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.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.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.Embryo Implantation: Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.Extremities: The farthest or outermost projections of the body, such as the HAND and FOOT.Blastocyst: 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.Embryonic Development: Morphological and physiological development of EMBRYOS.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.Limb Deformities, Congenital: Congenital structural deformities of the upper and lower extremities collectively or unspecified.Limb Salvage: An alternative to amputation in patients with neoplasms, ischemia, fractures, and other limb-threatening conditions. Generally, sophisticated surgical procedures such as vascular surgery and reconstruction are used to salvage diseased limbs.Embryonic and Fetal Development: Morphological and physiological development of EMBRYOS or FETUSES.Embryo Loss: Early pregnancy loss during the EMBRYO, MAMMALIAN stage of development. In the human, this period comprises the second through eighth week after fertilization.Fertilization in Vitro: An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.Phantom Limb: Perception of painful and nonpainful phantom sensations that occur following the complete or partial loss of a limb. The majority of individuals with an amputated extremity will experience the impression that the limb is still present, and in many cases, painful. (From Neurol Clin 1998 Nov;16(4):919-36; Brain 1998 Sep;121(Pt 9):1603-30)Cleavage Stage, Ovum: 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.Blastomeres: 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.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.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.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.Embryo Disposition: Utilization or disposal of an embryo that is fertilized but not immediately transplanted and resulting course of action.Mesoderm: The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.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.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.Zygote: The fertilized OVUM resulting from the fusion of a male and a female gamete.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.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.Cryopreservation: Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.Leg: The inferior part of the lower extremity between the KNEE and the ANKLE.Oocytes: 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).Lower Extremity: The region of the lower limb in animals, extending from the gluteal region to the FOOT, and including the BUTTOCKS; HIP; and LEG.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.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).Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)Embryo Research: Experimentation on, or using the organs or tissues from, a human or other mammalian conceptus during the prenatal stage of development that is characterized by rapid morphological changes and the differentiation of basic structures. In humans, this includes the period from the time of fertilization to the end of the eighth week after fertilization.Single Embryo Transfer: The techniques used to select and/or place only one embryo from FERTILIZATION IN VITRO into the uterine cavity to establish a singleton pregnancy.Cloning, Organism: The formation of one or more genetically identical organisms derived by vegetative reproduction from a single cell. The source nuclear material can be embryo-derived, fetus-derived, or taken from an adult somatic cell.Forelimb: A front limb of a quadruped. (The Random House College Dictionary, 1980)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).Ectogenesis: Embryonic and fetal development that takes place in an artificial environment in vitro.Ischemia: A hypoperfusion of the BLOOD through an organ or tissue caused by a PATHOLOGIC CONSTRICTION or obstruction of its BLOOD VESSELS, or an absence of BLOOD CIRCULATION.Nuclear Transfer Techniques: Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Ectoderm: The outer of the three germ layers of an embryo.Amputation: The removal of a limb or other appendage or outgrowth of the body. (Dorland, 28th ed)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).Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Pregnancy Rate: The ratio of the number of conceptions (CONCEPTION) including LIVE BIRTH; STILLBIRTH; and fetal losses, to the mean number of females of reproductive age in a population during a set time period.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.Sperm Injections, Intracytoplasmic: An assisted fertilization technique consisting of the microinjection of a single viable sperm into an extracted ovum. It is used principally to overcome low sperm count, low sperm motility, inability of sperm to penetrate the egg, or other conditions related to male infertility (INFERTILITY, MALE).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.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Fetal Viability: The potential of the FETUS to survive outside the UTERUS after birth, natural or induced. Fetal viability depends largely on the FETAL ORGAN MATURITY, and environmental conditions.Endoderm: The inner of the three germ layers of an embryo.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.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.Parthenogenesis: A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.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.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.Arm: The superior part of the upper extremity between the SHOULDER and the ELBOW.Blastoderm: A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.Sea Urchins: Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.Animals, Genetically Modified: ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.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).Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.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.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.Preimplantation Diagnosis: Determination of the nature of a pathological condition or disease in the OVUM; ZYGOTE; or BLASTOCYST prior to implantation. CYTOGENETIC ANALYSIS is performed to determine the presence or absence of genetic disease.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)Chimera: An individual that contains cell populations derived from different zygotes.Loop of Henle: The U-shaped portion of the renal tubule in the KIDNEY MEDULLA, consisting of a descending limb and an ascending limb. It is situated between the PROXIMAL KIDNEY TUBULE and the DISTAL KIDNEY TUBULE.Microinjections: The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.Ambystoma mexicanum: A salamander found in Mexican mountain lakes and accounting for about 30 percent of the urodeles used in research. The axolotl remains in larval form throughout its life, a phenomenon known as neoteny.Notochord: 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.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.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.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.Teratogens: An agent that causes the production of physical defects in the developing embryo.Xenopus: An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.Upper Extremity: The region of the upper limb in animals, extending from the deltoid region to the HAND, and including the ARM; AXILLA; and SHOULDER.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.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.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.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.Superovulation: Occurrence or induction of release of more ova than are normally released at the same time in a given species. The term applies to both animals and humans.Fibroblast Growth Factor 4: A HEPARIN binding fibroblast growth factor that may play a role in LIMB BUDS development.Polydactyly: A congenital anomaly of the hand or foot, marked by the presence of supernumerary digits.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.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.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.Mice, Inbred ICRGene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Ovum: A mature haploid female germ cell extruded from the OVARY at OVULATION.Coturnix: A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.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.Trans-Activators: Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.Pregnancy Outcome: Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Avian Proteins: Proteins obtained from species of BIRDS.Abnormalities, Drug-Induced: Congenital abnormalities caused by medicinal substances or drugs of abuse given to or taken by the mother, or to which she is inadvertently exposed during the manufacture of such substances. The concept excludes abnormalities resulting from exposure to non-medicinal chemicals in the environment.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Muscles: Contractile tissue that produces movement in animals.Mice, Inbred C57BLCell Lineage: The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.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.Gestational Age: The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.Cell Nucleus: 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)AmputeesUrochordata: A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.Cartilage: A non-vascular form of connective tissue composed of CHONDROCYTES embedded in a matrix that includes CHONDROITIN SULFATE and various types of FIBRILLAR COLLAGEN. There are three major types: HYALINE CARTILAGE; FIBROCARTILAGE; and ELASTIC CARTILAGE.Fallopian Tubes: A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.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.Genes, Lethal: Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.Embryo Implantation, Delayed: Delay in the attachment and implantation of BLASTOCYST to the uterine ENDOMETRIUM. The blastocyst remains unattached beyond the normal duration thus delaying embryonic development.Mice, Mutant Strains: Mice bearing mutant genes which are phenotypically expressed in the animals.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.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.DNA, Complementary: 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.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.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.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.