Microbial and viral-like rhodopsins present in coastal marine sediments from four polar and subpolar regions.

• Rhodopsins are broadly distributed. In this work we analyzed 23 metagenomes corresponding to marine sediment samples from four regions which share cold climate conditions (Norway; Sweden; Argentina and Antarctica). In order to investigate the genes evolution of viral-rodopsins, an initial set of 6224 bacterial rhodopsins sequences according COG5524 were retrieved from the 23 metagenomes. After selection by the presence of transmembrane domains and alignment 123 viral (51) and non-viral (72) sequences (>50 aminoacids) were finally included in further analysis. Viral rhodopsin genes were homologues of Phaeocystis globosa virus and Organic lake Phycodnavirus Non-viral microbial rhodopsin genes were ascribed to Bacteroidetes, Planctomycetes, Firmicutes, Actinobacteria, Cyanobacteria, Proteobacteria, Deinococcus-Thermus as well as Cryptophyta and Fungi. A re-screening using Blastp, using as queries the viral sequences previously described, retrieved 30 sequences (>100 aminoacids). Phylogeographic analysis revealed a geographycal clustering of the sequences affiliated to the viral group. This clustering was not observed for the microbial non-viral sequences. The phylogenetic reconstruction allowed us to propose the existence of a putative ancestor of viral rhodopsins (PAVR) genes related to Actinobacteria and Chloroflexi This is the first report about the existence of a phylogeographic association of the viral rhodopsins sequences from marine sediments.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

polar/subpolar

marine sediment

metagenomes

microbial rhodopsin

viral rhodopsin

phylogeography

Environmental Studies

Miljövetenskapliga studier

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)