|
Centrosomes
In cell biology, the centrosome (Latin centrum 'center' + Greek sōma 'body') (archaically cytocentre) is an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell, as well as a regulator of cell-cycle progression. The centrosome provides structure for the cell. The centrosome is thought to have evolved only in the metazoan lineage of eukaryotic cells. Fungi and plants lack centrosomes and therefore use other structures to organize their microtubules. Although the centrosome has a key role in efficient mitosis in animal cells, it is not essential in certain fly and flatworm species. Centrosomes are composed of two centrioles arranged at right angles to each other, and surrounded by a dense, highly structured mass of protein termed the pericentriolar material (PCM). The PCM contains proteins responsible for microtubule nucleation and anchoring — including γ-tubulin, pericentrin and ninein. In general, each centriole of the centrosome is based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrosome (borderless Version)-en
In cell biology, the centrosome (Latin centrum 'center' + Greek sōma 'body') (archaically cytocentre) is an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell (biology), cell, as well as a regulator of cell-cycle progression. The centrosome provides structure for the cell. The centrosome is thought to have evolved only in the metazoan lineage of Eukaryote, eukaryotic cells. Fungus, Fungi and plants lack centrosomes and therefore use other structures to organize their microtubules. Although the centrosome has a key role in efficient mitosis in animal cells, it is not essential in certain fly and flatworm species. Centrosomes are composed of two centrioles arranged at right angles to each other, and surrounded by a dense, highly structured mass of protein termed the pericentriolar material (PCM). The PCM contains proteins responsible for microtubule nucleation and anchoring — including Tubulin#γ-Tubulin, γ-tubulin, pericentrin and ninein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule Organizing Center
The microtubule-organizing center (MTOC) is a structure found in eukaryotic cells from which microtubules emerge. MTOCs have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division. The MTOC is a major site of microtubule nucleation and can be visualized in cells by immunohistochemical detection of γ-tubulin. The morphological characteristics of MTOCs vary between the different phyla and kingdoms. In animals, the two most important types of MTOCs are 1) the basal bodies associated with cilia and flagella and 2) the centrosome associated with spindle formation. Organization Microtubule-organizing centers function as the site where microtubule formation begins, as well as a location where free-ends of microtubules attract to. Within the cells, microtubule-organizing centers can take on many different forms. An array of microtubules can arrange themselv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubule
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, organell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pericentrin
Pericentrin (kendrin), also known as PCNT and pericentrin-B (PCNTB), is a protein which in humans is encoded by the ''PCNT'' gene on chromosome 21. This protein localizes to the centrosome and recruits proteins to the pericentriolar matrix (PCM) to ensure proper centrosome and mitotic spindle formation, and thus, uninterrupted cell cycle progression. This gene is implicated in many diseases and disorders, including congenital disorders such as microcephalic osteodysplastic primordial dwarfism type II (MOPDII) and Seckel syndrome. Structure PCNT is a 360 kDa protein which contains a series of coiled coil domains and a highly conserved PCM targeting motif called the PACT domain near its C-terminus. The PACT domain is responsible for targeting the protein to the centrosomes and attaching it to the centriole walls during interphase. In addition, PCNT possesses five nuclear export sequences which all contribute to its nuclear export into the cytoplasm, as well as one nuclear local ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prophase
Prophase () is the first stage of cell division in both mitosis and meiosis. Beginning after interphase, DNA has already been replicated when the cell enters prophase. The main occurrences in prophase are the condensation of the chromatin reticulum and the disappearance of the nucleolus. Staining and microscopy Microscopy can be used to visualize condensed chromosomes as they move through meiosis and mitosis. Various DNA stains are used to treat cells such that condensing chromosomes can be visualized as the move through prophase. The giemsa G-banding technique is commonly used to identify mammalian chromosomes, but utilizing the technology on plant cells was originally difficult due to the high degree of chromosome compaction in plant cells. G-banding was fully realized for plant chromosomes in 1990. During both meiotic and mitotic prophase, giemsa staining can be applied to cells to elicit G-banding in chromosomes. Silver staining, a more modern technology, in conjunction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Membrane