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.Vitrification: The transformation of a liquid to a glassy solid i.e., without the formation of crystals during the cooling process.Zona Pellucida: A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.Embryology: The study of the development of an organism during the embryonic and fetal stages of life.Fetal Death: Death of the developing young in utero. BIRTH of a dead FETUS is STILLBIRTH.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Uterus: The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus (the body) which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.Amputation Stumps: The part of a limb or tail following amputation that is proximal to the amputated section.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Germ Cells: The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Central Nervous System: The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.Pregnancy, Multiple: The condition of carrying two or more FETUSES simultaneously.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.Salamandridae: A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.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.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.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.Organogenesis: Formation of differentiated cells and complicated tissue organization to provide specialized functions.Genes, Insect: The functional hereditary units of INSECTS.Leg Injuries: General or unspecified injuries involving the leg.Toes: Any one of five terminal digits of the vertebrate FOOT.WingRegeneration: The physiological renewal, repair, or replacement of tissue.Cryoprotective Agents: Substances that provide protection against the harmful effects of freezing temperatures.Developmental Biology: The field of biology which deals with the process of the growth and differentiation of an organism.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.Reproductive Techniques: Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).Locomotion: Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.Spermatozoa: Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.Femoral Artery: The main artery of the thigh, a continuation of the external iliac artery.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.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.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.Research Embryo Creation: The creation of embryos specifically for research purposes.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).Trophoblasts: Cells lining the outside of the BLASTOCYST. After binding to the ENDOMETRIUM, trophoblasts develop into two distinct layers, an inner layer of mononuclear cytotrophoblasts and an outer layer of continuous multinuclear cytoplasm, the syncytiotrophoblasts, which form the early fetal-maternal interface (PLACENTA).Oogenesis: The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).Ambystoma: A genus of the Ambystomatidae family. The best known species are the axolotl AMBYSTOMA MEXICANUM and the closely related tiger salamander Ambystoma tigrinum. They may retain gills and remain aquatic without developing all of the adult characteristics. However, under proper changes in the environment they metamorphose.Cell Count: The number of CELLS of a specific kind, usually measured per unit volume or area of sample.TailNeural Tube Defects: Congenital malformations of the central nervous system and adjacent structures related to defective neural tube closure during the first trimester of pregnancy generally occurring between days 18-29 of gestation. Ectodermal and mesodermal malformations (mainly involving the skull and vertebrae) may occur as a result of defects of neural tube closure. (From Joynt, Clinical Neurology, 1992, Ch55, pp31-41)Popliteal Artery: The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries.Organizers, Embryonic: 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).Ectromelia: Gross hypo- or aplasia of one or more long bones of one or more limbs. The concept includes amelia, hemimelia, phocomelia, and sirenomelia.Tissue Transplantation: Transference of tissue within an individual, between individuals of the same species, or between individuals of different species.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.Caenorhabditis elegans: A species of nematode that is widely used in biological, biochemical, and genetic studies.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Organ Culture Techniques: A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)Oocyte Donation: Transfer of preovulatory oocytes from donor to a suitable host. Oocytes are collected, fertilized in vitro, and transferred to a host that can be human or animal.Insect Proteins: Proteins found in any species of insect.Mosaicism: The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.Microscopy, Electron, Scanning: 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.Homozygote: An individual in which both alleles at a given locus are identical.Infertility, Female: Diminished or absent ability of a female to achieve conception.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Cytoplasm: 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)Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Live Birth: The event that a FETUS is born alive with heartbeats or RESPIRATION regardless of GESTATIONAL AGE. Such liveborn is called a newborn infant (INFANT, NEWBORN).Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Foot: The distal extremity of the leg in vertebrates, consisting of the tarsus (ANKLE); METATARSUS; phalanges; and the soft tissues surrounding these bones.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.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Mice, Inbred CBAInfertility: Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.Gait: Manner or style of walking.Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Blastocyst Inner Cell Mass: The cluster of cells inside a blastocyst. These cells give rise to the embryonic disc and eventual embryo proper. They are pluripotent EMBRYONIC STEM CELLS capable of yielding many but not all cell types in a developing organism.Oryzias: The only genus in the family Oryziinae, order BELONIFORMES. Oryzias are egg-layers; other fish of the same order are livebearers. Oryzias are used extensively in testing carcinogens.
Furthermore, the number of the week is one more than the actual age of the embryo/fetus. For example, the embryo is 0 whole ... The limbs are long and thin. The fetus can make a fist with its fingers. Genitals appear well differentiated. Red blood cells ... The embryo becomes embedded in the endometrium in a process called implantation. In most successful pregnancies, the embryo ... The embryo spends the next few days traveling down the Fallopian tube. It starts out as a single cell zygote and then divides ...
Icons of Evolution
Homology in vertebrate limbs 4 Haeckel's embryos 5 Archaeopteryx 6 Peppered moth ... Haeckel's embryosEdit. PZ Myers, reviewing the chapter in which Wells takes on Haeckel's embryos, wrote: .mw-parser-output . ... Wells and Haeckel's Embryos Archived 2007-02-18 at the Wayback Machine PZ Myers. Pharyngula (blog), February 15, 2007. ... In 2003, Holt, Rinehart and Winston said it re-evaluated the use of the peppered moth and Haeckel's drawing of embryos from its ...
Kutsch, Wolfram (1989). "Formation of the receptor system in the hind limb of the locust embryo". Roux's Archives of ... In the latter, the organ increases in size proportionally to the growth of the limb containing it and has the shape of a fan. ... The organ itself has a semicircular shape inside the limb and is supplied by three different nerves, one of which also targets ... The bee organ is cone shaped branching out from its nerve and almost obstructs haemolymph flow through the limb. In the ...
If infected into the yolk sac, the embryo will succumb to death accompanied by hemorrhaging of the embryos and cause the foci ... For chickens, the most common manifestation of the disease is joint/limb lameness. Confirming infection of avian reovirus can ... and fibroblasts of the chick embryo. Of the following susceptible areas, liver cells from the chick embryo have been found to ... Inoculation of embryonic eggs through the yolk sac has shown that the virus usually kills the embryos within 5 or 6 days post ...
For instance, if a certain Hox gene is expressed, a region will develop into a limb; if a different Hox gene is expressed in ... A range of theories are based on the concept that minor modifications to animals' development as they grow from embryo to adult ... Some have been described as animal embryos and eggs, although some may represent the remains of giant bacteria. Another fossil ... Xiao, S.; Zhang, Y.; Knoll, A. H. (January 1998). "Three-dimensional preservation of algae and animal embryos in a ...
Hox genes in amphibians and reptiles
Hox genes are a group of related genes that control the body plan of an embryo along the head-tail axis. They are responsible ... This raises a question as to why humans which also possess an analog to these genes cannot regrow and regenerate limbs. Beside ... Hox genes play a massive role in some amphibians and reptiles in their ability to regenerate lost limbs, especially HoxA and ... Similar to an ancient tetrapod group with assorted limb types, it is important to note that amphibians are required for the ...
2010 in science
The other egg has a much less developed embryo, with only the hind limbs preserved. While this does not permit comparison on ... One of these embryos shows a much greater degree of bone development (ossification) than the other; it preserves ossified hind ... The embryos within these eggs are some of the most well-preserved of any oviraptorids, providing new information on oviraptorid ... Two eggs containing embryos found in the Upper Cretaceous Nanxiong Formation near Ganzhou, Jiangxi were referred to M. ...
Limb formation. Expression of Osr1 in the limb buds is initially restricted to the mesenchyme immediately below the ... embryos lacking Osr1 expression fail to grow a ureteric bud that migrates into the uncompacted metanephric mesenchyme. The ... Osr1 is expressed in the first and second branchial arches, in the limb buds, mouth and nasal pits, in the trunk, the forebrain ... embryonic skeletal limb joint morphogenesis. • metanephric mesenchymal cell differentiation. • posterior mesonephric tubule ...
As arthropods they have: segmented bodies with jointed limbs, all covered in a cuticle made of chitin and proteins; heads that ... where the embryos inside the fertilized eggs will start to develop before being laid. Males of the genus Tidarren amputate one ... Spiders also have in the joints of their limbs slit sensillae that detects force and vibrations. In web-building spiders, all ... Although all arthropods use muscles attached to the inside of the exoskeleton to flex their limbs, spiders and a few other ...
