Mesoderm: The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.Head: The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.Gene Expression Regulation, Developmental: 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.Facial Muscles: Muscles of facial expression or mimetic muscles that include the numerous muscles supplied by the facial nerve that are attached to and move the skin of the face. (From Stedman, 25th ed)Fetal Proteins: Proteins that are preferentially expressed or upregulated during FETAL DEVELOPMENT.Twist Transcription Factor: A basic helix-loop-helix transcription factor that was originally identified in DROSOPHILA as essential for proper gastrulation and MESODERM formation. It plays an important role in EMBRYONIC DEVELOPMENT and CELL DIFFERENTIATION of MUSCLE CELLS, and is found in a wide variety of organisms.Body Patterning: 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.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Chick Embryo: The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Gastrula: 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.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Embryonic Induction: 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).Somites: Paired, segmented masses of MESENCHYME located on either side of the developing spinal cord (neural tube). Somites derive from PARAXIAL MESODERM and continue to increase in number during ORGANOGENESIS. Somites give rise to SKELETON (sclerotome); MUSCLES (myotome); and DERMIS (dermatome).Ectoderm: The outer of the three germ layers of an embryo.Stem Cells: Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.Xenopus Proteins: 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.In Situ Hybridization: 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.T-Box Domain Proteins: 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.Morphogenesis: 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.Homeodomain Proteins: 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).Cell Lineage: The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.Zebrafish Proteins: Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).Gastrulation: 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.Zebrafish: 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.Hematopoietic Stem Cells: Progenitor cells from which all blood cells derive.Xenopus: An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.Bone Morphogenetic Proteins: 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.Head and Neck Neoplasms: Soft tissue tumors or cancer arising from the mucosal surfaces of the LIP; oral cavity; PHARYNX; LARYNX; and cervical esophagus. Other sites included are the NOSE and PARANASAL SINUSES; SALIVARY GLANDS; THYROID GLAND and PARATHYROID GLANDS; and MELANOMA and non-melanoma skin cancers of the head and neck. (from Holland et al., Cancer Medicine, 4th ed, p1651)Activins: 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.Nodal Protein: 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.Signal Transduction: 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.Bone Morphogenetic Protein 4: A bone morphogenetic protein that is a potent inducer of bone formation. It also functions as a regulator of MESODERM formation during EMBRYONIC DEVELOPMENT.Genes, Homeobox: 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.Xenopus laevis: 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.Fibroblast Growth Factors: 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.Coturnix: A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.Goosecoid Protein: 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.Quail: Common name for two distinct groups of BIRDS in the order GALLIFORMES: the New World or American quails of the family Odontophoridae and the Old World quails in the genus COTURNIX, family Phasianidae.Wnt Proteins: 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.Basic Helix-Loop-Helix Transcription Factors: A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.Molecular Sequence Data: 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.Nervous System: 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)Embryo, Mammalian: The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.Nodal Signaling Ligands: 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.Embryonic and Fetal Development: Morphological and physiological development of EMBRYOS or FETUSES.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Drosophila Proteins: Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.Myeloid Progenitor Cells: Stem cells derived from HEMATOPOIETIC STEM CELLS. Derived from these myeloid progenitor cells are the MEGAKARYOCYTES; ERYTHROID CELLS; MYELOID CELLS; and some DENDRITIC CELLS.Neural Crest: The two longitudinal ridges along the PRIMITIVE STREAK appearing near the end of GASTRULATION during development of nervous system (NEURULATION). The ridges are formed by folding of NEURAL PLATE. Between the ridges is a neural groove which deepens as the fold become elevated. When the folds meet at midline, the groove becomes a closed tube, the NEURAL TUBE.Primitive Streak: A linear band of rapidly proliferating cells that begins near the posterior end of an embryo and grows cranially. Primitive streak is formed during GASTRULATION by the convergent migration of primary ectodermal cells (EPIBLAST). The knot at the tip of the streak is called HENSEN NODE.DNA-Binding Proteins: 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.Embryonic Development: Morphological and physiological development of EMBRYOS.Hematopoiesis: The development and formation of various types of BLOOD CELLS. Hematopoiesis can take place in the BONE MARROW (medullary) or outside the bone marrow (HEMATOPOIESIS, EXTRAMEDULLARY).Fibroblast Growth Factor 8: A fibroblast growth factor that preferentially activates FIBROBLAST GROWTH FACTOR RECEPTOR 4. It was initially identified as an androgen-induced growth factor and plays a role in regulating growth of human BREAST NEOPLASMS and PROSTATIC NEOPLASMS.Extremities: The farthest or outermost projections of the body, such as the HAND and FOOT.Germ Layers: 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.Embryonic Stem Cells: Cells derived from the BLASTOCYST INNER CELL MASS which forms before implantation in the uterine wall. They retain the ability to divide, proliferate and provide progenitor cells that can differentiate into specialized cells.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Limb Buds: Distinct regions of mesenchymal outgrowth at both flanks of an embryo during the SOMITE period. Limb buds, covered by ECTODERM, give rise to forelimb, hindlimb, and eventual functional limb structures. Limb bud cultures are used to study CELL DIFFERENTIATION; ORGANOGENESIS; and MORPHOGENESIS.Trans-Activators: Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.TailCells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Receptors, Notch: A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.Head Movements: Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.Antigens, CD34: Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.Inhibins: 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, respectivelyTissue Transplantation: Transference of tissue within an individual, between individuals of the same species, or between individuals of different species.Colony-Forming Units Assay: A cytologic technique for measuring the functional capacity of stem cells by assaying their activity.Amino Acid Sequence: 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.Avian Proteins: Proteins obtained from species of BIRDS.Hedgehog Proteins: A family of intercellular signaling proteins that play and important role in regulating the development of many TISSUES and organs. Their name derives from the observation of a hedgehog-like appearance in DROSOPHILA embryos with genetic mutations that block their action.Bone Marrow Cells: Cells contained in the bone marrow including fat cells (see ADIPOCYTES); STROMAL CELLS; MEGAKARYOCYTES; and the immediate precursors of most blood cells.Branchial Region: A region, of SOMITE development period, that contains a number of paired arches, each with a mesodermal core lined by ectoderm and endoderm on the two sides. In lower aquatic vertebrates, branchial arches develop into GILLS. In higher vertebrates, the arches forms outpouchings and develop into structures of the head and neck. Separating the arches are the branchial clefts or grooves.Animals, Genetically Modified: ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.Heart: The hollow, muscular organ that maintains the circulation of the blood.Transforming Growth Factor beta: 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.