Editing Sex-determination system (section)

=== Polygenic sex determination ===
Polygenic sex determination is when the sex is primarily determined by genes that occur on multiple non-[[homologous chromosome]]s. The environment may have a limited, minor influence on sex determination. Examples include African cichlid fish (''[[Maylandia|Metriaclima]] spp.''), lemmings (''[[Wood lemming|Myopus schisticolor]]''), [[swordtail fish|green swordtail]],<ref name="Schartl-2004a" /> [[Japanese rice fish|medaka]],<ref name="Schartl-2004a" /> etc. In such systems, there is typically a dominance hierarchy, where one system is dominant over another if in conflict. For example, in some species of cichlid fish from Lake Malawi, if an individual has both the XY locus (on one chromosome pair) and the WZ locus (on another chromosome pair), then the W is dominant and the individual has a female phenotype.<ref>{{Cite journal |last1=Moore |first1=Emily C. |last2=Roberts |first2=Reade B. |date=June 2013 |title=Polygenic sex determination |url=https://linkinghub.elsevier.com/retrieve/pii/S0960982213004120 |journal=Current Biology |volume=23 |issue=12 |pages=R510–R512 |doi=10.1016/j.cub.2013.04.004|pmid=23787041 |bibcode=2013CBio...23.R510M }}</ref>

The sex-determination system of [[zebrafish]] is polygenic. Juvenile zebrafishes (0–30 days after hatching) have both ovary-like tissue to testis tissue. They then develop into male or female adults, with the determination based on a complex interaction genes on multiple chromosomes, but not affected by environmental variations.<ref>{{Cite journal |last1=Liew |first1=Woei Chang |last2=Bartfai |first2=Richard |last3=Lim |first3=Zijie |last4=Sreenivasan |first4=Rajini |last5=Siegfried |first5=Kellee R. |last6=Orban |first6=Laszlo |date=2012-04-10 |editor-last=Alsina |editor-first=Berta |title=Polygenic Sex Determination System in Zebrafish |journal=PLOS ONE |volume=7 |issue=4 |pages=e34397 |doi=10.1371/journal.pone.0034397 |doi-access=free |issn=1932-6203 |pmc=3323597 |pmid=22506019|bibcode=2012PLoSO...734397L }}</ref><ref>{{Cite journal |last1=Liew |first1=Woei Chang |last2=Orbán |first2=László |date=March 2014 |title=Zebrafish sex: a complicated affair |journal=Briefings in Functional Genomics |volume=13 |issue=2 |pages=172–187 |doi=10.1093/bfgp/elt041 |issn=2041-2649 |pmc=3954038 |pmid=24148942}}</ref>