单性生殖

单性生殖，又称为孤雌生殖（Parthenogenesis），是雌性动物或植物的卵子，不经过受精过程，而单独发育成后代的生殖方式，屬於無性生殖，但仍與一般无性生殖稍有區別。

单性生殖一般发生在多种植物和无脊椎动物中，但也有一些脊椎动物如某些爬行动物（如钩盲蛇、红尾蚺、科摩多巨蜥、哀鳞趾虎、新墨西哥鞭尾蜥），在一些特殊的鸟类（加州神鷲）和鲨鱼物種（如窄头双髻鲨、条纹斑竹鲨、黑边鳍真鲨）中也会出现"Female Sharks Can Reproduce Alone, Researchers Find" , Washington Post, Wednesday, May 23, 2007; Page A02。如水蚤、蜜蜂、蒲公英和一些禾类中，这些现象为“天然单性生殖”，人为的刺激未受精卵发育，成为“人工单性生殖”，曾经实验过将蚕、青蛙、番茄等成功地进行单性生殖，可以完整地保留母体性状。雄性小火蟻是唯一不須與雌性基因結合，可以繁殖自身後代的雄性物種。北美甚至變異出可以向其他雄性提取片段基因或單條染色體用來豐富自己後代基因多樣性的孤雌生殖鈍口螈。

产雄孤雌生殖
单性生殖的后代如果全为雄性，称为“产雄单性生殖”或“产雄孤雌生殖”，例如蜜蜂产育雄蜂、秋季後的蚜虫繁殖，就是一种产雄单性生殖，科莫多龍亦然；如果后代全为雌性，称为“产雌单性生殖”或「产雌孤雄生殖」，例如夏季的蚜虫繁殖，新墨西哥鞭尾蜥的繁殖等。

 注释 

 参考文献 
 Dawley, Robert M. & Bogart, James P. (1989). Evolution and Ecology of Unisexual Vertebrates. Albany, New York: New York State Museum. ISBN 1-55557-179-4.
 Fangerau H. (2005). Can Artificial Parthenogenesis sidestep ethical pitfalls in human therapeutic cloning? A historical perspective, Journal of Medical Ethics 31, 733-735
 Futuyma, Douglas J. & Slatkin, Montgomery. (1983). Coevolution. Sunderland, Mass: Sinauer Associates. ISBN 0-87893-228-3.

 Maynard Smith, John. (1978). The Evolution of Sex. Cambridge: Cambridge University Press. ISBN 0-521-29302-2.
 Michod, Richard E. & Levin, Bruce R. (1988). The Evolution of Sex. Sunderland, Mass: Sinauer Associates. ISBN 0-87893-459-6.
 Phillip C. Watts, Kevin R. Buley, Stephanie Sanderson, Wayne Boardman, Claudio Ciofi and Richard Gibson. (2006). Parthenogenesis in Komodo dragons. Nature 444, 1021-1022
 Schlupp, I. (2005) The evolutionary ecology of gynogenesis. Annu. Rev. Ecol. Evol. Syst. 36: 399-417.
 Simon, Jean-Christophe, Rispe, Claude & Sunnucks, Paul. (2002). Ecology and evolution of sex in aphids. Trends in Ecology & Evolution, 17, 34-39.
 Stearns, Stephan C. (1988). The Evolution of Sex and Its Consequences (Experientia Supplementum, Vol. 55). Boston: Birkhauser. ISBN 0-8176-1807-4.

 外部链接 
 Parthenogenesis of Mice at Nature.com 
 Reproductive behavior in whiptails at Crews Laboratory 
 Types of asexual reproduction
 Parthenogenesis in Incubated Turkey Eggs  from Oregon State University
 National Geographic NEWS: Virgin Birth Expected at Christmas – By Komodo Dragon 
 BBC NEWS: 'Virgin births' for giant lizards (Komodo dragon)
 REUTERS: Komodo dragon proud mum (and dad) of five
 Female sharks capable of virgin birth 
 Marmorkrebs.org
 Scientists confirm shark's ‘virgin birth’ Article by Steve Szkotak AP updated 1:49 a.m. ET, Fri., Oct. 10, 2008 

Category:動物生殖