Partial cloning of DMRT1 mRNA in carp (Cyprinus carpio)

DMRT1 has been suggested to be the first conserved gene involved in sex differentiation found from invertebrates to human. DMRT1 genes have been characterised in several species of fish, but have not been isolated in carp (Cyprinus carpio). Carp has been widely studied as an indicator of pollution in watercourses throughout South-Europe, and so the isolation of the DMRT1 gene is a major goal in the development of this organism as a bioindicator of various forms of water pollution. In this study DMRT1 mRNA from carp (Cyprinus carpio) was cloned in order to obtain a useful diagnostic tool to better investigate endocrine disruption in the aquatic environment. The sequence of previously isolated DMRT1 gene in several teleosts was used to identify conserved sequence motifs, which were then used to design degenerate and specific PCR primers. These primers allowed the isolation of the DMRT1 gene from carp. The gene has high sequence identity to similar genes from other fish species, but has particular sequence that is unique to this species. The carp DMRT1 sequence has been utilized to localize the DMRT1 mRNA in different tissues of male and female. RT-PCR detection system is developing to monitor in carp the expression of the DMRT1 gene with high sensitivity in different tissues. Preliminary results confirmed an important expression in the testis but we also detected a slight expression in the ovary. No expression was detected for the following tissues: brain, liver, gills, kidney, spleen and muscle.