Why Sequence Antarctic Marine Bacterioplankton?

Cold ocean regions are the norm on this planet, with 79% of the world’s ocean volume below 5 °C and some expansive regions, such as the Southern and Arctic Oceans, remaining constantly below freezing. In addition to the water column, sea ice forms over the Southern Ocean annually, doubling the size of the Antarctic continent (to more than 20 million km²), and covers a large portion of the Arctic ocean. The biomass in these waters and sea ice environments is dominated by a diverse community of eukaryotes, bacteria, and archaea. These organisms have combated the challenges to survival in these systems largely by modifications coded for in their genomes. The changes required are slight in terms of gene content, but they are significant in terms of gene modification.

The goal of this CSP project is to generate genome sequence data for Antarctic marine bacterioplankton assemblages (bacteria and archaea) from late winter and summer waters. The results will benefit three critical areas of study in Antarctic marine microbial ecology. First, they will aid studies of the phylogenetic and genomic diversity of Antarctic bacterioplankton. Second, they will address questions of endemicity in Antarctic marine bacterioplankton populations. Third, they will reveal the structural adaptations of microbial genomes to permanently cold environments. This project will contribute substantially to the field of marine microbial diversity and evolution in polar environments. The sequence information will make a significant contribution to a new international Antarctic Census of Marine Life program that aims to characterize diversity in the Antarctic marine environment at all biological levels over the next five years. The genes identified will also be used to design gene expression detection systems to better understand Antarctic bacterioplankton community structure, cellular function, and survival in subzero waters.

CSP project participants: Allison Murray (proposer) and Joseph Grzymski (Desert Research Inst.), Edward DeLong (MIT), and Hugh Ducklow (College of William & Mary).