The genome of the Antarctic midge, Antarctica’s only native insect, is reported this week in Nature Communications. The work highlights genes and biological processes that may have allowed this insect to adapt to its extreme natural environment.
The midge, Belgica antarctica, lives in the rocky outcrops of the Antarctic Peninsula and is termed an extremophile because of its ability to survive freezing, desiccation, high saline concentrations, strong winds and intense ultra violet exposure.
Joanna Kelley and colleagues have assembled the B. antarctica genome to provide clues as to how this insect has evolved to cope with such extreme environmental conditions. Researchers found a reduction in the number of repetitive genetic sequences and shorter stretches of DNA separating coding regions of the genome, compared to other insects such as mosquitoes and flies, leaving B. antarctica with the smallest insect genome assembled to date.
The team also report an abundance of genes associated with development, metabolism and stimulation response. They suggest that these evolved over time because of the strong pressure for natural selection. This work provides a valuable model for how genomes evolve in response to extreme environments.