Molecular cloning and expression analysis of Dmrt4 gene in half- smooth tongue sole (Cynoglossus semilaevis)

A complete Dmrt4 DNA sequence was cloned from Cynoglossus semilaevis.The DNA sequence was 2 271 bp long,containing one intron and two exons.The NJ-phylogenetic tree indicated that the Dmrt4 gene of C.semilaevis had high homology to other fishes.Real-time PCR revealed that Dmrt4 was expressed in all seven tissues we examined in both sexes.Expression was significantly higher in the male pituitary than in other tissues.The expression of Dmrt4 in the gonads of methyl testosterone-treated males and neo-males was higher than in normal males.However,there was no significant difference between normal females and the high tempera-ture-treated neo-males.This indicates that Dmrt4 is not critical for sex reversal.Dmrt4 was expressed at signifi-cantly higher levels during the gastrula stage than during other stages.Dmrt4 was expressed at higher levels in males than in females.Our results provide a molecular basis for the formation of all female groups of C.semilaevis.