Evolution, Expression, and Function of Gonadal Somatic Cell-Derived Factor

Fish gonads develop in very diverse ways different from mammalian gonads. This diversity is contributed by species-specific factors. Gonadal somatic cell-derived factor (Gsdf) is one such factor. The gsdf gene exists mostly in teleosts and is absent in many tetrapods, probably as a result of two gene losses during evolution. The gsdf transcript is expressed mainly in gonadal somatic cells, including Sertoli cell in testis and granulosa cells in ovary; however, these gonadal somatic cells can surround many types of germ cells at different developmental stages depending on the fish species. The function of gsdf is also variable. It is involved in germ cell proliferation, testicular formation, ovarian development and even male sex determination. Here, we summarize the common and diverse expression, regulation and functions of gsdf among different fish species with aspect of evolution.

Automated summary

Fish gonads develop differently from mammalian gonads, mainly due to species-specific factors such as the presence of the gsdf gene in teleosts but its absence in many tetrapods. The gsdf transcript is primarily expressed in gonadal somatic cells, with variable functions related to germ cell proliferation, testicular formation, ovarian development, and sex determination in different fish species. The common and diverse expression, regulation, and functions of gsdf among different fish species are summarized with respect to evolution.