Chironomid midges (Diptera) provide insights into genome evolution in extreme environments

Abstract

Extremophiles often undergo marked changes in genomic architecture, likely as a result of adaptation to the harsh environments they inhabit. These changes can involve gene duplications that affect subsequent gene evolution and the regulation of gene expression. Excellent examples of this are provided by two non-biting chironomid midges (Diptera, Chironomidae): Polypedilum vanderplanki, which in its larval form can withstand almost complete water loss, and Belgica antarctica, which exhibits freeze tolerance. This review presents recent studies on the molecular adaptations and evolutionary features of these and other extremophile chironomid genomes, as well as biotechnological applications of a cell line derived from P. vanderplanki that can survive air-drying. We highlight the importance of genomics in identifying molecular pathways and genomic modifications associated with adaptation to extreme environmental conditions.