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Invagination
Invagination is the process of a surface folding in on itself to form a cavity, pouch or tube. In developmental biology, invagination of Epithelium, epithelial sheets occurs in many contexts during Animal embryonic development, embryonic development. Invagination is critical for making the Archenteron, primitive gut during gastrulation in many organisms, forming the neural tube in Vertebrate, vertebrates, and in the morphogenesis of countless Organ (biology), organs and sensory structures. Models of invagination that have been most thoroughly studied include the ventral furrow in Drosophila melanogaster, ''Drosophila'' ''melanogaster'', neural tube formation, and gastrulation in many marine organisms. The cellular mechanisms of invagination vary from one context to another but at their core they involve changing the mechanics of one side of a sheet of cells such that this pressure induces a bend in the tissue. The term, originally used in embryology, has been adopted in other disc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Animal Embryonic Development
In developmental biology, animal embryonic development, also known as animal embryogenesis, is the developmental stage of an animal embryo. Embryonic development starts with the fertilization of an egg cell (ovum) by a sperm cell (spermatozoon). Once fertilized, the ovum becomes a single diploid cell known as a zygote. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo after passing through an organizational checkpoint during mid-embryogenesis. In mammals, the term refers chiefly to the early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. The main stages of animal embryonic development are as follows: * The zygote undergoes a series of cell divisions (called cleavage) to form a structure called a morula. * The morula develops into a structure called a blastula through a process called blastulation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Gastrulation
Gastrulation is the stage in the early embryonic development of most animals, during which the blastula (a single-layered hollow sphere of cells), or in mammals, the blastocyst, is reorganized into a two-layered or three-layered embryo known as the gastrula. Before gastrulation, the embryo is a continuous epithelial sheet of cells; by the end of gastrulation, the embryo has begun differentiation to establish distinct cell lineages, set up the basic axes of the body (e.g. dorsal–ventral, anterior–posterior), and internalized one or more cell types, including the prospective gut. Gastrula layers In triploblastic organisms, the gastrula is trilaminar (three-layered). These three germ layers are the ectoderm (outer layer), mesoderm (middle layer), and endoderm (inner layer).Mundlos 2009p. 422/ref>McGeady, 2004: p. 34 In diploblastic organisms, such as Cnidaria and Ctenophora, the gastrula has only ectoderm and endoderm. The two layers are also sometimes referred to as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Tissue Invagination
Tissue may refer to: Biology * Tissue (biology), an ensemble of similar (or dissimilar in structure but same in origin) cells that together carry out a specific function * '' Triphosa haesitata'', a species of geometer moth ("tissue moth") found in North America * '' Triphosa dubitata'', a species of geometer moth ("tissue") found in Afro-Eurasia Paper products * Tissue paper, a type of thin, gauzy translucent paper used for wrapping and cushioning items * Tissue (cloth), a thin, transparent, and lightweight fabric * Facial tissue, tissue paper used for cleaning the face * Japanese tissue, tissue paper from Japan made of vegetable fibers * Toilet paper Toilet paper (sometimes called toilet/bath/bathroom tissue, or toilet roll) is a tissue paper product primarily used to clean the human anus, anus and surrounding region of Human feces, feces (after defecation), and to clean the external gen ..., tissue paper used for cleaning the anus * Wrapping tissue, tissue paper used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Epithelium
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. These tissues also lack blood or lymph supply. The tissue is supplied by nerves. There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or ''compound'', either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Rho-associated Coiled-coil Kinase
Rho-associated protein kinase or Rho-associated coiled-coil kinase (ROCK) is a kinase belonging to the AGC (PKA/ PKG/PKC) family of serine-threonine specific protein kinases. It is involved mainly in regulating the shape and movement of cells by acting on the cytoskeleton. ROCKs ( ROCK1 and ROCK2) occur in mammals (human, rat, mouse, cow), zebrafish, ''Xenopus'', invertebrates ('' C. elegans'', mosquito, ''Drosophila'') and chicken. Human ROCK1 has a molecular mass of 158 kDa and is a major downstream effector of the small GTPase RhoA. Mammalian ROCK consists of a kinase domain, a coiled-coil region and a Pleckstrin homology (PH) domain, which reduces the kinase activity of ROCKs by an autoinhibitory intramolecular fold if RhoA-GTP is not present. Rat ROCKs were discovered as the first effectors of Rho and they induce the formation of stress fibers and focal adhesions by phosphorylating MLC (myosin light chain). Due to this phosphorylation, the actin binding of myosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Myosin Light Chain
