|
Cytochalasin B
Cytochalasin B, the name of which comes from the Greek ''cytos'' (cell) and ''chalasis'' (relaxation), is a cell-permeable mycotoxin. It was found that substoichiometric concentrations of cytochalasin B (CB) strongly inhibit network formation by actin filaments. Due to this, it is often used in cytological research. It inhibits cytoplasmic division by blocking the formation of contractile microfilaments. It inhibits cell movement and induces nuclear extrusion. Cytochalasin B shortens actin filaments by blocking monomer addition at the fast-growing end of polymers. Cytochalasin B inhibits glucose transport and platelet aggregation. It blocks adenosine-induced apoptotic body formation without affecting activation of endogenous ADP-ribosylation in leukemia HL-60 cells. It is also used in cloning through nuclear transfer. Here enucleated recipient cells are treated with cytochalasin B. Cytochalasin B makes the cytoplasm of the oocytes more fluid and makes it possible to aspirate the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermentek
Fermentek Ltd. is a biotechnological company in the Atarot industrial zone of Jerusalem, Israel. It specializes in the research, development and manufacture of biologically active, natural products isolated from microorganisms as well as from other natural sources such as plants and algae. The main microorganisms used are nonpathogenic actinomycetes, Nocardia and Streptomycetes. The fungi used are: Penicillium, Aspergillus, Fusarium and the like. None of these is a human pathogen. Fermentek does not sell to individuals. Most of its products are marketed through major international distributors specializing in chemicals, under their own brand names. Nevertheless, Fermentek has specific impact on the biochemical market, especially in the field of mycotoxins. Mycotoxins are toxic compounds produced by molds in human food and farm animal feeds, thus being economically important factors. Fermentek manufactures an extensive line of pure mycotoxins used as standards in food analysis. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Membrane
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of a cell, being selectively permeable to ions and organic molecu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contractile Ring
In molecular biology, an actomyosin ring or contractile ring, is a prominent structure during cytokinesis. It forms perpendicular to the axis of the spindle apparatus towards the end of telophase, in which sister chromatids are identically separated at the opposite sides of the spindle forming nuclei (Figure 1). The actomyosin ring follows an orderly sequence of events: identification of the active division site, formation of the ring, constriction of the ring, and disassembly of the ring. It is composed of actin and myosin II bundles, thus the term actomyosin. The actomyosin ring operates in contractile motion, although the mechanism on how or what triggers the constriction is still an evolving topic. Other cytoskeletal proteins are also involved in maintaining the stability of the ring and driving its constriction. Apart from cytokinesis, in which the ring constricts as the cells divide (Figure 2), actomyosin ring constriction has also been found to activate during wound closu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokinesis
Cytokinesis () is the part of the cell division process and part of mitosis during which the cytoplasm of a single eukaryotic cell divides into two daughter cells. Cytoplasmic division begins during or after the late stages of nuclear division in mitosis and meiosis. During cytokinesis the spindle apparatus partitions and transports duplicated chromatids into the cytoplasm of the separating daughter cells. It thereby ensures that chromosome number and complement are maintained from one generation to the next and that, except in special cases, the daughter cells will be functional copies of the parent cell. After the completion of the telophase and cytokinesis, each daughter cell enters the interphase of the cell cycle. Particular functions demand various deviations from the process of symmetrical cytokinesis; for example in oogenesis in animals the ovum takes almost all the cytoplasm and organelles. This leaves very little for the resulting polar bodies, which in most spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HeLa Cell
HeLa () is an immortalized cell line used in scientific research. It is the oldest human cell line and one of the most commonly used. HeLa cells are durable and prolific, allowing for extensive applications in scientific study. The line is derived from cervical cancer cells taken on February 8, 1951, from Henrietta Lacks, a 31-year-old African American mother of five, after whom the line is named. Lacks died of cancer on October 4, 1951. The cells from Lacks's cancerous cervical tumor were taken without her knowledge, which was common practice in the United States at the time. Cell biologist George Otto Gey found that they could be kept alive, and developed a cell line. Previously, cells cultured from other human cells would survive for only a few days, but cells from Lacks's tumor behaved differently. History Origin In 1951, Henrietta Lacks was admitted to the Johns Hopkins Hospital with symptoms of irregular vaginal bleeding; she was subsequently treated for cervical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithelial Cell
Epithelium or epithelial tissue is a thin, continuous, protective layer of Cell (biology), cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (Mesothelium, mesothelial) tissues line the outer surfaces of many internal organ (anatomy), 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 (biology), 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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centriole
