適応進化のメカニズムに関する分子集団遺伝学的研究

中性理论在分子进化中的发展确立了在进化过程中发生的大多数核苷酸替换是由中性突变的随机固定引起的。另一方面，我们可以看到生物在表型水平上的巨大多样性，其中许多已经用达尔文的适应性进化来解释。一些新出现的分子数据也与严格的中性突变理论相矛盾。本研究的思想是，适应是通过相对少量的变化，如基因复制，然后功能多样性，氨基酸交替取代，并在调节区的变化。我们成功地从DNA序列数据中发现了正选择和负选择的作用，并结合基于群体遗传学的理论分析，分子生物学的最新进展以非常高的速度积累了蛋白质的高级结构和基因相互作用等多样性的生物信息，也揭示了遗传网络的复杂性。为了在表型和分子水平上对复杂的进化有更深入的了解，需要在理论和实验上沿着沿着这条路线进一步推进群体遗传学。

The development of the neutral theory in molecular evolution established that the majority of nucleotide substitutions occurred during the course of evolution are caused by random fixation of neutral mutations. On the other hand, we can see tremendous amount of diversity of organisms at the phenotypic level, many of which has been explained in terms of Darwinian adaptive evolution. Some of newly emerging molecular data are contradictory to the strict neutral mutation theory as well. The present study was carried out with an idea that adaptation was achieved by a relatively small number of changes such as gene duplication followed by functional diversity, amino-acid-alternating substitutions, and changes in regulatory regions. We successfully detected the effects of positive and negative natural selection from DNA sequence data combined with theoretical analysis based on the population genetics.The recent advance of molecular biology has been accumulating diverse biological information such as high-order structure of proteins and gene interaction at very high rate, and also reveals the complication of genetic networks. Further advance of theoretical and experimental population genetics along this line will be needed to get a deep understanding of complicated evolution at the phenotypic and the molecular level.