It is shaped like an anvil, and has a long limb and a short limb that protrude from the point of articulation with the malleus ... Head and neck of a human embryo eighteen weeks old, with Meckel's cartilage and hyoid bar exposed. External and middle ear, ... Hearing Ear Ossicles hednk-023-Embryo Images at University of North Carolina Drake, Richard L.; Vogl, Wayne; Tibbitts, Adam W.M ... The final part of the long limb, was once described as a "fourth ossicle" by Pieter Paaw in 1615. ...
The net result is that this ubiquitin ligase complex is important for limb outgrowth in embryos. In the absence of cereblon, ... "Pomalidomide is nonteratogenic in chicken and zebrafish embryos and nonneurotoxic in vitro". Proc. Natl. Acad. Sci. U.S.A. 110 ... such as limb and auditory vesicle formation. ...
Ventral and dorsal, which describe structures derived from the front (ventral) and back (dorsal) of the embryo, before limb ... Anatomists divide the lower limb into the thigh (the part of the limb between the hip and the knee) and the leg (which refers ... The upper limbs are held out to each side, and the palms of the hands face forward. Using the standard anatomical position ... Body movements are always described in relation to the anatomical position of the body: upright stance, with upper limbs to the ...
Apical ectodermal ridge
... additional limb at an arbitrary location in the embryo. Transplantation of the AER to flank mesoderm between the normal limb ... and limb development halts. When the AER from a late limb bud is transplanted to an earlier limb bud, the limb forms normally. ... the limb forms normally. The converse - transplantation of an early limb bud to a late limb bud - also results in normal limb ... The converse - transplantation of an early limb bud to a late limb bud - also results in normal limb development. However, the ...
The color is changing from yellow to whitish yellow as the embryo develops. Embryo to peripatoid As the egg teeth, helped by ... The last embryonic stage moults to the "peripatoid" stage in which the trunk is of uniform diameter, and the limbs better ... Eggs which are about to hatch appear pinkish owing to the pinky-violet color of the contained embryos. The pigment occurs in ... In the peripatoid stage, the embryo is immobile, but in the "foetus" stage, it is capable of making writhing movements; it has ...
However, some recent evidence using microinjected embryos suggests that the cells are prespecified early in limb bud ... The fate of the mesodermal cells is thought to be patterned by the length of time spent in the progress zone during limb ... The progress zone is a layer of mesodermal cells immediately beneath the apical ectodermal ridge in the developing limb bud. ... Dudley, A. T.; Ros, M. A.; Tabin, C. (2002). "A re-examination of proximodistal patterning during vertebrate limb development ...
Bone morphogenetic protein 4
Hogan found out that if they did a laser mutation on mice embryos and causing a BMP4 homozygous null mutation, this embryo will ... Limb bud regulation and development of the lungs, liver, teeth and facial mesenchyme cells are other important functions ... In the embryo BMP4 helps establish dorsal-ventral axis formation in xenopus through inducing ventral mesoderm. In mice targets ... After they did these two in situ hybridizations in the mice embryos, they found that both green and red colors are found in the ...
"Fibroblast growth factors induce additional limb development from the flank of chick embryos". Cell. 80 (5): 739-46. doi: ... Tickle C (2000). "Limb development: an international model for vertebrate pattern formation". Int. J. Dev. Biol. 44 (1): 101-8 ... Tickle C (April 2003). "Patterning systems--from one end of the limb to the other". Dev. Cell. 4 (4): 449-58. doi:10.1016/S1534 ... Tickle C (January 2006). "Making digit patterns in the vertebrate limb". Nat. Rev. Mol. Cell Biol. 7 (1): 45-53. doi:10.1038/ ...
1992). "Homeotic genes of the bithorax complex repress limb development in the abdomen of the Drosophila embryo through the ... Hox genes (a subset of homeotic genes) are a group of related genes that control the body plan of an embryo along the head-tail ... Loss of function of Dfd in the embryo results in a failure of head involution (see labial gene), with a loss of larval head ... Similarly, mutations in the Hox genes can result in body parts and limbs in the wrong place along the body. Like a play ...
Studies of the mouse and chick homologs reveal roles in midbrain and limb development, organogenesis, embryo gastrulation and ... C Embryo Today. 81 (2): 84-92. doi:10.1002/bdrc.20092. PMC 2235195 . PMID 17600781. Tanaka A, Miyamoto K, Matsuo H, et al. ( ... 1997). "Genomic structure, sequence, and mapping of human FGF8 with no evidence for its role in craniosynostosis/limb defect ... of the gastrulating embryo. Fgf8 is expressed in the region where Otx2 and Gbx2 cross inhibit each other and is maintained ...
... vestigial hind limbs. Python embryos even have fully developed hind limb buds, but their later development is stopped by the ... Front limbs are nonexistent in all known snakes. This is caused by the evolution of their Hox genes, controlling limb ... Lizards have evolved elongate bodies without limbs or with greatly reduced limbs about twenty five times indepenently via ... The lack of limbs does not impede the movement of snakes. They have developed several different modes of locomotion to deal ...
Sp8 transcription factor
... regulate Fgf8 expression and limb outgrowth in vertebrate embryos". Development. 131 (19): 4763-74. doi:10.1242/dev.01331. PMID ... there would be a decreased length of the limb bud and possible failure of the limb tissue develop. Both Sp8 and Sp9 have been ... Sp8 mediates limb outgrowth during early development. Sp8 deletion in mice resulted in severe exencephaly. Sp8 is a zinc-finger ... Bell SM, Schreiner CM, Waclaw RR, Campbell K, Potter SS, Scott WJ (October 2003). "Sp8 is crucial for limb outgrowth and ...
Homeotic selector gene
Similar to brachiopods, isopods have swimming limbs on the second through eighth thoracic segments, however the limbs on the ... In the Drosophila embryo, Ubx is expressed at high levels in the metathorax and anterior abdominal segments; abd-A is expressed ... Changes in the expression and function of homeotic genes are responsible for the changes in the morphology of the limbs of ... Ubx is expressed in the thorax where it controls the development of swimming limbs. Isopods: Src expression is detected in both ...
The Japanese Silkie initially develops additional digits in the wing as an embryo, but these are lost prior to hatching. The ... May 2011). "The chicken polydactyly (Po) locus causes allelic imbalance and ectopic expression of Shh during limb development ... This causes ectopic SHH expression in the anterior of the developing limb bud, leading to increased tissue growth and digits. ... "Skeletal Analysis and Characterization of Gene Expression Related to Pattern Formation in Developing Limbs of Japanese Silkie ...
Sometimes an embryo started as conjoined twins, but one twin degenerated completely except for one or more limbs, which end up ... In humans and most land-dwelling animals, this means having five or more limbs. The extra limb is most commonly shrunken and/or ... The supernumerary limbs were smaller than the normal appendages but contained an equal number of digits.". Kim C, Yeo S, Cho G ... It is an example of an extra limb on a normal body axis. In July 2007 a child was born with four legs at the Lebowakgomo ...
08/933,564: "Chimeric Embryos and Animals Containing Human Cells." *^ Dowie, Mark (January-February 2004). "Gods and monsters" ... Chuong C-M (2009). "Limb pattern, physical mechanisms and morphological evolution - an interview with Stuart A. Newman". Int J ... Newman SA, Frisch HL (1979). "Dynamics of skeletal pattern formation in developing chick limb". Science. 205 (4407): 662-668. ... Newman's work in developmental biology includes a proposed mechanism for patterning of the vertebrate limb skeleton based on ...
