USAP-DC

The goals of this work are to determine the taxonomic identity of viable and preserved microbial cells, and decode the genetic repertoire that confers survival of burial and long-term viability within glacial ice. We will achieve these goals by utilizing subsamples from the ~65 ka record of the West Antarctic Ice Sheet Divide (WD) Ice Core. WD samples will be melted using the Desert Research Institute’s ice core melting system that is optimized for glaciobiological sampling. Microbial cells from the meltwater will be sorted using fluorescence-activated cell sorting, and individually sorted cells will have their genomes sequenced. The fluorescence-based methods will discern the viable (metabolically active) cells from those cells that are non-viable but preserved in the ice (DNA-containing). Our genomic analysis will identify the taxonomy of each cell, presence of known genes that confer survival in permanently frozen environments, and comparatively analyze genomes to determine the core set of genes required by viable cells to persist in an ice sheet. Accomplishing these goals contains significant risk because microbial cells within the ice sheet may have damaged membranes and DNA, rendering their genomes inadequate for sequencing. However, existing methods to study ice core biology cannot produce results with the low-biomass and small sample volumes from ice coring projects. While there are unknowns surrounding the suitability of the cells for flow cytometric sorting and single cell sequencing, making this project an exploratory endeavor; it will be a transformative step toward understanding the ecology of one of the most understudied environments on Earth.

Person	Role
Michaud, Alexander	Investigator and contact
Winski, Dominic A.	Co-Investigator

Antarctic Organisms and Ecosystems

Award # 2228257

USAP-2228257_1

None in the Database