Meiotic behaviour during pachytene and diakinesis of Isognomon alatus (Molusca-Isognomonidae) from Veracruz, Mexico

Abstract

Previous studies on the mitotic chromosomes of three populations of Isognomon alatus from different localities along the Gulf of Mexico revealed chromosome polymorphism and differences in the diploid number. In this study, an analysis of the meiotic behaviour of I. alatus from Veracruz, Mexico, has been carried out in order to obtain complementary information to the knowledge of the cytogenetics of this species. Our results indicate complementary homologous chromosomes during pachytene and 14 symmetric chiasmated bivalents during diakinesis. No sexual chromosomes were identified. There was no evidence of chromosome polymorphism nor intrapopulation alterations of the diploid number.