Goodman FR (2003). "Limb malformations and the human HOX genes". Am. J. Med. Genet. 112 (3): 256-65. doi:10.1002/ajmg.10776. ... anterior/posterior axis specification, embryo. • regulation of transcription, DNA-templated. • negative regulation of ... 1989). "Complementary homeo protein gradients in developing limb buds". Genes Dev. 3 (5): 641-50. doi:10.1101/gad.3.5.641. PMID ... end of this cluster have been associated with severe limb and genital abnormalities. In addition to effects during ...
Such severed arms remain sensitive to stimuli and move away from unpleasant sensations. Octopuses can replace lost limbs.[ ... The dorsal side of the disc grows upwards and forms the embryo, with a shell gland on its dorsal surface, gills, mantle and ... Octopuses offer many possibilities in biological research, including their ability to regenerate limbs, change the colour of ...
Tüvirakud - Vikipeedia, vaba entsüklopeedia
A fertilized female gamete (called a zygote) develops into an embryo.. *A seed develops which contains the embryo. The seed ... The narrow conical shape of northern conifers, and their downward-drooping limbs, help them shed snow. Many of them seasonally ... It was found recently that the pollen of conifers transfers the mitochondrial organelles to the embryo, a sort of meiotic drive ... Upon fertilization, the diploid egg will give rise to the embryo, and a seed is produced. The female cone then opens, releasing ...
The air space (7) provides the embryo with oxygen while it is hatching. This ensures that the embryo will not suffocate while ... Reptiles are tetrapod vertebrates, creatures that either have four limbs or, like snakes, are descended from four-limbed ... Alibardi, Lorenzo (2010). Morphological and cellular aspects of tail and limb regeneration in lizards a model system with ... When at rest, the turtle can retract the limbs into the body cavity and force air out of the lungs. When the turtle protracts ...
"The Soul of the Embryo: An Enquiry into the Status of the Human Embryo in the Christian Tradition", by David Albert Jones, ... Francis M. Cornford quotes Pindar by saying that the soul sleeps while the limbs are active, but when one is sleeping, the soul ... "Do Embryos Have Souls?", Father Tadeusz Pacholczyk, PhD, Catholic Education Resource Center". Catholiceducation.org. Retrieved ... There have been differing thoughts regarding whether human embryos have souls from conception, or there is a point between ...
Amyotrophic lateral sclerosis
In limb-onset ALS, the first symptoms are in arms or the legs. If the legs are affected first, people may experience ... The zebrafish has transparent embryos that can be injected with DNA or RNA and has a lifespan of up to two years. Induced ... No test can provide a definite diagnosis of ALS, although the presence of upper and lower motor neuron signs in a single limb ... In respiratory-onset ALS, this may occur before significant limb weakness is apparent. Most people with ALS die of respiratory ...
The incubation period is divided into three phases. In the first phase, the embryo has no functional organs and relies on ... The calcaneus spur found on the male's hind limb is used to deliver venom. ... This allows the yolk, which contains the embryo, to exchange waste and nutrients with the cytoplasm. ... which are kidney-shaped alveolar glands connected by a thin-walled duct to a calcaneus spur on each hind limb. The female ...
A chicken embryo, showing the paraxial mesoderm on both sides of the neural fold. The anterior (forward) portion has begun to ... This can be most easily seen by comparing the limb of a mole to a horse - in the former, the insertion point is positioned to ... All other muscles, including those of the limbs are hypaxial, and inervated by the ventral rami of the spinal nerves. ... The paraxial mesoderm is divided along the embryo's length into somites, corresponding to the segmentation of the body (most ...
Single cell sequencing
July 2014). "The DNA methylation landscape of human early embryos". Nature. 511 (7511): 606-10. Bibcode:2014Natur.511..606G. ... "Single-cell analysis uncovers convergence of cell identities during axolotl limb regeneration". Science. 362 (6413): eaaq0681 ... Pennisi E (April 2018). "Chronicling embryos, cell by cell, gene by gene". Science. 360 (6387): 367. Bibcode:2018Sci...360.. ... scRNA-Seq has provided considerable insight into the development of embryos and organisms, including the worm Caenorhabditis ...
Inbreeding causes early death (inbreeding depression) in the zebra finch Taeniopygia guttata. Embryo survival (that is, ... covering the hind limbs and feet, which may have been used in aerial maneuvering. ... The postcava receives blood from the limbs via the renal portal system. Unlike in mammals, the circulating red blood cells in ...
Evolution of mammals
Erect limbs. Understanding of the evolution of erect limbs in mammals is incomplete - living and fossil monotremes have ... The mother develops a kind of yolk sack in her womb that delivers nutrients to the embryo. Embryos of bandicoots, koalas and ... Limb posture. The therapsids had sprawling forelimbs and semi-erect hindlimbs. This suggests that Carrier's ... In fact, modern monotremes still have semi-sprawling limbs.. Therapsid family tree. (simplified from; only those that ...
The membrane has no hair follicles or sweat glands, except between the fingers. For bat embryos, apoptosis (cell death ... Both species make lateral gaits (the limbs move one after the other) when moving slowly but vampire bats move with a bounding ... This crucial genetic alteration helps create the specialised limbs required for powered flight. The relative proportion of ... and down the side of the body to the hind limbs and tail. This skin membrane consists of connective tissue, elastic fibres, ...
Acute lymphoblastic leukemia
Both tails and limbs can be regenerated. Adult frogs are unable to regrow limbs but tadpoles can do so. ... The ovum is at first rigidly held, but in fertilised eggs the innermost layer liquefies and allows the embryo to move freely. ... Their vertebral columns, limbs, limb girdles and musculature needed to be strong enough to raise them off the ground for ... They all have four limbs except for the legless caecilians and a few species of salamander with reduced or no limbs. The bones ...
This means the cells at the yolk's edge have cytoplasm continuous with that of the egg, which allows the yolk and embryo to ... Both the platypus and echidna species have spurs on their hind limbs. The echidna spurs are vestigial and have no known ... 1) Shell; 2) Yolk; 3) Yolk Sac; 4) Allantois; 5) Embryo; 6) Amniotic Fluid; 7) Amniotic Membrane; and 8) Membrane ...
In contrast to the rash in smallpox, the rash in chickenpox occurs mostly on the torso, spreading less to the limbs. ... part of a chicken embryo) and examining the resulting pock lesions under defined temperature conditions. Strains were ... Swollen joints limit movement, and arthritis may lead to limb deformities, ankylosis, malformed bones, flail joints, and stubby ...
Isolated limb perfusion (often used in melanoma), or isolated infusion of chemotherapy into the liver or the lung have ... A study in France between 1999 and 2011 came to the result that embryo freezing before administration of gonadotoxic agents to ... Arnon J, Meirow D, Lewis-Roness H, Ornoy A (2001). "Genetic and teratogenic effects of cancer treatments on gametes and embryos ... or embryos. As more than half of cancer patients are elderly, this adverse effect is only relevant for a minority of ...
b) Embryo undergoing type-A inversion (e.g., V. carteri). (c) Embryo undergoing type-B inversion (e.g., V. globator, V. aureus ... Herron, M. (2016). Moving without limbs! Linnaeus on Volvox. Fierce Roller Blog,  Archived 2016-06-03 at the Wayback Machine ... globator embryo in three successive stages of inversion. (g) Optical midsagittal cross sections of embryo in (f). (h) Traced ... Then the embryo undergoes inversion, during which the cell layer inverts to form a spheroidal daughter colony with the apical ...
