Molecular-Genetic Mechanisms of Sex Determination in Animals

Book excerpt: Gender (sex) is a set of morphological and physiological characteristics of the organism underlying sexual reproduction, the essence of which is reduced to fertilization, i.e. the fusion of male and female gametes (gametes) zygote, which develops into a new organism.Sexual reproduction of a species is considered as one of the mechanisms of its homeostasis. Thanks to this mechanism, numerous species have an evolutionary advantage. In the book, two authors will discuss the types of genetic sex determination and differentiation, mostly in multicellular animal organisms. Sex determination is both genetic and environmental process, the sex of an individual being established through an alternative physiological solution. There are two main postulated mechanisms of sex determination: genetic (GSD, Genetical Sex Determination) and environmental (ESD, Environmental Sex Determination).