Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.
The entity of a developing mammal (MAMMALS), generally from the cleavage of a ZYGOTE to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the FETUS.
The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.
Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.
The capability of bearing live young (rather than eggs) in nonmammalian species. Some species of REPTILES and FISHES exhibit this.
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.
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.
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.
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
A large stout-bodied, sometimes anadromous, TROUT found in still and flowing waters of the Pacific coast from southern California to Alaska. It has a greenish back, a whitish belly, and pink, red, or lavender stripes on the sides, with usually a sprinkling of black dots. It is highly regarded as a sport and food fish. Its former name was Salmo gairdneri. The sea-run rainbow trouts are often called steelheads. Redband trouts refer to interior populations of rainbows.
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.
Two membranous sacs within the vestibular labyrinth of the INNER EAR. The saccule communicates with COCHLEAR DUCT through the ductus reuniens, and communicates with utricle through the utriculosaccular duct from which the ENDOLYMPHATIC DUCT arises. The utricle and saccule have sensory areas (acoustic maculae) which are innervated by the VESTIBULAR NERVE.
Proteins obtained from species of fish (FISHES).
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.
Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.
A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
The relationships of groups of organisms as reflected by their genetic makeup.
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.
Sensory cells in the organ of Corti, characterized by their apical stereocilia (hair-like projections). The inner and outer hair cells, as defined by their proximity to the core of spongy bone (the modiolus), change morphologically along the COCHLEA. Towards the cochlear apex, the length of hair cell bodies and their apical STEREOCILIA increase, allowing differential responses to various frequencies of sound.
A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Morphological and physiological development of EMBRYOS.
In invertebrate zoology, a lateral lobe of the FOREBRAIN in certain ARTHROPODS. In vertebrate zoology, either of the corpora bigemina of non-mammalian VERTEBRATES. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1329)
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.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
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.
Early pregnancy loss during the EMBRYO, MAMMALIAN stage of development. In the human, this period comprises the second through eighth week after fertilization.
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.
Morphological and physiological development of EMBRYOS or FETUSES.
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.
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.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
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.
Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Utilization or disposal of an embryo that is fertilized but not immediately transplanted and resulting course of action.
An early embryo that is a compact mass of about 16 BLASTOMERES. It resembles a cluster of mulberries with two types of cells, outer cells and inner cells. Morula is the stage before BLASTULA in non-mammalian animals or a BLASTOCYST in mammals.
The fertilized OVUM resulting from the fusion of a male and a female gamete.
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.
The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.
The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
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).
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.
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.
The techniques used to select and/or place only one embryo from FERTILIZATION IN VITRO into the uterine cavity to establish a singleton pregnancy.
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.
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.
The middle germ layer of an embryo derived from three paired mesenchymal aggregates along the neural tube.
Embryonic and fetal development that takes place in an artificial environment in vitro.
Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.
The outer of the three germ layers of an embryo.
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
The 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.
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).
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.
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).
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.
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.
The inner of the three germ layers of an embryo.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
A unisexual reproduction without the fusion of a male and a female gamete (FERTILIZATION). In parthenogenesis, an individual is formed from an unfertilized OVUM that did not complete MEIOSIS. Parthenogenesis occurs in nature and can be artificially induced.
The 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).
A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.
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.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
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.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
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.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes.
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
A cartilaginous rod of mesodermal cells at the dorsal midline of all CHORDATE embryos. In lower vertebrates, notochord is the backbone of support. In the higher vertebrates, notochord is a transient structure, and segments of the vertebral column will develop around it. Notochord is also a source of midline signals that pattern surrounding tissues including the NEURAL TUBE development.
The 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)
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.
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.
Elements of limited time intervals, contributing to particular results or situations.
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.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
An individual that contains cell populations derived from different zygotes.
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.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
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).
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.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
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.
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.
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.
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.
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.
A subphylum of chordates intermediate between the invertebrates and the true vertebrates. It includes the Ascidians.
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.
An agent that causes the production of physical defects in the developing embryo.
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.
Delay in the attachment and implantation of BLASTOCYST to the uterine ENDOMETRIUM. The blastocyst remains unattached beyond the normal duration thus delaying embryonic development.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
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.
The developmental history of specific differentiated cell types as traced back to the original STEM CELLS in the embryo.
A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.
A genus of BIRDS in the family Phasianidae, order GALLIFORMES, containing the common European and other Old World QUAIL.
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.
The transformation of a liquid to a glassy solid i.e., without the formation of crystals during the cooling process.
A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
The study of the development of an organism during the embryonic and fetal stages of life.
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.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Genes that encode highly conserved TRANSCRIPTION FACTORS that control positional identity of cells (BODY PATTERNING) and MORPHOGENESIS throughout development. Their sequences contain a 180 nucleotide sequence designated the homeobox, so called because mutations of these genes often results in homeotic transformations, in which one body structure replaces another. The proteins encoded by homeobox genes are called HOMEODOMAIN PROTEINS.
The reproductive cells in multicellular organisms at various stages during GAMETOGENESIS.
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.
The condition of carrying two or more FETUSES simultaneously.
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.
Death of the developing young in utero. BIRTH of a dead FETUS is STILLBIRTH.
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.
Substances that provide protection against the harmful effects of freezing temperatures.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
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.
Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).
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.
The creation of embryos specifically for research purposes.
The functional hereditary units of INSECTS.
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).
The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
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.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
Goosecoid protein is a homeodomain protein that was first identified in XENOPUS. It is found in the SPEMANN ORGANIZER of VERTEBRATES and plays an important role in neuronal CELL DIFFERENTIATION and ORGANOGENESIS.
A species of nematode that is widely used in biological, biochemical, and genetic studies.
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.
The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.
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.
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.
Diminished or absent ability of a female to achieve conception.
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.
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
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.
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).
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)
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).
Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.
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.
Techniques for the artifical induction of ovulation, the rupture of the follicle and release of the ovum.
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)
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.
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.
Methods used to induce premature oocytes, that are maintained in tissue culture, to progress through developmental stages including to a stage that is competent to undergo FERTILIZATION.
Mice bearing mutant genes which are phenotypically expressed in the animals.
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
The field of biology which deals with the process of the growth and differentiation of an organism.
The variable phenotypic expression of a GENE depending on whether it is of paternal or maternal origin, which is a function of the DNA METHYLATION pattern. Imprinted regions are observed to be more methylated and less transcriptionally active. (Segen, Dictionary of Modern Medicine, 1992)
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.
Proteins found in any species of insect.
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.
A genus of CRUSTACEA of the order ANOSTRACA, found in briny pools and lakes and often cultured for fish food. It has 168 chromosomes and differs from most crustaceans in that its blood contains hemoglobin.
An extra-embryonic membranous sac derived from the YOLK SAC of REPTILES; BIRDS; and MAMMALS. It lies between two other extra-embryonic membranes, the AMNION and the CHORION. The allantois serves to store urinary wastes and mediate exchange of gas and nutrients for the developing embryo.
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.
The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.
Formation of differentiated cells and complicated tissue organization to provide specialized functions.
Artificial introduction of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.
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.
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.
Cells derived from the BLASTOCYST INNER CELL MASS which forms before implantation in the uterine wall. They retain the ability to divide, proliferate and provide progenitor cells that can differentiate into specialized cells.
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.
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.
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.
The chromosomal constitution of cells which deviate from the normal by the addition or subtraction of CHROMOSOMES, chromosome pairs, or chromosome fragments. In a normally diploid cell (DIPLOIDY) the loss of a chromosome pair is termed nullisomy (symbol: 2N-2), the loss of a single chromosome is MONOSOMY (symbol: 2N-1), the addition of a chromosome pair is tetrasomy (symbol: 2N+2), the addition of a single chromosome is TRISOMY (symbol: 2N+1).
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
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.
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).
The initial stages of the growth of SEEDS into a SEEDLINGS. The embryonic shoot (plumule) and embryonic PLANT ROOTS (radicle) emerge and grow upwards and downwards respectively. Food reserves for germination come from endosperm tissue within the seed and/or from the seed leaves (COTYLEDON). (Concise Dictionary of Biology, 1990)
The hollow, muscular organ that maintains the circulation of the blood.
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.
The farthest or outermost projections of the body, such as the HAND and FOOT.
Liquids transforming into solids by the removal of heat.
A colorless, odorless, viscous dihydroxy alcohol. It has a sweet taste, but is poisonous if ingested. Ethylene glycol is the most important glycol commercially available and is manufactured on a large scale in the United States. It is used as an antifreeze and coolant, in hydraulic fluids, and in the manufacture of low-freezing dynamites and resins.
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.
Messenger RNA that is stored in a masked state for translation at a later time. Distinguish from RNA, UNTRANSLATED which refers to non-messenger RNA, i.e. RNA that does not code for protein.
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.
An individual in which both alleles at a given locus are identical.
Proteins obtained from species of BIRDS.
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)
Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
Nutritive tissue of the seeds of flowering plants that surrounds the EMBRYOS. It is produced by a parallel process of fertilization in which a second male gamete from the pollen grain fuses with two female nuclei within the embryo sac. The endosperm varies in ploidy and contains reserves of starch, oils, and proteins, making it an important source of human nutrition.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
A tube of ectodermal tissue in an embryo that will give rise to the CENTRAL NERVOUS SYSTEM, including the SPINAL CORD and the BRAIN. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. For malformation of the neural tube, see NEURAL TUBE DEFECTS.
The integration of exogenous DNA into the genome of an organism at sites where its expression can be suitably controlled. This integration occurs as a result of homologous recombination.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
The plasma membrane of the egg.

Involvement of poly (ADP-ribose)-polymerase in the Pax-6 gene regulation in neuroretina. (1/9151)

The quail Pax-6 gene is expressed from two promoters named P0 and P1. P0 promoter is under the control of a neuroretina-specific enhancer (EP). This enhancer activates the P0 promoter specifically in neuroretina cells and in a developmental stage-dependent manner. The EP enhancer binds efficiently, as revealed by southwestern experiments, to a 110 kDa protein present in neuroretina cells but not in Quail Embryos Cells and Retinal Pigmented Epithelium which do not express the P0-initiated mRNAs. To study the role of p110 in Pax-6 regulation, we have purified the p110 from neuroretina cells extracts. Based on the peptide sequence of the purified protein, we have identified the p110 as the poly(ADP-ribose) polymerase (PARP). Using bandshift experiments and footprinting studies, we present evidence that PARP is a component of protein complexes bound to the EP enhancer that increases the on rate of the protein complex formation to DNA. Using PARP inhibitors (3AB and 6.5 Hphe), we show that these products are able to inhibit EP enhancer activity in neuroretina cells. Finally, we demonstrate that these inhibitors are able to decrease the expression of the P0-initiated mRNA in the MC29-infected RPE cells which, in contrast to the RPE cells, accumulated the PARP in response to v-myc expression. Our results suggest that PARP is involved in the Pax-6 regulation.  (+info)

even-skipped determines the dorsal growth of motor axons in Drosophila. (2/9151)

Axon pathfinding and target choice are governed by cell type-specific responses to external cues. Here, we show that in the Drosophila embryo, motorneurons with targets in the dorsal muscle field express the homeobox gene even-skipped and that this expression is necessary and sufficient to direct motor axons into the dorsal muscle field. Previously, it was shown that motorneurons projecting to ventral targets express the LIM homeobox gene islet, which is sufficient to direct axons to the ventral muscle field. Thus, even-skipped complements the function of islet, and together these two genes constitute a bimodal switch regulating axonal growth and directing motor axons to ventral or to dorsal regions of the muscle field.  (+info)

Fish swimbladder: an excellent mesodermal inductor in primary embryonic induction. (3/9151)

Swimbladder of the crucian carp, Carassius auratus, was found to be better as a vegatalizing tissue than other tissues, such as guinea-pig bone marrow, when presumptive ectoderm of Triturus gastrulae was used as reacting tissue. Swimbladder usually induced assemblies of highly organized mesodermal tissues, such as notochord, somites and pronephric tubules, some of which were covered by mesodermal epithelium without any epidermal covering. A special character of the effect of swimbladder was the rather frequent induction of solid balls of undifferentiated cells, which were identified as mesodermal or mesodermal and probably endodermal. These findings show that swimbladder has a strong and fast spreading vegetalizing effect on the responding presumptive ectoderm.  (+info)

