Análisis genético, evolutivo y funcional del sistema de cromosomas sexuales de Xenopus Tropicalis, única especie diploide del género

Abstract

In this study, the sexual chromosome system (Y>W>Z) of X. tropicalis has been investigated in the gonadal differentiation of hybrids between X. laevis and X. tropicalis species (species with different sexual chromosome systems and sex-determining genes), as well as the effect of different combinations of sexual chromosomes on sex reversal after exposure to hormonal compounds. The results show that the dm-w gene of X. laevis is dominant in the presence of X. tropicalis Z and Y chromosomes. Furthermore, the hybrids lack germ cells and are sterile. On the other hand, the constitution of sexual chromosomes influences the sensitivity to treatment and gonadal sex reversal. Finally, phenomena of polyploidization in X. tropicalis were investigated, where the production of unreduced gametes resulting in triploid individuals was observed. Fertility and offspring of triploid individuals were analyzed, identifying different types of progeny and subtle differences in the segregation of sexual chromosomes.