Molecular cloning,characterization and RT-PCR expression analysis of Dmrt1α from half-smooth tongue-sole,Cynoglossus semilaevis

Many genes are known to be involved in gonadal differentiation in vertebrates. Doublesex and mab-3-related transcription factor 1(Dmrt1),a gene that encodes a transcription factor with a DM-domain,is considered to be one of the essential genes controlling testicular differentiation in mammals,birds,reptiles,amphibians and fish. Dmrt1 has been suggested to be the first conserved gene involved in sex differentiation found from invertebrates to human. Half-smooth tongue-sole (Cynoglossus semilaevis) is a newly exploited and commercially important cultured marine flatfish. Females grow 2-3 times faster than males. To clarify the mechanism of sex reversal and gain all-female tongue sole stock would be significantly beneficial for aquaculture. The full-length cDNA of the half-smooth tongue-sole Dmrt1α was isolated from testis of tongue sole by using homologous cloning method,which was 1 149 bp in length,including 45 bp of 5’ terminal UTR,777 bp encoding region and 327 bp of 3’ terminal UTR. The putative Dmrt1α amino acid of tongue sole shared 41.9%-58.1% sequence identity with other fish Dmrt1. However there was only 32.6% and 33.7% sequence identify with that of mouse and human. The RT-PCR analysis reveals that Dmrt1α mRNA was only expressed in the testis,but not in ovary, brain,liver,spleen,kidney,muscle,skin,heart,head kidney,gill,intestine,and eyes. However,it also expressed in the testis of sex-reversed male treatment by Methyltestosterone or high temperature. These results suggested that Dmrt1α may be involved in the male sex determination of tongue sole.