Meeting Abstract

P1.91  Jan. 4  Cold Tolerance in Drosophila Species GIBBS, A. G.*; CLEAVES, L. S.; University of Nevada, Las Vegas; The Riparian Institute, Gilbert AZ allen.gibbs@unlv.edu

We examined resistance to cold in nine Drosophila species from different habitats. Three separate tests were administered to measure: 1) survival of a one-hour cold-shock exposure; 2) the ability of species to undergo rapid cold hardening at 0 and 4 ^oC; and 3) survival of each species during prolonged exposure to 0 ^oC. As expected, temperate-montane species were the most cold-tolerant, whereas the least cold-tolerant was the tropical species, D. paulistorum. Of the five species tested for rapid cold hardening, all exhibited the response. However, D. paulistorum exhibited rapid cold hardening only at 4 ^oC; exposure to 0 ^oC for one hour significantly reduced survival at lower temperatures. Survival at 0 ^oC varied widely among species, but paralleled the results of the cold-shock test. Drosophila paulistorum survived <5 hours, whereas D. virilis survived ~30 days in an ice bath. Desert species proved surprisingly cold-tolerant, especially D. mojavensis.