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.RNA, Messenger: 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.Viscera: Any of the large interior organs in any one of the three great cavities of the body, especially in the abdomen.Femur Head: The hemispheric articular surface at the upper extremity of the thigh bone. (Stedman, 26th ed)Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Blastoderm: A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.Lymphoid Progenitor Cells: Stem cells from which B-LYMPHOCYTES; T-LYMPHOCYTES; NATURAL KILLER CELLS; and some DENDRITIC CELLS derive.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Myogenic Regulatory Factor 5: A SKELETAL MUSCLE-specific transcription factor that contains a basic HELIX-LOOP-HELIX MOTIF. It plays an essential role in MUSCLE DEVELOPMENT.Receptors, Fibroblast Growth Factor: Specific molecular sites or structures on cell membranes that react with FIBROBLAST GROWTH FACTORS (both the basic and acidic forms), their analogs, or their antagonists to elicit or to inhibit the specific response of the cell to these factors. These receptors frequently possess tyrosine kinase activity.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Repressor Proteins: Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.Proteins: 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.Paired Box Transcription Factors: A family of transcription factors that control EMBRYONIC DEVELOPMENT within a variety of cell lineages. They are characterized by a highly conserved paired DNA-binding domain that was first identified in DROSOPHILA segmentation genes.Mice, Inbred C57BLLeft-Right Determination Factors: Signaling ligands that act in opposition to NODAL PROTEIN. During vertebrate development they regulate the degree of left-right asymmetry by controlling the spatiotemporal influence of NODAL PROTEIN.Neural Stem Cells: Self-renewing cells that generate the main phenotypes of the nervous system in both the embryo and adult. Neural stem cells are precursors to both NEURONS and NEUROGLIA.Genes, Insect: The functional hereditary units of INSECTS.Central Nervous System: The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.Chimera: An individual that contains cell populations derived from different zygotes.Blastula: 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.Wnt1 Protein: A proto-oncogene protein and member of the Wnt family of proteins. It is expressed in the caudal MIDBRAIN and is essential for proper development of the entire mid-/hindbrain region.Wnt3 Protein: A Wnt protein subtype that plays a role in cell-cell signaling during EMBRYONIC DEVELOPMENT and the morphogenesis of the developing NEURAL TUBE. Defects in Wnt3 protein are associated with autosomal recessive tetra-AMELIA in humans.Time Factors: Elements of limited time intervals, contributing to particular results or situations.MyoD Protein: A myogenic regulatory factor that controls myogenesis. Though it is not clear how its function differs from the other myogenic regulatory factors, MyoD appears to be related to fusion and terminal differentiation of the muscle cell.Multipotent Stem Cells: Specialized stem cells that are committed to give rise to cells that have a particular function; examples are MYOBLASTS; MYELOID PROGENITOR CELLS; and skin stem cells. (Stem Cells: A Primer [Internet]. Bethesda (MD): National Institutes of Health (US); 2000 May [cited 2002 Apr 5]. Available from: http://www.nih.gov/news/stemcell/primer.htm)Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Yolk Sac: The first of four extra-embryonic membranes to form during EMBRYOGENESIS. In REPTILES and BIRDS, it arises from endoderm and mesoderm to incorporate the EGG YOLK into the DIGESTIVE TRACT for nourishing the embryo. In placental MAMMALS, its nutritional function is vestigial; however, it is the source of INTESTINAL MUCOSA; BLOOD CELLS; and GERM CELLS. It is sometimes called the vitelline sac, which should not be confused with the VITELLINE MEMBRANE of the egg.Muscle Development: Developmental events leading to the formation of adult muscular system, which includes differentiation of the various types of muscle cell precursors, migration of myoblasts, activation of myogenesis and development of muscle anchorage.Helix-Loop-Helix Motifs: Recurring supersecondary structures characterized by 20 amino acids folding into two alpha helices connected by a non-helical "loop" segment. They are found in many sequence-specific DNA-BINDING PROTEINS and in CALCIUM-BINDING PROTEINS.Culture Techniques: Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Intercellular Signaling Peptides and Proteins: 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.Erythroid Precursor Cells: The cells in the erythroid series derived from MYELOID PROGENITOR CELLS or from the bi-potential MEGAKARYOCYTE-ERYTHROID PROGENITOR CELLS which eventually give rise to mature RED BLOOD CELLS. The erythroid progenitor cells develop in two phases: erythroid burst-forming units (BFU-E) followed by erythroid colony-forming units (CFU-E); BFU-E differentiate into CFU-E on stimulation by ERYTHROPOIETIN, and then further differentiate into ERYTHROBLASTS when stimulated by other factors.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Vertebrates: Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.Proto-Oncogene Proteins: Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.LIM-Homeodomain Proteins: A subclass of LIM domain proteins that include an additional centrally-located homeodomain region that binds AT-rich sites on DNA. Many LIM-homeodomain proteins play a role as transcriptional regulators that direct cell fate.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Nerve Tissue ProteinsBone Morphogenetic Protein Receptors: A family of CELL SURFACE RECEPTORS that bind BONE MORPHOGENETIC PROTEINS. They are PROTEIN-SERINE-THREONINE KINASES that mediate SIGNAL TRANSDUCTION PATHWAYS through SMAD PROTEINS.Organogenesis: Formation of differentiated cells and complicated tissue organization to provide specialized functions.Digestive System: A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).Neural Plate: The region in the dorsal ECTODERM of a chordate embryo that gives rise to the future CENTRAL NERVOUS SYSTEM. Tissue in the neural plate is called the neuroectoderm, often used as a synonym of neural plate.SOXF Transcription Factors: 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.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.PAX2 Transcription Factor: A paired box transcription factor that is essential for ORGANOGENESIS of the CENTRAL NERVOUS SYSTEM and KIDNEY.beta Catenin: 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.Endothelial Cells: Highly specialized EPITHELIAL CELLS that line the HEART; BLOOD VESSELS; and lymph vessels, forming the ENDOTHELIUM. They are polygonal in shape and joined together by TIGHT JUNCTIONS. The tight junctions allow for variable permeability to specific macromolecules that are transported across the endothelial layer.Muscles: Contractile tissue that produces movement in animals.Cloning, Molecular: 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.Rhombencephalon: The posterior of the three primitive cerebral vesicles of an embryonic brain. It consists of myelencephalon, metencephalon, and isthmus rhombencephali from which develop the major BRAIN STEM components, such as MEDULLA OBLONGATA from the myelencephalon, CEREBELLUM and PONS from the metencephalon, with the expanded cavity forming the FOURTH VENTRICLE.Microinjections: The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.Growth Substances: Signal molecules that are involved in the control of cell growth and differentiation.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Receptors, Growth Factor: Cell surface receptors that bind growth or trophic factors with high affinity, triggering intracellular responses which influence the growth, differentiation, or survival of cells.Bone Morphogenetic Protein 2: A potent osteoinductive protein that plays a critical role in the differentiation of osteoprogenitor cells into OSTEOBLASTS.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Insect Proteins: Proteins found in any species of insect.Tretinoin: An important regulator of GENE EXPRESSION during growth and development, and in NEOPLASMS. Tretinoin, also known as retinoic acid and derived from maternal VITAMIN A, is essential for normal GROWTH; and EMBRYONIC DEVELOPMENT. An excess of tretinoin can be teratogenic. It is used in the treatment of PSORIASIS; ACNE VULGARIS; and several other SKIN DISEASES. It has also been approved for use in promyelocytic leukemia (LEUKEMIA, PROMYELOCYTIC, ACUTE).Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
The neural stem/progenitor cells are unique because they are able to self-renew and are multipotent. This means they can ... Neurons that are early born have marker CTIP2 and are located adjacent to the TBR1 exhibiting preplate cells. Late born neurons ... Embryos have three layers: endoderm, mesoderm and ectoderm. Each turns into various body parts. The nervous system grows from ... Microencephaly is a developmental condition in which the brain remains undersized, producing an undersized head and ...
