds of cell division, resulting in the formation of a ball of cells called a blastocyst. The cleavage stage typically begins within a few hours of fertilization and continues for several days. During this time, the cells of the blastocyst undergo rapid division and differentiation, with some cells becoming the inner cell mass (ICM), which will eventually develop into the embryo, and others becoming the trophoblast, which will develop into the placenta. The cleavage stage is a critical period in the development of the embryo, as any errors or abnormalities during this time can lead to pregnancy complications or miscarriage. Therefore, monitoring the progress of the cleavage stage is an important part of prenatal care.

Bone Morphogenetic Protein 4 (BMP4) is a protein that plays a crucial role in the development and maintenance of bone tissue in the human body. It is a member of the transforming growth factor-beta (TGF-β) superfamily of proteins, which are involved in a wide range of cellular processes, including cell growth, differentiation, and migration. In the medical field, BMP4 is used as a therapeutic agent to promote bone growth and regeneration in a variety of conditions, including fractures, osteoporosis, and spinal cord injuries. It is also being studied as a potential treatment for other diseases, such as cancer and diabetes. BMP4 is produced by a variety of cells in the body, including osteoblasts (cells that produce bone tissue) and chondrocytes (cells that produce cartilage). It acts by binding to specific receptors on the surface of cells, which triggers a signaling cascade that leads to changes in gene expression and cellular behavior. Overall, BMP4 is a critical protein for the development and maintenance of bone tissue, and its therapeutic potential is being actively explored in the medical field.

Cloning, molecular, in the medical field refers to the process of creating identical copies of a specific DNA sequence or gene. This is achieved through a technique called polymerase chain reaction (PCR), which amplifies a specific DNA sequence to produce multiple copies of it. Molecular cloning is commonly used in medical research to study the function of specific genes, to create genetically modified organisms for therapeutic purposes, and to develop new drugs and treatments. It is also used in forensic science to identify individuals based on their DNA. In the context of human cloning, molecular cloning is used to create identical copies of a specific gene or DNA sequence from one individual and insert it into the genome of another individual. This technique has been used to create transgenic animals, but human cloning is currently illegal in many countries due to ethical concerns.

HMGB proteins, also known as high mobility group box proteins, are a family of non-histone chromosomal proteins that are found in the nuclei of eukaryotic cells. They are involved in a variety of cellular processes, including DNA replication, transcription, and repair. HMGB proteins are characterized by their ability to bind to DNA and facilitate the opening of nucleosomes, which are the basic units of chromatin. They are also involved in the regulation of gene expression and the maintenance of genome stability. In the medical field, HMGB proteins have been implicated in a number of diseases, including cancer, inflammatory disorders, and neurodegenerative diseases.

In the medical field, "cell aggregation" refers to the process by which cells clump together or aggregate to form a group or mass. This can occur naturally as cells grow and divide, or it can be induced by various factors such as chemical or mechanical stimuli. Cell aggregation is an important process in many areas of medicine, including tissue engineering, regenerative medicine, and cancer research. For example, in tissue engineering, cell aggregation is often used to create three-dimensional tissue constructs by culturing cells in a scaffold or matrix that promotes cell-cell interactions and aggregation. In cancer research, cell aggregation can be used to study the behavior of cancer cells and their interactions with other cells in the tumor microenvironment. For example, cancer cells can aggregate to form spheroids, which are three-dimensional structures that mimic the architecture of solid tumors. Studying cell aggregation in spheroids can provide insights into the mechanisms of cancer progression and the development of new treatments.

Beta-catenin is a protein that plays a crucial role in the regulation of cell adhesion and signaling pathways in the body. In the medical field, beta-catenin is often studied in the context of cancer, as mutations in the beta-catenin gene (CTNNB1) can lead to the development of various types of cancer, including colorectal cancer, endometrial cancer, and ovarian cancer. In normal cells, beta-catenin is a component of the cadherin adhesion complex, which helps cells stick together and maintain tissue integrity. However, in cancer cells, mutations in the beta-catenin gene can lead to the accumulation of beta-catenin in the cytoplasm and nucleus, where it can activate downstream signaling pathways that promote cell proliferation and survival. Beta-catenin is also involved in the regulation of other cellular processes, such as cell migration, differentiation, and apoptosis. As such, it is a potential target for the development of new cancer therapies.

