Author(s)

Antonina V. Trukhina, Aleksandr F. Smirnov

Department of Genetics and Biotechnology, St. Petersburg State University, St. Petersburg, Russia.

Sex determination system in birds is characterized by a homo-(Neognatae) and heteromorphic (Paleognatae) sex chromosomes. Heterogametic sex is female (ZZ/ZW system). DMRT1 gene is a gene regarded as a main male sex determining factor in this group of animals. The question remains about the participation of other factors (HEMOGEN, AMH etc.) in appearance of testis, and the role of steroid hormones in formation of ovaries. Complete sex inversion is not typical for species with genotypic sex determination (GSD), although the effect of estrogen metabolites is noted for birds. For birds epigenetic mechanisms of regulation (methylation of DNA and non-coding RNA) have been described for sex controlling genes such as CYP19A1 and DMRT1.

Bird, Sex Determination, Epigenetics, Dosage Compensation

Trukhina, A. and Smirnov, A. (2014) Problems of Birds Sex Determination. Natural Science, 6, 1232-1240. doi: 10.4236/ns.2014.615111.