A glial-neuronal signaling pathway revealed by mutations in a neurexin-related protein. (4/9151)

In the nervous system, glial cells greatly outnumber neurons but the full extent of their role in determining neural activity remains unknown. Here the axotactin (axo) gene of Drosophila was shown to encode a member of the neurexin protein superfamily secreted by glia and subsequently localized to axonal tracts. Null mutations of axo caused temperature-sensitive paralysis and a corresponding blockade of axonal conduction. Thus, the AXO protein appears to be a component of a glial-neuronal signaling mechanism that helps to determine the membrane electrical properties of target axons.  (+info)

Mitochondrial gene expression is regulated at the level of transcription during early embryogenesis of Xenopus laevis. (5/9151)

Mitochondrial transcription in the early Xenopus laevis embryo resumes several hours before active mtDNA replication, effectively decoupling mtDNA transcription and replication. This developmental feature makes Xenopus embryogenesis an appealing model system to investigate the regulation of mitochondrial transcription. Studies reported here refine our understanding of the timing, magnitude, and mechanism of this transcriptional induction event. Northern analyses of six mitochondrial mRNAs (normalized to mtDNA) reveal that transcript levels remain basal between fertilization and gastrulation and then undergo a coordinate induction, culminating in a 20-28-fold increase over egg levels by 48 h of development. Measurement of mitochondrial run-on transcription rates demonstrates a good correlation between transcription rates and transcript levels, showing that transcription itself is the primary determinant of transcript abundance. Experimental increases in mitochondrial ATP and energy charge also correlate with patterns of transcript levels and transcription rates, suggesting that developmental changes in the biochemical composition of the mitochondrial matrix could be regulating transcriptional activity. Consistent with this idea, transcriptional run-on rates in mitochondria of early embryos can be stimulated by the addition of tricarboxylic acid cycle intermediates to the run-on reaction. However, mitochondria of later stages do not show this response to the addition of metabolite. In combination, these data suggest that mitochondrial transcription is under metabolic regulation during early Xenopus embryogenesis.  (+info)

2,3,7,8-Tetrachlorodibenzo-p-dioxin alters cardiovascular and craniofacial development and function in sac fry of rainbow trout (Oncorhynchus mykiss). (6/9151)

Hallmark signs of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity in rainbow trout sac fry, are yolk sac edema, hemorrhage, craniofacial malformation, and growth retardation culminating in mortality. Our objective was to determine the role of cardiovascular dysfunction in the development of this toxicity. An embryotoxic TCDD dose (385 pg/g egg) caused a progressive reduction in blood flow in rainbow trout sac fry manifested first and most dramatically in the 1st and 2nd branchial arches and vessels perfusing the lower jaw. Blood flow was reduced later in the infraorbital artery and occipital vein of the head as well as segmental vessels and caudal vein of the trunk. Reduced perfusion occurred last in gill branchial arteries involved with oxygen uptake and the subintestinal vein and vitelline vein involved with nutrient uptake. Although heart rate throughout sac fry development was not affected, heart size at 50 days post-fertilization (dpf) was reduced far more than body weight or length, suggesting that the progressive circulatory failure caused by TCDD is associated with reduced cardiac output. Craniofacial development was arrested near hatch, giving rise to craniofacial malformations in which the jaws and anterior nasal structures were underdeveloped. Unlike the medaka embryo, in which TCDD causes apoptosis in the medial yolk vein, endothelial cell death was not observed in rainbow trout sac fry. These findings suggest a primary role for arrested heart development and reduced perfusion of tissues with blood in the early-life stage toxicity of TCDD in trout.  (+info)

Conversion of lacZ enhancer trap lines to GAL4 lines using targeted transposition in Drosophila melanogaster. (7/9151)

Since the development of the enhancer trap technique, many large libraries of nuclear localized lacZ P-element stocks have been generated. These lines can lend themselves to the molecular and biological characterization of new genes. However they are not as useful for the study of development of cellular morphologies. With the advent of the GAL4 expression system, enhancer traps have a far greater potential for utility in biological studies. Yet generation of GAL4 lines by standard random mobilization has been reported to have a low efficiency. To avoid this problem we have employed targeted transposition to generate glial-specific GAL4 lines for the study of glial cellular development. Targeted transposition is the precise exchange of one P element for another. We report the successful and complete replacement of two glial enhancer trap P[lacZ, ry+] elements with the P[GAL4, w+] element. The frequencies of transposition to the target loci were 1.3% and 0.4%. We have thus found it more efficient to generate GAL4 lines from preexisting P-element lines than to obtain tissue-specific expression of GAL4 by random P-element mobilization. It is likely that similar screens can be performed to convert many other P-element lines to the GAL4 system.  (+info)

Involvement of protein kinase C in 5-HT-stimulated ciliary activity in Helisoma trivolvis embryos. (8/9151)

1. During development, embryos of the pulmonate gastropod, Helisoma trivolvis, undergo a rotation behaviour due to the co-ordinated beating of three bands of ciliated epithelial cells. This behaviour is in part mediated by the neurotransmitter serotonin (5-HT) released from a pair of identified embryonic neurons. Using time-lapse videomicroscopy to measure ciliary beat frequency (CBF) in response to pharmacological manipulations, we determined whether protein kinase C (PKC) is involved in mediating 5-HT-stimulated ciliary beating. 2. Diacylglycerol (DAG) analogues sn-1,2-dioctanoyl glycerol (DiC8; 100 microM) and 1-oleoyl-2-acetyl-sn-glycerol (OAG; 100 microM), partially mimicked the 5-HT-induced increase in CBF. In contrast, application of OAG in the absence of extracellular Ca2+ did not result in an increase in CBF. 3. 5-HT-stimulated CBF was effectively blocked by PKC inhibitors bisindolylmaleimide (10 and 100 nM) and calphostin C (10 nM). In addition, bisindolylmaleimide (100 nM) inhibited DiC8-induced increases in CBF. At a higher concentration (200 nM), bisindolylmaleimide did not significantly reduce 5-HT-stimulated cilio-excitation. 4. Two different phorbol esters, phorbol 12-myristate 13-acetate (TPA; 0.1, 10 or 1000 nM) and phorbol 12beta, 13alpha-dibenzoate (PDBn; 10 microM) did not alter basal CBF. TPA (1 microM) did not alter 5-HT-stimulated CBF. Likewise, the synthetic form of phosphatidylserine, N-(6-phenylhexyl)-5-chloro-1-naphthalenesulphonamide (SC-9; 10 microM), did not increase CBF, whereas a strong increase in CBF was observed upon exposure to 5-HT. 5. The results suggest that a DAG-dependent, phorbol ester-insensitive isoform of PKC mediates 5-HT-stimulated CBF in ciliated epithelial cells from embryos of Helisoma trivolvis.  (+info)

