| 词条 | Ciona intestinalis |
| 释义 |
| name = Vase tunicate |image=Cionaintestinalis.jpg |image_caption=Ciona intestinalis | regnum = Animalia | phylum = Chordata | subphylum = Tunicata | classis = Ascidiacea | ordo = Enterogona | subordo = Phlebobranchia | familia = Cionidae | genus = Ciona | species = C. intestinalis | binomial = Ciona intestinalis | binomial_authority = (Linnaeus, 1767) }}Ciona intestinalis (sometimes known by the common name of vase tunicate) is an ascidian (sea squirt), a tunicate with very soft tunic. Its Latin name means, literally, "pillar of intestines", referring to the fact that its body is a soft, translucent column-like structure, resembling a mass of intestines sprouting from a rock.[1] It is a globally distributed cosmopolitan species. Since Linnaeus described the species, Ciona intestinalis has been used as a model invertebrate chordate in developmental biology and genomics.[2] Studies conducted between 2005 and 2010 have shown that there are at least two, possibly four, sister species.[3][4][5] More recently its has been shown that one of these species has already been described as Ciona robusta.[6] By anthropogenic means, the species has invaded various parts of the world and is known as an invasive species.[7][8] Although Linnaeus first categorised this species as a kind of mollusk, Alexander Kovalevsky found a tadpole-like larval stage during development that shows similarity to vertebrates. Recent molecular phylogenetic studies as well as phylogenomic studies support that sea squirts are the closest invertebrate relatives of vertebrates.[9] Its full genome has been sequenced using a specimen from Half Moon Bay in California, USA,[10] showing a very small genome size, less than 1/20 of the human genome, but having a gene corresponding to almost every family of genes in vertebrates. AppearanceCiona intestinalis is a solitary tunicate with a cylindrical, soft, gelatinous body, up to 20 cm long. The body colour and colour at the distal end of siphons are major external characters distinguishing sister species within the species complex.[11]The body of Ciona is bag-like and covered by a tunic, which is a secretion of the epidermal cells. The body is attached by a permanent base located at the posterior end, while the opposite extremity has two openings, the buccal and atrial siphons. Water is drawn into the ascidian through the buccal (oral) siphon and leaves the atrium through the atrial siphon (cloacal). EcologyCiona intestinalis is a hermaphroditic broadcast spawner but cannot self-fertilize.[12] Eggs and sperm, when released, can stay in the water column for 1 to 2 days while the larvae are free-swimming for 2 to 10 days. Ciona intestinalis is considered to be an invasive species and grows in dense aggregations on any floating or submerged substrate, particularly artificial structures like pilings, aquaculture gear, floats and boat hulls, in the lower intertidal to sub-tidal zones. It often grows with or on other fouling organisms. It is thought to spread to new areas mainly through hull fouling. Since its larvae can live for up to 10 days, this species may also be transferred through the release of bilge or ballast water. {{Howto|section|date=June 2014}}Because of the potential impact of C. intestinalis introduction to new habitats, fish and shellfish harvesters are advised to avoid transfer of harvested shellfish and fishing gear to other areas, to dry gear thoroughly before transfer, to inspect boat hulls and, if necessary, to clean them thoroughly, disinfect with bleach or vinegar and dry before moving to other areas. It is also recommended to dispose of any organisms removed from boat hulls or gear on land and to release bilge water on land or disinfect it. Sexual reproductionC. intestinalis is an hermaphrodite that releases sperm and eggs into the surrounding seawater almost simultaneously. C. intestinalis is self-sterile, and thus has been used for studies on the mechanism of self-incompatibility.