Japan Geoscience Union Meeting 2016

Presentation information

International Session (Poster)

Symbol B (Biogeosciences) » B-CG Complex & General

[B-CG04] Earth and Planetary Science Frontiers for Life and Global Environment

Sun. May 22, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Yohey Suzuki(Graduate School of Science, The University of Tokyo), Yoshinori Takano(Japan Agency for Marine-Earth Science and Technology (JAMSTEC)), Shingo Kato(Japan Agency for Marine-Earth Science and Technology), Katsunori Yanagawa(Graduate School of Social and Cultural Studies, Kyushu University), Tadashi Yokoyama(Department of Earth and Space Science, Graduate School of Science, Osaka University)

5:15 PM - 6:30 PM

[BCG04-P04] Effects of sedimentary redox conditions on Eukaryotic DNA recorded in deep-sea sediments

*Yasuhiko T. Yamaguchi1, Mariko Kouduka1, Toshitsugu Yamazaki2, Noriko Kawamura3, Koji Seike2, Yukihiro SAKURAMOTO2, Natsumi Okutsu2, Yohey Suzuki1 (1.Department of Earth and Planetary Science, The University of Tokyo, 2.Atmosphere and Ocean Research Institute, The University of Tokyo, 3.Japan Coast Guard Academy)

Keywords:Redox condition, Marine sediments, Biodiversity, DNA, Eukaryote

Eukaryotic DNA in marine sediments can be a useful indicator of both ancient marine ecosystem in water column and living microbial eukaryotes in sediments. However, the environmental factors that influence the composition and preservation of eukaryotic DNA in marine sediments are poorly characterized. In this study, we examined effects of sedimentary redox conditions on the diversity of eukaryotic communities recorded in deep-sea surface sediment samples from 8 sites of the Japan Sea (from oxygenated abyssal sediments to sulfidic sediments in methane seeps) using a combination of various geochemical and molecular-biological tools. Sedimentary redox conditions were characterized by depth profiles of pore water (oxygen, nitrate, iron, sulfide, etc.) and bulk sedimentary organic matter (TOC, TN, δ13C, δ15N). The concentration and diversity of 18S rDNA in the sediment samples were investigated by qPCR and pyrosequencing. Decreases in 18S rDNA concentration with sediment depth were rapid in the oxic sediments, while decreases were moderate in the anoxic sediments and the sulfidic sediments. The community composition based on 18S rDNA sequences also varied with the sedimentary redox conditions. These results suggest that redox conditions of surface sediments can be important factors controlling the composition and preservation of eukaryotic DNA in deep-sea sediments.