Elucidation of the machinery of biodiversity on the basis of evolutionary genetics

基于进化遗传学阐明生物多样性机制

基本信息

批准号：
10836024
负责人：
GOJOBORI Takashi
金额：
$ 2.18万
依托单位：
National Institute of Genetics
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

In this research project, from the viewpoint of evolutionary genetics we attempted to elucidate biodiversity that living organisms have acquired through evolution since the beginning of 3.5 billion years ago. Currently, a lot of complete genome sequences from a variety of species such as human are available, and hundreds of genome-sequencing projects are thought to be underway. Thus, these genomes gave us an opportunity to initiate the project of biodiversity analysis.In the first academic year we conducted detection of duplicated regions in eukaryotic genomes such as human. In order to improve the accuracy of the detection, we developed a new statistical method of finding significant duplicated regions. Consequently, we successfully identified 74 duplicated regions in human, 59 in yeast, and 197 in worm. We constructed a database for these results, so that anyone can access our data through Internet by using a graphical user interface. The times of duplication events were estimated so as to study what the duplication affect to evolution.In the second academic year, in order to analyze the MHC region of human in detail, a large DNA sequence (〜400 kb) in the region was newly determined. As a result, we found large genome duplication, and reconstructed the evolutionary process of the duplication. Moreover, high nucleotide diversity was found in non-coding regions, implying that hitchhiking effects might have occurred in the regions. Next, we extended our study to microbes, and could reveal that in general bacterial genome structures are quite unstable even in operons that are believed to be functionally important units. In addition, we developed a new method for the detection of evolutionary direction of GC-content change, which leads to high diversity of genomes.

在这个研究项目中，我们试图从进化遗传学的角度来阐明生物体自35亿年前开始进化以来所获得的生物多样性。目前，我们已经获得了来自多种物种（例如人类）的大量完整基因组序列。，并且数百个基因组测序项目正在进行中，因此，这些基因组给了我们启动生物多样性分析项目的机会。在第一学年，我们对人类等真核基因组中的重复区域进行了检测。改善为了提高检测的准确性，我们开发了一种新的统计方法来查找显着的重复区域，我们成功地识别出人类中的 74 个重复区域、酵母中的 59 个重复区域和蠕虫中的 197 个重复区域。通过使用图形用户界面通过互联网访问我们的数据，估计重复事件的次数，以研究重复对进化的影响。在第二学年，为了详细分析人类的MHC区域，进行了大量的研究。 DNA序列（~400 kb）的区域被重新确定，结果发现了大的基因组重复，并重建了重复的进化过程，而且在非编码区域发现了高核苷酸多样性，这意味着搭便车效应可能存在。接下来，我们将研究扩展到微生物，并且可以揭示，即使在被认为具有重要功能的操纵子中，细菌基因组结构通常也相当不稳定。此外，我们开发了一种检测细菌基因组的新方法。进化GC含量变化的方向，导致基因组的高度多样性。