It was found that early in development, Eomesodermin/Tbr2 controls early differentiation of the cardiac mesoderm. In fact, lack ... This, may lead to the microcephaly (small head size due to improper brain development) seen in Eomesodermin/Tbr2 deficient mice ... Eomesodermin/Tbr2 is expressed highly in the intermediate progenitor stage of the developing neuron. Neurons, the primary ... It has been found experimentally through knock out studies, that mice lacking Eomesodermin/Tbr2 during early development have a ...
The BMP4 signaling has been found in formation of early mesoderm and germ cells. Limb bud regulation and development of the ... Also in conjunction with FGF2 it can produce progenitor thyroid cells from pluripotent stem cells in mice and hmans. BMP4 has ... BMP4 helps in the patterning of the developing head though inducing apoptosis of the neural crest cells; this is done in the ... BMP4 antagonizes organizer tissue and is expressed in early development in ectoderm and mesoderm tissue. Upon gastrulation, the ...
... of expression in the embryo it is also expressed in nonsomitic paraxial mesoderm that goes on to form the muscles of the head, ... there is one important early enhancer that initiates expression. Termed the early epaxial enhancer, its activation provides the ... It remains clear that each population of myogenic progenitor cells (for different locations in the embryo) is regulated by a ... This early expression of Myf5 in the epaxial dermamyotome is involved with the very formation of myotome, but nothing beyond ...
The paraxial mesoderm forms the somitomeres, which give rise to mesenchyme of the head and organize into somites in occipital ... In all bilaterian animals, the mesoderm is one of the three primary germ layers in the very early embryo. The other two layers ... "Human embryonic stem cell-derived mesoderm-like epithelium transitions to mesenchymal progenitor cells". Tissue Engineering. ... There are three important components, the paraxial mesoderm, the intermediate mesoderm and the lateral plate mesoderm. ...
Morphogenesis is important for creating the three germ layers of the early embryo (ectoderm, mesoderm and endoderm) and for ... A single tissue, formed from a single type of progenitor cell or stem cell, often consists of several differentiated cell types ... head, trunk and tail). Regional specification is initiated by the presence of cytoplasmic determinants in one part of the ... By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal ...
Early Development in Birds. Print Stegmann, TJ (May 1999). "New approaches to coronary heart disease: induction of ... Amaya E, Musci TJ, Kirschner MW (Jul 1991). "Expression of a dominant negative mutant of the FGF receptor disrupts mesoderm ... Head Trauma: Basic, Preclinical, and Clinical Directions. New York: Wiley. pp. 165-187. ISBN 0-471-36015-5. Blaber M, DiSalvo J ... developing cerebral cortex by reducing neuronal differentiation and hence permitting the self-renewal of cortical progenitor ...
By the early teens, the thymus begins to atrophy and thymic stroma is mostly replaced by adipose tissue. Nevertheless, residual ... From the jugular lymph sacs, lymphatic capillary plexuses spread to the thorax, upper limbs, neck and head. Some of the ... Lymphatic vessels develop from lymph sacs that arise from developing veins, which are derived from mesoderm. The first lymph ... The primary or central lymphoid organs generate lymphocytes from immature progenitor cells. The thymus and the bone marrow ...
This suggests that early expression of TCF21 is important for expansion of the SMC compartment of the coronary circulation, ... Capsulin transcripts were also found to mark the spiral septum of the heart and progenitor cells that give rise to the ... 6q23-q24 was the chosen chromosomal region due to frequently described LOH in human head and neck squamous cell carcinomas ( ... The TCF21 product is mesoderm-specific and expressed in embryonic epicardium, mesenchyme-derived tissues of lung, gut, gonad, ...
This early-injury response includes epithelial cell stretching for wound closure, the migration of interstitial progenitors ... Head regeneration requires complex reconstruction of the area, while foot regeneration is much simpler, similar to tissue ... In certain species, like Limnodrilus, autolysis can be seen within hours after amputation in the ectoderm and mesoderm. ... Second, these progenitor cells then proliferate and differentiate until they have completely replaced the missing structure. ...
The intermediate mesoderm gives rise to the urogenital tract and consists of cells that migrate from the middle region of the ... From head to tail, these are the infundibulum, bulbus cordis, primitive ventricle, primitive atrium, and the sinus venosus. ... Human embryogenesis is the process of cell division and cellular differentiation of the embryo that occurs during the early ... Brent AE, Schweitzer R, Tabin CJ (April 2003). "A somitic compartment of tendon progenitors". Cell. 113 (2): 235-48. doi: ...
... but soon becomes separated from them by the mesoderm, which grows medially and surrounds it. From the mesoderm surrounding the ... Notogenesis is the development of the notochord by the epiblasts that make up the floor of the amnion cavity.[2] The progenitor ... Section through the head of a human embryo, about twelve days old, in the region of the hind-brain. ... The notochord is the defining feature of chordates, and was present throughout life in many of the earliest chordates. Although ...
GDF10 is closely related to BMP3 and has a roles in head formation and, it is presumed, in skeletal morphogenesis. It is also ... It has a dual nature of function; it both inhibits and induces early stages of development in embryos. GDF5 is expressed in the ... Kim J, Wu H, Lander A, Lyons K, Matzuk M, Calof A (2005). "GDF11 controls the timing of progenitor cell competence in ... GDF1 is expressed chiefly in the nervous system and functions in left-right patterning and mesoderm induction during embryonic ...
In mouse models, Mafb mRNA and protein were detected in both craniofacial ectoderm and neural crest-derived mesoderm between ... including head tossing and running in circles. This mice dies at birth due to renal failure whereas the Mafb -/- mice dies of ... "Downregulation of mafB expression in T-helper cells during early differentiation in vitro". Scandinavian Journal of Immunology ... "Virally mediated MafB transduction induces the monocyte commitment of human CD34+ hematopoietic stem/progenitor cells". Cell ...
In addition to the release of acrosomal vesicles, there is explosive polymerisation of actin to form a thin spike at the head ... It is believed that early in the development of angiosperm linages, there was a duplication in this mode of reproduction, ... especially if their progenitors have been subjected to very different conditions, have an immense advantage in height, weight, ... the ectoderm and the mesoderm, and the genetic code of the father becomes fully involved in the development of the embryo; ...
High levels of Ngn1 and Ngn2 are required to specify neuronal identity of cortical progenitors only in early stages of ... lethal of scute acts in the somatic mesoderm to define cell cluster from which muscle progenitors will be single out. The ... The patterns of expression of the proneural genes lead to different modes of neuroblasts formation in the head and trunk. Co- ... promote neurogenesis in progenitors that express high levels of Neurogenin-1 and gliogenesis in progenitors that express low ...
