【作者】 黄宝欢；

【导师】 刘晓辉；

【作者基本信息】 中国农业科学院 ， 农药学， 2010， 硕士

【摘要】 褐家鼠(Rattus norvegicus)是广泛分布于世界各地的重要害鼠。目前,对该物种种群动态和繁殖特性的研究多集中于生理生态方面,而利用分子生物学方法对其野生种群繁殖特性的遗传机制研究则未见报道。本研究以哈尔滨(中温带,北纬44°-46°)和湛江(南亚热带,北纬20°-21°)自然条件下的成年雄性褐家鼠为研究对象,在两地全年逐月同步采集样本,运用荧光定量PCR方法分析雄鼠睾丸组织中减数分裂Stra8、Scp3、Dmc1基因各mRNA转录本的表达量,分析和比较两地雄鼠该3个基因年度内不同月份的表达量特征。此外,还分别对两地雄鼠进行室内反季节光周期处理,比较光照改变对高低纬度雄鼠减数分裂基因表达量的影响,初步探讨鼠类繁殖策略的进化与环境适应性的关系,具体结果如下:1.哈尔滨和湛江雄鼠的Stra8、Scp3和Dmc1基因在2008-2009年度内不同月份的表达特征呈现出一定的相似性:在夏季(6、7月)均为活跃期,在冬季(2月、11月)均为低谷期。此外,湛江雄鼠该3个基因的表达在春季(3月)又有一小活跃期,而哈尔滨雄鼠则没有。对同一月份里哈尔滨和湛江两个不同纬度地区雄鼠Stra8、Scp3、Dmc1基因表达量的比较结果发现,湛江雄鼠3个减数分裂基因表达水平总体高于哈尔滨雄鼠,两地雄鼠3个基因表达量主要在春季(3月)和冬季(11、12月)存在显著差异(P<0.05)。这些结果表明,高低纬度地区的雄性褐家鼠减数分裂基因的表达既有种内相似性,也表现出了对不同自然环境适应的差异性。2.哈尔滨和湛江野外雄鼠Stra8、Scp3和Dmc1基因表达量与繁殖器官指数之间相关性分析结果如下:(1)Stra8、Scp3和Dmc1基因两两之间均呈极显著的正相关(P<0.01),这表明该3个减数分裂基因之间的表达有密切联系;(2)哈尔滨雄鼠3个繁殖器官指数之间呈正相关(P<0.01),而湛江雄鼠的相关性不高;(3)3个减数分裂基因表达量与其繁殖器官指数之间总体上呈负相关,其具体原因有待进一步研究。3.反季节光照处理对哈尔滨和湛江雄鼠Stra8、Scp3和Dmc1基因表达影响的研究结果如下:(1)经过光照处理的两地雄鼠减数分裂基因表达与自然条件下(对照)的表达变化情况大体上一致,不过光照处理加重了趋势表现程度,而且哈尔滨雄鼠对光照反应敏感性强于湛江雄鼠;(2)不同光周期对哈尔滨雄鼠3个减数分裂基因的表达影响程度不一致,如短光照处理后基因表达呈上升的趋势,而长光照处理后呈下降的趋势;(3)同一光周期对不同纬度地区的雄性褐家鼠减数分裂基因表达的影响也不一致,如短光照处理后哈尔滨雄鼠基因表达呈上升的趋势,而湛江雄鼠则呈下降的趋势。这些结果表明,光周期对高低纬度地区雄鼠Stra8、Scp3和Dmc1基因的表达影响既有相同之处,又有不同的地方。更多还原

【Abstract】 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.更多还原