Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Germline
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
{{short description|Population of cells of a multicellular organism that pass on their genetic material to the progeny}} [[File:Watsonia meriana detail of cormlets on inflorescence IMG 6909.JPG|thumb|Cormlets of ''[[Watsonia meriana]]'', an example of [[apomixis]]]] [[File:Clathria_tuberosa_(Sponge).jpg|thumb|''[[Clathria]] tuberosa'', an example of a sponge that can grow indefinitely from somatic tissue and reconstitute itself from [[Cell potency#Totipotency|totipotent]] separated somatic cells]] In [[biology]] and [[genetics]], the '''germline''' is the population of a [[multicellular organism]]'s cells that develop into [[germ cell]]s. In other words, they are the cells that form [[gamete]]s ([[Egg cell|eggs]] and [[sperm]]), which can come together to form a [[zygote]]. They differentiate in the [[gonad]]s from [[Germ cell|primordial germ cells]] into [[Gametogonium|gametogonia]], which develop into [[gametocyte]]s, which develop into the final gametes.<ref>{{Cite journal |last1=Yao |first1=Chunmeng |last2=Yao |first2=Ruqiang |last3=Luo |first3=Haining |last4=Shuai |first4=Ling |date=2022 |title=Germline specification from pluripotent stem cells |journal=Stem Cell Research & Therapy |volume=13 |issue=1 |pages=74 |doi=10.1186/s13287-022-02750-1 |doi-access=free |pmc=8862564 |pmid=35189957}}</ref> This process is known as [[Gametogenesis#Stages|gametogenesis]]. Germ cells pass on genetic material through the process of sexual reproduction. This includes [[Fertilisation|fertilization]], [[Genetic recombination|recombination]] and [[meiosis]]. These processes help to increase genetic diversity in offspring.<ref>{{Cite journal |last1=Zickler |first1=Denise |last2=Kleckner |first2=Nancy |date=2015 |title=Recombination, Pairing, and Synapsis of Homologs during Meiosis |url=https://cshperspectives.cshlp.org/content/7/6/a016626 |journal=Cold Spring Harbor Perspectives in Biology |language=en |volume=7 |issue=6 |pages=a016626 |doi=10.1101/cshperspect.a016626 |pmc=4448610 |pmid=25986558}}</ref> Certain organisms reproduce asexually via processes such as [[apomixis]], [[parthenogenesis]], [[autogamy]], and [[cloning]].<ref>{{Cite book |title=Fertilization in protozoa and metazoan animals: cellular and molecular aspects |date=2000 |publisher=Springer |isbn=978-3-540-67093-3 |editor-last=Tarín |editor-first=Juan J. |location=Berlin Heidelberg |editor-last2=Cano |editor-first2=Antonio}}</ref><ref>Lowe, Andrew; Harris, Stephen; Ashton, Paul (1 April 2000). ''Ecological Genetics: Design, Analysis, and Application''. John Wiley & Sons. {{ISBN|978-1-444-31121-1}}.</ref> Apomixis and Parthenogenesis both refer to the development of an embryo without fertilization. The former typically occurs in plants seeds, while the latter tends to be seen in nematodes, as well as certain species of reptiles, birds, and fish.<ref>{{Cite journal |last1=Niccolò |first1=Terzaroli |last2=Anderson |first2=Aaron W. |last3=Emidio |first3=Albertini |date=2023 |title=Apomixis: oh, what a tangled web we have! |journal=Planta |language=en |volume=257 |issue=5 |pages=92 |doi=10.1007/s00425-023-04124-0 |pmc=10066125 |pmid=37000270|bibcode=2023Plant.257...92N }}</ref><ref>{{Cite journal |last1=Dudgeon |first1=Christine L. |last2=Coulton |first2=Laura |last3=Bone |first3=Ren |last4=Ovenden |first4=Jennifer R. |last5=Thomas |first5=Severine |date=2017 |title=Switch from sexual to parthenogenetic reproduction in a zebra shark |journal=Scientific Reports |language=en |volume=7 |issue=1 |pages=40537 |doi=10.1038/srep40537 |pmc=5238396 |pmid=28091617|bibcode=2017NatSR...740537D }}</ref> Autogamy is a term used to describe self pollination in plants.<ref>{{Cite journal |last=Eckert |first=Christopher G. |date=February 2000 |title=Contributions of Autogamy and Geitonogamy to Self-Fertilization in a Mass-Flowering, Clonal Plant |url=http://doi.wiley.com/10.1890/0012-9658(2000)081[0532:COAAGT]2.0.CO;2 |journal=Ecology |language= |publisher=Ecological Society of America |volume=81 |issue=2 |pages=532–542 |doi=10.1890/0012-9658(2000)081[0532:COAAGT]2.0.CO;2 |issn=0012-9658 |via=John Wiley and Sons|url-access=subscription }}</ref> Cloning is a technique used to creation of genetically identical cells or organisms.