Analysis Of Stra8, Scp3 And Dmc1 Gene Expressions In Male Rattus Norvegicus From Harbin And Zhanjiang

Norway rat (Rattus norvegicus) is a major pest in the world. The dynamics and reproductive characteristics of this species population were studied mainly in physiology and ecology, but these researches about molecular biological method have not been reported. In this study, R. norvegicus samples were collected simultaneously month by month in the filed of Harbin (in temperate regions, 44°-46°N) and Zhanjiang (in South Asian tropics, 20°-21°N). Tnen three meiotic genes, Stra8, Scp3, Dmc1 gene expressions of adult male rats were analyzed by Real-time fluorescent quantitative PCR (FQ-PCR), comparing with monthly changes and latitude differences between Harbin and Zhanjiang. In addition, wild male rats from Harbin and Zhanjiang were held in short-photoperiod and long-photoperiod, respectively, to analyze the influences of different photoperiods on the three meiotic gene expressions. The main results were as follows:1. Stra8, Scp3 and Dmc1 gene expressions of wild male rats from Harbin and Zhanjiang in 2008 and 2009 years were active and high in June or July, and low in February or November. Furthermore, theses gene expressions of the rats from Zhanjiang were also active in March, while these were not found in the rats from Harbin. The expression levels of the three genes of rats from Zhanjiang were higher than those from Harbin. The differences of the gene expressions of rats were mainly in spring and winter between Harbin and Zhanjiang. These relults indicated that R. norvegicus adopted different reproductive strategies, and adapted to different natural environment.2. The correspondence analyses of three meiotic genes expressions and gonad indexes of male R. norvegicus from Harbin and Zhanjiang were performed, respectively. A significant positive correlation was found between each other meiotic gene expressions (P<0.01), which showed these genes were closely associated with each other. And a significant positive correlation (P<0.01) was among testis index, epididymis index and seminal vesicle index of R. norvegicus form Harbin, but it was not of those from Zhanjiang. At the same time, it was a negative correlation between gene expressions and gonad indexes, and further studies were necessary.3. The results of three meiotic genes expressions of adult male rats from Harbin and Zhanjiang held in short-photoperiod and long-photoperiod, showed the trends of genes expression were similar with the rats in the natural environment (control), and male rats from Harbin were more evident than those from Zhanjiang in the response to photoperiod changes. Three meiotic gene expressions of male rats from Harbin held in different photoperiods were not identical, which was an upward trend in short-photoperiod and a downward trend in long-photoperiod. In addition, three meiotic gene expressions of male rats from Harbin and Zhanjiang were also different in the same short-photoperiod. It showed an upward trend for rats from Harbin, however a downward trend for rats from Zhanjiang in short-photoperiod. All of these indicated that Stra8, Scp3 and Dmc1 gene expressions of male R. norvegicus from Harbin and Zhanjiang were both the same and different in different photoperiods.