Transcription Factor 7-Like 1 Protein (TCF7L1) is a protein that plays a role in regulating gene expression in the body. It is a member of the TCF/LEF family of transcription factors, which are proteins that bind to specific DNA sequences and control the activity of genes. TCF7L1 is involved in a variety of biological processes, including cell growth, differentiation, and development. It has been implicated in a number of diseases, including cancer, and is the subject of ongoing research in the medical field.

In the medical field, "Anura" refers to a group of amphibians known as frogs and toads. Anura is a taxonomic order that includes over 6,000 species of frogs and toads found worldwide. These animals are characterized by their moist skin, long hind legs for jumping, and a lack of a tail in adulthood. Frogs and toads play important roles in many ecosystems as predators, prey, and as indicators of environmental health. They are also commonly used in scientific research and as pets.

Transforming Growth Factor beta (TGF-β) is a family of cytokines that play a crucial role in regulating cell growth, differentiation, and migration. TGF-βs are secreted by a variety of cells, including immune cells, fibroblasts, and epithelial cells, and act on neighboring cells to modulate their behavior. TGF-βs have both pro-inflammatory and anti-inflammatory effects, depending on the context in which they are released. They can promote the differentiation of immune cells into effector cells that help to fight infections, but they can also suppress the immune response to prevent excessive inflammation. In addition to their role in immune regulation, TGF-βs are also involved in tissue repair and fibrosis. They can stimulate the production of extracellular matrix proteins, such as collagen, which are essential for tissue repair. However, excessive production of TGF-βs can lead to fibrosis, a condition in which excessive amounts of connective tissue accumulate in the body, leading to organ dysfunction. Overall, TGF-βs are important signaling molecules that play a critical role in regulating a wide range of cellular processes in the body.

Wnt proteins are a family of signaling molecules that play a crucial role in regulating cell proliferation, differentiation, migration, and survival. They are secreted by cells and bind to receptors on the surface of neighboring cells, activating a signaling cascade that regulates gene expression and cellular behavior. In the medical field, Wnt proteins are of great interest because they are involved in a wide range of diseases and conditions, including cancer, developmental disorders, and neurodegenerative diseases. For example, mutations in Wnt signaling pathways have been implicated in the development of colorectal cancer, and dysregulated Wnt signaling has been linked to the progression of other types of cancer as well. Wnt proteins are also being studied as potential therapeutic targets for a variety of diseases. For example, drugs that target Wnt signaling have shown promise in preclinical studies for the treatment of cancer, and there is ongoing research into the use of Wnt signaling inhibitors for the treatment of other conditions, such as inflammatory bowel disease and osteoporosis.

Cell differentiation is the process by which cells acquire specialized functions and characteristics during development. It is a fundamental process that occurs in all multicellular organisms, allowing cells to differentiate into various types of cells with specific functions, such as muscle cells, nerve cells, and blood cells. During cell differentiation, cells undergo changes in their shape, size, and function, as well as changes in the proteins and other molecules they produce. These changes are controlled by a complex network of genes and signaling pathways that regulate the expression of specific genes in different cell types. Cell differentiation is a critical process for the proper development and function of tissues and organs in the body. It is also involved in tissue repair and regeneration, as well as in the progression of diseases such as cancer, where cells lose their normal differentiation and become cancerous.

In the medical field, "DNA, Complementary" refers to the property of DNA molecules to pair up with each other in a specific way. Each strand of DNA has a unique sequence of nucleotides (adenine, thymine, guanine, and cytosine), and the nucleotides on one strand can only pair up with specific nucleotides on the other strand in a complementary manner. For example, adenine (A) always pairs up with thymine (T), and guanine (G) always pairs up with cytosine (C). This complementary pairing is essential for DNA replication and transcription, as it ensures that the genetic information encoded in one strand of DNA can be accurately copied onto a new strand. The complementary nature of DNA also plays a crucial role in genetic engineering and biotechnology, as scientists can use complementary DNA strands to create specific genetic sequences or modify existing ones.