In cell biology a centriole is a cylindrical organelle composed mainly of a protein called tubulin. Centrioles are found in most eukaryotic cells, but are not present in conifers ( Pinophyta), flowering plants ( angiosperms) and most fungi, and are only present in the male gametes of charophytes, bryophytes, seedless vascular plants, cycads, and ''Ginkgo''. A bound pair of centrioles, surrounded by a highly ordered mass of dense material, called the pericentriolar material (PCM), makes up a structure called a centrosome. Centrioles are typically made up of nine sets of short microtubule triplets, arranged in a cylinder. Deviations from this structure include crabs and ''Drosophila melanogaster'' embryos, with nine doublets, and '' Caenorhabditis elegans'' sperm cells and early embryos, with nine singlets. Additional proteins include centrin, cenexin and tektin. The main function of centrioles is to produce cilia during interphase and the aster and the spindle durin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binucleated Cells
Binucleated cells are cells that contain two nuclei. This type of cell is most commonly found in cancer cells and may arise from a variety of causes. Binucleation can be easily visualized through staining and microscopy. In general, binucleation has negative effects on cell viability and subsequent mitosis. They also occur physiologically in hepatocytes, chondrocytes and in fungi (dikaryon). Causes * Cleavage furrow regression: Cells divide and almost complete division but then the cleavage furrow begins to regress and the cells merge. This is thought to be caused by nondisjunction in chromosomes but the mechanism by which it occurs is not well understood. * Failed cytokinesis: The cell can fail to form a cleavage furrow, leading to both nuclei remaining in one cell. * Multipolar spindles: Cells contain three or more centrioles, resulting in multiple poles. This leads to the cells pulling chromosomes in many directions that end in multiple nuclei found in one cell. * Mer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Division
Mitosis () is a part of the cell cycle in eukaryotic cells in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis is an equational division which gives rise to genetically identical cells in which the total number of chromosomes is maintained. Mitosis is preceded by the S phase of interphase (during which DNA replication occurs) and is followed by telophase and cytokinesis, which divide the cytoplasm, organelles, and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic phase (M phase) of a cell cycle—the division of the mother cell into two daughter cells genetically identical to each other. The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are preprophase (specific to plant cells), prophase, prometaphase, metaphase, anaphase, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitosis
Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identical cells in which the total number of chromosomes is maintained. Mitosis is preceded by the S phase of interphase (during which DNA replication occurs) and is followed by telophase and cytokinesis, which divide the cytoplasm, organelles, and cell membrane of one cell into two new cell (biology), cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic phase (M phase) of a cell cycle—the cell division, division of the mother cell into two daughter cells genetically identical to each other. The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are preprophase (specific to plant ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interphase
Interphase is the active portion of the cell cycle that includes the G1, S, and G2 phases, where the cell grows, replicates its DNA, and prepares for mitosis, respectively. Interphase was formerly called the "resting phase," but the cell in interphase is not simply dormant. Calling it so would be misleading since a cell in interphase is very busy synthesizing proteins, transcribing DNA into RNA, engulfing extracellular material, and processing signals, to name just a few activities. The cell is quiescent only in G0. Interphase is the phase of the cell cycle in which a typical cell spends most of its life. Interphase is the "daily living" or metabolic phase of the cell, in which the cell obtains nutrients and metabolizes them, grows, replicates its DNA in preparation for mitosis, and conducts other "normal" cell functions. A common misconception is that interphase is the first stage of mitosis, but since mitosis is the division of the nucleus, prophase is actually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multinucleate
Multinucleate cells (also known as multinucleated cells or polynuclear cells) are eukaryotic cells that have more than one nucleus, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coordinated, synchronous manner where all nuclei divide simultaneously or asynchronously where individual nuclei divide independently in time and space. Certain organisms may have a multinuclear stage of their life cycle. For example, slime molds have a vegetative, multinucleate life stage called a plasmodium. Multinucleate cells, depending on the mechanism by which they are formed, can be divided into "syncytia" (formed by cell fusion) or " coenocytes" (formed by nuclear division not being followed by cytokinesis). Some bacteria, such as '' Mycoplasma pneumoniae'', a pathogen of the respiratory tract, may display multinuclear filaments as a result of a delay between genome replication and cellular division. Terminology Some biologists use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
