Molecular population genetic study of the regulatory systems of the heat shock genes

热休克基因调控系统不仅为研究高等生物转录调控机制提供了一个有吸引力的模型，而且为研究转录调控系统的适应性进化提供了良好的材料。关于热休克基因在果蝇、酵母和人类中的转录调控机制，已经积累了许多分子知识。基于这些知识，我们计划研究热休克基因调控系统的适应性进化。我们计划以黑胃果蝇为材料进行以下实验：(1)热休克基因转录调控未知因子的调查；(2)转录因子HSF的分子克隆；(3)果蝇种内和种间遗传变异的分子群体遗传学。我们还研究了包括热休克基因在内的多基因家族分子进化的理论方面。结果表明：(1)利用P转座子建立了约4000株增强子诱捕菌株。研究了冷热休克处理下的突变株。我们获得了大约10个这样的序列并继续搜索。(2)从果蝇基因组文库中克隆了4个HSF基因克隆。我们现在正在分析这些克隆的分子结构。(3)对黑腹果蝇和其他亲缘种的HSF基因PCR产物进行了测序。我们得到了一些结果，但还没有完成。在理论研究方面，我们通过计算机模拟研究了不同种群规模下多基因多态性水平，包括突变效应、不均匀杂交效应、遗传漂变效应和自然选择效应。

The regulatory system of the heat shock genes are not only an attractive model for the study of the regulatory mechanism of transcription in higher organisms, but also an excellent material for studying the adaptive evolution of transcription regulation system. Many molecular knowledge have been accumulated on the regulatory mechanism of transcription of heat shock genes in Drosophila, yeast and humans.Based on these knowledge, we planed to study the adaptive evolution of the regulatory system in the heat shock genes. We planed the following experiments using Drosophila melanogaster as materials : (1) Survey of unknown factors which regulate the transcription of heat shock genes, (2) molecular cloning of the transcription factor, HSF and (3) molecular population genetics of genetic variation within and between the Drosophila species. We also studied the theoretical aspects of molecular evolution of maltigene families including heat shock genes. We obtained the following results : (1) We established about 4000 enhancer trap strains using P transposon. We surveyed mutant strains under the heat and cold shock treatment. We obtained about 10 such straing and continuing searching. (2) We cloned four HSF gene clones from Drosophila genomic library. We are now analyzing the molecular structure of these clones. (3) We sequenced PCR products of HSF for several populations of Drosophila melanogaster and other sibling species. We obtained some of the results but not completed. For the theoretical study, we did computer simulation and studied the polymorphic level of multigenes at various population sizes including the effects of mutations, unequal crossing overs, genetic drift and natural selection.