[13] Self/non-self-recognition molecules are considered to play a key role in the process of interaction between sperm and the vitelline coat of the egg. It appears that self/non-self recognition in ascidians such as C. intestinalis is mechanistically similar to self-incompatibility systems in flowering plants.[13] Self-incompatibility promotes out-crossing which provides the adaptive advantage at each generation of masking deleterious recessive mutations (i.e. genetic complementation).[14]Cell signallingIn the sea squirt C. intestinalis a CB1 and CB2-type cannabinoid receptors is found to be targeted to axons, indicative of an ancient role for cannabinoid receptors as axonal regulators of neuronal signalling.[15] GeneticsC. intestinalis was one of the first animals to have its full genome sequenced, in 2002. It has a relatively small genome (about 160 Mbp) consisting of 14 pairs of chromosomes with about 16,000 genes.[16]Hox genesThe draft genome analysis identified nine Hox genes, which are Ci-Hox1, 2, 3, 4, 5, 6, 10, 12, and 13.[10] Ciona savignyi, the closest relative of Ciona intestinalis, also have the same set of Hox genes. The organization of Hox genes is only known for C. intestinalis among ascidians. The nine Hox genes are located on two chromosomes; Ci-Hox1 to 10 on one chromosome and Ci-Hox12 and 13 on another. The intergenic distances within the Ciona Hox genes are extraordinarily long. Seven Hox genes, Ci-Hox1 to 10, are distributed along approximately half the length of the chromosome. Comparisons to Hox gene expression and location in other species suggests that the Hox genes in ascidian genomes are under a dispersing condition.[17] GEVIsA majority of genetically encoded voltage indicator are based on the C. intestinalis voltage-sensitive domain (Ci-VSD). References1. ^{{cite book|last1=Lane|first1=Nick|title=Life Ascending: The Ten Great Inventions of Evolution|publisher=W. W. Norton & Company|isbn=0393338665|page=192|url=https://books.google.com/?id=zHyK5z3mkWwC&pg=PA192&lpg=PA192&dq=pillar+of+intestines+sea+squirt#v=onepage&q=pillar%20of%20intestines%20sea%20squirt&f=false|date=2010-06-14}} 2. ^{{cite journal|last=Satoh|first=Nori|title=The ascidian tadpole larva: comparative molecular development and genomics.|journal=Nature Reviews Genetics|year=2003|volume=4|pages=285–295|doi=10.1038/nrg1042|pmid=12671659|issue=4}} 3. ^{{cite journal|last=Suzuki|first=Miho M|author2=Nishikawa T|author3=Bird A|title=Genomic approaches reveal unexpected genetic divergence within Ciona intestinalis|journal=J Mol Evol|year=2005|volume=61|issue=5|pages=627–635|doi=10.1007/s00239-005-0009-3}} 4. ^{{cite journal|last=Caputi|first=Luisi |author2=Andreakis N |author3=Mastrototaro F |author4=Cirino P |author5=Vassillo M |author6=Sordino P|title=Cryptic speciation in a model invertebrate chordate|journal=Proceedings of the National Academy of Sciences USA|volume=104|issue=22 |pages=9364–9369|doi=10.1073/pnas.0610158104|year=2007 |pmc=1890500}} 5. ^{{cite journal|last=Zhan|first=A|author2=Macisaac HJ|author3=Cristescu ME|title=Invasion genetics of the Ciona intestinalis species complex: from regional endemism to global homogeneity|journal=Molecular Ecology|volume=19|issue=21|pages=4678–4694|doi=10.1111/j.1365-294x.2010.04837.x|pmid=20875067|year=2010}} 6. ^ {{cite journal|last=Brunetti|first=Riccardo|author2=Gissi C|author3=Pennati R| author4=Caicci F| author5=Gasparini F| author6=Manni L|title= Morphological evidence that the