The experiments described here were designed to reveal the distribution in the frog early embryo of components which are sufficient for specification of the dorsal structures of the embryonic body axis. The approach was to allow cleavage planes to divide the embryo into various well-defined regions and to transplant cells from each region into recipient embryos which would otherwise fail to form axial structures. Partial or complete body axis development could then be scored by the use of external criteria or histological methods. Recipients were embryos which had been irradiated before first cleavage with ultraviolet light on the vegetal surface. Irradiated embryos display a well-characterized set of deficiencies in the dorsal structures of the body axis, but their development can be rescued toward normalcy in several ways. In particular, transplantation of certain small groups of blastomeres from the normal 32- to 64-cell embryo into irradiated recipients was sufficient to cause partial or ...
Neurula definition is - an early vertebrate embryo which follows the gastrula and in which nervous tissue begins to differentiate and the basic pattern of the vertebrate begins to emerge.
Light micrograph showing a section of frog embryo in advanced gastrulation. Magnification 60X when printed at 10cm. - Stock Image C009/3462
Ectopic expression Ectopic expression. Embryos a-c are viewed laterally with the posterior pole to the right, embryos d-i are viewed dorsally. Expression of Wun
Since Darwins time, waterbirds have been considered an important vector for the dispersal of continental aquatic invertebrates. Bird movements have facilitated the worldwide invasion of the American brine shrimp Artemia franciscana, transporting cysts (diapausing eggs), and favouring rapid range expansions from introduction sites. Here we address the impact of bird migratory flyways on the population genetic structure and phylogeography of A. franciscana in its native range in the Americas. We examined the sequence variation for two mitochondrial gene fragments (COI and 16S for a subset of the data) in a large set of population samples representing the entire native range of A. franciscana. Furthermore, we performed Mantel tests and redundancy analyses (RDA) to test the role of flyways, geography and human introductions on the phylogeography and population genetic structure at a continental scale. A. franciscanamitochondrial DNA was very diverse, with two main clades, largely corresponding to Pacific
Many findings indicate that active retinoids (vitamin A metabolites, which are known to be hormone-like ligands), are regulatory signals during embryogenesis. Treating early vertebrate embryos with retinoids can cause teratogenesis. Notably, it generates specific defects in the main body axis. Considering other data showing that early vertebrate embryos contain physiolocally relevant concentrations of endogenous active retinoids and express retinoid binding proteins and receptors, it is not unlikely that retinoids act as developmental signals, which regulate axial patterning in the early vertebrate embryo. The purpose of this review is to discuss this point, referring to retinoid teratogenesis, and to the availabilities and functions of retinoid ligands, biding proteins and receptors in the early embryo.
TY - JOUR. T1 - Embryonic exposure to 4-methylimidazole leads to zebrafish myofibril misalignment. AU - Tsai, Jen Ning. AU - Sun, Chiao Yin. AU - Ding, Yu Ju. AU - Wang, Yun Hsin. AU - Lo, Kang Chieh. AU - Wen, Chi Chung. AU - Lin, Jia Wei. AU - Chang, Chiung Fang. AU - Hsu, Li Sung. AU - Chen, Hui Min. AU - Fong, Tsorng Harn. AU - Chen, Yau Hung. PY - 2018/1/1. Y1 - 2018/1/1. N2 - 4-methylimidazole (4-MI) is an imidazole-derived organic chemical compound that can be used as a raw material in the manufacture of diverse chemicals and has been identified as an ingredient of caramel color in soybean sauce, beers, and other soft drinks. The aim of the present study was to investigate the teratogenic effects of 4-MI during zebrafish embryogenesis. Zebrafish embryos were treated with different dosages of 4-MI (0-120 mM) for different exposure durations (12-60 hours). The percentages of embryos with malformed phenotypes increased as the exposure dosages and duration time of 4-MI increased. We also used ...
Founder cells for most early lineages of the sea urchin embryo are probably specified through inductive intercellular interactions. It is shown here that a complete respecification of cell fate occurs when 16-cell stage micromeres from the vegetal pole of a donor embryo are implanted into the animal pole of an intact recipient embryo. Animal pole cells adjacent to the transplanted micromeres are respecified from presumptive ectoderm into vegetal plate founder cells. These induced vegetal plate cells express the entire battery of genes characteristic of the endogenous vegetal plate cells. The ectopic vegetal plate invaginates during gastrulation to form a second archenteron which differentiates properly into a tripartite gut, as shown by the spatial pattern of expression of an endoderm-specific marker gene. Thus, transplanted micromeres can signal neighboring cells to induce them to change their fate. ...
In vertebrate species, induction of the embryonic axis is initiated by the transport of maternally supplied determinants, initially localized to the vegetal pole of the egg, toward the prospective organizer in the animal region. This transport process remains incompletely understood. Here, we review studies involving embryonic manipulations, visualization, and functional analysis of the cytoskeleton and loss- and gain-of-function conditions, which provide insights in this process. Transport of dorsal determinants requires cytoskeletal reorganization of a vegetal array of microtubules, microtubule motors, and an off-center movement of the vegetal cortex with respect to the inner egg core, a so-called cortical rotation. Additional mechanisms may be used in specific systems, such as a more general animally directed movement found in the teleost embryo. Initial polarity of the microtubule movement depends on early asymmetries, which are amplified by the movement of the outermost cortex. An interplay between
FGF signaling is involved in patterning and tissue formation of early vertebrate embryos (reviewed by Sivak and Amaya, 2004; Böttcher and Niehrs, 2005). Expression of XFD, a dominant negative form of Xenopus FGF receptor 1 (FGFR1), in Xenopus and zebrafish embryos results in loss of trunk and tail tissues (Amaya et al., 1991; Amaya et al., 1993; Griffin et al., 1995). FGF signaling has also been shown to be required for neural induction (Streit et al., 2000; Wilson et al., 2000; Böttcher and Niehrs, 2005), for organizer-independent induction of posterior neural tissue (Kudoh et al., 2002; Kudoh et al., 2004), anterior neurectoderm formation (Hongo et al., 1999) and posterior mesoderm development (Draper et al., 2003).. Perhaps due to the pleiotropic effects that result from inhibition of FGF signaling in early embryos, a role of FGF signaling in dorsal axis establishment - as distinct from mesoderm induction, posterior development and neural induction - has not been emphasized in recent ...
To study the frequency of germ-line transformation and to examine the reproducibility of tissue-specific transgene expression, we produced several lines of transgenic zebrafish expressing a recombinant chloramphenicol acetyltransferase (CAT) gene. Supercoiled plasmids containing both Rous sarcoma virus and SV-40 promoter sequences upstream of the CAT coding region were injected into zebrafish embryos prior to first cleavage. CAT activity could be detected in batches of injected embryos as early as 8 h and up to at least 12 days post-fertilization. Approximately 18% of injected fish raised to maturity exhibited CAT activity in their fins, and approximately 5% of injected fish became stable germ-line transformants. Breeding studies indicated that although transgenic founder fish were frequently germ-line mosaics, transgenic individuals of subsequent generations were fully hemizygous for the transgene marker. The transgenes present in the F1 progeny of four independent lines were relatively well ...
Sea urchin embryos and larvae provide an inexpensive high‐throughput system for determining developmental actions of neuropharmacologic agents or environmental neurotoxins in both applied and basic biologic contexts
EUGENE, Ore. - (April 18, 2013) - Using spinning disk microscopy on barely day-old zebra fish embryos, University of Oregon scientists have gained a new window on how synapse-building components move to worksites in the central nervous system.
Dejelling embryos: Wait at least one hour after fertilisation, any time after this embryos may be dejellied. Decant the MBS off the embryos, leaving them semi-dry and stuck to the bottom of the dish. Cover the embryos in the 2% cysteine solution, which will dissolve the jelly coats surrounding the eggs. With occasional, mild agitation, the embryos will be liberated in 5-7 minutes. It is important not to swirl eggs too vigorously when dejellying as this can cause axis duplications in some cases. Once the jelly coat is dissolved, the cysteine solution must be removed immediately (it can be reused). The embryos are then washed 3-4 times in a large volume of 0.1xMBS to remove residual cysteine. If left in the cysteine solution too long, or not washed enough, the plasma membrane will be damaged and the embryos will die! ...
DIC phenotype -- Reduced cleavage furrow ingression in second embryonic division; a phenotype not observed in either single (or36 mutation or zen-4 RNAi) treatments, cf RNAi [cgc4544]:air- ...
Despite the exposure of the fraud, Darwin and the biologists who supported him continued to regard Haeckels drawings as a reference source. And that further encouraged Haeckel. In the years that followed he produced further series of comparative embryo illustrations. He prepared diagrams showing fish, salamander, turtle, chicken, rabbit and human embryos side by side. The noteworthy aspect of these was how the embryos of these different life forms initially resembled one another very closely and gradually diverged over the course of their development. The similarity between the human and fish embryos in particular was very striking indeed. So much so that fictitious gills could be seen in the human embryo drawings, just as in those of the fish. Under the scientific guise he gave these illustrations, Haeckel launched his theory of recapitulation: Ontology Repeats Phylogeny. The meaning of the slogan was this; according to Haeckel, during the developmental process it undergoes in the egg or ...
Spatial expression pattern of MBC in wild-type embryos. Anterior is to the left and dorsal to the top in all except A. (A) Stage 13 embryos from the progeny of
PHILADELPHIA--During embryonic development, cells migrate to their eventual location in the adult body plan and begin to differentiate into specific cell types. Thanks to new research at the University of Pennsylvania, there is new insight into ...
Preimplantation Genetic Testing (PGT) has dramatically increased the live birth rates of children born as a result of IVF. These techniques help your IVF team to analyze and understand the health of your embryo prior to transfer into the uterus.
Vertebrate development is a complex orchestration of cell and tissue movements. Tracing individual cell positions can rapidly become a large-scale problem because cell numbers often grow exponentially in the early embryo. A typical approach consists
The biomarkers for stress in fish covers described the reviewing class, adopting efforts to find general in the major change, just of cure, focusing course or guidance. share you other to go what offers behavioral in Surfactant? Without the empirical two PEEP, previously would appreciate an consultant.
Concentration gradients of small diffusible molecules called morphogens are key regulators of development, specifying position during pattern formation in the embryo. It is now becoming clear that additional or alternative mechanisms involving interactions among cells are also crucial for positional …
What if you could witness the development of a new life, taking your time to study every detail, every single cell, from every angle, moment by moment? Sonia Furtado talks to the scientists who made this possible by creating a digital zebrafish embryo.
Should you transfer one embryo or two for IVF? What are the chances of success with transferring one vs two embryos? And what are the risks?
Early embryos develop a protective protein shield to help prevent attack from the mothers immune system, new research shows
So, today was it....our transfer day! We had a different doctor perform our transfer Dr Sanfillipo-he was amazing! I was so pleased with his bedside manor. When Dr Sanfillipo came in we got the final result of our embryos-Of the five, three were mature. All three of the mature ones fertilized. Today we had two embryos come in at 6A (6 cells, quality A) and one at a 4B (4 cells, quality B). He said the 6As were perfect (the B was still pretty good)! You cant get anything better than an A. The picture I have showing is what a 6 cell embryo looks like (this one is not mine). We had only planned on implanting 2/3 of the embryos-however, the 4 cell was not able to be frozen. The embryos need to be at least 5 cells. So, instead of discarding the embryo we decided to implant that one as well ...
strain OP494 (unc-119(tm4063) III; wgIs494) whole organism hermaphrodite late embryo 5 hours post synchronization using egg bleaching genetically modified using ...
At what stage of animal development do cells first move from the surface of the embryo into the interior, resulting in a two- or three-layered embryo? ...
Atmospheric CO2 concentrations have risen from a preindustrial value of ∼280 ppm to a current value of 387 ppm because of human activities (Solomon et al., 2007). Simulation models project that concentrations could reach 1200 ppm by the end of this century and nearly 2000 ppm by approximately 2300 (Caldeira and Wickett, 2003; Caldeira and Wickett, 2005). Diffusion of atmospheric CO2 in the surface ocean causes an increase in the partial pressure of CO2 (PCO2) and is likely to decrease pH by 0.2-0.4 units over the course of this century and by up to 0.77 units by 2300 (Caldeira and Wickett, 2003; Caldeira and Wickett, 2005; Turley et al., 2009). Such a decline in pH of surface waters will reduce carbonate ion (CO2-3) concentrations and the degree of calcium carbonate (CaCO3) saturation in seawater, which could negatively affect marine organisms that synthesize a carbonate skeleton. Exposure to high CO2 levels and subsequent lowered pH may have biological consequences for juveniles and adults of ...