During early development, Pax3 expression also occurs at the lateral and posterior margins of the neural plate, which is the ... A subset of these Pax3-expressing dermomyotome-derived cells also serves as an ongoing progenitor pool for skeletal muscle ... Pax3 expression is first seen in the pre-somitic paraxial mesoderm, and then ultimately becomes restricted to the dermomyotome ... "Fusion of a fork head domain gene to PAX3 in the solid tumour alveolar rhabdomyosarcoma". primary. Nature Genetics. 5 (3): 230- ...
... s (ES cells) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre ... AST-OPC1 is a population of cells derived from human embryonic stem cells (hESCs) that contains oligodendrocyte progenitor ... and mesoderm. These include each of the more than 220 cell types in the adult body. Pluripotency distinguishes embryonic stem ... it was used by a research team headed by Rudolf Jaenisch of the Whitehead Institute for Biomedical Research in Cambridge, ...
Valente T, Junyent F, Auladell C (June 2005). "Zac1 is expressed in progenitor/stem cells of the neuroectoderm and mesoderm ... "L-selectin defines a bone marrow analog to the thymic early T-lineage progenitor". Blood. 103 (8): 2990-6. doi:10.1182/blood- ... Imaoka S, Mori T, Kinoshita T (February 2007). "Bisphenol A causes malformation of the head region in embryos of Xenopus laevis ... May 2004). "Abundant progenitor cells in the adventitia contribute to atherosclerosis of vein grafts in ApoE-deficient mice". ...
All muscles are derived from paraxial mesoderm. The paraxial mesoderm is divided along the embryo's length into somites, ... All muscle cells produce adenosine triphosphate (ATP) molecules which are used to power the movement of the myosin heads. ... During development, myoblasts (muscle progenitor cells) either remain in the somite to form muscles associated with the ... and do not find any unique set of proteins to both bilaterians and cnidarians and ctenophores that are not present in earlier, ...
This early-injury response includes epithelial cell stretching for wound closure, the migration of interstitial progenitors ... In certain species, such as Limnodrilus, autolysis can be seen within hours after amputation in the ectoderm and mesoderm. ... Regeneration among hydra occurs as foot regeneration arising from the basal part of the body, and head regeneration, arising ... First, adult cells de-differentiate into progenitor cells which will replace the tissues they are derived from.[56][57] Second ...
Early Development in Birds. Print *^ a b Stegmann, TJ (May 1999). "New approaches to coronary heart disease: induction of ... Finklestein S.P.; Plomaritoglou A. (2001). "Growth factors". In Miller L.P., Hayes R.L. Co-edited by Newcomb J.K. (ed.). Head ... Thus the functions of FGFs in developmental processes include mesoderm induction, anterior-posterior patterning,[8] limb ... developing cerebral cortex by reducing neuronal differentiation and hence permitting the self-renewal of cortical progenitor ...
By the early teens, the thymus begins to atrophy and thymic stroma is mostly replaced by adipose tissue. Nevertheless, residual ... The primary or central lymphoid organs generate lymphocytes from immature progenitor cells. ... neck and head.[20] Some of the plexuses enlarge and form lymphatic vessels in their respective regions. Each jugular lymph sac ... which are derived from mesoderm. ... the lymphatic drainage of the head, limbs, and body cavity ...
Early expression[edit]. In mice, during gastrulation on embryological day 7.5, cells fated to become intermediate mesoderm show ... renal vesicle progenitor cell differentiation. • middle ear morphogenesis. • embryonic skeletal joint morphogenesis. • ... Osr1 is the earliest marker of the intermediate mesoderm, which will form the gonads and kidneys. This expression is not ... Expressed in the intermediate mesoderm and required in pronephros formation.[27] Danio rerio Zebrafish zOsr Pronephros ...
The striking segmented pattern of the spine is established during embryogenesis when somites are rhythmically added to the posterior of the embryo. Somite formation begins around the third week when the embryo begins gastrulation and continues until around 52 somites are formed. The somites are spheres, formed from the paraxial mesoderm that lies at the sides of the neural tube and they contain the precursors of spinal bone, the vertebrae ribs and some of the skull, as well as muscle, ligaments and skin. Somitogenesis and the subsequent distribution of somites is controlled by a clock and wavefront model acting in cells of the paraxial mesoderm. Soon after their formation, sclerotomes, which give rise to some of the bone of the skull, the vertebrae and ribs, migrate, leaving the remainder of the somite now termed a dermamyotome behind. This then splits to give the myotomes which will form the muscles and dermatomes which will form the skin ...
The limb bud is a structure formed early in limb development. As a result of interactions between the ectoderm and underlying mesoderm, formation occurs roughly around the fourth week of development as mesenchymal cells from the lateral plate mesoderm and the somites begin to proliferate to the point where they create a bulge under the ectodermal cells above. The limb bud remains active throughout much of limb development, and its signaling stimulates formation of another signaling center, the apical ectodermal ridge (AER) as well as formation of the zone of polarizing activity (ZPA) within the mesenchyme. The mesenchymal cells of the limb bud, which stimulate AER formation as well as maintain AER activity, determine what type of limb will form. ZPA signaling will establish polarity of the limb, as well as sustain proper AER activity. The upper limb bud appears in the third week of development and the lower limb bud appears ...
Nodal, a known mesodermal inducer of the TGFB superfamily,[18] has been implicated in streak formation. Mouse embryos mutant for Nodal fail to gastrulate and lack most mesoderm,[19] but more than playing a role in mesoderm induction, Nodal regulates the induction and/or maintenance of the primitive streak.[19] In the presence of hypoblast, Nodal is unable to induce ectopic streaks in the chick embryo, while its removal, induces expression of Nodal, Chordin and Brachyury,[13] suggesting that the hypoblast must have a certain inhibitory effect on Nodal signaling. Indeed, the multifunctional antagonist of Nodal, Wnt and BMP signaling, Cerberus (produced in the hypoblast) and Cerberus-Short (which inhibits only Nodal), through its effect on Nodal signaling, inhibits streak formation.[13] Eventually, the hypoblast gets displaced anteriorly by the moving endoblast, allowing streak formation at the posterior end. ...
... is a secretory protein that in humans is encoded by the NODAL gene which is located on chromosome 10q22.1. It belongs to the Transforming Growth Factor (TGF-β) superfamily. Like many other members of this superfamily it is involved in cell differentiation in early embryogenesis, playing a key role in signal transfer from the node, in the anterior primitive streak, to lateral plate mesoderm (LPM). Nodal signaling is important very early in development for mesoderm and endoderm formation and subsequent organization of left-right axial structures. In addition, Nodal seems to have important functions in neural patterning, stem cell maintenance and many other developmental processes, including left/right handedness. Nodal can bind type I and type II Serine/Threonine kinase receptors, with Cripto-1 acting as its co-receptor. Signaling through SMAD 2/3 and subsequent translocation of SMAD 4 to the nucleus ...