The parapodia ("limbs") of annelids that have them often bear more complex chetae at their tips - for example jointed, comb- ... Pearson, R.D. (2003). "The Determined Embryo". In Hall, B.K.; Pearson, R.D.; Müller, G.B. Environment, Development, and ... Polychaetes have parapodia that function as limbs, and nuchal organs that are thought to be chemosensors. Most are marine ... In these phyla the "fates" of the embryo's cells, in other words the roles their descendants will play in the adult animal, are ...
Males have short, red-brown fur, fading to pale buff below and on the limbs. Females are smaller than males and are blue-grey ... she has the ability to freeze the development of an embryo until the previous joey is able to leave the pouch. This is known as ... It has two forelimbs with small claws, two muscular hind-limbs, which are used for jumping, and a strong tail which is often ... They usually stand up on their hind limbs and attempt to push their opponent off balance by jabbing him or locking forearms. If ...
During the development of morphological features while in the embryo, or embryogenesis, a cluster of cells grow underneath the ... Trueman JWH (1990), Comment: evolution of insect wings: a limb exite plus endite model Canadian Journal of Zoology ... appendages on the respective inner and outer aspects of the primitive arthropod limb. This was advanced by Trueman based on ... which can be observed in insect species as early the embryo, and in the earliest stages of the life cycle. ...
Fibroblast growth factors induce additional limb development from the flank of chick embryos. - PubMed - NCBI
A limb bud is thus established that can generate the appropriate signals to develop into a complete limb. The additional limbs ... Fibroblast growth factors induce additional limb development from the flank of chick embryos.. Cohn MJ1, Izpisúa-Belmonte JC, ... Fibroblast growth factors (FGFs) act as signals in the developing limb and can maintain proliferation of limb bud mesenchyme ... or FGF-4 and placed in the presumptive flank of chick embryos induce formation of ectopic limb buds, which can develop into ...
When We Were Embryos | University of California, Irvine - Limb Regeneration
The best evidence is that all vertebrate embryos can regenerate the developing limb bud as embryos. This has been demonstrated ... In chick embryos, an amputated limb bud fails to regenerate because the epidermal covering fails to reform. If you graft a new ... Amputations of developing mammalian limb buds are very difficult because the embryo develops inside the uterus of the mother. ... In humans, the developing limb can get amputated at later stages by amniotic constriction bands, and these limbs fail to ...
Limb development in mouse embryos: protection against teratogenic effects of 6-diazo-5 oxo-L-norleucine (DON) in vivo and in...
Limb development in mouse embryos: protection against teratogenic effects of 6-diazo-5 oxo-L-norleucine (DON) in vivo and in ... Limb development in mouse embryos: protection against teratogenic effects of 6-diazo-5 oxo-L-norleucine (DON) in vivo and in ... Limb development in mouse embryos: protection against teratogenic effects of 6-diazo-5 oxo-L-norleucine (DON) in vivo and in ... Limb development in mouse embryos: protection against teratogenic effects of 6-diazo-5 oxo-L-norleucine (DON) in vivo and in ...
KAKEN - Research Projects | Assessment of embryotoxic potential of mixtures of environmental chemicals using rat embryo limb...
The objective of this study was to evaluate the usefulness of rat embryo limb bud cell cultures (LBC) for analyzing joint ... Assessment of embryotoxic potential of mixtures of environmental chemicals using rat embryo limb bud cell cultures. Research ... Limb bud cell cultures / Environmental chemicals / Embryotoxicity / Toxicity assessment of mixtures / Organochlorine compounds ...
Homeotic Genes of the Bithorax Complex Repress Limb Development in the Abdomen of the Drosophila Embryo Through the Target Gene...
Limb development is repressed in the abdominal segments of the Drosophila embryo by the hometic genes of the Bithorax complex ( ... Limb development is repressed in the abdominal segments of the Drosophila embryo by the hometic genes of the Bithorax complex ( ... Homeotic Genes of the Bithorax Complex Repress Limb Development in the Abdomen of the Drosophila Embryo Through the Target Gene ... Homeotic Genes of the Bithorax Complex Repress Limb Development in the Abdomen of the Drosophila Embryo Through the Target Gene ...
Interactions between FGF18 and retinoic acid regulate differentiation of chick embryo limb myoblasts - Nottingham ePrints
Interactions between FGF18 and retinoic acid regulate differentiation of chick embryo limb myoblasts ... During limb development Pax3 positive myoblasts delaminate from the hypaxial dermomyotome of limb level somites and migrate ... We propose a model where interactions between FGF18 in the distal limb and retinoic acid in the proximal limb regulate the ... Interactions between FGF18 and retinoic acid regulate differentiation of chick embryo limb myoblasts. Developmental Biology, ...
000267 - ROP/GnLeJ
E4.5 embryos have an index nine times that of controls. (MGI Ref ID J:5768)*more than one third of cells contain mitotic ... limbs/digits/tail phenotype. *decreased caudal vertebrae number*the number of tail vertebrae is usually reduced by a third ... embryo phenotype. *abnormal notochord morphology*at E10 there is a reduced rate of cell division in the notochord ... embryo phenotype. *abnormal notochord morphology*noticeable at E10 as a reduced rate of cell division in the notochord ...
008459 - STOCK Mirc1|tm1.2Tyj|/J
limbs/digits/tail phenotype. *abnormal phalanx morphology*the fifth mesophalanx of the forelimb is absent in E18.5 embryos ... limbs/digits/tail phenotype. *brachyphalangia*the fifth mesophalanx of the forelimb is shortened in E18.5 embryos ... embryo phenotype. *decreased embryo size*at E13.5, mutants can be distinguished by their smaller size ... limbs/digits/tail phenotype. *brachyphalangia*however, other long bones in the hands are only marginally shorter than in wild- ...
Wollknäuel is required for embryo patterning and encodes the Drosophila ALG5 UDP-glucose:dolichyl-phosphate glucosyltransferase...
Research Highlight - Stumped on limb regeneration? New clues from the axolotl. Douglas Melton and colleagues identify the early ... in wol mutant embryos (E). (F,G) Lateral views of cellularizing embryos. Expression of dpp is reduced in wol embryos (G). ... We stained embryos derived from wol germline clones (hereafter called wol embryos) with an engrailed (en) RNA probe (Fig. 1D-F ... J-N) Lateral views of pre-cellular embryos showing changes in gt and kni expression in wol and cad embryos as compared with ...
WNT signals control FGF-dependent limb initiation and AER induction in the chick embryo - GeoScience.net
WNT signals control FGF-dependent limb initiation and AER induction in the chick embryo ... Thus, three WNT signals mediated by beta-catenin control both limb initiation and AER induction in the vertebrate embryo. US$ ... WNT signals control FGF-dependent limb initiation and AER induction in the chick embryo. ... WNT signals control FGF-dependent limb initiation and AER induction in the chick embryo. International Journal of Developmental ...
Pediatric orthopedic deformities. Volume 2, Developmental disorders of the lower extremity: hip to knee to ankle and foot ...
Chick Embryo Studies; 1.2.2 General Aspects of Human Hip Development; 184.108.40.206 Origin of Limb Bud; 220.127.116.11 Acetabular Labrum and ... Chick Embryo Studies; 1.2.2 General Aspects of Human Hip Development; 18.104.22.168 Origin of Limb Bud; 22.214.171.124 Acetabular Labrum and ... as well as rotational and angular deformities of the lower limb are discussed in detail. Presentation for each deformity ... as well as rotational and angular deformities of the lower limb are discussed in detail. Presentation for each deformity ...