Intracellular and Extracellular pH and Ca Are Bound to Control Mitosis in the Early Sea Urchin Embryo via ERK and MPF Activities. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Fertilized, but still unsegmented, eggs of the sea urchin Paracentrotus lividus have been centrifugated at 30,000 gravity. A comparison has been made between the cytochemical reactions of the different layers (RNA, polysaccharides, acid phosphatase) and the fine structure as shown in thin sections studied with the electron microscope.. ...
We investigated the mechanisms of intermediate cell mass (ICM) expansion in zebrafish chordin (Chd) morphant embryos and examined the role of BMPs in relation to this phenotype. At 24 h post-fertilization (hpf), the expanded ICM of embryos injected with chd morpholino (MO) (Chd MO embryos) contained a monotonous population of hematopoietic progenitors. In situ hybridization showed that hematopoietic transcription factors were ubiquitously expressed in the ICM whereas vascular gene expression was confined to the periphery. BMP4 (but not BMP2b or 7) and smad5 mRNA were ectopically expressed in the Chd MO ICM. At 48 hpf, monocytic cells were evident in both the ICM and circulation of Chd MO but not WT embryos. While injection of BMP4 MO had no effect on WT hematopoiesis, co-injecting BMP4 with chd MOs significantly reduced ICM expansion. Microarray studies revealed a number of genes that were differentially expressed in Chd MO and WT embryos and their roles in hematopoiesis has yet to be ...
24) A comparative study on fluorescent cholesterol analogs as versatile cellular reporters (2016) Sezgin E, Can FB, Schneider F, Clausen MP, Galiani S, Stanly TA, Waithe D, Colaco A, Honigmann A, Wustner D, Platt F, Eggeling C. J Lipid Res 57: 299-309. 25) Bifunctional Sphingosine for Cell-Based Analysis of Protein-Sphingolipid Interactions (2016) Haberkant P, Stein F, Höglinger D, Gerl MJ, Brügger B, Van Veldhoven PP, Krijgsveld J, Gavin AC, Schultz C ACS Chem Biol 11:222-230. 26) Proteomic dataset of the sea urchin Paracentrotus lividus adhesive organs and secreted adhesive (2016) Lebesgue N, da Costa G, Ribeiro RM, Ribeiro-Silva C, Martins GG, Matranga V, Scholten A, Cordeiro C, Heck AJ, Santos R. Data Brief 7: 1497-1505. 27) Deciphering the molecular mechanisms underlying sea urchin reversible adhesion: A quantitative proteomics approach (2016) Lebesgue N, da Costa G, Ribeiro RM, Ribeiro-Silva C, Martins GG, Matranga V, Scholten A, Cordeiro C, Heck AJ, Santos R J Proteomics 138: ...
Zebrafish (Danio rerio) is a well-recognized model for the study of vertebrate developmental genetics, yet at the same time little is known about the transcriptional events that underlie zebrafish embryogenesis. Here we have employed microarray analysis to study the temporal activity of developmentally regulated genes during zebrafish embryogenesis. Transcriptome analysis at 12 different embryonic time points covering five different developmental stages (maternal, blastula, gastrula, segmentation, and pharyngula) revealed a highly dynamic transcriptional profile. Hierarchical clustering, stage-specific clustering, and algorithms to detect onset and peak of gene expression revealed clearly demarcated transcript clusters with maximum gene activity at distinct developmental stages as well as co-regulated expression of gene groups involved in dedicated functions such as organogenesis. Our study also revealed a previously unidentified cohort of genes that are transcribed prior to the mid-blastula transition,
Hydrated encysted embryos of the brine shrimp Artemia franciscana have the ability to withstand years in anaerobic sea water using metabolic strategies that enable them to inactivate all cell metabolic activities and then to resume development when placed in aerobic sea water. However, this unique characteristic of Artemia franciscana embryos is lost during a very short period, at the embryonic­larval transition period of development, coincident with the appearance of prenauplius larvae. Thus, while encysted embryos show complete inhibition of proteolysis over at least 4 years under anoxia, control of this activity, together with resistance to anoxia, is lost in newly hatched nauplius larvae after only a few days in anaerobic sea water. In contrast to encysted embryos, young larvae in anaerobic sea water produce large amounts of lactic acid, which reaches a concentration of nearly 50 mmol l-1 within 12 h of incubation. The accumulated lactic acid is believed to reduce the intracellular pH ...
etv5a expression was analyzed by whole-mount in situ hybridization and quantitative real-time PCR of zebrafish embryos at developmental stages ranging from one-cell stage to 48 hours post fertilization (hpf). A strong and ubiquitous signal was detected from one-cell to the oblong stage, which indicated that etv5a was expressed as a maternal mRNA (Fig. 1A-C). Ubiquitous expression was observed throughout the whole embryo before gastrulation (Fig. 1D,E). During early gastrulation (75% epiboly), expression localized to the ventral mesoderm (arrowhead in Fig. 1F,G). At later stages, etv5a expression became confined to the lateral mesoderm as demonstrated by the presence of two longitudinal stripes at the six-somite stage (Fig. 1H-J). A previous study showed that cells present in this region are multipotent progenitors that give rise to hematopoietic, endothelial and pronephric derivatives (Gering et al., 1998). etv5a expression was maintained in the posterior lateral mesoderm (Fig. 1K-N) during ...
The potential of the developing zebrafish model for toxicology and drug discovery is limited by inefficient approaches to manipulating and chemically exposing zebrafish embryos-namely, manual placement of embryos into 96- or 384-well plates and exposure of embryos while still in the chorion, a barrier of poorly characterized permeability enclosing the developing embryo. We report the automated dechorionation of 1600 embryos at once at 4 h postfertilization (hpf) and placement of the dechorionated embryos into 96-well plates for exposure by 6 hpf. The process removed ≥95% of the embryos from their chorions with 2% embryo mortality by 24 hpf, and 2% of the embryos malformed at 120 hpf. The robotic embryo placement allocated 6-hpf embryos to 94.7% ± 4.2% of the wells in multiple 96-well trials. The rate of embryo mortality was 2.8% (43 of 1536) from robotic handling, the rate of missed wells was 1.2% (18 of 1536), and the frequency of multipicks was ,0.1%. Embryo malformations observed at 24 hpf ...
The zebrafish genome contains ten genes that encode class II cytokine-like peptides, of which the two that are related most closely to mammalian interferon gamma (IFN-γ) were named IFN-γ1 and IFN-γ2. Although the zebrafish has become a popular model system to study immune mechanisms, and although interferons are central regulators of immunity, which zebrafish cytokines correspond functionally to mammalian IFN-γ has not been established. We used zebrafish embryos to assay the functions of IFN-γ1 and IFN-γ2, and have identified a subset of zebrafish homologs of the mammalian IFN-responsive genes as IFN-γ targets in the zebrafish embryo: these genes are upregulated in response to raised levels of either IFN-γ1 or IFN-γ2. Infection studies using two different pathogens show that IFN-γ signalling is required for resistance against bacterial infections in the young embryo and that the levels of IFN-γ need to be regulated tightly: raising IFN-γ levels sensitizes fish embryos against ...
Maternal-zygotic interactions involving the three genes dorsal (dl), twist (twi) and snail (sna) are described. The results suggest that all three are involved in the process by which the dorsoventral pattern of the Drosophila embryo is established. First, the lethal embryonic mutant phenotypes are rather similar. In homozygous twi or sna embryos invagination of the ventral presumptive mesodermal cells fails to occur, and the resulting embryos are devoid of internal organs. This is very similar to the dominant phenotype described for dl; in the case of dl, however, the effect is a maternal one dependent on the mutant genotype of the female. Second, a synergistic interaction has been found whereby dominant lethality of twi- or sna-bearing zygotes is observed in embryos derived from heterozygous dl females at high temperature. The temperature sensitivity of this interaction permitted definition of a temperature-sensitive period which is probably that of dl. This was found to extend from ...
In D. melanogaster, the subdivision of dorsal ectoderm into amnioserosa (AS) and dorsal epidermis is controlled by the combined actions of two morphogens of the TGF-β family, Decapentaplegic (Dpp) and Screw (Scw). They form an extracellular gradient with peak levels of Dpp/Scw signalling in the dorsal-most region of the embryo. Dpp/Scw signalling is transduced to the nucleus by a complex containing the phosphorylated Smad transcription factor, pMad and the co-Smad, Medea, which are responsible for the transcriptional activation of a number of targets in specific dorsal territories, including zerknullt (zen) gen. zen encodes a homeobox transcription factor, which is expressed for a brief period of time in the early developing embryo and is required for all aspects of AS formation, including the initial cell shape changes that drive the morphogenesis of the AS epithelium. However, the number and nature of Zen-target genes involved in AS differentiation subsequent to its specification are currently
Beta-catenin, a component of the wnt-signal-transduction pathway, is essential for the formation of the dorsal axis in Xenopus laevis embryos. On the dorsal side of the embryo, beta-catenin is translocated into the nuclei via a process linked to cortical rotation. When cortical rotation is blocked by UV-irradiation, nuclear beta-catenin is found in the vegetal pole of the embryo. Here we show that overexpression of beta-catenin in animal cap explants, in the absence of mesoderm induction, is sufficient to activate the expression of genes with dorsalizing activity such as siamois (sia) and nodal-related 3 (nr3) but not goosecoid (gsc). In embryos ventralized by UV-treatment, the expression of the dorsal-specific genes sia, nr3 and gsc is induced at the vegetal pole after the Mid-Blastula-Transition (MBT). While nr3 and sia expression continues in these embryos until gastrula stages, gsc transcription cannot be maintained. We propose that the spatial separation of the expression domains of genes ...
Genealogical concordance is a critical overlay of all phylogenetic analyses, irrespective of taxonomic level. To assess such patterns of congruence we have compiled and derived sequence data for two mitochondrial (16S rRNA, COI) and two nuclear (ITS1, p26) markers in 14 American populations of the hypersaline branchiopod Artemia franciscana. Cladistic analysis revealed three reciprocally monophyletic mitochondrial clades. For nuclear DNA, incomplete lineage sorting was evident presumably as a result of slower coalescence or male-mediated dispersal. Our findings capture the genealogical interval between gene splitting and population divergence. In this sense, strong indications are provided in favour of a superspecies status and ongoing speciation in A. franciscana.
We investigated the effects of short-term exposure of bare TiO2NPs and polyelectrolyte-coated TiO2NPs in the 5-25 nm size range, at relatively high concentrations (of 500 and 1000 mg/L) under light or dark conditions, in D. rerio embryos. The biological endpoints investigated included embryo viability and mRNA transcript levels of antioxidant and membrane transport genes relative to control embryos. The presence of nanoparticles on the surface of embryos was assessed using TEM. The results confirm an accumulation of TiO2NPs on the outer surface (chorion) of the embryo, but not within the embryo. No significant difference in embryo viability was detected following each exposure regime. The expression of antioxidant biomarker, SOD2, was significantly impacted by the type of TiO2NP, with TiO2NPs/PSS/PAH coating exposure showing down regulation; the concentration of the nanoparticles, with down regulation at 500 mg/L; and dark/light condition with down regulation in the light. The expression levels ...
In developmental biology, an embryo is divided into two hemispheres: the animal pole and the vegetal pole within a blastula. The animal pole consists of small cells that divide rapidly, in contrast with the vegetal pole below it. In some cases, the animal pole is thought to differentiate into the later embryo itself, forming the three primary germ layers and participating in gastrulation. The animal pole is heavily pigmented while the vegetal pole remains unpigmented.[1] The vegetal pole contains large yolky cells that divide very slowly, in contrast with the animal pole above it. In some cases, the vegetal pole is thought to differentiate into the extraembryonic membranes that protect and nourish the developing embryo, such as the placenta in mammals and the chorion in birds. The development of the animal-vegetal axis occurs prior to fertilization.[2] Sperm entry can occur anywhere in the animal hemisphere.[3] The point of sperm entry defines the dorso-ventral axis - cells opposite the region ...
Purpose: The olfm1 gene encodes a secreted glycoprotein highly conserved in vertebrates. There are two olfm1 genes in zebrafish, olfm1a and olfm1b. Both of these genes are expressed in the brain and retina starting from 16 h post fertilization to adults. We generated a null mutant of both olfm1a and olfm1b genes and analyzed its retinal structure and visual function.. Methods: Olfm1a and olfm1b mutant alleles with nonsense point mutations were obtained from the Wellcome Trust Sanger Institute. Olfm1a and olfm1b null mutants were bred to generate double null mutant (olfm1a/b null). Spontaneous movement, optokinetic and optomotor responses, behavioral responses to light increments and decrements and electroretinogram (ERG) to increased (ON) and decreased (OFF) illumination were compared between olfm1a/b null and wild-type larvae 7 days post fertilization (dpf). The retinal morphology was examined by immunostaining of frozen sections. Total RNA was isolated from 3 and 7 dpf larvae for RNA ...
