Nematode Worms (Caenorhabditis Elegans)
Caenorhabditis elegans (Template:IPAc-enTemplate:refn) is a free-living transparent nematode about 1 mm in length[1] that lives in temperate soil environments. It is the type species of its genus.[2] The name is a blend of the Greek caeno- (recent), rhabditis (rod-like)[3] and Latin elegans (elegant). In 1900, Maupas initially named it Rhabditides elegans. Osche placed it in the subgenus Caenorhabditis in 1952, and in 1955, Dougherty raised Caenorhabditis to the status of genus.[4]
C. elegans is an unsegmented pseudocoelomate and lacks respiratory or circulatory systems.[5] Most of these nematodes are hermaphrodites and a few are males.[6] Males have specialised tails for mating that include spicules.
In 1963, Sydney Brenner proposed research into C. elegans, primarily in the area of neuronal development. In 1974, he began research into the molecular and developmental biology of C. elegans, which has since been extensively used as a model organism.[7] It was the first multicellular organism to have its whole genome sequenced, and in 2019 it was the first organism to have its connectome (neuronal "wiring diagram") completed.[8][9][10]
See Also
References
- ↑ Wood; "The Nematode Caenorhabditis elegans'" , pp. 1 , ISBN: 978-0-87969-433-3
- ↑ Sudhaus W, Kiontke K; "Phylogeny of Rhabditis subgenus Caenorhabditis (Rhabditidae, Nematoda)" , https://doi.org/10.1111/j.1439-0469.1996.tb00827.x
- ↑ καινός (caenos) = new, recent; ῥάβδος (rhabdos) = rod, wand.
- ↑ Caenorhabditis elegans, http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G900S2.htm
- ↑ Wallace RL, Ricci C, Melone G; "A cladistic analysis of pseudocoelomate (aschelminth) morphology." , https://doi.org/10.2307/3227041
- ↑ Introduction to sex determination, http://www.wormbook.org/chapters/www_introsexdetermination/introsexdetermination.html
- ↑ Brenner S: The genetics of Caenorhabditis elegans. Genetics 1974. (PMID 4366476) [PubMed] [DOI] [Full text] Methods are described for the isolation, complementation and mapping of mutants of Caenorhabditis elegans, a small free-living nematode worm. About 300 EMS-induced mutants affecting behavior and morphology have been characterized and about one hundred genes have been defined. Mutations in 77 of these alter the movement of the animal. Estimates of the induced mutation frequency of both the visible mutants and X chromosome lethals suggests that, just as in Drosophila, the genetic units in C. elegans are large.
- ↑ White JG et al.: The structure of the nervous system of the nematode Caenorhabditis elegans. Philos Trans R Soc Lond B Biol Sci 1986. (PMID 22462104) [PubMed] [DOI] The structure and connectivity of the nervous system of the nematode Caenorhabditis elegans has been deduced from reconstructions of electron micrographs of serial sections. The hermaphrodite nervous system has a total complement of 302 neurons, which are arranged in an essentially invariant structure. Neurons with similar morphologies and connectivities have been grouped together into classes; there are 118 such classes. Neurons have simple morphologies with few, if any, branches. Processes from neurons run in defined positions within bundles of parallel processes, synaptic connections being made en passant. Process bundles are arranged longitudinally and circumferentially and are often adjacent to ridges of hypodermis. Neurons are generally highly locally connected, making synaptic connections with many of their neighbours. Muscle cells have arms that run out to process bundles containing motoneuron axons. Here they receive their synaptic input in defined regions along the surface of the bundles, where motoneuron axons reside. Most of the morphologically identifiable synaptic connections in a typical animal are described. These consist of about 5000 chemical synapses, 2000 neuromuscular junctions and 600 gap junctions.
- ↑ White JG: Getting into the mind of a worm--a personal view. WormBook 2013. (PMID 23801597) [PubMed] [DOI] [Full text]
- ↑ Template:cite magazine