Sex Determination Model in Pink Salmon Oncorhynchus gorbuscha (Walbaum, 1792) (Salmonidae, Osteichthyes) Controlled by Multi-Copy Genes Located in Sex Chromosomes

Abstract

This article is devoted to presenting the hypothesis explaining the fact of a considerable prevalence of phenotypic males among the triploid pink salmon as well as the regular occurrence of intersexes, which were revealed by us. This hypothesis also explains the large proportion (in some cases) in pink salmon populations of the individuals whose genetic sex does not match the phenotypic sex. We assume that the genes encoding the factors that contribute to the transformation of individuals into males (but not the marker sequences of the Y chromosome) are present not only in the Y chromosome of pink salmon but also in the X chromosome, although in smaller quantities.