7) head involution. Before considering these ten tissue movements in some detail, it should be made clear that there are other programs of cell movement, including trachea formation, imaginal disc development and segregation of neuroblasts from the neuroectoderm. The initial structuring or ground work for most of these events can be traced back to the four maternal systems which establish polarity in the egg and, as a consequence, in the zygote. Thus these events are related to patterns of segmentation built early in development. Ventral furrow formation and dorsal closure have their origins in the dorsoventral system; the other eight events originate with the anterior group, the posterior group and the terminal group of maternal genes, all of which are responsible for anterior-posterior polarity. Gastrulation begins three hours after fertilization. By this time there have been 13 mitotic cycles. Prior to the 10th cycle, the dividing nuclei lie in the interior of the egg, but move out toward the ...
Fig. 5. Antisense Otx2 morpholino oligonucleotide rescues convergent extension and Xbra expression blocked by IGF-I and Otx2. Embryos at 4-cell stage were dorsaly-injected with IGF-I or Otx2-Myc mRNA alone or co-injected with Otx2 morpholino. They were either allowed to develop to various stages for phenotypes or fixed at stage 10.5 for in situ hybridization. (A) An uninjected embryo at stage 14 showing correct neural plate formation. (B) An Otx2-Myc-injected embryo with gastrulation defect and open blastopore. (C) Otx2 morpholino rescues blastopore closure and neural plate formation in Otx2-Myc-injected embryo. (D) Western blot showing that Otx2 morpholino specifically blocks translation of Otx2-Myc mRNA. (E) A control embryo at stage 38. (F) An Otx2-Myc-injected embryo at equivalent stage with dorsal development defect and shortened trunk and posterior region. (G) Otx2 morpholino rescues trunk and posterior development. (H-L) Otx2 morpholino rescues Xbra and Xwnt11 expression. (H) An ...
During embryogenesis, cells acquire distinct fates by transitioning through transcriptional states. To uncover these transcriptional trajectories during zebrafish embryogenesis, we sequenced 38,731 cells and developed URD, a simulated diffusion-based computational reconstruction method. URD identifi …
Great for hatching brine shrimp eggs. Includes hatching container, air pump, air line tubing, air stone, salt, unit of brine shrimp eggs, fine-mesh net, and instructions. Refill includes eggs, air stone, and salt.
Helmholtz Centre for Environmental Research. Researchers at the Helmholtz Centre for Environmental Research (UFZ), together with colleagues from the Swiss Eawag aquatic research institute, have discovered a protein which transports chemicals out of the embryo of the zebrafish and in this way protects the embryo against toxic substances. However, certain environmental chemicals render this protective mechanism ineffective, so that the fish embryos become more sensitive to toxic substances. The study, published in the scientific journal BMC Biology, could prove to be of great importance for the future assessment of chemicals.. Fish possess a number of different mechanisms for protection against harmful substances in an aquatic environment. These include, for example, molecular transport systems, such as the so called ABC (ATP binding cassette) transporters, which prevent the penetration of toxic substances into cells. ABC transporters have been well investigated for mammals. For fish and their ...
The Roman Catholic Bishops of England (RCBE) have told the UK parliament that inter-species embryos - those containing genetic information from both human and animals - should not be treated any differently from normal embryos, and that women should be given the chance to carry their genetic offspring to term.. There is currently a real shortage of human eggs for use in embryonic stem cell (ES cell) research. It is hoped the problem can be overcome through creating embryos by transferring human genetic material into hollowed out animal eggs. The resulting entity - a cybrid - would be over 99 per cent genetically human and less than one per cent animal. As it stands, the new draft Human Tissue and Embryos Bill will ban the creation of embryos that contain genetic material from both animals and humans, but will make an exception for certain types of research, including cybrid embryos. The draft Bill imposes a strict 14 day time limit on the use of these entities in research, at which point ...
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Sea urchins and other echinoderms are a useful model system for studying many problems in early development. Historically, sea urchins were a key model system in elucidating a variety of classic developmental problems, including the mechanisms of fertilization and egg activation, cleavage, gastrulation, and the regulation of pattern formation in the early embryo. In addition, early studies of the the molecular basis of early development were carried out in this system. Gametes can be obtained easily, sterility is not required, and the eggs and early embryos of many commonly used species are beautifully transparent. In addition, the early development of sea urchin embryos is highly synchronous, i.e., when a batch of eggs is fertilized, all of the resulting embryos typically develop on the same time course. This makes biochemical and molecular studies of early embryos possible in this system, and has led to a number of major discoveries ...
The spatial and temporal pattern of mitoses during the fourteenth nuclear cycle in a Drosophila embryo reflects differences in cell identities. We have analysed the domains of mitotic division in zygotic mutants that exhibit defects in larval cuticular pattern along the dorsoventral axis. This is a powerful means of fate mapping mutant embryos, as the altered position of mitotic domains in the dorsoventral pattern mutants correlate with their late cuticular phenotypes. In the mutants twist and snail, which fail to differentiate the ventrally derived mesoderm, mitoses specific to the mesoderm are absent. The lateral mesectodermal domain shows a partial ventral shift in twist mutants but a proportion of ventral cells do not behave characteristically, suggesting that twist has a positive role in the establishment of the mesoderm. In contrast, snail is required to repress mesectodermal fates in cells of the presumptive mesoderm. In the absence of both genes, the mesodermal and the mesectodermal ...
Cell Lineage of the Ilyanassa Embryo: Evolutionary Acceleration of Regional Differentiation during Early Development. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
This method utilizes zebrafish embryos to efficiently test the vascular invasive ability of cancer cells. Fluorescent cancer cells are...
Vistahermosa Reproduction Unit.. Several aspects have to be evaluated so that the strategy to be followed is successful: number of embryos obtained, embryo quality grade, age of the patient, associated pathologies, complementary techniques and if it is an IVF or ovodonation cycle.. But why on day 3 or day 5? Dr. Avilés explains that these are the days in which the quality of the embryos can be more easily analyzed according to morphological parameters: shape, size, number of cells, fragments or vacuoles of the cells; and kinetic parameters: times of cell division. Also, depending on the implantation potential, the selection of the embryos includes 4 grades, from A to D, with A being very high and D being the lowest.. Transferring on day 3 or on day 5 will depend fundamentally on the number of embryos we have, especially because the fact that an embryo does not reach day 5 in the laboratory does not mean that it does not evolve in the uterus, which is its natural environment, says ...
CiteSeerX - Scientific documents that cite the following paper: Four-dimensional cardiac imaging in living embryos via postacquisition synchronization of nongated slice sequences,
The embryo(s) which are transferred to your uterus are just microscopic ball of cells. You cannot see your embryo with your naked eye; you need a microscope , which would enlarge it several hundred times , before you can view it. When your embryos fail to implant and give rise to a pregnancy, they die and disintegrate. Cells die in the human body all the time, and these dead cells are removed by your bodys scavenging machinery. When you get periods after a failed cycle, only the endometrium which is formed during that particular IVF cycle is sloughed off. Since you took lots of hormones , your endometrial lining might be thicker than usual and you might experience heavier menstrual bleeding or you might have more clots (which appears like a tissue) than you normally do. This doesnt mean you are having a miscarriage or that the transferred embryo was expelled ...
Several evolutionarily conserved proteins constitute a universal mitotic trigger that is precisely controlled during the orderly cell divisions of embryogenesis. As development progresses, the mechanisms controlling this trigger change. Early divisions are executed by maternally synthesized gene products, and in Xenopus they are timed by the accumulation and periodic degradation of cyclin, a trigger component. Later, the zygotic genome assumes control, and in Drosophila, zygotic transcription is required for production of another trigger protein, the product of string. After this transition to zygotic control, pulses of string transcription define the timing of highly patterned embryonic cell divisions and cyclin accumulation is not rate limiting.. ...
One PLOS paper details a study of pleiotropy in C. Elegans, finding that 50% of genes involved in embryogenesis are pleiotropic. Whats more, these genes tend to occupy central (rather than initial or final) positions in protein pathways10. Pleiotropy, when viewed in the light of evolution, is usually discussed as a constraining factor. That is, a single mutation may be beneficial or neutral in one tissue, but harmful in another, increasing the likelihood that pleiotropic gene mutations would be selected against. The effect of pleiotropy neednt always be one of constraint, however. For example, in the case of parsimonious pleiotropy11, knowing that a mutation that fails to harm sperm is also unlikely to harm the brain, the sperm may relax strict mutation checking controls a tad. Note that evolutionary pressures favoring pleiotropy tend to negate the popular notion of modularity in gene expression ...
One PLOS paper details a study of pleiotropy in C. Elegans, finding that 50% of genes involved in embryogenesis are pleiotropic. Whats more, these genes tend to occupy central (rather than initial or final) positions in protein pathways10. Pleiotropy, when viewed in the light of evolution, is usually discussed as a constraining factor. That is, a single mutation may be beneficial or neutral in one tissue, but harmful in another, increasing the likelihood that pleiotropic gene mutations would be selected against. The effect of pleiotropy neednt always be one of constraint, however. For example, in the case of parsimonious pleiotropy11, knowing that a mutation that fails to harm sperm is also unlikely to harm the brain, the sperm may relax strict mutation checking controls a tad. Note that evolutionary pressures favoring pleiotropy tend to negate the popular notion of modularity in gene expression ...
Synonyms for gastrulations in Free Thesaurus. Antonyms for gastrulations. 4 words related to gastrula: conceptus, fertilized egg, embryo, archenteron. What are synonyms for gastrulations?
آرتمیا سخت پوست کوچکی با ارزش اقتصادی بالاست که مدل تحقیقاتی بسیار مناسبی برای محققان می باشد. این موجود با تحمل محدوده های بسیار متنوع از شرایط بسیار مختلف اکولوژیک در بیش از 600 نقطه زمین و نیز 18 زیستگاه در ایران توزیع شده است. دریاچه بختگان در استان فارس یکی از زیستگاههای طبیعی آرتمیای پارتنوژنز در ایران می باشد. با توجه به وجود یک آرتمیای دو جنسی ناشناخته در این دریاچه، گونه این جمعیت غیر بومی مورد تحقیق قرار گرفت. بدین منظور 4 مارکر مولکولی مختلف شامل دو ژن Na/K ATPase، 16S-12S با روش پی سی آر- آر اف ال پی[1] و دو ناحیه COI و HSP26به روش تعیین توالیمورد تحقیق قرار گرفت. DNA
Embryonic exposure to TCDD impacts osteogenesis of the axial skeleton in Japanese medaka, Oryzias latipes. ALTD Watson, A Planchart, CJ Mattingly, C Winkler, DM Reif, SW Kullman. Toxicological Sciences, kfw229. Read more ...
University of Melbourne, The Ludwig Institute for Cancer Research (Melbourne Tumour Biology Branch) Affiliated with the Department of Surgery, ...
The National Institutes of Health proposed lifting its moratorium on funding for research on part-animal, part-human embryos - which raises a huge dilemma, says bioethicist Insoo Hyun.
Hello Has anyone out there imported embryos from overseas. I have 4 embryos still created by partners sperm and donated egg. I successfully gave birth to a little girl but want to try for another one next year but the embryos are in - page 2
The transfer of donated embryos, or embryo donation is the transfer of embryos given by a couple (after IVF) to a recipient for the purpose of pregnancy.
The source-sink model, first proposed by biologist Francis Crick in 1970, is a theoretical system for how morphogens distribute themselves across small fields of early embryonic cells. A morphogen is a substance that determines the fate and phenotype of a group of cells through a concentration gradient of itself across that group. Cricks theory has been experimentally confirmed with several morphogens, most notably with the protein bicoid , the first discovered morphogen. The model provides a theoretical structure for the understanding of some features of early embryonic development.. Format: Articles Subject: Theories ...
The source-sink model, first proposed by biologist Francis Crick in 1970, is a theoretical system for how morphogens distribute themselves across small fields of early embryonic cells. A morphogen is a substance that determines the fate and phenotype of a group of cells through a concentration gradient of itself across that group. Cricks theory has been experimentally confirmed with several morphogens, most notably with the protein bicoid , the first discovered morphogen. The model provides a theoretical structure for the understanding of some features of early embryonic development.. Format: Articles Subject: Theories ...
Browse decades of harmonized childhood cancer data and discover how this multi-species repository accelerates the search for cures.