Embryo and Embryonic Development | Encyclopedia.com
Source for information on Embryo and Embryonic Development: UXL Encyclopedia of Science dictionary. ... Embryo and embryonic development The term embryo applies to the earliest form of life, produced when an egg (female ... A few days after upper limb bud extension, the lower limb buds evolve further. Much more brain development occurs at this time ... The embryo may die and be expelled.. During week three the embryo grows to a length of about 0.08 inches (2 millimeters) long ...
Limb bud - definition of limb bud by The Free Dictionary
limb bud synonyms, limb bud pronunciation, limb bud translation, English dictionary definition of limb bud. n. 1. Botany a. A ... Limb regeneration partially recapitulates portions of embryonic limb development where the early developing embryo forms limb ... initiation of limb bud, early patterning of the limb and late limb morphogenesis.. The Genetics of Split-Hand/Foot Malformation ... Other measurement ideas include wing bud length, limb bud length, embryo area, heart rate, and vasculature branching.. ...
Hensen's node from vitamin A-deficient quail embryo induces chick limb duplication and retains its normal asymmetric expression...
Hensens node from vitamin A-deficient quail embryo induces chick limb duplication and retains its normal asymmetric expression ... Chick limb buds from quail embryos raised in a vitamin A-deficient diet induced normal limb duplication, suggesting that RA ... Hensens node from vitamin A-deficient quail embryo induces chick limb duplication and retains its normal asymmetric expression ... Retinoid-deficient quail embryos from eggs laid by quail raised on a vitamin A-deficient diet showed normal temporal asymmetric ...
Interaction between the signaling molecules WNT7a and SHH during vertebrate limb development: dorsal signals regulate...
Growth and patterning of the vertebrate limb are controlled by the ridge, posterior mesenchyme, and non-ridge ectoderm. ... Growth and patterning of the vertebrate limb are controlled by the ridge, posterior mesenchyme, and non-ridge ectoderm. ... Interaction between the signaling molecules WNT7a and SHH during vertebrate limb development: dorsal signals regulate ... and SHH during limb out-growth and patterning. ... Chick Embryo * DNA Primers * Ectoderm / physiology * Embryonic ...
Gene Ontology Classifications
Gene Ontology Classifications
CPS49-induced neurotoxicity does not cause limb patterning anomalies in developing chicken embryos<...
CPS49 exposure does not cause defects in limb size when added to late developing chicken limbs. In contrast, in early limb buds ... CPS49 exposure does not cause defects in limb size when added to late developing chicken limbs. In contrast, in early limb buds ... CPS49 exposure does not cause defects in limb size when added to late developing chicken limbs. In contrast, in early limb buds ... CPS49 exposure does not cause defects in limb size when added to late developing chicken limbs. In contrast, in early limb buds ...
NIOSHTIC-2 Publications Search - 00120077 - Long- and short-term effects of carbaryl exposure in chick embryos.
Embryo viability and the incidence of external malformations were recorded. Five days after treatment, mortality rates were ... Malformations included subcutaneous edema, lower limb deformities, and one unilateral ophthalmia. The authors concludes that ... Embryo viability and the incidence of external malformations were recorded. Five days after treatment, mortality rates were ... No malformations were seen in any of the 5 day embryos. Mortality rates after 12 days were greater than those at 5 days. ...
Gli2 and Gli3 Localize to Cilia and Require the Intraflagellar Transport Protein Polaris for Processing and Function
... affect Shh signaling in the murine limb bud. Our data show that loss of Tg737 results in altered Gli3 processing that abrogates ... such as left-right axis specification and limb and neural tube patterning. Genetic studies indicate that IFT proteins are ... Embryos Is the Subject Area "Embryos" applicable to this article? Yes. No. ... Limb buds Is the Subject Area "Limb buds" applicable to this article? Yes. No. ...
2002 Fall Fetal Loss Syndrome | TheHorse.com
Prenatal development - Wikipedia
Furthermore, the number of the week is one more than the actual age of the embryo/fetus. For example, the embryo is 0 whole ... The limbs are long and thin. The fetus can make a fist with its fingers. Genitals appear well differentiated. Red blood cells ... The embryo becomes embedded in the endometrium in a process called implantation. In most successful pregnancies, the embryo ... The embryo spends the next few days traveling down the Fallopian tube. It starts out as a single cell zygote and then divides ...
Mummy may have first artificial limb - Palaeontology, Archaeology & History - Unexplained Mysteries Discussion Forums
Plantago in A Checklist for the South China Botanical Garden, Guangzhou, Guangdong Province, P. R. China @ efloras.org
Tubby-like protein 3 (TULP3) regulates patterning in the mouse embryo through inhibition of Hedgehog signaling. - PubMed - NCBI
Expression of Sox9, Hoxd12, Ptch1, Gli1 and Shh in limb buds. Expression in both forelimb and hindlimb buds is shown (anterior ... G) TULP3 was found in nuclear and cytoplasmic factions from E9.5 embryos. HDAC2, which is enriched in nuclear fractions, and β- ... Tubby-like protein 3 (TULP3) regulates patterning in the mouse embryo through inhibition of Hedgehog signaling.. Norman RX1, Ko ... In addition, TULP3 is required for proper Shh-dependent limb patterning and for maintaining the correct balance between ...
Manipulating the Mouse Embryo: A Laboratory Manual, Fourth Edition
Limb Formation. Neurulation: Formation of the Nervous System. Regional Diversification in the Neural Tube. Neural Crest. ... Embryo Transfer. Background. Role of Zona Pellucida in Embryo Transfer. Number of Embryos to Transfer. Recipient Females. ... Female Embryo Donor Mice for Generation of ES Cell Chimeras. Fertile Stud Male Mice. Production of Embryo Donors. Embryo ... Embryo Collection and Culture. Quality Control. Preparation of Embryo Culture Media. Pipettes for Embryo Handling. Collection ...
... cleavage is the division of cells in the early embryo. The zygotes of many species undergo rapid cell cycles with no ... Limb development: Limb bud - Apical ectodermal ridge/AER - Eye development - Cutaneous structure development - Heart ... The inner cells adhere to one side of the cavity to form the inner cell mass (ICM) and will give rise to the embryo and some ... At this stage, the embryo is called a blastocyst. References *^ Early Development of the Nematode Caenorhabditis elegans. ...
Free Chiropractic Flashcards about GA2 E4 Embryo
Embryo. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests. ... anomaly with no limb development. 75 amelia. T/F Concerning the metacarpals and metatarsals of digits 2-5, secondary centers of ... T/F In general, the limbs reach the cartilagenous state at 10 weeks of embryonic development.. 74 F -6-7weeks. ...
BeiGene | Press Releases
Embryo-Fetal Toxicity. Do not use lenalidomide during pregnancy. Lenalidomide, a thalidomide analogue, caused limb ... If lenalidomide is used during pregnancy, it may cause birth defects or embryo-fetal death. In females of reproductive ... WARNING: EMBRYO-FETAL TOXICITY, HEMATOLOGIC TOXICITY, and VENOUS and ARTERIAL THROMBOEMBOLISM. ...
FDA Expands Indication for REVLIMID® (lenalidomide) as a Maintenance Treatment for Patients with Multiple Myeloma Following...
Embryo-Fetal Toxicity Do not use REVLIMID during pregnancy. Lenalidomide, a thalidomide analogue, caused limb abnormalities in ... To avoid embryo-fetal exposure to lenalidomide, REVLIMID is only available through a restricted distribution program, the ... If lenalidomide is used during pregnancy, it may cause birth defects or embryo-fetal death. In females of reproductive ...