Milagros Cerrón Arauco was born on April 27, 2004, in Huancayo, Peru. Although most of Milagros' internal organs, including her heart and lungs, are in perfect condition, she was born with serious internal defects, including a deformed left kidney and a very small right one located very low in her body. In addition, her digestive, urinary tracts and genitals share a single tube. This birth defect occurs during the gastrulation week (week 3) of embryonic development. Gastrulation establishes the three germ layers: ectoderm, mesoderm and endoderm. It seems that complications such as defects in the urogenital system as mentioned above can be possibly due to malformations in the intermediate mesoderm. A four-hour operation to insert silicone bags between her legs to stretch the skin was successfully completed on February 8, 2005. A successful operation to separate her legs to just above the knee took place May 31, 2005, in a "Solidarity ...
... is the formation of different tissues from undifferentiated cells. These cells are constituents of three primary germ layers, the endoderm, mesoderm, and ectoderm. The science of the microscopic structures of the tissues formed within histogenesis is termed histology. A germ layer is a collection of cells, formed during animal and mammalian embryogenesis. Germ layers are typically pronounced within vertebrate organisms; however, animals or mammals more complex than sponges (eumetazoans and agnotozoans) produce two or three primary tissue layers. Animals with radial symmetry, such as cnidarians, produce two layers, called the ectoderm and endoderm. Therefore, they are diploblastic. Animals with bilateral symmetry produce a third layer in-between called mesoderm, making them triploblastic. Germ layers will eventually give rise to all of an animal's or mammal's tissues and organs through a process called organogenesis. The endoderm is one ...
Bone morphogenetic protein 4, or BMP4, is a transforming growth factor that causes the cells of the ectoderm to differentiate into skin cells. Without BMP4 the ectoderm cells would develop into neural cells. Axial mesoderm cells under the ectoderm secrete inhibitory signals called chordin, noggin and follistatin. These inhibitory signals prevent the action of BMP4, which would normally make the cells ectoderm; as a result, the overlying cells take their normal course and develop into neural cells. The cells in the ectoderm that circumscribe these neural cells do not receive the BMP4 inhibitor signals and as a result BMP4 induces these cells to develop into skin cells.[8] Neural plate border specifiers are induced as a set of transcription factors. Distalless-5, PAX3 and PAX7 prevent the border region from becoming either neural plate or epidermis.[1] These induce a second set of transcription factors called neural crest specifiers, which cause cells to become neural crest ...
Eye formation in the human embryo begins at approximately three weeks into embryonic development and continues through the tenth week. Cells from both the mesodermal and the ectodermal tissues contribute to the formation of the eye. Specifically, the eye is derived from the neuroepithelium, surface ectoderm, and the extracellular mesenchyme which consists of both the neural crest and mesoderm. Neuroepithelium forms the retina, ciliary body, iris, and optic nerves. Surface ectoderm forms the lens, corneal epithelium and eyelid. The extracellular mesenchyme forms the sclera, the corneal endothelium and stroma, blood vessels, muscles, and vitreous. The eye begins to develop as a pair of optic vesicles on each side of the forebrain at the end of the 4th week of pregnancy. Optic vesicles are outgrowings of the brain which make contact with the surface ectoderm and this contact induces changes necessary for further development of the eye. Through ...
FGFs are multifunctional proteins with a wide variety of effects; they are most commonly mitogens but also have regulatory, morphological, and endocrine effects. They have been alternately referred to as "pluripotent" growth factors and as "promiscuous" growth factors due to their multiple actions on multiple cell types.[14][15] Promiscuous refers to the biochemistry and pharmacology concept of how a variety of molecules can bind to and elicit a response from single receptor. In the case of FGF, four receptor subtypes can be activated by more than twenty different FGF ligands. Thus the functions of FGFs in developmental processes include mesoderm induction, anterior-posterior patterning,[8] limb development, neural induction and neural development,[16] and in mature tissues/systems angiogenesis, keratinocyte organization, and wound healing processes. FGF is critical during normal development of both vertebrates and invertebrates and any irregularities in their function leads ...
... is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo. Although embryogenesis occurs in both animal and plant development, this article addresses the common features among different animals, with some emphasis on the embryonic development of vertebrates and mammals. The egg cell is generally asymmetric, having an "animal pole" (future ectoderm and mesoderm) and a "vegetal pole" (future endoderm). It is covered with protective envelopes, with different layers. The ...
På grunn av den store plommemassen hos amnioter er ikke cellekløyvingen i stand til å bryte opp eggcellen, og fosteret dannes som en liten skive på toppen av plommen. Gastrulasjonen kan derfor ikke foregå på samme måte som hos dyr med mindre plommemasse, men foregår som cellebevegelser i fosterskiven. Den cephale enden av primitivfuren har en innsynkning som kalles primitivgropen, omkranset av en forhøyning av epiblast som kalles primitivknuten.[3]. Epiblastceller frigjør seg langs primitivfuren og migrerer ned i rommet mellom epiblast og hypoblast. Cellene presser hypoblast til side og bytter ut den originale hypoblast med et lag av definitivt eller sekundært endoderm. Andre migrerer lateralt eller kranialt mellom endoderm og epiblast og samler seg til et tredje kimlag, det intraembryonale mesoderm. Etter at gastrulasjonen er ferdig kalles epiblast ektoderm. Epiblasten gir altså opphav til alle de tre kimlagene. Hos lavere organismer vil gastrulasjonen gi opphav til en ...
Y prif brosesau sy'n cymryd rhan yn natblygiad embryonig anifeiliaid yw: rhagnodi rhanbarthol, morffogenesis, gwahaniaethu gan gelloedd, twf, a rheolaeth gyffredinol o amseru. Mae rhagnodi rhanbarthol yn cyfeirio at y prosesau sy'n creu'r patrwm gofodol a geir mewn pelen neu daflen o gelloedd sydd yr un fath cyn datblygu. Dyw camau cyntaf rhagnodi rhanbarthol ddim yn creu celloedd â gwahaniaethau gweithredol, ond yn hytrach creir poblogaethau o gelloedd wedi ymrwymo i ffurfio rhan penodol o'r organeb. Mae'r rhain yn cael eu diffinio gan gyfuniadau o ffactorau trawsgrifio penodol yn cael eu troi ymlaen. Mae morffogenesis yn ymwneud â sut mae siapau tri-dimensiwn yn cael eu ffurfio. Mae'n cynnwys y trefniant a geir mewn symudiadau celloedd yn unigol ac mewn taflenni. Mae'n bwysig ar gyfer creu tri haen germ cynnar yr embryo (yr ectoderm, y mesoderm a'r endoderm) ac ar gyfer adeiladu strwythurau cymhleth yn ystod datblygiad organau. Mae gwahaniaethu gan gelloedd yn cyfeirio'n ...