Proteins are complex biomolecules made up of amino acids that play a crucial role in many biological processes in the human body. In the medical field, proteins are studied extensively as they are involved in a wide range of functions, including: 1. Enzymes: Proteins that catalyze chemical reactions in the body, such as digestion, metabolism, and energy production. 2. Hormones: Proteins that regulate various bodily functions, such as growth, development, and reproduction. 3. Antibodies: Proteins that help the immune system recognize and neutralize foreign substances, such as viruses and bacteria. 4. Transport proteins: Proteins that facilitate the movement of molecules across cell membranes, such as oxygen and nutrients. 5. Structural proteins: Proteins that provide support and shape to cells and tissues, such as collagen and elastin. Protein abnormalities can lead to various medical conditions, such as genetic disorders, autoimmune diseases, and cancer. Therefore, understanding the structure and function of proteins is essential for developing effective treatments and therapies for these conditions.

Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white metal that is highly reactive and flammable. In the medical field, lithium is primarily used as a mood stabilizer to treat bipolar disorder, a mental health condition characterized by extreme mood swings, including manic episodes and depression. Lithium works by regulating the levels of certain neurotransmitters in the brain, such as dopamine and serotonin, which are involved in mood regulation. It is typically administered as a daily pill or liquid and is considered effective in preventing and treating manic and depressive episodes in people with bipolar disorder. However, lithium can also have side effects, including tremors, weight gain, and kidney problems, and requires careful monitoring by a healthcare provider.

DNA-binding proteins are a class of proteins that interact with DNA molecules to regulate gene expression. These proteins recognize specific DNA sequences and bind to them, thereby affecting the transcription of genes into messenger RNA (mRNA) and ultimately the production of proteins. DNA-binding proteins play a crucial role in many biological processes, including cell division, differentiation, and development. They can act as activators or repressors of gene expression, depending on the specific DNA sequence they bind to and the cellular context in which they are expressed. Examples of DNA-binding proteins include transcription factors, histones, and non-histone chromosomal proteins. Transcription factors are proteins that bind to specific DNA sequences and regulate the transcription of genes by recruiting RNA polymerase and other factors to the promoter region of a gene. Histones are proteins that package DNA into chromatin, and non-histone chromosomal proteins help to organize and regulate chromatin structure. DNA-binding proteins are important targets for drug discovery and development, as they play a central role in many diseases, including cancer, genetic disorders, and infectious diseases.

Cytoskeletal proteins are a diverse group of proteins that make up the internal framework of cells. They provide structural support and help maintain the shape of cells. The cytoskeleton is composed of three main types of proteins: microfilaments, intermediate filaments, and microtubules. Microfilaments are the thinnest of the three types of cytoskeletal proteins and are composed of actin filaments. They are involved in cell movement, cell division, and muscle contraction. Intermediate filaments are thicker than microfilaments and are composed of various proteins, including keratins, vimentin, and desmin. They provide mechanical strength to cells and help maintain cell shape. Microtubules are the thickest of the three types of cytoskeletal proteins and are composed of tubulin subunits. They play a crucial role in cell division, intracellular transport, and the maintenance of cell shape. Cytoskeletal proteins are essential for many cellular processes and are involved in a wide range of diseases, including cancer, neurodegenerative disorders, and muscle diseases.

The cell nucleus is a membrane-bound organelle found in eukaryotic cells that contains the cell's genetic material, or DNA. It is typically located in the center of the cell and is surrounded by a double membrane called the nuclear envelope. The nucleus is responsible for regulating gene expression and controlling the cell's activities. It contains a dense, irregularly shaped mass of chromatin, which is made up of DNA and associated proteins. The nucleus also contains a small body called the nucleolus, which is responsible for producing ribosomes, the cellular structures that synthesize proteins.

