Meiotic gynogenesis revealed not homogametic female sex determination system in Siberian sturgeon (Acipenser baeri Brandt)

Meiotic gynogenesis was induced in a Siberian sturgeon (Acipenser baeri Brandt) by heat shock after egg activation with UV-irradiated sperm of a hybrid Siberian sturgeon × Russian sturgeon (Acipenser gueldenstaedti Brandt). Microsatellite DNA analysis was applied for verification of unipaternal inheritance in the gynogenetic diploid group of fish. All the analyzed gynogenetic diploids possessed only maternal genotype in the examined experimental group of fish. Histological analysis of gonads of 50 gynogenetic diploids, obtained from one family, showed 81% of females and 19% of males. The observed sex ratio suggested that the Siberian sturgeon does not have a female homogametic sex determination system.