molecularly determined Ciona intestinalis type A and type B are different species: Ciona robusta and Ciona intestinalis|journal=Journal of Zoological Systematics and Evolutionary Research |year=2015|volume=53|issue=3|pages=186–193|doi= 10.1111/jzs.12101 }} 7. ^{{cite journal | last1 = Blum | first1 = J.C. | last2 = Chang | first2 = AL. | last3 = Liljesthröm | first3 = M. | last4 = Schenk | first4 = M.E. | last5 = Steinberg | first5 = M.K. | last6 = Ruiz | first6 = G.M. | year = 2007 | title = The non-native solitary ascidian Ciona intestinalis (L.) depresses species richness | url = | journal = Journal of Experimental Marine Biology and Ecology | volume = 342 | issue = | pages = 5–14 | doi=10.1016/j.jembe.2006.10.010}} 8. ^{{cite news|url=http://www.southerngazette.ca/News/Local/2013-06-11/article-3272927/The-vase-tunicate-has-landed/1|title=The vase tunicate has landed|last=Herridge|first=Paul|date=June 11, 2013|work=The Southern Gazette|accessdate=June 26, 2013|location=Marystown, Newfoundland and Labrador}} 9. ^{{cite journal|last=Putnam|first=NH |author2=Butts T |author3=Ferrier DE |author4=Furlong RF |author5=Fellsten U|title=The amphioxus genome and the evolution of the chordate karyotype.|journal=Nature|volume=453|pages=1064–71|doi=10.1038/nature06967|issue=7198|pmid=18563158|date=June 2008|display-authors=etal}} 10. ^1 {{cite journal|last=Dehal|first=P |author2=Satou Y |author3=Campbell RK|title=The draft genome of Ciona intestinalis: insights into chordate and vertebrate origins.|journal=Science|volume=298|pages=2157–2166|doi=10.1126/science.1080049|pmid=12481130|issue=5601|date=December 2002|display-authors=etal}} 11. ^{{cite journal|last=Sato|first=Atsuko|author2=Satoh N.|author3=Bishop JDD|title=Field identification of the ascidian species complex Ciona intestinalis in the region of symatory|journal=Marine Biology|year=2012|volume=159|issue=7|pages=1611–1619|doi=10.1007/s00227-012-1898-5}} 12. ^{{cite journal|last=Harada|first=Y|author2=Takagi Y|title=Mechanisms of self-fertility in a hermaphroditic chordate|journal=Science|year=2008|volume=320|issue=5875|pages=548–50|doi=10.1126/science.1152488|pmid=18356489|display-authors=etal}} 13. ^1 {{cite journal |vauthors=Sawada H, Morita M, Iwano M |title=Self/non-self recognition mechanisms in sexual reproduction: new insight into the self-incompatibility system shared by flowering plants and hermaphroditic animals |journal=Biochem. Biophys. Res. Commun. |volume=450 |issue=3 |pages=1142–8 |date=August 2014 |pmid=24878524 |doi=10.1016/j.bbrc.2014.05.099 |url=http://linkinghub.elsevier.com/retrieve/pii/S0006-291X(14)00980-2}} 14. ^{{cite journal |vauthors=Bernstein H, Byerly HC, Hopf FA, Michod RE |title=Genetic damage, mutation, and the evolution of sex |journal=Science |volume=229 |issue=4719 |pages=1277–81 |date=September 1985 |pmid=3898363 |doi= 10.1126/science.3898363|url=http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=3898363}} 15. ^{{Cite journal|last=Elphick|first=Maurice R.|date=2012-12-05|title=The evolution and comparative neurobiology of endocannabinoid signalling|journal=Philosophical Transactions of the Royal Society B: Biological Sciences|volume=367|issue=1607|pages=3201–3215|doi=10.1098/rstb.2011.0394|issn=0962-8436|pmc=3481536|pmid=23108540}} 16. ^Shoguchi et al., Molecular Cytogenetic Characterization of Ciona intestinalis Chromosomes. Zoological Science, 22, 2001 17. ^Ikuta, Tetsuro, and Hidetoshi Saiga. "Organization of Hox genes in ascidians: Present, past, and future." Developmental Dynamics 233.2 (2005): 382-89. External links{{Commons category|Ciona intestinalis}}
4 : Enterogona|Animals described in 1767|Animal models|Cosmopolitan animals |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。