A myosin light chain is a light chain (small polypeptide subunit) of myosin. Myosin light chains were discovered by Chinese biochemist Cao Tianqin (Tien-chin Tsao) when he was a graduate student at the University of Cambridge in England. Structure and function Myosin light chain classes Structurally, myosin light chains belong to the EF-hand family, a large family of Ca2+- binding proteins. MLCs contain two Ca2+ - binding EF-hand motifs. MLCs isoforms modulate the Ca2+of force transduction and cross-bridge kinetics. Myosin light chains (MLCs) can be broadly classified into two groups: * Essential or alkali MLC (MLC1 or ELC), * Regulatory MLC (MLC2 or RLC). Essential and regulatory MLCs have molecular masses of 22 and 19 kDa, respectively. Structurally, MLC2 contains a serine residue that is lacking in MLC1. The presence of this amino acids allows the regulation of the conformational changes (from compacted to an elongated form) by a Ca2+-mediated phosphorylation mechanis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Protein Subunit
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "''coassembles''") with others to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A subunit is often named with a Greek or Roman letter, and the numbers of this type of subunit in a protein is indicated by a subscript. For example, ATP synthase has a type of subunit called α. Three of these are present in the ATP synthase molecule, leading to the designation α3. Larger groups of subunits can also be specified, like α3β3-hexamer and c-ring. Naturally occurring proteins that have a relatively small number of subunits are referred to as oligomeric.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Phosphorylation
In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor. A common phosphorylating agent (phosphate donor) is ATP and a common family of acceptor are alcohols: : This equation can be written in several ways that are nearly equivalent that describe the behaviors of various protonated states of ATP, ADP, and the phosphorylated product. As is clear from the equation, a phosphate group per se is not transferred, but a phosphoryl group (PO3-). Phosphoryl is an electrophile. This process and its inverse, dephosphorylation, are common in biology. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Protein phosphorylation often activates (or deactivates) many enzymes. During respiration Phosphorylation is essential to the processes of both anaerobic and aerobic respiration, which involve the production of adenosine triphosphate (ATP), the "high-energy" exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Zebrafish
The zebrafish (''Danio rerio'') is a species of freshwater ray-finned fish belonging to the family Danionidae of the order Cypriniformes. Native to South Asia, it is a popular aquarium fish, frequently sold under the trade name zebra danio (and thus often called a " tropical fish" although it is both tropical and subtropical). The zebrafish is an important and widely used vertebrate model organism in scientific research, particularly developmental biology, but also gene function, oncology, teratology, and drug development, in particular pre-clinical development. It is also notable for its regenerative abilities, and has been modified by researchers to produce many transgenic strains. Taxonomy The zebrafish is a derived member of the genus '' Brachydanio'', of the family Cyprinidae. It has a sister-group relationship with '' Danio aesculapii''. Zebrafish are also closely related to the genus '' Devario'', as demonstrated by a phylogenetic tree of close species. Distri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Midbrain-hindbrain Boundary
The isthmic organizer, or isthmus organizer, also known as the midbrain−hindbrain boundary (MHB), is a secondary organizer region that develops at the junction of the midbrain and metencephalon (embryonic hindbrain). The MHB Gene expression, expresses Cell signaling, signaling molecules that regulate the Cellular differentiation, differentiation and patterning of the adjacent neuroepithelium. This allows for the development of the midbrain and hindbrain as well as the specification of Neuron, neuronal subtypes in these regions.Siegelbaum, Steven A., and A. James Hudspeth. Principles of neural science. Eds. Eric R. Kandel, James H. Schwartz, and Thomas M. Jessell. Vol. 5. New York: McGraw-hill, 2013. The fact that the MHB is sufficient for the development of the mid and hindbrain was shown in an experiment where quail MHB Cell (biology), cells transplanted into the forebrain of a chicken, chick were able to induce an Ectopic expression, ectopic midbrain and cerebellum. Development ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Optic Cup (embryology)
During embryonic development of the eye, the outer wall of the bulb of the optic vesicles becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup (or ophthalmic cup), consisting of two strata of cells. These two strata are continuous with each other at the cup margin, which ultimately overlaps the front of the lens and reaches as far forward as the future aperture of the pupil. The optic cup is part of the diencephalon and gives rise to the retina The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional ... of the eye. References External links Overview at temple.edu Embryology of nervous system Eye {{eye-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |