title: Single-cell genomics shedding light on marine Thaumarchaeota diversification.
abstract: Previous studies based on analysis of amoA, 16S ribosomal RNA or accA gene sequences have established that marine Thaumarchaeota fall into two phylogenetically distinct groups corresponding to shallow- and deep-water clades, but it is not clear how water depth interacts with other environmental factors, including light, temperature and location, to affect this pattern of diversification. Earlier studies focused on single-gene distributions were not able to link phylogenetic structure to other aspects of functional adaptation. Here, we analyzed the genome content of 46 uncultivated single Thaumarchaeota cells sampled from epi- and mesopelagic waters of subtropical, temperate and polar oceans. Phylogenomic analysis showed that populations diverged by depth, as expected, and that mesopelagic populations from different locations were well mixed. Functional analysis showed that some traits, including putative DNA photolyase and catalase genes that may be related to adaptive mechanisms to reduce light-induced damage, were found exclusively in members of the epipelagic clade. Our analysis of partial genomes has thus confirmed the depth differentiation of Thaumarchaeota populations observed previously, consistent with the distribution of putative mechanisms to reduce light-induced damage in shallow- and deep-water populations.
authors.affiliation: Department of Marine Sciences, University of Georgia, Athens, GA, USA. hluo2006@gmail.com.
authors.forename: Haiwei
authors.initials: H
authors.lastname: Luo
authors.affiliation: Department of Marine Sciences, University of Georgia, Athens, GA, USA.
authors.forename: Bradley B
authors.initials: BB
authors.lastname: Tolar
authors.affiliation: Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA.
authors.forename: Brandon K
authors.initials: BK
authors.lastname: Swan
authors.affiliation: Department of Marine Sciences, University of Georgia, Athens, GA, USA.|State Key Laboratory of Marine Geology, Tongji University, Shanghai, China.
authors.forename: Chuanlun L
authors.initials: CL
authors.lastname: Zhang
authors.affiliation: Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA.
authors.forename: Ramunas
authors.initials: R
authors.lastname: Stepanauskas
authors.affiliation: Department of Marine Sciences, University of Georgia, Athens, GA, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Ann Moran
authors.affiliation: Department of Marine Sciences, University of Georgia, Athens, GA, USA. aquadoc@uga.edu.
authors.forename: James T
authors.initials: JT
authors.lastname: Hollibaugh
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics*; D023281:Genomics / Q000379:methods*; D009792:Oceans and Seas; D010802:Phylogeny; D019642:RNA, Archaeal / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D059010:Single-Cell Analysis / Q000379:methods*
chemical_list: D019642:RNA, Archaeal; D012336:RNA, Ribosomal, 16S