Meeting Abstract

56-6   09:15 - 09:30  Rapid cold hardening protects against sublethal cold injury and but fails to preserve reproductive behaviors in Drosophila melanogaster Unfried, LN*; Teets, NM; University of Kentucky; University of Kentucky laura.unfried@uky.edu

Rapid cold hardening (RCH) is a type of phenotypic plasticity in which cold tolerance is increased following a brief chilling period. While the ability of RCH to protect against lethal temperatures is well established, the extent to which RCH protects against sublethal cold injury is unclear. Sublethal low temperatures are more commonly experienced than lethal conditions in the field, so to further our understanding of the ability of RCH to protect against nonlethal cold injury, we assessed a variety of performance-related traits following RCH and cold stress in Drosophila melanogaster. Experiments were conducted in Canton-S flies, and to demonstrate that this line has a robust RCH response, we exposed flies to cold shock for 2 h at -4.5°C with and without a 2 h RCH pretreatment at 4°C. Flies that were directly cold shocked had nearly 100% mortality, while nearly all flies survived when they were treated with RCH prior to cold shock, indicating that our conditions elicit a strong RCH response. To then test whether RCH protects against sublethal cold, we exposed flies to nonlethal cold shock for 2 h at -2°C with and without RCH, and following these treatments we assessed fecundity, fertility, chill coma recovery, and tissue damage. We found that reproductive behaviors were not preserved following hardening and chill coma recovery did not vary regardless of treatment. However, we did find that hardened flies were protected against cold-induced tissue damage. In ongoing experiments, we are measuring energy stores, locomotor activity, and metabolic rate following cold stress. Together, these experiments will provide a comprehensive assessment of the ability of RCH to preserve performance following cold stress.