Embrüonaalsed tüvirakud (totipotentsed ehk kõigevõimelised) on saadud blastotsüsti ehk lootepõiekese sisemassi rakkudest.[7] Embrüonaalsed tüvirakud on pluripotentsed ja annavad alguse kolmele põhilisele lootelehele: ektoderm, endoderm ja mesoderm. Nad võivad diferentseeruda enam kui kahesajaks rakutüübiks, mis esinevad täiskasvanud kehas. Pea kõik tüvirakkudega seotud uuringud on läbi viidud kas hiire (mES) või inimese embrüonaalsete tüvirakkudega (hES). Mõlemad vajavad diferentseerumata oleku säilitamiseks väga erinevaid tingimusi.[8] Inimese embrüonaalseid tüvirakke saab tavalistest rakkudest eristada mitmete spetsiifiliste transkriptsioonifaktorite ekspressiooni ja raku pinnaretseptorite abil.. Embrüonaalsed tüvirakud vajavad diferentseerumiseks väga spetsiifilisi signaale. Kui selliseid rakke süstida teise kehasse, siis hakkavad rakud diferentseeruma paljudeks eri rakkudeks, põhjustades nii teatud tüüpi kasvaja, mida nimetatakse teratoomiks.. Embrüonaalsed ...
Scl/Tal1 can induce these progenitors from early mesoderm mainly at the expense of the somitic paraxial mesoderm. We show that ... 1Ad; arrow; n=18/22; 1D), but not in the head paraxial mesoderm or in the nkx2.5+ (Chen and Fishman, 1996) cardiogenic mesoderm ... 6H, green arrow; n=11/15), suggesting an expansion of early ventral progenitors that have not yet switched on early blood and ... Gain-of-function studies suggest an earlier role for scl/tal1 consistent with its expression in early lateral mesoderm prior to ...
... dual inhibition of Wnt/β-catenin and Nodal specifies head mesoderm. Remarkably, the progenitors derived from embryonic stem ... specifies head mesoderm and unravel the mechanism that diversifies head and trunk muscle programmes during early mesoderm fate ... that of head muscles is ill defined. Here, we show that, unlike the myogenic trunk paraxial mesoderm, head mesoderm development ... Divergent early mesoderm specification underlies distinct head and trunk muscle programmes in vertebrates.. Title. Divergent ...
... revealing the normal migratory capacity of head mesoderm progenitors (Fig. 3E). In the presence of SB-505124, however, ... 1991). Expression of a Xenopus homolog of Brachyury (T) is an immediate-early response to mesoderm induction. Cell 67, 79-87. ... Nodal signalling is necessary for convergent extension of dorsal mesoderm and for head mesoderm migration. Embryos lacking ... Nodal activity is necessary for convergent extension in axial mesoderm and for head mesoderm migration. Using morpholino- ...
Dorsal-Paraxial Mesoderm. Dorsolateral Prefrontal Neocortex. Duodenum. Early Endoderm Progenitor. Early Endoderm Progenitor ( ... Early Endoderm Progenitor. Uterus. Thalamus. Substantia Nigra Pars Compacta. Head Mesenchyme. Anal Canal. Lymph Nodes. Hair. ... Mesoderm Progenitor. Prostate. Fallopian Tube. Cholinergic Progenitor. Penis. Glutamatergic Progenitor. Middle ear. Fetal ... Mesoderm Progenitor. Mesoderm Progenitor (Uniprot/TrEMBL) Mesonephric Ducts. Microglia. Midbrain. Middle First Trimester. ...
Within the pharyngeal mesoderm, SHF progenitors produce the right ventricle, parts of the atria, and cardiac muscle tissue of ... Pharyngeal mesoderm regulatory network controls cardiac and head muscle morphogenesis. Proc Natl Acad Sci U S A. 2012;109(46): ... Nkx-2.5 - a novel murine Homeobox gene expressed in early heart progenitor cells and their myogenic descendants (Vol 119, Pg ... recent findings have recognized increased heterogeneity of muscle origins and progenitor fates of the vertebrate head [85,86,87 ...
... how progenitor like stem-like of the early mesoderm and nervous system acquire these different axial cell fates during early ... In the nervous system for example, a cell in the anterior-head makes a forebrain-derived neuron or an eye cell, whereas a nerve ... One of the earliest and most dramatic events in early development is the formation of the body axes. As early embryos, we all ... These early stem cells are totipotential and can develop into all cell types of the embryo. At a critical stage, cells commit ...
span" data-trigger="SectionLoaded"> Lateral Plate Mesoderm (Gastrulation Derivatives) * PureStem E15, Meso-prx/latp Progenitor ... span" data-trigger="SectionLoaded"> Inner Cell Mass (Early Embryonic Tissues) * Line H9 (WA09) ... span" data-trigger="SectionLoaded"> Head Mesenchyme (Muscoskeletal System) * Frontonasal Process *span" data-trigger=" ... span" data-trigger="SectionLoaded"> Paraxial Mesoderm (Gastrulation Derivatives) * PureStem E15, Meso-prx/latp Progenitor ...
The neural stem/progenitor cells are unique because they are able to self-renew and are multipotent. This means they can ... Neurons that are early born have marker CTIP2 and are located adjacent to the TBR1 exhibiting preplate cells. Late born neurons ... Embryos have three layers: endoderm, mesoderm and ectoderm. Each turns into various body parts. The nervous system grows from ... Microencephaly is a developmental condition in which the brain remains undersized, producing an undersized head and ...
... when mesendoderm progenitor cells form long-lasting cell-cell contacts, the cells become head mesoderm, while in case they only ... Earlier this year, he obtained an Advanced Grant of the European Research Council. First author Vanessa Barone was a student in ... researchers looked at progenitor cells within the forming anterior axial mesendoderm that give rise to either the head mesoderm ... required for head mesoderm cell fate specification and differentiation, and Nodal signalling, in turn, promoting cell-cell ...
... and the lateral mesoderm differentiation in addition to mesenchymal duct progenitors caudal elongation of the femoral head ... This is similar to losing position in the early stages.The basics . How canimprove my appetite. You will decrease diffusive ... The more you constrict the fistula with a am h and mcmahon awnt is a process that further signals from trunk paraxial mesoderm ... After their condition and its dorsoventral axis fixed the pronephric mesoderm in the glomerulus was a start, and provided not ...
Expression of hthE54-GFP in heart progenitors of Md, T1-T3 segments (arrow heads) and in somatic mesoderm (with A-P graded ... show enhancer activities at earliest stage of appearance (arrow or arrow heads: dorsal/cardiac mesoderm) and A″ to P″ at latest ... but not in somatic mesoderm, requires tin. (G, G′) tshL8-LacZ expression in cardiogenic mesoderm, but not in somatic mesoderm, ... E, E′) midE19-GFP expression in cardioblast progenitors requires tin. (F, F′) RhoLE102-GFP expression in cardiogenic mesoderm, ...
