深海に棲息する巨大ウイルスの生態

概要

令和4年度

京都大学化学研究所 スーパーコンピュータシステム 利用報告書
深海に棲息する巨大ウイルスの生態
Ecology of giant virus in deep ocean

The Ogata Lab Institute for Chemical Research Kyoto University Liu Wenwen
研究成果概要
Giant viruses (GVs) are large double-stranded DNA viruses that infect a variety of eukaryotic
microorganisms. According to the large-scale metagenomic data analyses, GVs are proved to be
broadly distributed at a high density and exhibit infectious activity in the ocean, potentially play
critical roles in the ecological and evolutionary dynamics of eukaryotic communities.
In the marine system, knowledge about GVs is so far mainly focused on the photic zone. The
investigations of GVs in the aphotic layer (at depths below 200 m) are limited because of the
lower organism density and the high difficulty to conduct a large volume of sampling for
extracting high-quality of DNA and RNA from eukaryotic microorganisms and viruses. So far
only few studies reported focusing on conserved marker genes with low phylogenetic
resolution.
In this research, by sampling at different layer in the East Indian Ocean, enough DNA were
extracted for sequencing. 18S v4 region were ampliconed and sequenced by next generation
sequencing. Eukaryotes community structures were figured out by using Qiime in
supercomputer, a pipeline for analyzing 18S barcoding sequencing results. The result showed
that community composition of eukaryotic microorganisms, which served as host of GV,
changed greatly between different ocean layers. That indicate GV communities may also
evolute a correspond strategy to adapt to such change of their host and a rush environment
condition in deep sea layer. Further research will focus on the genetic composition and
infectious activity of the GVs and probe the interactions between the GVs and eukaryotic
microbes in the aphotic layer. ...