In the medical field, "trans-activators" refer to proteins or molecules that activate the transcription of a gene, which is the process by which the information in a gene is used to produce a functional product, such as a protein. Trans-activators can bind to specific DNA sequences near a gene and recruit other proteins, such as RNA polymerase, to initiate transcription. They can also modify the chromatin structure around a gene to make it more accessible to transcription machinery. Trans-activators play important roles in regulating gene expression and are involved in many biological processes, including development, differentiation, and disease.

Intercellular signaling peptides and proteins are molecules that are secreted by cells and act as messengers to communicate with other cells. These molecules can be hormones, growth factors, cytokines, or other signaling molecules that are capable of transmitting information between cells. They play a crucial role in regulating various physiological processes, such as cell growth, differentiation, and apoptosis, as well as immune responses and inflammation. In the medical field, understanding the function and regulation of intercellular signaling peptides and proteins is important for developing new treatments for various diseases and disorders, including cancer, autoimmune diseases, and neurological disorders.

RNA, or ribonucleic acid, is a type of nucleic acid that is involved in the process of protein synthesis in cells. It is composed of a chain of nucleotides, which are made up of a sugar molecule, a phosphate group, and a nitrogenous base. There are three types of RNA: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). In the medical field, RNA is often studied as a potential target for the development of new drugs and therapies. For example, some researchers are exploring the use of RNA interference (RNAi) to silence specific genes and treat diseases such as cancer and viral infections. Additionally, RNA is being studied as a potential biomarker for various diseases, as changes in the levels or structure of certain RNA molecules can indicate the presence of a particular condition.

In the medical field, a cell lineage refers to the developmental history of a cell, tracing its origin back to a common ancestor cell and following its subsequent divisions and differentiation into specialized cell types. Cell lineage is an important concept in the study of stem cells, which have the potential to differentiate into a wide variety of cell types. By understanding the cell lineage of stem cells, researchers can better understand how they develop into specific cell types and how they might be used to treat various diseases. In addition, cell lineage is also important in the study of cancer, as cancer cells often arise from normal cells that have undergone mutations and have begun to divide uncontrollably. By studying the cell lineage of cancer cells, researchers can gain insights into the genetic and molecular changes that have occurred during cancer development and identify potential targets for cancer therapy.

Histones are proteins that play a crucial role in the structure and function of DNA in cells. They are small, positively charged proteins that help to package and organize DNA into a compact structure called chromatin. Histones are found in the nucleus of eukaryotic cells and are essential for the proper functioning of genes. There are five main types of histones: H1, H2A, H2B, H3, and H4. Each type of histone has a specific role in the packaging and organization of DNA. For example, H3 and H4 are the most abundant histones and are responsible for the formation of nucleosomes, which are the basic unit of chromatin. H1 is a linker histone that helps to compact chromatin into a more condensed structure. In the medical field, histones have been studied in relation to various diseases, including cancer, autoimmune disorders, and neurodegenerative diseases. For example, changes in the levels or modifications of histones have been linked to the development of certain types of cancer, such as breast cancer and prostate cancer. Additionally, histones have been shown to play a role in the regulation of gene expression, which is important for the proper functioning of cells.

Glycoproteins are a type of protein that contains one or more carbohydrate chains covalently attached to the protein molecule. These carbohydrate chains are made up of sugars and are often referred to as glycans. Glycoproteins play important roles in many biological processes, including cell signaling, cell adhesion, and immune response. They are found in many different types of cells and tissues throughout the body, and are often used as markers for various diseases and conditions. In the medical field, glycoproteins are often studied as potential targets for the development of new drugs and therapies.

The Central Nervous System (CNS) is a complex network of nerves and neurons that controls and coordinates all bodily functions in the human body. It is composed of the brain and spinal cord, which are protected by the skull and vertebral column, respectively. The brain is the control center of the CNS and is responsible for processing sensory information, controlling movement, regulating bodily functions, and governing emotions and thoughts. It is divided into several regions, including the cerebrum, cerebellum, and brainstem. The spinal cord is a long, thin, tubular structure that extends from the base of the brain down through the vertebral column. It serves as a communication pathway between the brain and the rest of the body, transmitting signals from the body's sensory receptors to the brain and from the brain to the body's muscles and glands. Together, the brain and spinal cord make up the central nervous system, which is responsible for controlling and coordinating all bodily functions, including movement, sensation, thought, and emotion.