Remnant abdominal segments in cirripedes (barnacles). Non-mammalian vertebrate embryos depend on nutrients from the yolk sac. ... alongside the presence of an empty yolk sac with the embryo. Dolphin embryonic limb buds. Leaf formation in some cacti species ... in vertebrate embryo development. Note that in fish, the arches continue to develop as branchial arches while in humans, for ... of the developmental plasticity that exists within embryos..." Atavisms occur because genes for previously existing ...
Di Berardino M.A. (2006). "Origin and Progress of Nuclear Transfer in Nonmammalian Animals". In Verma P.J.; Trounson A.O. (eds ... Development of Tumor Nuclear-Transplant Embryos". Annals of the New York Academy of Sciences. 126 (1): 115-126. doi:10.1111/j. ...
... embryo, nonmammalian MeSH A16.254.300.200 - chick embryo MeSH A16.254.300.400 - chorioallantoic membrane MeSH A16.254.300.600 ...
Xenopus tropicalis and Xenopus laevis (African clawed frog) - eggs and embryos from these frogs are used in developmental ... used in the study of the song system of songbirds and the study of non-mammalian auditory systems. Zebrafish (Danio rerio, a ...
The AGM region is derived from the mesoderm layer of the embryo. During organogenesis (around the fourth week in human embryos ... The formation of the AGM region has been best described in non-mammalian vertebrates such as Xenopus laevis. Shortly after ... RUNX1 knockout studies have shown a complete removal of definitive haematopoietic activity in all foetal tissues before embryo ... Furthermore, isolated organ cultures of the AGM from mice embryos can autonomously initiate hematopoietic stem cell activity, ...
... the 1-cell embryo is easy to see and micro-inject with transgenic DNA, and zebrafish have the capability of regenerating their ... for the development of bio-medically important proteins Their use as indicators of aquatic pollutants Developing new non-mammalian ...
In the embryo, the embryonic cloaca divides into a posterior region that becomes part of the anus, and an anterior region that ... Nonmammalian synapsids are sometimes (inaccurately) called "mammal-like reptiles". Therapsids, a group of synapsids, descended ... Studies on Permian coprolites suggest that non-mammalian synapsids of the epoch already had fur, setting the evolution of hairs ... Amniotic eggs, however, have internal membranes that allow the developing embryo to breathe but keep water in. Hence, amniotes ...
The presence of microorganisms in both the oocytes and in the embryos of sponges has been confirmed. Many insects depend on ... Most research on vertical transmission in non-mammalian vertebrates focuses on pathogens in agricultural animals (e.g. chicken ... Microbiota may be passed on to offspring via bacteriocytes associated with the ovaries or developing embryo, by feeding larvae ... Brock, J.A.; Bullis, R. (2001). "Disease prevention and control for gametes and embryos of fish and marine shrimp". Aquaculture ...
Pinealocytes in many non-mammalian vertebrates have a strong resemblance to the photoreceptor cells of the eye. Evidence from ... by developmental formation of a paired structure that subsequently fuses into a single pineal gland in developing embryos of ...
Philosopher Nicolas Malebranche was the first to advance the hypothesis that each embryo could contain even smaller embryos ad ... Ova were known in some non-mammalian species, and semen was thought to spur the development of the preformed organism contained ... Driesch's experiments on the development of the embryos of sea urchins are considered to have been decisively in favor of ... As opposed to "strict" preformationism, it is the notion that "each embryo or organism is gradually produced from an ...
In non-mammalian vertebrates, loss of one SOXB1 protein results in minor phenotypic differences. This supports the claim that ... SOX1 expression is restricted to the neuroectoderm by proliferating progenitor cells in the tetrapod embryo. The induction of ...
As the embryo is readily accessible, its development can be easily followed (unlike mice). This also allows the use of ... Poultry continues to be used as a model for many studies in non-mammalian immunology. Studies in bird behaviour include the use ...
NAE 20:4 (AEA) play a key role, because, for the embryo to become attached to the lining of the uterus, a particular amount ( ... Soderstrom K (2009). "Lessons from nonmammalian species". In Kendall D, Alexander S (eds.). Behavioral Neurobiology of the ... An earlier 2004 research in to the course of ectopic pregnancy, a result of embryo retention in the fallopian tube, found that ... October 2004). "Aberrant cannabinoid signaling impairs oviductal transport of embryos". Nature Medicine. 10 (10): 1074-80. doi: ...
... but even more interesting is his passion for non-mammalian systems. These systems include plants, energy generating bacteria, ... High-throughput Mechanotransduction in Drosophila Embryos with Mesofluidics. Lab on a Chip 19: 1141-1152 (2019, cover). Egan, P ...
Duboc, V; Röttinger, E; Lapraz, F; Besnardeau, L; Lepage, T (2005). "Left-right asymmetry in the sea urchin embryo is regulated ... H+-V-ATPase-dependent proton flux is necessary for consistent left-right patterning of non-mammalian vertebrates". Development ... As in the brain, developmental bioelectrics can integrate information across significant distance in the embryo, for example ... Using light to control ion flux-dependent signals in Xenopus embryos". The International Journal of Developmental Biology. 58 ( ...
The mother develops a kind of yolk sack in her womb that delivers nutrients to the embryo. Embryos of bandicoots, koalas and ... However, it is generally agreed that endothermy first evolved in non-mammalian synapsids such as dicynodonts, which possess ... The embryo is born at a very early stage of development, and is usually less than 2 in (5.1 cm) long at birth. It has been ... Placentals' best-known feature is their method of reproduction: The embryo attaches itself to the uterus via a large placenta ...
In the embryo, the nasal region develops from neural crest cells which start their migration down to the face during the fourth ... Reptiles and most non-mammalian therapsids have a large, paired, intramembranous bone behind the premaxilla called the ...
Many non-mammalian synapsids have three bones in the interparietal region as adults: one midline bone and two lateral bones. In ... Paired postparietals have also been observed in Alligator mississippiensis embryos, although they are incorporated into the ...
It has been shown in both mammalian and non-mammalian animal models that cortical granule migration depends on cytoskeleton ... the exocytosis of cortical granules may also contribute towards protection and support of the developing embryo during ... Peptidylarginine deiminiase is a secretory protein within the cortical granule that contributes to regulation of the embryo's ... briefly or undergo a modification shortly after fertilization because only small amounts of p32 are present on the embryo. ...
Hox genes are a group of related genes that control the body plan of an embryo along the head-tail axis. They are responsible ... It is thought that this elasticity may allow for developmental variation across non-mammalian taxa. This is of course true for ... On the other hand, recent studies of a small number of non-mammalian taxa propose greater dissimilarity than initially ... Researchers found the results to suggest that Hox cluster expansion and transposon accumulation are common features of non-mammalian ...
All non-mammalian amniotes use this system including lizards, crocodilians, dinosaurs (and their descendants the birds) and ... which developed in eggs with internal membranes which allowed the developing embryo to breathe but kept water in. The first ...
"The homeotic gene fork head encodes a nuclear protein and is expressed in the terminal regions of the Drosophila embryo". Cell ... such as the first haplotype map for a non-mammalian species. To further exploit and advance the understanding of genetic ...
In pig embryos, the mandible ossifies on the side of Meckel's cartilage, while the posterior part of that cartilage is ossified ... Luo, Zhexi; Crompton, Alfred W. (1994-09-07). "Transformation of the quadrate (incus) through the transition from non-mammalian ...
It does have a large and easily manipulated embryo, however. The ease of manipulation in amphibian embryos has given them an ... Emerging Infectious Diseases 10(12). Christensen-Dalgaard, Jakob (2005). "Directional hearing in nonmammalian tetrapods". In ... for distribution throughout the embryo) or early embryo (for distribution only into daughter cells of the injected cell). ... Xenopus embryos and eggs are a popular model system for a wide variety of biological studies, in part because they have the ...
In non-mammalian four-legged animals, the bone homologous to the stapes is usually called the columella; however, in reptiles, ... Rodriguez-Vazquez, J. F. (August 2005). "Development of the stapes and associated structures in human embryos". Journal of ...
Another characteristic is the number of embryos in the egg case. Some species contain only one embryo while others can have up ... Berkovitz, Barry; Shellis, Peter (2017). The Teeth of Non-Mammalian Vertebrates. pp. 5-27. doi:10.1016/b978-0-12-802850-6.00002 ... When a female skate is fertilized, a protected case forms around the embryo called an egg case, or more commonly mermaid's ...
While the non-mammalian animal egg was obvious, the doctrine ex ovo omne vivum ("every living [animal comes from] an egg"), ... Upon germination, the embryo grows into a seedling. In the moss Physcomitrella patens, the Polycomb protein FIE is expressed in ... The resulting zygote develops into an embryo inside the ovule. The ovule, in turn, develops into a seed and in many cases, the ... Soon after fertilisation the FIE gene is inactivated (the blue colour is no longer visible, left) in the young embryo. In algae ...
... from 800 albino embryos, only 29 survived to full adulthood. Early studies on fish led some researchers to describe albinism as ... Whilst this does not state specifically that non-mammalian albino animals (or plants) are white, this can be inferred from "... ... embryo Whale shark (Rhincodon typus) Whitespotted bamboo shark (Chiloscyllium plagiosum) Zebra shark (Stegostoma fasciatum) A ... but ignore the several other pigments that non-mammalian animals have and also structural colouration. For example, "Absence of ...
As the embryo transforms from a round blob of cells into a wormlike structure, a narrow strip of ectoderm running along the ... In non-mammalian vertebrates, the surface of the cerebrum is lined with a comparatively simple three-layered structure called ...
Aromatase, an estrogen-synthesizing enzyme which acts as a steroid hormone, plays a key role in sex determination in many non-mammalian ... from the oocyte to swimming tailbud embryos or larvae. Studies looked at the newts' ability to regenerate (which was faster in ...
The air space (7) provides the embryo with oxygen while it is hatching. This ensures that the embryo will not suffocate while ... At best, the cladists suggest, we could say that the traditional Reptilia are 'non-avian, non-mammalian amniotes'.[18] ... The albumin (9) further protects the embryo and serves as a reservoir for water and protein. The allantois (8) is a sac that ... The eggshell (1) protects the crocodile embryo (11) and keeps it from drying out, but it is flexible to allow gas exchange. The ...
The incubation period is divided into three phases.[62] In the first phase, the embryo has no functional organs and relies on ... The venom appears to have a different function from those produced by non-mammalian species; its effects are not life- ... This allows the yolk, which contains the embryo, to exchange waste and nutrients with the cytoplasm.[64] ...
In the embryo, the liver is the main site of red blood cell production.) The production can be stimulated by the hormone ... Cohen, W. D. (1982). "The cytomorphic system of anucleate non-mammalian erythrocytes". Protoplasma. 113: 23-32. doi:10.1007/ ...
Each embryo develops in its own egg. Familiar examples of ovoviviparous fish include guppies, angel sharks, and coelacanths. ... The lining of the spiral intestine is similar to that of the small intestine in teleosts and non-mammalian tetrapods. In ... Some viviparous fish exhibit oophagy, in which the developing embryos eat other eggs produced by the mother. This has been ... In such species the mother retains the eggs and nourishes the embryos. Typically, viviparous fish have a structure analogous to ...
Mammalian and non-mammalian jaws. In the mammal configuration, the quadrate and articular bones are much smaller and form part ... In the course of the development of the embryo, the incus and malleus arise from the same first pharyngeal arch as the mandible ... The first fully terrestrial vertebrates were amniotes - their eggs had internal membranes which allowed the developing embryo ... All non-mammalian amniotes use this system including lizards, crocodilians, dinosaurs (and their descendants the birds) and ...
While the non-mammalian animal egg was obvious, the doctrine ex ovo omne vivum ("every living [animal comes from] an egg"), ... The resulting zygote develops into an embryo inside the ovule. The ovule, in turn, develops into a seed and in many cases, the ... Soon after fertilisation the FIE gene is inactivated (the blue colour is no longer visible, left) in the young embryo. [13] ... The resulting zygote then gives rise to an embryo, which will grow into a new diploid individual (sporophyte). In seed plants, ...
In non-mammalian vertebrates, the surface of the cerebrum is lined with a comparatively simple three-layered structure called ... For vertebrates, the early stages of neural development are similar across all species.[60] As the embryo transforms from a ...
The lining of the spiral intestine is similar to that of the small intestine in teleosts and non-mammalian tetrapods.[22] ... Between weeks six and ten the small intestine rotates anticlockwise, as viewed from the front of the embryo. It rotates a ...
July 1996). "The whale shark, Rhincodon typus, is a livebearer: 300 embryos found in one 'megamamma' supreme". Environ. Biol. ... most notably being by far the largest living nonmammalian vertebrate. It is the sole member of the genus Rhincodon and the only ... "Paternity analysis in a litter of whale shark embryos". Endangered Species Research. 12 (2): 117-124. doi:10.3354/esr00300 ...
