Gynogenesis

from Wikipedia, the free encyclopedia

The gynogenesis is a form of asexual reproduction , wherein the incubation period ( oogenesis ) as a result of a triggering stimulus contact the oocyte with sperm without fertilization is started, so that the paternal genetic information will not be recorded. Gynogenesis occurs more when the male and female germ cells belong to closely related species , mainly in species that do not require copulation , but fertilize themselves as free spawners in the water. Here one will clone the egg produced whose chromosomes haploid or diploid or polyploid , or can accept mixed forms thereof.

The counterpart , asexual reproduction based on a sperm, is called androgenesis . In botany this process is called pseudogamy .

Examples

The Amazon Parrot reproduces by means of gynogenesis. The all-female population uses the sperm of conspecifics (above all of the parent species P. mexicana and P. latipinna ) to reproduce. One also speaks of sexual parasitism. In the wolffish , only “hybrid females” are capable of gynogenesis, who “can do without the male genome when cloning, but need brief contact with sperm for egg maturation without merging.”

Use by humans

In aquaculture , use is made of being able to breed related fish with roe using sperm . Efforts are made to influence the degree of ploidy and the sex of the organisms that are formed through the choice of environmental conditions, such as pressure or UV light .

literature

  • KP Lampert, M. Schartl: The origin and evolution of a unisexual hybrid: Poecilia formosa. Philos Trans R Soc Lond B Biol Sci. 2008 Sep 12; 363 (1505): 2901-9. doi : 10.1098 / rstb.2008.0040

Web links

Individual evidence

  1. ↑ a b c d P. E. Ihssen et al .: Ploidy manipulation and gynogenesis in fishes: cytogenetic and fisheries applications. Transactions of the American Fisheries Society, Vol. 119, No. 4, 1990, pp. 698-717, doi : 10.1577 / 1548-8659 (1990) 119 <0698: PMAGIF> 2.3.CO; 2 .
  2. ↑ Pandian, TJ, R. Koteeswaran: Ploidy induction and sex control in fish. Hydrobiologia, Vol. 384, No. 1-3, 1998, pp. 167-243, doi : 10.1023 / A: 1003332526659
  3. ↑ http://www.morgenpost.de/printarchiv/wissen/article259135/Steinbeisser-klonen-sich-selbst.html
  4. ↑ Morgan, Andrew J., et al .: Effective UV dose and pressure shock for induction of meiotic gynogenesis in southern flounder (Paralichthys lethostigma) using black sea bass (Centropristis striata) sperm. Aquaculture Volume 259, No. 1, 2006, pp. 290-299 doi : 10.1016 / j.aquaculture.2006.05.045 .