Metalloendopeptidases are a class of enzymes that contain a metal ion, typically zinc, as a cofactor. These enzymes are involved in the cleavage of peptide bonds in proteins, specifically at the N-terminal end of the peptide chain. They are found in a variety of organisms, including bacteria, plants, and animals, and play important roles in many biological processes, such as blood clotting, digestion, and the regulation of hormone levels. Metalloendopeptidases are classified based on the specific metal ion they contain and the mechanism by which they cleave peptide bonds. For example, zinc metalloendopeptidases use a nucleophilic attack by a water molecule coordinated to the zinc ion to cleave the peptide bond, while copper metalloendopeptidases use a different mechanism involving the coordination of a histidine residue to the copper ion. In the medical field, metalloendopeptidases are the target of several drugs, including ACE inhibitors, which are used to treat high blood pressure and heart failure. These drugs block the action of angiotensin-converting enzyme (ACE), a zinc metalloendopeptidase that plays a key role in the regulation of blood pressure. Other metalloendopeptidases are being studied as potential targets for the treatment of a variety of diseases, including cancer, Alzheimer's disease, and diabetes.

In the medical field, cytoplasm refers to the gel-like substance that fills the cell membrane of a living cell. It is composed of various organelles, such as mitochondria, ribosomes, and the endoplasmic reticulum, as well as various dissolved molecules, including proteins, lipids, and carbohydrates. The cytoplasm plays a crucial role in many cellular processes, including metabolism, protein synthesis, and cell division. It also serves as a site for various cellular activities, such as the movement of organelles within the cell and the transport of molecules across the cell membrane. In addition, the cytoplasm is involved in maintaining the structural integrity of the cell and protecting it from external stressors, such as toxins and pathogens. Overall, the cytoplasm is a vital component of the cell and plays a critical role in its function and survival.

