McMurdo Dry Valleys LTER. aquatic metagenome

High latitude environments, such as the Antarctic McMurdo Dry Valley lakes, are subject to seasonally segregated light/dark cycles, which have important consequences for microbial diversity and function on an annual basis. Due largely to the logistical difficulties of sampling polar environments during the darkness of winter, little is known about planktonic microbial community responses to the cessation of photosynthetic primary production during the austral sunset, which lingers from approximately February until April. The MIRADA datasets allow us to hypothesize that changes in bacterial, archaeal, and eukaryotic community structure shift in favor of chemoautotrophs and mixotrophs during the transition to polar night. This work represents the first concurrent molecular characterization, using 454 pyrosequencing of hypervariable regions of the small subunit ribosomal RNA gene, of bacterial, archaeal, and eukaryotic communities in permanently ice-covered lakes Fryxell and Bonney before and during the polar night transition.