Triploid plover female provides support for a role of the W chromosome in avian sex determination

• Published in: Biology letters (2005) Vol. 8; no. 5; pp. 787 - 789
• Main Authors: Küpper, Clemens, Augustin, Jakob, Edwards, Scott, Székely, Tamás, Kosztolányi, András, Burke, Terry, Janes, Daniel E.
• Format: Journal Article
• Language: English
• Published: England The Royal Society 23.10.2012
• Subjects: Aneuploidy; Animals; Biological Sciences; Biologiska vetenskaper; Birds; Charadrius alexandrinus; chicken z-chromosome; Chromosome Aberrations; cross-species utility; dosage compensation; Evolutionary Biology; Female; Genetic Markers; Humans; kentish; Male; microsatellite loci; Microsatellite Repeats - genetics; Microsatellites; Ploidies; Polymorphism, Genetic; Sex Chromosomes; Sex Determination; Sex Determination Processes; zebra finch
• ISSN: 1744-9561; 1744-957X
• DOI: 10.1098/rsbl.2012.0329

Two models, Z Dosage and Dominant W, have been proposed to explain sex determination in birds, in which males are characterized by the presence of two Z chromosomes, and females are hemizygous with a Z and a W chromosome. According to the Z Dosage model, high dosage of a Z-linked gene triggers male development, whereas the Dominant W model postulates that a still unknown W-linked gene triggers female development. Using 33 polymorphic microsatellite markers, we describe a female triploid Kentish plover Charadrius alexandrinus identified by characteristic triallelic genotypes at 14 autosomal markers that produced viable diploid offspring. Chromatogram analysis showed that the sex chromosome composition of this female was ZZW. Together with two previously described ZZW female birds, our results suggest a prominent role for a female determining gene on the W chromosome. These results imply that avian sex determination is more dynamic and complex than currently envisioned.