A novel male-associated marker for sex identification in Ussuri catfish Pseudobagrus ussuriensis

Abstract

The Ussuri catfish Pseudobagrus ussuriensis is a promising aquaculture fish with sexual dimorphism that males grow 2–3 times faster than females. Therefore, all-male breeding could increase production of this fish, and sex-linked markers would be useful during the breeding process. In this study, a male-associated marker named PuGT54 was isolated in P. ussuriensis from a previously constructed microsatellite library. A total of 185 P. ussuriensis individuals containing 95 females and 90 males were used to test the usage of this maker. And results showed that sexes of all individuals were successfully identified, indicating the high reliability and accuracy of this marker for sex identification. Furthermore, the male-specific fragment amplified by this maker was cloned and sequenced, which was 118 base pairs in length. As homologous genes of this fragment was not found through BLASTn, detailed information of the male-specific fragment is unknown presently. Nevertheless, this marker would be helpful in conservation, breeding and ecological study of P. ussuriensis.