Expression of aquaporins in response to distinct dehydration stresses that confer stress tolerance in the Antarctic midge Belgica antarctica

• Published in: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology Molecular & integrative physiology, 2021-06, Vol.256, p.110928-110928, Article 110928
• Main Authors: Yoshida, Mizuki, Lee, Richard E., Denlinger, David L., Goto, Shin G.
• Format: Article
• Language: English
• Subjects: Antarctic midge; Aquaporin; Dehydration; Gene expression; Stress tolerance
• ISSN: 1095-6433; 1531-4332
• DOI: 10.1016/j.cbpa.2021.110928

Larvae of the Antarctic midge Belgica antarctica Jacobs (Diptera: Chironomidae) are highly tolerant of diverse environmental stresses, including freezing, severe desiccation, and osmotic extremes. Furthermore, dehydration confers subsequent desiccation and freeze tolerance. While a role for aquaporins—channels for water and other solutes—has been proposed in these dehydration processes, the types of aquaporins involved in dehydration-driven stress tolerance remain unknown. In the present study, we investigated expression of six aquaporins (Drip, Prip, Eglp1, Eglp2, Aqp12L, and Bib) in larvae of B. antarctica subjected to three different dehydration conditions: desiccation, cryoprotective dehydration, and osmotic dehydration. The expression of Drip and Prip was up-regulated under desiccation and cryoprotective dehydration, suggesting a role for these aquaporins in efficient water loss under these dehydration conditions. Conversely, expression of Drip and Prip was down-regulated under osmotic dehydration, suggesting that their expression is suppressed in larvae to combat dehydration. Larval water content was similarly decreased under all three dehydration conditions. Differences in responses of the aquaporins to the three forms of dehydration suggests distinct water management strategies associated with different forms of dehydration stress. [Display omitted] •The Antarctic midge acquires stress tolerance by dehydration through aquaporins.•Two aquaporins were up-regulated after desiccation and cryoprotective dehydration.•Expression of these aquaporins decreased after osmotic dehydration.•Different forms of dehydration stress elicit different forms of water management.