莲草直胸跳甲两地理种群响应热胁迫的生殖差异及分子调控机理

Insects can generate adaptive evolution under environmental stresses is one of important ways in which they cope with climate changes. However, temperature stress is often the most direct impetus to adaptive evolution of insects. Our previous study found that the fecundity of Hainan-Wanning population was significantly higher than that of Hunan-Changsha population in Agasicles hygrophila at high temperature stresses. Therefore, we speculate that differences in the fecundities were observed between the two geographic populations of A. hygrophila because one or a few of the key genes related to reproduction play an important regulation role in the process of reproduction. In view of this, based on the results of our previous studies, Hunan-Changsha and Hainan-Wanning populations of A. hygrophila were treated as research materials. Firstly, we compare differences in the fecundities between the two geographic populations of the beetle after three their generations experienced continuously high temperature stresses. Secondly, female ovary transcriptome sequences of the two geographic populations at normal and high temperatures will be determined by using high-throughput HiSeq sequencing technology, and the differentially expressed genes associated with reproduction are found based on a comparison method. Finally, the function of the key differentially expressed genes will be further validated. We will definitude the differential expression pattern of heat-dependent reproductive response genes in the two geographic populations of the beetle, and the regulation mechanisms of the key genes on reproduction of the beetle. The results of this study resolve not only the molecular mechanisms of heat-dependent reproductive response of A. hygrophila, but also provide a novel idea for obtaining heat-resistant population of the beetle based on gene regulation pathway.

昆虫应对气候变化的一种重要方式就是在环境胁迫下产生适应性进化，而温度胁迫常成为昆虫适应性进化的最为直接的动力。前期研究发现，在高温胁迫下莲草直胸跳甲海南万宁种群的繁殖力显著高于湖南长沙种群，由此我们推测：“高温胁迫下两个地理种群生殖存在差异必然是由于某个或某些生殖相关的关键基因起到了调控作用”。鉴于此，本项目在前期研究基础上，以莲草直胸跳甲湖南长沙种群和海南种群为研究材料，首先比较高温连续胁迫3代后两地理种群繁殖力的差异；其次，利用HiSeq高通量测序技术，对常温和高温下两地理种群雌虫卵巢转录组进行测序，并通过比较找到与生殖相关的差异表达基因；最后，利用RNA干扰技术对差异表达关键基因进行功能验证；以明确该叶甲的热生殖响应基因在两个地理种群中的差异表达模式及关键基因对生殖的调控机理。这一研究结果不仅解析了莲草直胸跳甲热生殖响应的分子机制，且为通过基因调控途径获得耐热种群提供新的思路。

昆虫应对气候变化的一种重要方式就是在环境胁迫下产生适应性进化，而温度胁迫常成为昆虫适应性进化的最为直接的动力。前期研究发现，在高温胁迫下莲草直胸跳甲海南万宁种群的繁殖力显著高于湖南长沙种群，由此我们推测：“高温胁迫下两个地理种群生殖存在差异必然是由于某个或某些生殖相关的关键基因起到了调控作用”。鉴于此，本项目在前期研究基础上，以莲草直胸跳甲湖南长沙种群和海南种群为研究材料，首先比较高温连续胁迫3代后两地理种群繁殖力的差异；其次，利用HiSeq高通量测序技术，对常温和高温下两地理种群雌虫卵巢转录组进行测序，并通过比较找到与生殖相关的差异表达基因；最后，利用RNA干扰技术对差异表达关键基因进行功能验证；以明确该叶甲的热生殖响应基因在两个地理种群中的差异表达模式及关键基因对生殖的调控机理。这一研究结果不仅解析了莲草直胸跳甲热生殖响应的分子机制，且为通过基因调控途径获得耐热种群提供新的思路。