Non-mammalian species do not have a brain structure that looks like the mammalian hippocampus, but they have one that is ... "Study of pallial neurogenesis in shark embryos and the evolutionary origin of the subventricular zone". Brain Structure and ...
The term "tectal plate" or "quadrigeminal plate" is used to describe the junction of the gray and white matter in the embryo. ( ... The homologous structure to the superior colliculus in non mammalian vertebrates including fish and amphibians, is called the ...
2016). Embryo-like fossils are described from the Ediacaran Doushantuo Formation (China) by Yin et al. (2016), who argue that ... Rachel N. O'Meara; Robert J. Asher (2016). "The evolution of growth patterns in mammalian versus nonmammalian cynodonts". ... embryo-like fossils as metazoans". Geology. 44 (9): 735-738. Bibcode:2016Geo....44..735Y. doi:10.1130/G38262.1. Karma Nanglu; ... at least some of these fossils represent crown-animal embryos. New fossil material of Oesia disjuncta is described by Nanglu et ...
The lining of the spiral intestine is similar to that of the small intestine in teleosts and non-mammalian tetrapods. In ... formed by the fusion of the paired organs in the embryo. Fish ovaries may be of three types: gymnovarian, secondary gymnovarian ... although even this forms from the fusion of paired structures in the embryo. Under a tough membranous shell, the tunica ...
B snurposomes are found in the amphibian oocyte nuclei and in Drosophila melanogaster embryos. B snurposomes appear alone or ... ISBN 978-3-8171-1781-9. Cohen WD (1982). "The cytomorphic system of anucleate non-mammalian erythrocytes". Protoplasma. 113: 23 ...
In the first phase, the embryo has no functional organs and relies on the yolk sac for sustenance. The yolk is absorbed by the ... The venom appears to have a different function from those produced by non-mammalian species; its effects are not life- ... This allows the yolk, which contains the embryo, to exchange waste and nutrients with the cytoplasm. There is no official term ...
Nonmammalian" by people in this website by year, and whether "Embryo, Nonmammalian" was a major or minor topic of these ... "Embryo, Nonmammalian" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical ... Below are the most recent publications written about "Embryo, Nonmammalian" by people in Profiles. ... Below are MeSH descriptors whose meaning is more general than "Embryo, Nonmammalian". ...
Embryo/growth & development. Embryonic Development. Embryo/injuries. Prenatal Injuries Embryo, Nonmammalian/growth & ...
Embryo, Nonmammalian/physiology. MH -. Embryonic Induction/*physiology. MH -. Fibroblast Growth Factor, Basic/*pharmacology. ... embryos during mesoderm induction. Phosphoinositide cycle stimulation during treatment of. explants with basic fibroblast ...
Embryo, Nonmammalian / drug effects * Embryo, Nonmammalian / physiology * Embryonic Induction / drug effects* * Fibroblast ... This level of expression can be raised to levels normally induced in the embryo by another mammalian growth factor, TGF-beta, ... We show that the Xenopus embryo contains an mRNA encoding a protein highly homologous to basic FGF. These results together with ... induction of mesoderm by FGF and TGF-beta and the identification of an mRNA coding for FGF in the early Xenopus embryo Cell. ...
... specifying position during pattern formation in the embryo. It is now becoming clear that additional or alternative mechanisms ... Specifying positional information in the embryo: looking beyond morphogens Cell. 2007 Jul 27;130(2):205-9. doi: 10.1016/j.cell. ... specifying position during pattern formation in the embryo. It is now becoming clear that additional or alternative mechanisms ... Embryo, Nonmammalian / metabolism* ...
Embryo, Nonmammalian • Embryonic Development • Epithelial Cells • Epithelium • Genes, Insect • Image Processing, Computer- ... My interest is the modeling of the closure of the dorsal opening of the drosophila embryo in the process of morphogenesis. The ... and derives its name from experiments involving laser ablations of the drosophila embryo. The group includes postdocs and ...
Embryo, Nonmammalian • Embryonic Development • Epithelial Cells • Epithelium • Genes, Insect • Image Processing, Computer- ... My interest here is the modeling of the closure of the dorsal opening of the drosophila embryo in the process of morphogenesis ...
Briefly, 0.1 µl BrdU or EdU (10 mg/ml) was injected into the lateral ventricle of developing chick embryos, and the embryos ... The evolution of basal progenitors in the developing non-mammalian brain Message Subject (Your Name) has sent you a message ... Electroporation was performed at E4 and the chick embryos were collected at E7. Arrowheads (I,J), GFP+/Tbr2+ cells. (K-P) ... The evolution of basal progenitors in the developing non-mammalian brain. Tadashi Nomura, Chiaki Ohtaka-Maruyama, Wataru ...
Embryo, Nonmammalian. Gene Dosage. Gene Expression Regulation, Developmental. Molecular Sequence Data. Oligonucleotides / ... Synthetic oligonucleotides containing the myb target site were used to purify a protein from sea urchin embryo nuclear extracts ...
Embryo, Nonmammalian. Gene Expression Regulation, Developmental. Genetic Markers. Genome. Microinjections. Molecular Sequence ... Using a combination of MO1 and MO2 in wild-type embryos, or by injecting solely MO1 in ichabod embryos, we obtain expression of ... embryos. Reduction of beta-catenin-2 function in wild-type embryos by injection of morpholino antisense oligonucleotides (MOs) ... MOs directed against beta-catenin-1 (MO1), by contrast, had no ventralizing effect on wild-type embryos. beta-catenin-2 is thus ...
Differences between the mammalian and nonmammalian mechanisms of Cdt1 degradation likely account for this; in addition to the ... These systems enable tracking of individual cells in the whole fish embryo to provide a "digital embryo," a three-dimensional ... Transplantation of fluorescent cells from Cecyil or Cecyil2 embryos into nonfluorescent recipient embryos can generate mosaic ... time-lapse imaging of this organ in developing embryos is a formidable task. Thus, we used multiple fixed embryos to examine ...
Embryo, Nonmammalian; Germ Layers; Notochord; Organizers, Embryonic; Neural Plate Research Organizations. Pediatrics: Pediatric ... del Viso F, Khokha M: Generating diploid embryos from Xenopus tropicalis. Methods Mol Biol. 2012. PMID: 22956081 ... We are also interested in morphogenesis that provides shape to the developing embryo. ... Embryonic exposure to propylthiouracil disrupts left-right patterning in Xenopus embryos. FASEB J. 2013 Feb; 2012 Nov 12. PMID ...
Changed Embryo, Mammalian to Embryo, Nonmammalian when there is evidence in the citation that the species is nonmammalian. ... Added Embryo, Nonmammalian when there is evidence that both mammal and non-mammal embryos are discussed. ... In 2008 the MeSH Heading "Embryo" was replaced by the MeSH Heading "Embryo, Mammalian." "Embryo" was retained as an Entry Term ... Added Embryo, Nonmammalian when there is no evidence as to what species is discussed. ...
Embryo, Nonmammalian [A16.331]. *Gastrula [A16.331.600]. Below are MeSH descriptors whose meaning is related to "Gastrula". ...
Categories: Embryo, Nonmammalian Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, ...
w1118 embryos were injected by the Duke University Non-Mammalian Model Systems Flyshop. A minimum of five lines were recovered ... to 4-hr-old embryos. In contrast, high levels of the 2.7-kb transcripts are expressed in early embryos and throughout ... In situ hybridization to whole embryos was carried out as described (Tautz and Pfeifle 1989), using digoxigenin labeling and ... This interpretation is supported by the observation that homozygous embryos derived from heteroallelic mothers show variable ...
Embryo, Nonmammalian. dc.subject.mesh. Embryonic Development. dc.subject.mesh. Gills. dc.subject.mesh. Nanoparticles. ... Embryos exposed to particles via both epidermis and intestine showed highest uptake and eventually accumulated particles in the ... Embryos exposed to particles via both epidermis and intestine showed highest uptake and eventually accumulated particles in the ... This is addressed by exposing three different life stages of the zebrafish embryo in order to cover the following exposure ...
Finally, electroporated embryos represent a valuable source of MO-loaded or DNA transfected cells for in vitro analysis. The ... Finally, electroporated embryos represent a valuable source of MO-loaded or DNA transfected cells for in vitro analysis. The ... Simple adjustments can be made to the electroporation chamber to suit the shape of different aged embryos and to alter the size ... Simple adjustments can be made to the electroporation chamber to suit the shape of different aged embryos and to alter the size ...
Embryo, Nonmammalian. *Extracellular Matrix/genetics/metabolism. *Fluorescence Recovery After Photobleaching. *Point Mutation ... d-e) The recruitment of talin was measured in neomycin treated embryos (d) and in rhea17 embryos (e). Talin recruitment was ... d-e) The recruitment of talin was measured in neomycin treated embryos (d) and in rhea17 embryos (e). Talin recruitment was ... In contrast there was no such reduction in the rhea17 embryos suggesting the G340E mutant talin protein interacts with the ...
tetrapod embryos. This resulted in the divergence of amniotes from amphibians. Another thirty million years (310 million years ... synapsids (including mammals) from the sauropsids (including birds and non-avian, non-mammalian reptiles). Of course, other ...
In mouse embryos, the earliest Lhx6-expressing cells of the cortex first appeared at E13.5 as a column of cells bordering the ... In nonmammalian forms, its neuroblasts mature in situ without radical migration away from their matrix. However, neuroblasts ... Analysis of mouse embryos carrying loss-of-function mutations in both Dlx1 and Dlx2 genes has shown that the dorsal migration ... After 2 d in vitro (DIV), slices prepared from E13 and E14 embryos displayed numerous labeled neurons emerging from the MGE. A ...
Expression of Exogenous Genes in Xenopus Oocytes, Eggs, and Embryos Koichiro Shiokawa, Chie Koga, Yuzuru Ito, Mikihito Shibata ... The chap- ters in this book are grouped by their expression hosts, including E. coli, yeast, mammalian cells, nonmammalian ...
Embryo, Nonmammalian. 2. 2003. 146. 0.080. Why? Magnetic Resonance Spectroscopy. 1. 2005 ...
DNA Damage and Checkpoint Signaling in the Preimplantation Embryo 26 6. Concluding Remarks 35 References 36 ... 2. Nonmammalian Development: The Chicken Embryo 403. 3. Rabbit Embryo Development 404. 4. Bovine Embryo Development 406. 5. ... 5. EpiSCs Represent the EPI Lineage of the Postimplantation Embryo 378. 6. Interconversion of Embryo-Derived Stem Cell Lines ... 6. Human and Nonhuman Primate Embryo Development 410. 7. Species-Specific Genes in Embryo Development 414. 8. Summary 416. ...
FROM EMBRYO TO ADOLESCENCE. Embryo, Fetal, and Childhood Development. Development proceeds from conception to adulthood through ... Numerous studies have evaluated developmental effects of RF fields on mammals, birds, and other nonmammalian species.53,54 ... Many of the cells are still omnipotential stem cells, and if the embryo survives a toxic exposure it can recuperate without an ... Edwards MJ, Saunders RD, Shiota K. Effects of heat on embryos and foetuses. Int J Hyperthermia.2003;19 :295- 324. ...
Hematopoiesis originates in the yolk sac of embryos and transitions to the liver of the fetus. Two waves of hematopoietic ... Their recent studies indicate that the primitive erythroid lineage in mice as "mammalian", rather than "non-mammalian" in ... Chapter Title: Ontogeny of erythropoiesis in the mammalian embryo. Book Title: Red Cell Development. Author List: McGrath KE, ... laboratory is to elucidate the cellular and molecular events underlying the initiation of hematopoiesis in the mammalian embryo ...
44.embryo, nonmammalian 7 ƪ4.667%. 45.leukemia 7 ƪ4.667%. 46.mice, knockout 7 ƪ4.667% ...
Mammalian and Non Mammalian Toxicology. Mammalian and Non Mammalian Toxicology. Level 3. In vivo assays providing data about ... Xenopus embryo thyroid signalling assay (When/if TG is available).. *Amphibian metamorphosis assay (OECD TG 231). ... In vitro assays providing data about selected endocrine mechanism(s) / pathways(s) (Mammalian and non mammalian methods) ...
  • A recently developed MS2-MCP technique for imaging nascent messenger RNA in living Drosophila embryos allows us to quantify the dynamics of the developmental transcription process. (
  • Exploring uptake and biodistribution of polystyrene (nano)particles in zebrafish embryos at different developmental stages. (
  • For developmental toxicity, the mouse Embryonic Stem Cell test and the rat Whole Embryo Culture are commonly used, but assays in non-mammalian whole organisms are currently proposed as they more fully represent the complexity of early development. (
  • As such, this project will show whether zebrafish embryos can bioactivate, and thus detect, proteratogens or not, which is key information when considering this alternative assay for developmental toxicity testing. (
  • Developmental toxicity of metaldehyde in the embryos of Lymnaea stagnalis (Gastropoda: Pulmonata) co-exposed to the synergist piperonyl butoxide. (
  • Clove Oil and AQUI-S Efficacy for Zebrafish Embryo, Larva, and Adult Anesthesia. (
  • Second, the zebrafish embryo survives on yolk for the first 3-4 days of development, after which its digestive system is fully functional and the embryonic fish begins feeding on day 5. (
  • Bioactivation of human proteratogens in the zebrafish embryo model, a potential alternative test for development toxicity assessment. (
  • In vitro metabolism of pregnenolone to 7alpha-hydroxypregnenolone by rainbow trout embryos. (
  • The long-term aim of Dr. Palis' laboratory is to elucidate the cellular and molecular events underlying the initiation of hematopoiesis in the mammalian embryo. (
  • Targeted disruption of genes in the mouse that result in failure of the emergence or maturation of the primitive erythroid lineage leads to early fetal death, indicating that the primitive erythroid lineage is necessary for survival of the mammalian embryo. (
  • Into the mammalian embryo, two crucial ovarian pathways have already been defined. (