After the 7th cleavage has produced 128 cells, the morula becomes a blastula. The blastula is usually a spherical layer of ... The morula develops into a structure called a blastula through a process called blastulation. The blastula develops into a ... "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 ...
Only when the blastocoel is formed does the early embryo become a blastula. The blastula precedes the formation of the gastrula ... The blastula stage of early embryo development begins with the appearance of the blastocoel. The origin of the blastocoel in ... Blastula-stage cells can behave as pluripotent stem cells in many species. Pluripotent stem cells are the starting point to ... The blastula (from Greek βλαστός (blastos meaning sprout)) is a hollow sphere of cells known as blastomeres surrounding an ...
After the zygote has become an embryo, it continues dividing into a hollow sphere of cells, which is a blastula. These outer ... "blastula , biology , Britannica". www.britannica.com. Retrieved 8 April 2022. "Blastulation , Cleavage and Early Development , ... After blastulation, the single-layered blastula expands and reorganizes into multiple layers, a gastrula (seen in the figure to ... the eight-cell stage embryo forms into a slightly different type of blastula, called a blastocyst. Other species such as sea ...
Cleavage ends with the formation of the blastula, or of the blastocyst in mammals. Depending mostly on the concentration of ... 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 ... Gastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered ... Gastrulation takes place after cleavage and the formation of the blastula, or blastocyst. Gastrulation is followed by ... 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 or blastocyst stage embryo can appear as a ball of cells ... The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into ... blastula, gastrulation, and organogenesis. Cleavage is the period of rapid mitotic cell divisions that occur after ...
Sea urchin blastula proteins BP10 and SpAN. C. elegans hypothetical proteins F42A10.8 and R151.5. Neuropilin (A5 antigen), a ...
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 this stage in mammals the blastula develops into the blastocyst containing an inner cell mass, and outer trophectoderm. It ...
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): ...
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. ...
Growth and accretion are started with blastula and gastrula. Aristotle's On the Heavens founded cosmology. Earth's ...
Germ cells are set aside in the embryo at the blastula stage, which are incorporated into the gonads during organogenesis. The ... germ layers form during gastrulation of the blastula. The term triploblast may refer to any egg cell 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 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. As of 2022, 2.16 million living animal species have been described-of which around ...
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 ...
Even with the BCNE center (Blastula chordin and noggin expression center) removed from the blastula, the Nieuwkoop Center is ... 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 ... 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 ...
The development of trichimella start with cleavage, blastula, morphogenesis, and, lastly, larva. The cleavage is the first ...
"Coupling of zygotic transcription to mitotic control at the Drosophila mid-blastula transition". Development. 136 (12): 2101- ...
Hungry for new opportunities? Were hiring! Apply today and bring home that bacon. ...
Blastula is an Italian duo consisting of percussionist Cristiano Calcagnile and singer Monica Demuru. Scarnoduo features 16 ... BLASTULA / Scarnoduo (Amirani). Je suis sans voix, entièrement conquis par ce disque, réduit à létat de petit tas informe de ... Blastula est un duo italien formé du percussionniste Cristiano Calcagnile et de la chanteuse Monica Demuru. Scarnoduo présente ... Libellés : Al-Yaman, Amirani Records, Blastula, Braagas, Gianni Lenoci, Gianni Mimmo, Indies Scope, Journal découte / ...
Late-blastula period:. In the loach, this period corresponded to the time from 6 to 9 hpf. In zebrafish, the expression of gsc ... The late-blastula period in zebrafish is subdivided to oblong, sphere, dome and 30% epiboly periods by external ... Such a turning point in cell division is referred to as the mid-blastula transition (MBT), which is characterized by cell cycle ... Morphological change during the late-blastula stage. External appearance of the embryo at 6 (A), 7 (B) and 8 hpf (C, D). Scale ...
After the 7th cleavage has produced 128 cells, the morula becomes a blastula. The blastula is usually a spherical layer of ... The morula develops into a structure called a blastula through a process called blastulation. The blastula develops into a ... "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 ...
Frog Embryo in the Blastula Stage. Illustration of the animal-vegetal gradient in Xenopus laevis ( African clawed frog) eggs ...
In sponges, blastula larvae swim to a new location and develop into a new sponge. In most other groups, the blastula undergoes ... A zygote initially develops into a hollow sphere, called a blastula, which undergoes rearrangement and differentiation. ... develop through a blastula (hollow ball) stage, and integrate muscle tissue, nervous tissue, and collagen into their body. ...