<ref>{{Cite journal |last1=Bonetti |first1=G. |last2=Donato |first2=K. |last3=Medori |first3=M. C. |last4=Dhuli |first4=K. |last5=Henehan |first5=G. |last6=Brown |first6=R. |last7=Sieving |first7=P. |last8=Sykora |first8=P. |last9=Marks |first9=R. |last10=Falsini |first10=B. |last11=Capodicasa |first11=N. |last12=Miertus |first12=S. |last13=Lorusso |first13=L. |last14=Dondossola |first14=D. |last15=Tartaglia |first15=G. M. |date=2023 |title=Human Cloning: Biology, Ethics, and Social Implications |url=https://clinicaterapeutica.it/ojs/index.php/1/article/view/806/581 |journal=La Clinica Terapeutica |language=it |volume=174 |issue=6 |doi=10.7417/ct.2023.2492}}</ref> In sexually reproducing organisms, cells that are not in the germline are called [[somatic cell]]s. According to this definition, [[mutation]]s, recombinations and other genetic changes in the germline may be passed to offspring, but changes 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] {{webarchive |url=https://web.archive.org/web/20110430051516/http://www.eoearth.org/article/Mutation?topic=49496 |date=April 30, 2011 }}</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 |url=https://archive.org/details/invertebrates0000brus |url-access=registration | publisher = Sinauer Associates | location = Sunderland | year = 1990 | isbn = 978-0878930982 }}</ref> and many plants. For example, many varieties of [[citrus]],<ref>{{Cite journal |last=Wakana |first=Akira |last2=Uemoto |first2=Shunpei |date=1988 |title=Adventive Embryogenesis in Citrus (Rutaceae). II. Postfertilization Development |url=https://www.jstor.org/stable/2443771 |journal=American Journal of Botany |volume=75 |issue=7 |pages=1033–1047 |doi=10.2307/2443771 |issn=0002-9122|url-access=subscription }}</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=https://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> In an earlier stage of genetic thinking, there was a clear distinction between germline and somatic cells. For example, [[August Weismann]] proposed and pointed out, a germline cell is immortal in the sense that it is part of a lineage that has reproduced indefinitely since the beginning of life and, barring accident, could continue doing so indefinitely.<ref name="Weismann1892">{{cite book|author=August Weismann|title=Essays upon heredity and kindred biological problems|url=https://archive.org/details/essaysuponhered02weisgoog|year=1892|publisher=Clarendon press}}</ref> However, it is now known in some detail that this distinction between somatic and germ cells is partly artificial and depends on particular circumstances and internal cellular mechanisms such as [[telomeres]] and controls such as the selective application of [[telomerase]] in germ cells, [[stem cells]] and the like.<ref>Watt, F. M. and B. L. M. Hogan. 2000 Out of Eden: Stem Cells and Their Niches ''Science 287:1427-1430''.</ref> Not all multicellular organisms [[Cellular differentiation|differentiate]] into somatic and germ lines,<ref name=":0">{{Cite journal|last1=Radzvilavicius|first1=Arunas L.|last2=Hadjivasiliou|first2=Zena|last3=Pomiankowski|first3=Andrew|last4=Lane|first4=Nick|date=2016-12-20|title=Selection for Mitochondrial Quality Drives Evolution of the Germline|journal=PLOS Biology|volume=14|issue=12|pages=e2000410|doi=10.1371/journal.pbio.2000410|issn=1545-7885|pmc=5172535|pmid=27997535 |doi-access=free }}</ref> but in the absence of specialised technical human intervention practically all but the simplest multicellular structures do so. In such organisms somatic cells tend to be practically [[Cell potency#Totipotency|totipotent]], and for over a century sponge cells have been known to reassemble into new sponges after having been separated by forcing them through a sieve.<ref name= "Brusca"/> ''Germline'' can refer to a lineage of cells spanning many generations of individuals—for example, the germline that links any living individual to the hypothetical [[last universal common ancestor]], from which all plants and animals [[common descent|descend]].
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)