Paraxial Mesoderm Cells Trunk Mesoderm *span" data-trigger="SectionLoaded"> Epiblast (Early Embryonic Tissues) * Primordial ... Muscle Progenitor Cells Mandibular Arch Muscles * Muscle Progenitor Cells Hyoid Arch Muscles ... span" data-trigger="SectionLoaded"> Head Mesenchyme (Muscoskeletal System) * Branchial Arch 2 *span" data-trigger=" ... span" data-trigger="SectionLoaded"> Paraxial Mesoderm (Gastrulation Derivatives) * Paraxial Mesoderm Cells Trunk Mesoderm ...
Few studies have been carried out to show the fate of early mesoderm cells. Lineage tracing of paraxial mesoderm shows that ... Other connective tissues and bone in the head and neck have been shown to be of neural crest lineage as well (Billon et al., ... Tang, W. Zeve, D. Suh, J.M. Bosnakovski, D. Kyba, M. Hammer, R.E. Tallquist, M.D. Graff, J.M. (2008). White fat progenitor ... The primitive mesoderm differentiates into the paraxial, intermediate, and lateral mesoderms. Generally the embryonic mesoderm ...
It was found that early in development, Eomesodermin/Tbr2 controls early differentiation of the cardiac mesoderm. In fact, lack ... This, may lead to the microcephaly (small head size due to improper brain development) seen in Eomesodermin/Tbr2 deficient mice ... Eomesodermin/Tbr2 is expressed highly in the intermediate progenitor stage of the developing neuron. Neurons, the primary ... It has been found experimentally through knock out studies, that mice lacking Eomesodermin/Tbr2 during early development have a ...
Depletion of VZ progenitors leads to an early termination of cortical neurogenesis. Pax6 immunostaining in control (A,C,E) or ... Dotted lines demarcate the cortical wall; analysis excluded the overlying head ectoderm and mesoderm. Tbr1/BrdU immunostaining ... mRNA production as early as E11.5 in the cortical VZ (arrowheads) during the period of increased early neurogenesis in Emx1; ... Early excess of cortical neurons and later deficit in Emx1;TKOs. (A-D) βIII tubulin and (g-n) Tbr1 immunostaining showing ...
... can be coaxed to make mesoderm, the layer of cells in the early embryo with the potential to make kidney cells. From there, ... Each nephron is shaped like the head of a wrench leading into a long convoluted tube that bends and winds. Blood is filtered at ... Littles team finds amazing is how exactly these types of cells, the nephrons and their progenitors and collecting duct cells, ... Kidney organoids are made with human cells, so they mimic early human kidney development more closely than mouse models, ...
Dorsal-Paraxial Mesoderm. Dorsolateral Prefrontal Neocortex. Duodenum. Early Endoderm Progenitor. Early Endoderm Progenitor ( ... Splanchnic Mesoderm. Granulocytes. Teeth Enamel. Skull and Branchial Cartilages. Head Mesenchyme. Glutamatergic Progenitor. ... Early Endoderm Progenitor. Neural Crest Mesenchymal Stem Cells. Lateral Mesoderm. Fetal Heart. Hematopoietic Progenitor. ... Mesoderm Progenitor. Mesoderm Progenitor (Uniprot/TrEMBL) Mesonephric Ducts. Microglia. Midbrain. Middle First Trimester. ...
Early Floor Plate Cells Mesencephalic Floor Plate *span" data-trigger="SectionLoaded"> Head Mesenchyme (Muscoskeletal System) * ... span" data-trigger="SectionLoaded"> Mesoderm (Gastrulation Derivatives) * Mesendoderm Cells Anterior Primitive Streak ... Stromal Vascular Preadipocyte Progenitor Cells Vascular Adipose *span" data-trigger="SectionLoaded"> Brain (Nervous System) * ... span" data-trigger="SectionLoaded"> Primitive Streak (Early Embryonic Tissues) * Primitive streak-like cells(Hinton A et. al. ...
Tissue-level coordination of cardiac progenitor cells in the early mouse embryo produces a temporal compartmentalization of ... Early patterning and specification of cardiac progenitors in gastrulating mesoderm * WP Devine ... at early head fold stage (EHF, ~E7.5), the cardiogenic region is visualized as a flat horse shoe-shaped tdtomato+ mesodermal ... Early lineage restriction in temporally distinct populations of Mesp1 progenitors during mammalian heart development * F ...
Tirosh-Finkel, L; Elhanany, H; Rinon, A; Tzahor, E (2006). Mesoderm progenitor cells of common origin contribute to the head ... Rinon, A; Nathan, E; Tzahor, E (2009). p53 involvement in early cranial neural crest development in the chick. Developmental ... Tzahor, E; Evans, SM (2011). Pharyngeal mesoderm development during embryogenesis: implications for both heart and head ... Pharyngeal mesoderm regulatory network controls cardiac and head muscle morphogenesis. Proceedings Of The National Academy Of ...
An exception is the head region, where certain progenitor cells are derived from ectoderm by way of the neural crest cells. ... in the head region, it is sometimes called ectomesenchyme) is established in the early embryo. Maturation and proliferation of ... The mesoderm, the middle embryonic germ layer, gives rise to almost all of the connective tissues of the body. ...
Free flashcards to help memorize facts about WVSOM Class of 2012 Early Morphogenesis. Other activities to help include hangman ... embryonic mesoderm, including the heart tube, splanchnic extraembryonic mesoderm, somatic extraembryonic mesoderm and ... cytotrophoblast cells surrounded by the synctiotrophoblast, these are the progenitors of all chorionic villi:. primary villi. ... head mesenchyme. somitomeres in what regions become somites?. medial and posterior. the somites differentiate into what 3 ...
The AX becomes the hindgut lip, a progenitor pool for the fetal‐placental interface. (a) Just prior to turning, the AX is ... Simmons,, D. G., Natale,, D. R., Begay,, V., Hughes,, M., Leutz,, A., & Cross,, J. C. (2008). Early patterning of the chorion ... Wilkinson,, D. G., Bhatt,, S., & Herrmann,, B. G. (1990). Expression pattern of the mouse T gene and its role in mesoderm ... al, allantois; hf, headfold; hp, head process; n, node; ntc, notochord; pps, embryonic posterior primitive streak ...
In the embryo, early progenitors exhibit a broad potential with cis-regulatory elements for developmental genes existing in a ... including the ability to make the mesoderm-like ectomesenchymal precursors of the head skeleton. ... How then does this specific loss of ectomesenchyme relate to the earlier delay in CNC specification? In one model, early- ... Alternatively H3.3 incorporation could act to maintain mesoderm-like potential in the CNC ectoderm from an earlier time in ...
Muscle stem cells arise either in unsegmented paraxial mesoderm (anterior head muscle progenitors) or in segmented mesoderm of ... Here we investigated early disease stages in this model to determine initial pathological events and effects of Bcl-2 on their ... Bcl-2 expression identifies an early stage of myogenesis and promotes clonal expansion of muscle cells. Dominov JA , Dunn JJ , ... Bcl-2 inhibits the innate immune response during early pathogenesis of murine congenital muscular dystrophy. Jeudy S , Wardrop ...
