Metagenomic analysis of lacustrine viral diversity along a latitudinal transect of the Antarctic Peninsula

Abstract

Environmental viruses constitute the most abundant biological entities on earth, and harbor an enormous genetic diversity. While their strong influence on the ecosystem is widely acknowledged, current knowledge about their diversity and distribution remains limited. Here we present the metagenomic study of viral communities from freshwater bodies located along a transect of the Antarctic Peninsula. These ecosystems were chosen on the basis of environmental and biogeographical variation. The results obtained indicate that the virus assemblages were diverse, and that the larger fraction represented viruses with no close relatives in the databases. Comparisons to existing metaviromes showed that the communities studied were dissimilar to other freshwater viromes including those from the Arctic. Finally, we observed no indication of there being a reduction in either viral richness or diversity estimates with increasing latitude along the studied transect, further adding to the controversy regarding the possible existence of latitudinal gradients of diversity in the microbial world.

Keywords: Antarctic Peninsula; lacustrine environments; latitudinal gradient; metagenomics; ssDNA viruses; viruses.