The Importance of Structural and Storage Lipids for Insect Cold Tolerance and Overwintering

Abstract

Cold shapes insect physiology, including lipid metabolism. Lipids are indeed among primary targets of cold injuries. Consequently, insects possess several physiological adjustments linked with cold tolerance to protect lipid structures. Furthermore, lipid (fat) reserves are the principal source of energetic fuel during overwintering. In this review, we highlight the most recent literature dealing with cellular and organismal changes in lipid metabolism in response to cold. We first highlight the role of structural changes in membrane phospholipids and other adjustments that could be involved in membrane protection. We then discuss how fat reserves change in response to cold, also during overwintering, and how fat stores relate to cold tolerance. We end our review with an overview of genes and proteins implicated in fat synthesis, accumulation, and use in response to cold or diapause. This will help to increase our understanding of physiological and genomic mechanisms involved in lipid metabolism during overwintering.

Keywords: Dormancy, Freezing, Chilling, Homeoviscous adaptation, Triacylglycerols, Global warming