  • is indispensable for the expression of early mesoderm markers and is, therefore, an obligatory factor in mesodermal competence and/or maintenance. (stanford.edu)
  • We identified several novel targets upregulated by RA receptor signaling in the early gastrula that are expressed in the circumblastoporal ring and linked to mesodermal development. (stanford.edu)
  • In this mini-review we will focus on the current knowledge about (1) SMC origin from various embryonic mesodermal progenitors and (2) phenotypic heterogeneity in neonatal and adult vessel walls in various animal models. (ahajournals.org)
  • We previously generated eve mesoderm-specific mutants by combining an eve null mutant with a rescuing transgene that includes the entire locus, but with the mesodermal enhancer removed. (ahajournals.org)
  • Our lab is studying the processes of mesoderm patterning and mesodermal tissue development in Drosophila . (fau.eu)
  • For example, the mesodermally-expressed homeobox gene tinman cooperates with the ectodermally-secreted factor Dpp, a TGF-beta molecule of the BMP family, to subdivide the mesoderm into a ventral and a dorsal portion and to determine dorsal mesodermal derivatives. (fau.eu)
  • Dysferlin-deficiency due to mutations in the dysferlin gene leads to muscular dystrophy (Miyoshi myopathy (MM), limb girdle muscular dystrophy type 2B (LGMD2B), distal myopathy with anterior tibial onset (DMAT)), typically with early adult onset. (atgcchecker.com)
  • Bouwmeester, Cerberus is a head-inducing secreted factor expressed in the anterior endoderm of Spemann's organizer. (xenbase.org)
  • Using the Xenopus system, we show that RAR?2 plays a specific role in somite number and size, restriction of the presomitic mesoderm anterior border, somite chevron morphology and hypaxial myoblast migration. (stanford.edu)
  • During oogenesis and early embryonic development in Drosophila , translation of proteins from maternally deposited mRNAs is tightly controlled. (sdbonline.org)
  • A genetic screen was performed in Drosophila melanogaster for genes involved in Wingless/Wnt secretion, and the p24 protein family members Baiser , CHOp24 , Eclair and a v-SNARE protein Sec22 , were identified that are involved in the early secretory pathway of Wingless/Wnt. (sdbonline.org)
  • Second, the application of molecular techniques such as gene cloning, in situ hybridization to sectioned tissues, immunofluorescence, and the A B C D E Figure 1 Stages in early Drosophila development. (sciencedocbox.com)
  • Later on, in the 1970s, the achaete-scute complex, a complex of genes that are involved in regulating the early steps of neural development in Drosophila, were identified[by whom? (wikipedia.org)
  • We are interested in learning how the heart is formed during embryogenesis and, more specifically, the cellular origins of distinct heart progenitor populations. (weizmann.ac.il)
  • During vertebrate heart development, two progenitor populations, first and second heart fields (FHF, SHF), sequentially contribute to longitudinal subdivisions of the heart tube (HT), with the FHF contributing the left ventricle and part of the atria, and the SHF the rest of the heart. (elifesciences.org)
  • The vertebrate head arose due to the evolution of neural crest and sensory placodes. (els.net)
  • These results demonstrate for the first time an early and essential role for RAR?2 in vertebrate somitogenesis. (stanford.edu)
  • In doing this, they are recapitulating the earliest event in the transition from invertebrates to vertebrate forms, a transition which occurred at least six hundred million years ago. (bio.net)
  • Molecularly, this process involves the binding of Dpp-activated signal transducers (the Smad proteins Mad and Medea), together with the Tinman protein itself, to target enhancers of genes such as tinman , bagpipe , and even-skipped , which results in their spatially-restricted activation in the dorsal mesoderm. (fau.eu)
  • Other spatial cues such as Wingless and the forkhead domain protein Sloppy Paired provide additional inputs for subdividing the dorsal mesoderm into heart, gut muscle, and somatic muscle primordia. (fau.eu)
  • The cranial mesoderm and cranial NCC are required for both the development of the head and heart and therefore, cardiac and craniofacial abnormalities often occur together. (els.net)
  • Our study reveals that both in vitro and in vivo the proximal Runx1 isoform marks a hemogenic endothelium cell population, whereas the subsequent expression of distal Runx1 defines fully committed definitive hematopoietic progenitors. (bloodjournal.org)
  • This transient wave of primitive erythrocyte generation, defined as primitive hematopoiesis, is shortly followed by the production of definitive hematopoietic progenitors in the yolk sac. (bloodjournal.org)
  • In mice, Runx1 deletion results in midgestation lethality 14 , 15 and a complete block in development of definitive hematopoietic progenitors. (bloodjournal.org)
  • Importantly, the lateral plate mesoderm also gives rise to the hemangioblast and subsequently the hematopoietic stem cell (HSC). (biolegend.com)
  • Conditions such as peer pressure parent child relationship problems or if it is used to compile information to assist with complying with these manoeuvres then tracheal intubation all children should be measured at least stage the lateral plate mesoderm both express bmp mrna pourquie watanabe and le roith d inhibition of gsk results in fewer branches than control pronephoi with the bevel uppermost and aligned with the. (qhrtechnologies.com)
  • In each side, the mesoderm remains thin and is known as the lateral plate. (wikipedia.org)
  • The primitive streak reaches into the extraembryonic space, where it marks the site of arterial union and creates a progenitor cell pool. (wiley.com)
  • Intriguingly, taste function is often distorted in patients receiving targeted irradiation for head and neck tumors, as well as in cancer patients treated with a variety of specific chemotherapeutics, suggesting that taste cell turnover may be perturbed. (ucdenver.edu)
  • SDF1α induces cell division in cerebellar ventricular zone progenitors and also functions as a chemoattractant. (nih.gov)
  • RL progenitors are labelled light green while granule cell progenitors exiting the RL are labelled dark green. (nih.gov)
  • My gear is a pen, notebook, and collection of research abstracts, and I am headed down to a meeting in the sunny beach town of La Jolla, CA, where some of the most innovative and cutting edge research in stem cell biology is taking place at research institutions like The Salk Institute, The Scripps Research Institute, and UC San Diego. (blogspot.com)
  • When a stem cell divides, one daughter cell remains a stem cell while the other daughter cell or progenitor cell differentiates into a particular cell type. (stemsave.com)
  • The proteins secure the regular spacing of sensory organs showing partial redundancy and may function in early lateral inhibition events as well as in cell sorting processes. (sdbonline.org)
  • Our studies have led to the identification of many new genes that are implicated in the regulation of epiblast pluripotency and the formation of multipotent mesoderm progenitors. (cancer.gov)
  • At early postimplantation (E5.5-E6.5), the VE epithelium comprises several subpopulations, generally encompassing: the extraembryonic VE (exVE), a cuboidal epithelium overlying the ExE, and the embryonic VE (emVE), a squamous epithelium overlying the epiblast [ 4 - 9 ]. (royalsocietypublishing.org)
  • Note reduced ISL1 levels in the cardiac mesoderm (white arrows) in control, but not in Sirt1 fl/- Isl1-Cre + , littermates after chemical induction of hypoxia responses. (jci.org)