A centriole showing the nine triplets of microtubules. Transmission electron microscope image.

Schematic of centriole showing microtubule triplets

A centriole is a barrel shaped organelle^[1] found in most eukaryotic cells, though absent in higher plants and fungi.^[2] The walls of each centriole are usually composed of nine triplets of microtubules. Deviations from this include Drosophila melanogaster embryos, with nine doublets and Caenorhabditis elegans sperm cells and early embryos, with nine singlets.^{[3] [4]} These make for more stable structures than unmodified tubulin. An associated pair of centrioles, arranged perpendicularly, constitutes the compound structure known as the centrosome.^[1] Image File history File links Size of this preview: 481 × 600 pixelsFull resolution (1283 × 1600 pixel, file size: 901 KB, MIME type: image/jpeg) Please see the file description page for further information. ... Image File history File links Size of this preview: 481 × 600 pixelsFull resolution (1283 × 1600 pixel, file size: 901 KB, MIME type: image/jpeg) Please see the file description page for further information. ... Microtubules are one of the components of the cytoskeleton. ... Transmission electron microscopy (TEM) is an imaging technique whereby a beam of electrons is focused onto a specimen causing an enlarged version to appear on a fluorescent screen or layer of photographic film (see electron microscope), or can be detected by a CCD camera. ... Image File history File links Centriole-schema. ... Image File history File links Centriole-schema. ... Microtubules are one of the components of the cytoskeleton. ... Schematic of typical animal cell, showing subcellular components. ... Kingdoms Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Divisions Non-seed-bearing plants Equisetophyta Lycopodiophyta Psilotophyta Pteridophyta Superdivision Spermatophyta Pinophyta Cycadophyta Ginkgophyta Gnetophyta Magnoliophyta The vascular plants are those plants that have specialized cells for conducting water and sap within their tissues, including the flowering plants, conifers and other gymnosperms, but not mosses, algae, and the like (nonvascular... Divisions Chytridiomycota Zygomycota Ascomycota Basidiomycota The Fungi (singular: fungus) are a large group of organisms ranked as a kingdom within the Domain Eukaryota. ... Microtubules are one of the components of the cytoskeleton. ... Binomial name Meigen, 1830[1] Drosophila melanogaster (from the Greek for black-bellied dew-lover) is a two-winged insect that belongs to the Diptera, the order of the flies. ... Binomial name Maupas, 1900 Caenorhabditis elegans (IPA: ) is a free-living nematode (roundworm), about 1 mm in length, which lives in temperate soil environments. ... For other uses, see Sperm (disambiguation). ... Tubulin is the protein which makes up microtubules. ... Fig. ... The centrosome is the main microtubule organizing center (MTOC) of the cell as well as a regulator of cell-cycle progression. ...

Function

In replication, each new paired set of centrioles is composed of the original centriole, plus a newly-made centriole. If the centrioles are used in forming motility organelles, flagella or cilia, the older of the two centrioles, the mother centriole, becomes the basal body which organizes the structure of the organelle.^[5] A basal body is a short cylindrical array of microtubules plus their associated proteins found at the base of a eukaryotic cell cilium or flagellum. ... Schematic of typical animal cell, showing subcellular components. ...

References