Diferenzas entre revisións de «Liña xerminal»

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(traducido de en:Germline)
 
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[[Ficheiro:Watsonia meriana detail of cormlets on inflorescence IMG 6909.JPG|miniatura|''[[Watsonia meriana]]'', un exemplo de [[apomixe]].]]
[[Ficheiro:Clathria_tuberosa_(Sponge).jpg|miniatura|''[[Clathria]] tuberosa'', un exemplo de esponxa que pode crecer indefinidamente do tecido somático e reconstituírse a partir de células somáticas separadas [[potencia celular|totipotentes]].]]
En [[bioloxía]] e [[xenética]], a '''liña xerminal''' dun [[organismo multicelular]] é a poboación de células corporais que se diferencian ou son segregadas no proceso usual de [[reprodución]] e poden pasartransmitir o seu material xenético á proxenie.<ref name="NieuwkoopSutasurya1979">{{cite book|author1=Pieter Dirk Nieuwkoop|author2=Lien A. Sutasurya|title=Primordial Germ Cells in the Chordates: Embryogenesis and Phylogenesis|url=http://books.google.com/books?id=Zu08AAAAIAAJ|year=1979|publisher=CUP Archive|isbn=978-0-521-22303-4}}</ref> As células da liña xerminal deromínanse [[célula xerminal|células xerminais]].<ref name="ZagrisDuprat1995">{{cite book|author1=Nikolas Zagris|author2=Anne Marie Duprat|author3=Antony Durston|title=Organization of the Early Vertebrate Embryo|url=http://books.google.com/books?id=lFH7RnOHsRAC&pg=PA2|date=30 November 1995|publisher=Springer|isbn=978-0-306-45132-4|pages=2–}}</ref> Por exemplo, nos animais as células xerminais son os [[gameto]]s como os [[espermatozoide]]e e [[óvulo]]s e as células das que derivan. Por tanto, son células xerminais os [[gametocito]]s ([[ovocito]], [[espermatocito]]), que producen os [[gameto]]s, e as que producen os gametocitos, chamadas [[gametogonia]]s ([[espermatogonia]], [[ovogonia]]).<ref name="ZagrisDuprat1995"/> Nos organismos con [[reprodución sexual]], as células que non forman parte da liña xerminal denomínanse [[célula somática|células somáticas]].
 
AsComo anorma rulexeral thiso passingmodo onde happenstransmitir viao amaterial xenético processé ofun proceso de ''[[sexualreprodución reproductionsexual]]''; typicallytipicamente ité isun aproceso processque thatinclúe includescambios systematicsistemáticos changesno tomaterial thexenético, geneticque material,se changesorixinan thatdurante arise duringa [[Geneticrecombinación recombinationxenética|recombinationrecombinación]], [[meiosismeiose]] ande [[fertilizationfecundación]] orou [[FertilizationFecundación|syngamysingamia]] forpor exampleexemplo. HoweverPorén, therehai aremoitas many exceptionsexcepcións, includingincluíndo processesprocesos ande conceptsconceptos suchcomo asvarias variousformas forms ofde [[apomixisapomixe]], [[Reproduction#Autogamy|autogamyautogamia]], [[Parthenogenesispartenoxénese#AutomixisAutomixe|automixisautomixe]], [[cloningclonación]], orou [[parthenogenesispartenoxénese]].<ref name="TarinCano2000">{{cite book|author1=Juan J. Tarin|author2=Antonio Cano|title=Fertilization in Protozoa and Metazoan Animals: Cellular and Molecular Aspects|url=http://books.google.com/books?id=3YguEHvZtjgC|date=14 September 2000|publisher=Springer|isbn=978-3-540-67093-3}}</ref><ref name="LoweHarris2009">{{cite book|author1=Andrew Lowe|author2=Stephen Harris|author3=Paul Ashton|title=Ecological Genetics: Design, Analysis, and Application|url=http://books.google.com/books?id=W3UkvPORFRcC&pg=PA108|date=1 April 2009|publisher=John Wiley & Sons|isbn=978-1-4443-1121-1|pages=108–}}</ref>
 
According to this view [[mutation]]s, recombinations and other genetic changes in the germline may be passed to offspring, but a change in a somatic cell will not be.<ref>C.Michael Hogan. 2010. [http://www.eoearth.org/article/Mutation?topic=49496 ''Mutation''. ed. E.Monosson and C.J.Cleveland. Encyclopedia of Earth. National Council for Science and the Environment. Washington DC]</ref> This need not apply to somatically reproducing organisms, such as some [[Sponge|Porifera]]<ref name= "Brusca">{{cite book |author1=Brusca, Richard C. |author2=Brusca, Gary J. | title = Invertebrates | publisher = Sinauer Associates | location = Sunderland | year = 1990 | isbn = 0878930981 }}</ref> and many plants. For example, many varieties of [[citrus]],<ref>Akira Wakana and Shunpei Uemoto. Adventive Embryogenesis in Citrus (Rutaceae). II. Postfertilization Development. American Journal of Botany Vol. 75, No. 7 (Jul., 1988), pp. 1033-1047 Published by: Botanical Society of America Article Stable URL: http://www.jstor.org/stable/2443771</ref> plants in the [[Rosaceae]] and some in the [[Asteraceae]], such as ''[[Taraxacum]]'' produce seeds apomictically when somatic [[diploid]] cells displace the ovule or early embryo.<ref name="Peter2009">{{cite book|author=K V Ed Peter|title=Basics Of Horticulture|url=http://books.google.com/books?id=NWMa741kG_gC&pg=PA9|date=5 February 2009|publisher=New India Publishing|isbn=978-81-89422-55-4|pages=9–}}</ref>
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