Basic Manipulations of Blastula, Gastrula, and Early Neurula Embryos. 7. Removal of membranes from embryos; isolation of animal ... 9. Animal cap isolation; dorsal/ventral pigment and cell-size differences in blastula animal region; transplanting ectodermal ... caps from blastula embryos; examination of mesodermal induction by recombinants of animal and vegetal tissue (J. Gurdon). 8. ...
a Sketch of nuclear compartmentalization in a typical nucleus and in the nucleus of a late blastula (sphere) stage zebrafish ... To determine the role of transcription in euchromatin organization, we used zebrafish embryos at the late blastula (sphere) ... show nuclear mid-sections of a single nucleus taken from zebrafish embryonic cell culture corresponding to the late blastula ( ... followed two prominent transcription sites that precede nucleus-wide transcription in practically all nuclei of late blastula ...
After a certain number of cells is reached, the organism, now known as a blastula, undergoes gastrulation, a process that forms ... The cells of the blastula move from their original positions established into their new locations based on their future ...
blastula stage (xenopus). XAO:1000003. cleavage stage (xenopus). XAO:1000004. gastrula stage (xenopus). XAO:1000005. neurula ...
Slides for mitosis are sections of onion root-tip and whitefish blastula. Slides for meiosis are sections of lily anthers and ...
morulla or blastula up 5days ball of undifferentiated totipotent cells Blastocyst by day 5 Hollow Ball of cells, external and ...
Ikinabit din kay Baer ang pagkakatuklas ng blastula. Inilathala ni Baer ang kaniyang mga natuklasan, kasama na ang kaniyang ...
But single cells, even blastulas of cells, are not equal to a human being. Or another way to look at things is that human ...
By contrast, Xfoxi1c is expressed only after the gastrula stage and not during the blastula and gastrula stages(Pohl et al., ... 1A). Xfoxi1a was widely expressed in the animal cap region at the blastula stage(Fig. 1B). Interestingly, Xfoxi1a expression ... To understand the role of Xfoxi1a during the early steps of embryogenesis (blastula to early neurula), we first performed whole ... they are expressed widely in the animal side of the embryo at the late blastula stage and in the anteroventral ectoderm at the ...
In mammals, the blastula is known as the blastocyst, but it is very similar to the blastula you looked at earlier. It turns out ... Now go forward in development a little to the embryonic structure you looked at earlier called the blastula - the hollowed-out ...
One of the main differences is that the blastula is not hollow but is filled with yolk cells. The lip is the point where the ... blastula) and reorganizes into a multilayered and multidimensional structure called the gastrula. ...
Cocktails and Drinks with Scotch whisky .
Its expression appeared to be limited to the ovary, oocyte, egg and the early embryonic stages leading up to the mid-blastula ...
Mid blastula periode. Coincides with maternal zygotic transitions (MZT) and zygotic genome activate. ...
blastula. 6.99e-08. 10. bilaminar disc. 6.99e-08. 10. inner cell mass. 6.99e-08. 10. ...
An easy riddle from The Riddler that did not even require coding! Given that a tree changes colours at a random time A distributed according to a Uniform distribution (over (0,1)) and that it sheds its leave at a random time B distributed according to a Uniform distribution (over (A,1)), what is the time when a maximal number of trees show their new colour?. Which means optimising in t the probability that A,t,B. Which is equal to -(1-t)log(1-t) and maximal for t=1-e⁻¹, resulting in a (maximal) fraction of e⁻¹ of the trees holding to their new colour at that time. ...
The process of the blastulas formation is known as blastulation.. Although the blastula may appear to be composed solely of ... As a result, the embryo takes on the appearance of a hollow ball, and this stage is referred to as the blastula or ... After the blastula stage, the next important phase in embryonic development is gastrulation. Gastrulation involves a series of ... The blastula consists of an outer layer of cells called the trophoblast and an inner cell mass. ...
... mid-blastula) to stage 46 (when primary organogenesis is complete). BCA produced 29, 83, and 100% mortality at 10,000, 12,000 ...
During later blastula stages, it is expressed in the endoderm precursors of the veg1 ring of cells distal to the vegetal pole ... This negative autoregulation is restricted to the mesodermal veg2 territory during the blastula stage as shown by WMISH ... of the blastula. Later, its expression is restricted to the blastopore region and the posterior of the invaginating archenteron ...
... we performed in vivo imaging from late blastula to epiboly stages using a GFP-tagged version of ZO-1. We found that EVL cells ... which arise at the dorsal margin of the late blastula by a process of cell ingression that converts the superficial epithelial ...
Animal caps derived from embryos injected with 50 pg Xbra-GR RNA or left uninjected were dissected at blastula stages and then ...
