Characterizing the variability of Chlorophyta from McMurdo Dry Valley streams for future bioprospecting

The numerous ephemeral glacial meltwater streams that flow during the summer in the McMurdo Dry Valleys of South Victoria Land, Antarctica, provide habitats for microbial mats. One of the common mat types is comprised of Chlorophyta. This green mat was commonly thought to be predominantly comprised of chlorophyte taxa of the genus Prasiola. Previous genetic sequencing of green mat from the McMurdo Dry Valleys indicated Prasiola as a minor component,although, this may have been due to underrepresentation of Prasiola in PCR primers. These mats grow both in the main thalweg, exposed to scouring events, and in the interstitial spaces between rocks for protection. While the presence of these mats is regularly monitored, their taxonomic makeup is still under investigation. Using 18S rRNA gene sequencing, we examined the composition of the chlorophyte-dense mats from between rocks and in the main channel from several streams across two valleys.