报告题目：Genome Evolution of a Versatile Lineage – From Cultures to Single Cell Genomics
报 告 人：罗海伟 香港中文大学海洋微型生物学方向首席研究员
摘要：In the past decade molecular microbial ecology has provided major insights into the genomic diversity of marine bacterioplankton, but we know little about how such diversity evolved. Phylogenomics and population genetics reveal the evolutionary processes giving rise to genetic diversity, but they have rarely been integrated into microbial ecology. In this talk, I will discuss the use of these theories and approaches to understand the genetic diversity of the dominant and metabolically versatile marine Roseobacter clade. Phylogenomic analyses showed that the patch-adapted Roseobacters experienced a significant genome innovation through lateral gene transfer, and the timing coincided with the diversification of modern eukaryotic phytoplankton about 250 million years ago. Population genetic analyses suggest that evolutionary processes of an uncultivated Roseobacter lineage toward streamlined genomes and low G+C content are explained equally well by genetic drift as by the more frequently invoked explanation of natural selection. Thus, evolutionary analyses gave insights into microbial genetic diversity.