Embryonic DevelopmentEmbryologyMouse embryosVertebrate embryosRegenerationNormal limbDistal limbLower limbsPolarityRegenerateApical ectodQuail embryosFibroblastOutgrowthGenesYolkProximal to distalDevelopment of limbsFrog embryosMutant embryosZebrafish embryosMammalian limbDevelopmental BiologyPlacentaSpermAmphibianDeformitiesBuds formEvolution of limbsTransplantationAdultSkeletalSalamandersHuman embryoMiceEctopicAmnioticStagesMolecularAxolotlSpinal cordMesenchymalLiving organismPostimplantationFormationHomozygotes
- The term embryonic development refers to changes that take place as an embryo matures. (encyclopedia.com)
- T/F In general, the limbs reach the cartilagenous state at 10 weeks of embryonic development. (studystack.com)
- Both fish and land animals possess clusters of Hoxa and Hoxd genes, which are necessary for both fin and limb formation during embryonic development. (innovations-report.com)
- Above: Martin Cohn, a University of Florida scientist whose interest in embryonic development and evolution led him to discover the molecular building blocks that shape limb and skeletal development, was named a Howard Hughes Medical Institute Early Career Scientist today (March 26. (ufl.edu)
- Micro-magnetic resonance imaging study of live quail embryos during embryonic development. (bath.ac.uk)
- The study of changes that take place in the embryo is known as embryology. (encyclopedia.com)
- Classic descriptions of upper limb development and embryology relied solely on detailed descriptions of the gross morphology of the developing embryo. (medscape.com)
- The first edition of Manipulating the Mouse Embryo appeared in 1986 as an outgrowth of Cold Spring Harbor Laboratory courses on the molecular embryology of the mouse held in the early 1980s, and authors of the first two editions included Brigid Hogan, Rosa Beddington, Frank Costantini, and Liz Lacy. (cshlpress.com)
- In embryology , cleavage is the division of cells in the early embryo . (bionity.com)
- Cohn and Zheng, also members of the UF Genetics Institute, found that the developing digits of male and female mouse embryos are packed with receptors for sex hormones. (bio-medicine.org)
- However, when inserted into transgenic mouse embryos, the fish Hox genes were only active in the mouse arm but not in the digits, showing that the fish DNA lacks essential genetic elements for digit formation. (innovations-report.com)
- The best evidence is that all vertebrate embryos can regenerate the developing limb bud as embryos. (uci.edu)
- A regulatory loop between the fibroblast growth factors FGF-8 and FGF-10 plays a key role in limb initiation and AER induction in vertebrate embryos. (geoscience.net)
- In the gastrulation stage, vertebrate embryos look more different from one another (some are ball-shaped, for example, and some are flattened). (scienceblogs.com)
- Eventually vertebrate embryos pass through a "phylotypic" stage in which they look a lot like other vertebrate embryos, before taking on their distinctive identities. (scienceblogs.com)
- In this study, we have established efficient CRISPR/Cas9 mediated gene knockin approaches in the axolotl ( Ambystoma mexicanum ), which has allowed us to genetically mark two critical stem cell pools for limb and spinal cord regeneration. (pnas.org)
- Our genetic fate mapping establishes the role of PAX7 + satellite cells for limb muscle regeneration. (pnas.org)
- Using these techniques, we have labeled and traced the PAX7-positive satellite cells as a major source contributing to myogenesis during axolotl limb regeneration. (pnas.org)
- Concerning muscle regeneration, a previous study has shown that two salamander species, axolotl and newt ( Notophthalmus viridescens ), use divergent source cells during limb muscle regeneration ( 2 ). (pnas.org)
- The studies took place in still-developing animals, whose cells are likely much more flexible when it comes to inducing regeneration, says Hans-Georg Simon , a developmental biologist at Northwestern University, in Chicago, who studies limb and heart regeneration. (technologyreview.com)
- Human regeneration, he said, is likely still in the future, but not too far off - it's possible one of his current graduate students or postdoctoral researchers will crack it, and limb regeneration will be a part of the medical toolkit. (livescience.com)
- But limb regeneration (of the kind salamanders do) is more than just replacing tissue. (livescience.com)
- Liver is also quite different than limb regeneration in salamanders ," Roy said. (livescience.com)
- Gardiner said Godwin's work was a step toward understanding limb regeneration. (livescience.com)
- The key to human regeneration is from week 3 to week 8 after fertilization of the egg when we are an embryo. (nextbigfuture.com)
- This association shows a potential link to a capacity, albeit limited, for regeneration that might be exploited to enhance joint repair and establish a basis for human limb regeneration. (sciencemag.org)
- Some animals, such as zebrafish, bichir, and axolotl, with a high regenerative capacity, regulate limb regeneration by a circuit of microRNA (miRNA) conserved across species ( 1 ). (sciencemag.org)
- Chick limb buds from quail embryos raised in a vitamin A-deficient diet induced normal limb duplication, suggesting that RA does not directly affect limb bud duplication. (readabstracts.com)
- The ball of cells begins to develop the way a normal limb does, forming new muscle and bone to produce an entirely new limb. (technologyreview.com)
- Required for normal limb and cardiac valve development during embryogenesis. (uniprot.org)
- We propose a model where interactions between FGF18 in the distal limb and retinoic acid in the proximal limb regulate the timing of myogenic gene expression during limb bud development. (nottingham.ac.uk)
- To investigate whether the uniqueness of proximal and distal limb regenerates could be attributed simply to differing blastemal growth characteristics, their increase in volume, cell number and cell-cycle times were determined. (biologists.org)
- The additional limbs have reversed polarity. (nih.gov)
- Transplantation of a specific region (the ' dorsal lip ') onto another embryo leads to a duplication of the embryo in opposite polarity. (prezi.com)
- This pathway was initially identified as a regulator of segment polarity in Drosophila embryos, and based on its involvement in promoting mammary tumors in the mouse. (keystonesymposia.org)
- In chick embryos, an amputated limb bud fails to regenerate because the epidermal covering fails to reform. (uci.edu)
- If you graft a new apical epidermis, or provide the appropriate chemical signals that the epidermis normally produces (fibroblast growth factor), then the amputated limb bud will regenerate. (uci.edu)
- These experiments have been done in mice, and as in the case with frogs, amputated limb structures can regenerate depending on the stage of development. (uci.edu)
- In humans, the developing limb can get amputated at later stages by amniotic constriction bands, and these limbs fail to regenerate. (uci.edu)
- Presumably, if the limb bud is damaged or amputated at very early stages they would regenerate as in the case with frogs. (uci.edu)
- A method to regrow damaged wings in chicken embryos could shed light on how to regenerate limbs in other species-including humans. (technologyreview.com)
- Now researchers in San Diego have been able to regenerate wings in chicken embryos, which can't normally grow new limbs. (technologyreview.com)
- While many animals have this capacity-within the animal kingdom, more species can regenerate limbs than cannot-mammals have largely lost it. (technologyreview.com)
- In frogs, which can regenerate limbs when they are tadpoles but not as adults, activating the genes extended the period of time that tadpoles could regenerate. (technologyreview.com)
- None of the animals that can regenerate limbs show this type of immune response. (technologyreview.com)
- Could Humans Ever Regenerate a Limb? (livescience.com)
- What has been lost will not regrow, and hence you cannot re-amputate the liver, as opposed to limbs in a salamander, which can be amputated multiple times and each time a new limb will regenerate. (livescience.com)
- Salamanders lacking macrophages failed to regenerate their limbs, and instead formed scars. (livescience.com)
- Unlike these animals, humans cannot regenerate whole limbs. (sciencemag.org)
- The actual regulation of the process of outgrowth is discussed in Positioning, Regulation, and Patterning of Limb Development. (medscape.com)
