[B-BG02] [JJ] 地球惑星科学と微生物生態学の接点

[BBG02-P02] 南海トラフコア試料を対象とした基質誘導ベースのメタゲノム解析法による金属イオン応答遺伝子の網羅的探索

*森澤 高至¹、諸野 祐樹²、寺田 武志³、西川 聡美⁴、大下 紘貴¹、稲垣 史生²、芦内 誠⁴、若松 泰介⁴ (1.高知大学大学院総合人間自然科学研究科、2.国立研究開発法人海洋研究開発機構、3.マリン・ワーク・ジャパン、4.高知大学農学部)

キーワード：海底下堆積物、遺伝子機能、南海トラフ、メタゲノム、SIGEX、金属イオン

There are still large room for discovery in gene function and its potential of life in natural environment especially for the least-explored environments such as the subseafloor biosphere. We have employed substrate-induced gene expression (SIGEX) approach to screen DNA fragment that induce gene expression as a response to presence of substrates such as metal ions, D-amino acids, and persistent chemicals from metagenomic shotgun libraries prepared with subseafloor sediment samples of Nankai Trough.
Constructed metagenomics shotgun libraries that confers gfp gene downstream of the inserted DNA fragment were induced by metal ions including Ni²⁺, Co²⁺, Mg²⁺, Mn²⁺, Mo⁶⁺, and Ga³⁺, followed by sorting of clones with green fluorescence by a cell sorter. From sorted clones, we secondary screened clones for its response to the induction of each metal ion. Clones isolated by using Ni²⁺, Ga³⁺ showed specific response to each metal ion used for isolation. Also there were other type of clones that showed response to induction by multiple metal ions. DNA sequence analysis revealed that while around half of the clones had database-identifiable DNA fragment, other half did not show any match to DNA sequences in database. This study showed great potential of SIGEX-based approach to find function of DNA fragments from large pool on unknown environmental DNA of natural environment.