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，从进化遗传学的角度来看，我们试图阐明生物多样性以来生物体从35亿年前开始就通过进化而获得的生物多样性。当前，可以提供许多来自各种物种的完整基因组序列，并且认为正在进行数百个基因组测序项目正在进行中。这是这些基因组为我们提供了一个机会来启动生物多样性分析项目。在第一学年，我们在人类等真核基因组中检测了重复的区域。为了提高检测的准确性，我们开发了一种新的统计方法，以找到重要的重复区域。因此，我们成功地确定了人类中的74个重复区域，酵母中的59个地区，蠕虫中的197个地区。我们为这些结果构建了一个数据库，以便任何人都可以使用图形用户界面通过Internet访问我们的数据。估计了复制事件的时代，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，该地区的大型DNA序列（〜400 kb）被新确定。结果，我们发现了较大的基因组复制，并重建了重复的进化过程。此外，在非编码区域发现了高核苷酸的多样性，这意味着在该地区可能发生了搭便车的影响。接下来，我们将研究扩展到微生物，并且可以揭示一般细菌基因组结构即使在被认为在功能上重要的单位的操纵子中也是非常不稳定的。此外，我们开发了一种新方法来检测GC含量变化的进化方向，从而导致基因组的多样性。