- Early in limb outgrowth, a thickening develops along the ventromedial border of the limb bud. (medscape.com)
- This underlying layer, known as the progress zone (PZ), is also essential in limb outgrowth. (medscape.com)
- The AER and PZ work as a functional unit responsible for the outgrowth of the limb along the proximodistal axis, and the marginal blood vessel may convey messenger proteins that integrate this process. (medscape.com)
- Limb development is repressed in the abdominal segments of the Drosophila embryo by the hometic genes of the Bithorax complex (BX-C). Localized expression of the homeobox gene Distal-less (DII) is required for leg development in thoracic segments. (nih.gov)
- Thus DII may serve as a downstream target gene through which the homeotic genes control abdominal segment identity in the Drosophila embryo. (nih.gov)
- When the genes were turned on in chicken embryos that had had their developing wings removed, the action triggered the growth of a new limb. (technologyreview.com)
- If the genes were turned on for too long, abnormal limbs developed. (technologyreview.com)
- And if the genes were expressed too late in development, new limbs were unable to grow. (technologyreview.com)
- This shows the expression of fish Hox genes in a mouse embryo. (innovations-report.com)
- The team of Denis Duboule, professor at the University of Geneva (UNIGE) and the Ecole polytechnique fédérale de Lausanne (EPFL), Switzerland, had recently shown that, during mammalian development, Hoxd genes depend on a 'bimodal' 3-dimensional DNA structure to direct the development of the characteristic subdivision of the limbs into arm and paw, a division which is absent from fish fins. (innovations-report.com)
- The activation of these proteins by Hox genes initiates signaling cascades that involve the Wnt signaling pathway and FGF signals in limb buds. (rug.nl)
- Because the parameters measured by the researchers in this study occur before any embryonic genes are expressed, the results indicate that embryos are likely predestined for survival or death before even the first cell division. (healthcanal.com)
- The caption explains that the early embryos of these animals look much the same, but the genes in corresponding parts of the embryo guide development by different paths. (scienceblogs.com)
- His work showing that Hox9 genes determine where limbs develop along the trunk was published in the journal Nature in 1997. (ufl.edu)
- He went on to discover the molecular basis for loss of limbs during snake evolution and the role of Hox genes in the origin of jaws - findings that were published in Nature in 1999 and 2002. (ufl.edu)
Proximal to distal2
Development of limbs3
- The study also paves the way for the possibility of creating better simulations of cell remodeling and the early development of limbs. (healthcanal.com)
- U of T engineers Yu Sun (left) and Rodrigo Fernandez-Gonzalez (right), along with SickKid's researcher Sevan Hopyan have discovered a link between physical forces and the development of limbs in embryos. (phys.org)
- University of Toronto engineers and a pediatric surgeon have joined forces to discover that physical forces like pressure and tension affect the development of limbs in embryos-research that could someday be used to help prevent birth defects. (phys.org)
- Phenotype of Jag2 del2 homozygous mutant embryos. (nih.gov)
- Jag2 del2 /Jag2 del2 homozygous mutant embryos ( e ) exhibit syndactyly of both fore- and hindlimbs. (nih.gov)
- Most of the Fasn -/- mutant embryos died before implantation and the Fasn +/- embryos died at various stages of their development. (pnas.org)
- Limb development in vertebrates is an area of active research in developmental biology. (wikipedia.org)
- Developmental biology is a newly-developing subject that is attracting much interest because of exciting findings being made using a combination of classical embryo manipulation with more modern techniques. (indigo.ca)
- Developmental disorders of the hip - developmental dysplasia of the hip (DDH), Legg-Calvé-Perthes disease (LCP), coxa vara including slipped capital femoral epiphysis (SCFE), and femoroacetabular impingement (FAI) - the knee, the ankle and foot, as well as rotational and angular deformities of the lower limb are discussed in detail. (worldcat.org)
Evolution of limbs2
- In their review, Paul Frenette and colleagues give an overview of niche heterogeneity at distinct stages of hematopoietic stem cell ontogeny, from the embryo to the adult. (biologists.org)
- Luskin responds by showing a picture of embryo development from egg to adult. (scienceblogs.com)
- Finally, we discuss the bearing of pycnogonid cheliphore development on the evolution of the raptorial first limb pair in Chelicerata and support a multi-articled adult limb as the plesiomorphic state of the chelicerate crown group, arising ontogenetically via postembryonic segmentation of a three-articled embryonic limb. (springer.com)
- Parker, M. H., Seale, P. & Rudnicki, M. A. Looking back to the embryo: defining transcriptional networks in adult myogenesis. (nature.com)
- Many investigations into the development of the limb skeletal pattern have been influenced by the "positional information" concept proposed by Lewis Wolpert in 1971. (wikipedia.org)
- In tune with this idea, efforts have been made to identify diffusive signaling molecules (morphogens) that traverse orthogonal axes of developing limbs and determine locations and identities of skeletal elements in a concentration-dependent fashion. (wikipedia.org)
- By following the prenatal development of the limb buds of mice, which have a digit length ratio similar to humans, the scientists controlled the gene signaling effects of androgen also known as testosterone and estrogen. (bio-medicine.org)
- Denis Duboule's team, at the UNIGE and the EPFL, Switzerland, compared the structure and behavior of these gene clusters in embryos from mice and zebrafish. (innovations-report.com)
- To answer this question, the geneticists inserted into mice embryos the genomic regions that regulate Hox gene expression in fish fins. (innovations-report.com)
- Remarkably, beads soaked in FGF-1, FGF-2, or FGF-4 and placed in the presumptive flank of chick embryos induce formation of ectopic limb buds, which can develop into complete limbs. (nih.gov)
- In the presumptive hindlimb region, another Wnt gene, Wnt-8c, controls Fgf-10 expression, and is also capable of inducing ectopic limb formation in the flank. (geoscience.net)
- Although this is not completly accurate, the document goes on to describe various stages of embryo development. (encyclopedia.com)
- They used unique tools, including micro-chiseling ablating lasers, atomic force microscopes and layer-by-layer computer models, to explore the early stages of limbs in unprecedented detail. (healthcanal.com)
- This fourth edition of The Mouse Manual - Manipulating the Mouse Embryo - appears 28 years after the first edition and once again is the definitive reference source on mouse development, transgenesis techniques, and molecular biology. (cshlpress.com)
- Cohn, whose uses the tools of genetics, genomics and molecular biology to study limb development, said his lab began studying the digit ratios after Zheng became determined to find an explanation. (bio-medicine.org)
- Analyzing molecular clocks in the form of nonenzymatically deamidated proteins, we unmasked a position-dependent gradient (distal high, proximal low) of protein turnover, indicative of a gradient of tissue anabolism reflecting innate tissue repair capacity in human lower limb cartilages that is associated with expression of limb-regenerative microRNAs. (sciencemag.org)
- But if one looks beneath the surface, embryos and cancers share a number of cellular and molecular features. (biologists.org)
- A developmental process is a morphologically observable event such as limb bud formation or the development of digits. (medscape.com)
- Msx is a homeodomain-containing transcriptional factor that plays an essential role in pattern formation in vertebrata and invertebrata embryos. (bioone.org)
- Because they had tracked the embryos' development so closely, they were then able to go back and identify three specific parameters collectively associated with successful blastocyst formation: the duration of first cytokinesis (the last step of a period in the cell cycle called mitosis in which the cell physically divides), the time between first and second mitoses, and the synchronicity of the second and third mitoses. (healthcanal.com)