The nuclear envelope, also known as the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus, which encloses the genetic material. The nuclear envelope consists of two lipid bilayer membranes: an inner nuclear membrane and an outer nuclear membrane. The space between the membranes is called the perinuclear space. It is usually about 10–50 nm wide. The outer nuclear membrane is continuous with the endoplasmic reticulum membrane. The nuclear envelope has many nuclear pores that allow materials to move between the cytosol and the nucleus. Intermediate filament proteins called lamins form a structure called the nuclear lamina on the inner aspect of the inner nuclear membrane and give structural support to the nucleus. Structure The nuclear envelope is made up of two lipid bilayer membranes, an inner nuclear membrane and an outer nuclear membrane. These membranes are connected to each other by nuclear pores. Two sets of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molly Sheehan Wikipedia 1
Molly, Mollie or mollies may refer to: Animals * ''Poecilia'', a genus of fishes ** ''Poecilia sphenops'', a fish species * A female mule (horse–donkey hybrid) People * Molly (name) or Mollie, a female given name, including a list of persons and characters with the name * Molly Pitcher, one of several American women believed to have helped fight against British forces during the American Revolution * Molly Malone, a mythical 19th-century Irish fishmonger and associated folk song and statue * Molly Mormon, a stereotype of a Latter-day Saints woman Dance and theatre * ''Molly'' (musical), a 1973 Broadway musical * Molly dance, a form of English Morris dance Film and television * ''Molly'' (1983 film), an Australian film by Ned Lander * ''Molly'' (1999 film), an American film starring Elisabeth Shue * '' Molly: An American Girl on the Home Front'', a 2006 made-for-television film * '' The Roads Not Taken'' (working title ''Molly''), a 2020 American drama film by Sally Potter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodor Boveri
Theodor Heinrich Boveri (12 October 1862 – 15 October 1915) was a German zoologist, comparative anatomist and co-founder of modern cytology. He was notable for the first hypothesis regarding cellular processes that cause cancer, and for describing ''chromatin diminution in nematodes''. Boveri was married to the American biologist Marcella O'Grady (1863–1950). Their daughter Margret Boveri (1900–1975) became one of the best-known journalists in post-World War II Germany. Work Using an optical microscope, Boveri examined the processes involved in the fertilization of the animal egg cell; his favorite research objects were the nematode ''Parascaris'' and sea urchins. Boveri's work with sea urchins showed that it was necessary to have all chromosomes present in order for proper embryonic development to take place. This discovery was an important part of the Boveri–Sutton chromosome theory. He also discovered, in 1888, the importance of the centrosome for the formation of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edouard Van Beneden
Édouard Joseph Louis Marie Van Beneden (5 March 1846 in Leuven – 28 April 1910 in Liège), son of Pierre-Joseph Van Beneden, was a Belgian embryologist, cytologist and marine biologist. He was professor of zoology at the University of Liège. He contributed to cytogenetics by his works on the roundworm ''Ascaris''. In this work he discovered how chromosomes organized meiosis (the production of gametes). Van Beneden elucidated, together with Walther Flemming and Eduard Strasburger, the essential facts of mitosis, where, in contrast to meiosis, there is a qualitative and quantitative equality of chromosome distribution to daughter cells. (See karyotype). Publications * ''Recherches sur la composition et la signification de l'œuf'' 186Full text available from Archive.org * ''La maturation de l'oeuf, la fecondation, et les pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walther Flemming
Walther Flemming (21 April 1843 – 4 August 1905) was a German biologist and a founder of cytogenetics. He was born in Sachsenberg (now part of Schwerin) as the fifth child and only son of the psychiatrist Carl Friedrich Flemming (1799–1880) and his second wife, Auguste Winter. He graduated from the ''Gymnasium der Residenzstadt'', where one of his colleagues and lifelong friends was writer Heinrich Seidel. Career Flemming trained in medicine at the University of Prague, graduating in 1868. Afterwards, he served in 1870–71 as a military physician in the Franco-Prussian War. From 1873 to 1876 he worked as a teacher at the University of Prague. In 1876 he accepted a post as a professor of anatomy at the University of Kiel. He became the director of the Anatomical Institute and stayed there until his death. With the use of aniline dyes he was able to find a structure which strongly absorbed basophilic dyes, which he named chromatin. He identified that chromatin was corre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cilium
The cilium, plural cilia (), is a membrane-bound organelle found on most types of eukaryotic cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea. The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans have a similar structure to motile cilia that enables swimming through liquids; they are longer than cilia and have a different undulating motion. There are two major classes of cilia: ''motile'' and ''non-motile'' cilia, each with a subtype, giving four types in all. A cell will typically have one primary cilium or many motile cilia. The structure of the cilium core called the axoneme determines the cilium class. Most motile cilia have a central pair of single microtubules surrounded by nine pairs of double microtubules called a 9+2 axoneme. Most non-motile cilia have a 9+0 axoneme that lacks the central pair o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-en.svg "Click for more on -> Centrosomes")