They should be near or past the blastula stage at this point (note the gas bubbles stuck to the egg jelly) - its hard to be ...
... early blastula, (g) late blastula, (h) pre-early gastrula, (i) early gastrula, (j) pre middle gastrula, (k) middle gastrula, (l ... 1e), while the blastula stage 7:30 h AF (Fig. 1f, g). 9:30 h AF, pre-early gastrula stage was determined (Fig. 1h) and ...
... are unresponsive to manipulation of cWnt levels during the early establishment of the A/P axis at late blastula and early ...
  • This time corresponded to the late-blastula period. (bioone.org)
  • To determine the role of transcription in euchromatin organization, we used zebrafish embryos at the late blastula (sphere) stage. (nature.com)
  • This negative autoregulation is restricted to the mesodermal veg2 territory during the blastula stage as shown by WMISH analysis of MASO injected embryos. (caltech.edu)
  • A) Induction of Xwnt11 by Xbra -GR. Animal caps derived from embryos injected with 50 pg Xbra -GR RNA or left uninjected were dissected at blastula stages and then treated with 10-6 M dexamethasone (DEX) for 3 hours or left untreated. (xenbase.org)
  • Gastrulation is defined as an early developmental process in which an embryo transforms from a one-dimensional layer of epithelial cells (blastula) and reorganizes into a multilayered and multidimensional structure called the gastrula. (swirlzcupcakes.com)
  • During later blastula stages, it is expressed in the endoderm precursors of the veg1 ring of cells distal to the vegetal pole of the blastula. (caltech.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)
  • One of the main differences is that the blastula is not hollow but is filled with yolk cells. (swirlzcupcakes.com)
  • The different cells derived from cleavage, up to the blastula stage, are called blastomeres. (wikipedia.org)
  • The morula develops into a structure called a blastula through a process called blastulation. (wikipedia.org)
  • After the 7th cleavage has produced 128 cells, the morula becomes a blastula. (wikipedia.org)
  • The morula develops into a structure called a blastula through a process called blastulation. (wikipedia.org)
  • After the 7th cleavage has produced 128 cells, the morula becomes a blastula. (wikipedia.org)
  • Biogenetic law of Ernst Haeckel assumed a parallelism between ontogeny and phylogeny, and asserted that embryogenesis is a recapitulation of ancient organisms because all animals start their existence from a one-celled stage and develop into morula, blastula and then gastrula stages 2 , 3 . (nature.com)
  • For example, we still do not know how to explain the common early embryonic stages, such as the morula, blastula and gastrula, in evolutionary terms. (nature.com)
  • Their argument is that every zygote, blastula, morula, and fetus is a child, so each one saved -- every marginal improvement, as it were -- is important in its own right. (dorfonlaw.org)
  • Tres a quatro dias apos a fecundacao, o embriao chega ao utero na fase morula, formado por aproximadamente doze a dezesseis blastomeros, apos dois a tres dias, ele esta implantado no utero sendo considerado blastula blastocito ou blastocisto. (web.app)
  • However, in Xenopus blastula, chromatin tethering to the NE depends on nuclear filamentous actin that develops in a blastula-specific manner. (nih.gov)
  • To investigate whether chromatin tethering operates in the blastula through INMPs, we experimentally introduced INMPs into Xenopus egg extracts that recapitulate nuclear formation in fertilized eggs. (nih.gov)
  • We subsequently found that the LBR level was very low in the Xenopus blastula but was elevated after the blastula stage. (nih.gov)
  • These results suggest that LBR-mediated chromatin tethering is circumvented in the Xenopus blastula, as it is detrimental to embryonic development. (nih.gov)
  • Dorsal induction from dorsal vegetal cells in Xenopus occurs after mid-blastula transition. (wikigenes.org)
  • Surface activity and locomotion of Fundulus deep cells during blastula and gastrula stages. (mbl.edu)
  • 2. Epigenetic complexity during the zebrafish mid-blastula transition. (nih.gov)
  • Downregulation of Cdc25 activity at the Drosophila mid-blastula transition is critical in order to remodel cell cycle progression. (nih.gov)
  • We showed that Cdk1 downregulation at the mid-blastula transition (through the downregulation of Cdc25) is responsible for dramatically lengthening S-phase. (nih.gov)
  • The blastula develops in one of two ways, which actually divides the whole animal kingdom in half. (bhaskarhealth.com)
  • The blastula develops a pore at one end, called a blastopore. (bhaskarhealth.com)
  • Only some of the early dorsal β-catenin signature genes were activated at blastula whereas others required the induction of endomesoderm , as indicated by their inhibition by Cerberus overexpression. (xenbase.org)
  • A blastula resembles a hollow ball with the layer of cells surrounding a fluid-filled cavity (blastocele). (nih.gov)
  • The blastula continues to develop, eventually forming a structure called the gastrula. (bhaskarhealth.com)
  • Is the mammalian blastula and consists of the trophoblast and the inner cell mass. (preparingtobecome.com)