  • Cryoprotective effects of antifreeze proteins delivered into zebrafish embryos. (
  • Therefore, both AFP4 proteins are essential for gastrulation of zebrafish embryos. (
  • Moreover, the acquisition of pluripotency in chicken embryos occurs at around EGK.VI to VIII. (
  • In vertebrate embryos, genetic manipulation of Notch signaling has demonstrated the importance of this pathway in driving artery endothelial cell differentiation. (
  • Hematopoietic stem and progenitor cells (HSPCs) hyperproliferate and arrest during differentiation in embryos lacking functional PTEN, resulting in enhanced numbers of blood cell progenitors, but no mature blood cells. (
  • Because of the optical transparency of the embryos, small size at maturity and ease of culture, Zebrafish has become a popular organism to study embryonic development for biologist worldwide. (
  • The successful isolation and in vitro culture of embryonic stem cells (ESC) from mouse embryos have enabled technological breakthroughs and revolutionized our understanding of the molecular mechanisms regulating mammalian development ( Evans, 2011 ). (
  • The recent reconstruction of a digital embryo using single-cell transcriptomics and light sheet imaging, and new understandings of the timing of embryonic stem cell specialisation, will aid our understanding of this complex area of biology. (
  • During vertebrate embryogenesis, embryonic cell movements are very critical for morphogenesis and establishment of normal embryo architecture [ 1 ]. (
  • Double homozygous ptena-/-ptenb-/- mutant embryos are embryonic lethal and display a pleiotropic phenotype, including hyperproliferation of endothelial cells, resulting in hyperbranching of blood vessels. (
  • Hematopoiesis originates in the yolk sac of embryos and transitions to the liver of the fetus. (
  • On the other hand, these genes are switched off in cells from chick embryos and in older zebra finch stem cells. (
  • We describe here the generation of a Fucci derivative using zebrafish homologs of Cdt1 and geminin, which provides sweeping views of cell proliferation in whole fish embryos. (
  • For decades, researchers have successfully cryopreserved - frozen and thawed - mammal embryos and a variety of animal sperm, but scientists were unable to do the same for fish embryos. (
  • Now, with a pairing of gold nanoparticles and lasers that thaw at millions of degrees per minute, University of Minnesota scientists successfully cryopreserved zebra fish embryos. (
  • Mary Hagedorn, marine biologist at the Smithsonian Conservation Biology Institute, worked to cryopreserve fish embryos for 20 years, but it wasn't possible until she used the University's technology. (
  • Hagedorn started delving into cryopreserving fish embryos in 1993 with little luck. (
  • The fish embryos' size, much larger than mammal embryos, and their impermeable membranes made them incredibly difficult for Hagedorn and others to cryopreserve. (
  • Innate pluripotency of mouse embryos transits from naive to primed state as the inner cell mass differentiates into epiblast. (
  • Pluripotent' stem cells-which are able to produce cells of any type-can be obtained from young mouse embryos. (
  • 1997) Placental abnormalities in mouse embryos lacking the orphan nuclear receptor ERRα. (
  • Curiously, the stem cells that have been collected from other mammal embryos are already in this primed state. (
  • The approach that we use is to image neurons in intact, non-mammalian vertebrate embryos as a means to provide new insight into the cellular, molecular, and activity-dependent processes that guide synaptogenesis in the central nervous system. (
  • In contrast there was no such reduction in the rhea17 embryos suggesting the G340E mutant talin protein interacts with the membrane as well as the WT protein. (
  • We found that zebrafish AR regulates male sexual determination, because the majority of aruab105/105 mutant embryos developed ovaries and displayed female secondary sexual characteristics. (
  • Research resources to be shared include genetically modified or mutant organisms, sperm, embryos, protocols for genetic and phenotypic screens, mutagenesis protocols, and genetic and phenotypic data for all mutant strains. (
  • The mutant phenotype can be initially observed in tadpoles after stage 39/40, when mutant embryos display markedly reduced pigmentation in the retina and the trunk. (
  • Research resources include genetically modified or mutant organisms, embryos, protocols for genetic and phenotypic screens, mutagenesis protocols, and genetic data. (
  • mmy encodes an antagonist of Decapentaplegic (Dpp) signaling, and mmy mutant embryos have expanded ectopic Dpp activity in the dorsal epidermis. (
  • Moreover, there is a differential requirement for PTPs during regeneration, in that mutant zebrafish embryos lacking Shp2 or pten do not regenerate, whereas RPTPalpha is dispensable for regeneration. (
  • Embryo, Nonmammalian" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (
  • We are also interested in morphogenesis that provides shape to the developing embryo. (
  • Investigation of Islet2a function in zebrafish embryos: Mutants and morphants differ in morphologic phenotypes and gene expression. (
  • Reduction of beta-catenin-2 function in wild-type embryos by injection of morpholino antisense oligonucleotides (MOs) specific for this gene (MO2) results in the same ventralized phenotypes as seen in ichabod embryos, and administration of MO2 to ichabod embryos increases the extent of ventralization. (
  • However, the extent to which these phenotypes are conserved in nonmammalian vertebrates is not well understood. (
  • We show that the Xenopus embryo contains an mRNA encoding a protein highly homologous to basic FGF. (
  • Blastomere injection of mRNA or antisense oligonucleotides has proven effective in analyzing early gene function in Xenopus.Double-targeted transfection provides a unique opportunity to monitor axon-target interaction in vivo.Finally, electroporated embryos represent a valuable source of MO-loaded or DNA transfected cells for in vitro analysis. (
  • Xenopus laevis tadpoles offer a uniquely accessible model system in which dynamic events can be studied because of the translucency of the embryos and because of their accessibility to experimental manipulation. (
  • Thus, by using the visual system of Xenopus tadpoles as an in vivo model our group has provided unique evidence on how dynamic is synapse formation and stabilization and has demonstrated both permissive and instructive roles for BDNF during synaptogenesis in living embryos. (
  • Xenopus zinc finger transcription factor IA1 (Insm1) expression marks anteroventral noradrenergic neuron progenitors in Xenopus embryos. (
  • The development of chick and other bird embryos shares many parallels with that of mammals. (
  • The experiments also suggest that both birds and mammals have naive pluripotent stem cells during the early stages of embryo development. (
  • Gestation is the carrying of an embryo or foetus inside the female's womb in mammals and non-mammalian species. (
  • Therefore, biologists wonder whether the naive state is exclusive to mice embryos, or whether it is present in other animals but has so far remained undetected. (
  • Dr. Holt is the co-Chair of the Health and Safety subcommittee of the Companion and Domestic Animals and Endangered Species group of the International Embryo Transfer Society. (
  • The aim of this research project is to assess the bioactivation capacity of zebrafish embryos by using molecular techniques that target specific CYP isoenzymes. (
  • SpMyb functions as an intramodular repressor to regulate spatial expression of CyIIIa in sea urchin embryos. (
  • Synthetic oligonucleotides containing the myb target site were used to purify a protein from sea urchin embryo nuclear extracts by affinity chromatography. (
  • To solve this, researchers injected the embryos with antifreeze chemicals and gold nanoparticles, then dipped them in liquid nitrogen to freeze them, Khosla said. (
  • beta-catenin-2 is thus specifically required for organizer formation and this function is apparently required maternally, because the ichabod mutation causes a reduction in maternal transcription of the gene and a reduced level of beta-catenin-2 protein in the early embryo. (
  • Co-exposure to the PBO (measured concentrations between 0.47-0.56 mg·L(-1)) reduced hatching success from 100% to 47% and resulted in a 30% reduction in embryo growth (shell height) in snail embryos co-exposed to metaldehyde at 34-36 mg·L(-1) over 21 d. (
  • pdgfra mutants and Mirn140-injected embryos shared a range of facial defects, including clefting of the crest-derived cartilages that develop in the roof of the larval mouth. (
  • However, embryos in chicken eggs do not contain naive ESCs. (
  • It is possible that this is due to chicken eggs being laid when the embryos have reached a later stage in development where the naive stem cells have already matured into the primed cells. (
  • s findings show that finch eggs are laid at an earlier stage of embryo development than chicken eggs. (
  • No eggs or embryos from any non-mammalian species have ever been frozen, so this is a gateway for all of that," Hagedorn said. (
  • The key to successful cryopreservation is the ability to warm the embryo fast enough so no ice crystals form in it, Khosla said. (
  • Improved technologies for the cryopreservation of embryos and gametes are needed for several scientific and economic reasons. (
  • These observations sounded alarm bells and stimulated research into the impacts of in vivo and in vitro conditions on the health of embryos and offspring. (
  • Xenotransplantation of human cancer cells in embryos or adult zebrafish presents the advantage of following cancer cell behavior in vivo. (
  • Embryo-larval BDE-47 exposure causes decreased pathogen resistance in adult male fathead minnows (Pimephales promelas). (
  • Waterborne exposure of zebrafish embryos to micromole concentrations of ioxynil and diethylstilbestrol disrupts thyrocyte development. (
  • His research interests focus on the cross-talk between gametes and embryos, and the maternal tract. (
  • Concentration gradients of small diffusible molecules called morphogens are key regulators of development, specifying position during pattern formation in the embryo. (
  • Our study demonstrates the effectiveness of using the Cul4 Ddb1 -mediated Cdt1 degradation pathway common to all metazoans for the development of a G 1 marker that works in the nonmammalian animal model. (
  • You will then hear about early mammalian development, from fertilization to gastrulation with a focus on zygotic genome activation and the transfer of control from the mother (oocyte) to embryo. (
  • Ear development is also affected in nop embryos when both zygotic and maternal hsp6 is mutated: otoliths are often reduced or abnormal in morphology, as seen in some mouse HPS mutations, but to our knowledge not described in the BLOC-2 subset of HPS mutations nor described in non-mammalian systems previously. (
  • In the absence of chronic data on potential hazards to non-target freshwater molluscs, a laboratory study was conducted to investigate the impact of metaldehyde on embryo development in the gastropod Lymnaea stagnalis (RENILYS strain) and using zinc as a positive control. (
  • We report here that the protein tyrosine phosphatase Pez is expressed transiently in discrete locations in developing brain, heart, pharyngeal arches, and somites in zebrafish embryos. (
  • We used antisense morpholino oligonucleotide technology to knockdown leptin-(A) gene expression in developing zebrafish embryos and measured its effects on metabolic rate and cardiovascular function. (
  • 48 hpf embryos and acid production in 72 hpf embryos could be rescued to that of wildtype embryos by recombinant leptin coinjected with antisense morpholino. (
  • Expression of Noonan Syndrome-variant of Shp2 (D61G) induces morphological defects in zebrafish embryos (top 3 embryos compared to non-injected control at the bottom). (
  • Although the ichabod mutation does not functionally alter the beta-catenin-2 reading frame, the level of maternal beta-catenin-2, but not beta-catenin-1, transcript is substantially lower in ichabod, compared with wild-type, embryos. (
  • compared the stem cells in chick embryos to those from another bird called the zebra finch. (
  • FRAP experiments with GFP-SAS-4 transgenic embryos reveal that SAS-4 is recruited to the centrosome once per cell cycle, at the time of organelle duplication. (
  • University of Minnesota researchers are using gold nanotechnology to cryopreserve zebrafish embryos, and demonstrated the laser on Thursday, July 13, 2017 in Nils Hasselmo Hall in Minneapolis, Minnesota. (
  • Finally, electroporated embryos represent a valuable source of MO-loaded or DNA transfected cells for in vitro analysis. (
  • The experiments show that the finch embryos contain stem cells that share several features with mouse ESCs. (
  • The technology balances heating and cooling of the embryo to avoid ice crystallization, and therefore damage to the cells, instead forming a glass-like cell structure. (
  • At 5 weeks, the cells of the embryo specialise into the nervous system, organs, skin etc. (
  • Trypanosoma cruzi strain Peru was cultivated in the presence of an established cell line of Triatoma infestans embryo cells (TI- 32). (
  • Particles larger than 50nm were predominantly adsorbed onto the intestinal tract and outer epidermis of zebrafish embryos. (
  • Embryos exposed to particles via both epidermis and intestine showed highest uptake and eventually accumulated particles in the eye, whereas uptake of particles via the chorion and epidermis resulted in marginal uptake. (
  • The transparent embryo is injected with gold particles, placed on a small slide within the laser, submerged in liquid nitrogen and then hit with the laser. (
  • Pairing the laser with the injected gold particles, which absorb the energy, allowed the embryos to warm successfully. (
  • Embryos depleted of either wanderlust (wand), which encodes a putative chondroitin sulfate synthase, or super sex combs, which encodes an O-GlcNAc transferase, had Dpp activity expanded ectopically beyond the LE epidermis, identifying these transferases as a Dpp antagonists. (
  • University researchers used gold nanoparticles and lasers to freeze and thaw the first live fish embryo. (