The Seasonal Patterns Of Genes Expression Related To Photoperiodism And Reproduction In Male Brandt’s Voles

Brandt’s vole (Lasiopodomys brandtii) is a major pest rodent species in grassland of InnerMongolia, China. Our previous studies showed that the weight of male gonadal organs and hormonelevels gradually increased from the spring (April), reached the peak near the summer solstice, thandecreased and reached its lowest level at autumn (end of August to mid-September). Meanwhile, thethree key genes, Stra8, Scp3and Dmc1which control meiosis in testis, also showed a similar trend ofexpression. It indicated that the summer solstice might be key point for reproductive controlling inBrandt’s voles. We selected Dio2, Dio3, GnRH, RFRP-3and Kiss-1as candidate genes to study controlmechanism of seasonal reproduction in Brandt’s voles. The main results as follow:1. We Cloned three gene fragments and two full-length genes of male Brandt’s vole: The length ofthe partial cDNAs of Dio2, Dio3, GnRH, RFRP-3, and Kiss-1are494bp,408bp,148bp,262bp,494bpand obtain the full-length of GnRH, RFRP-3by3’-RACE and5’-RACE.2. The expression tendency of Dio2in males of all ages is consistent, and showed a short-term highexpression around the summer solstice. Dio3expressed extremely low in the hypothalamus, and Dio2may be more important in the main Dio2/Dio3regulatory system. The expression pattern of Dio2and itsrelationship with photoperiod and periodical variation of reproductive characters indicates the Dio2might play important function in regulation of reproduction in Brandt’s voles.3. The expression patterns of Dio2, Dio3, GnRH, RFRP-3, and Kiss-1and their mutual correlationindicated that Dio2/Dio3regulatory system might trigger a process leading to gradually suppression ofreproductive activity around the summer solstice.