The Duplicated Y-specific Gene Is Conserved and Linked to Maleness in Silversides of the Genus .

Sex-determining genes have been successively isolated in several teleosts. In and , the gene has been identified as a master sex-determining gene. However, whether this gene is conserved along related species is still unknown. In this study, the presence of and its association with phenotypic sex was analyzed in 10 species of genus. The primer sets from that amplify both successfully generated fragments that correspond to and in all species. The full sequences of and isolated for four key species revealed higher identity values among presumptive , including the 0.5 Kbp insertion in the third intron and -specific insertions/deletions. was present in all specimens, regardless of species and sex, whereas was amplified in most but not all phenotypic males. Complete association between -homologue with maleness was found in and whereas . , , and showed varied degrees of phenotypic/genotypic sex mismatch. The conservation of gene in provide an interesting framework to study the evolution and the ecological interactions of genotypic and environmental sex determination in this group.