Meeting Abstract
123.3 Monday, Jan. 7 Physiological and Genomic Variation in Rapid Cold Hardening and Developmental Acclimation in Drosophila melanogaster EGGE, AR*; NOH, S; ELLER, OC; HAHN, DA; MORGAN, TJ; Kansas State University; Kansas State University; Kansas State University; University of Florida; Kansas State University aegge@ksu.edu
Adaptation and plastic responses to daily and seasonal fluctuations can lie in both long- and short-term adaptive responses controlled by functional regions of the genome. The rapid cold hardening response (RCH) and the developmental acclimation response (DACC) are two types of acclimation that have been widely explored. RCH manifests itself as an increase in survivorship or fitness of an organism following a pre-treatment of minutes to hours at a cooler temperature before exposure to a cold shock temperature, while DACC pre-treatment spans egg-to-adult development. Full physiological and genetic analyses of the variation in RCH and DACC have yet to be explored. Drosophila melanogaster is a cosmopolitan species often used as a model organism for tracking genetic responses to environmental stresses and adaptation. Our research focuses on the comparison of short (RCH) and long term (DACC) cold acclimation in the Drosophila Genetic Reference Panel (DGRP) to determine the genetic and physiological sources of variation among lines of natural Drosophila melanogaster. Each line was reared at both 18° C and 25° C, and tested for survivorship at a one-hour cold shock and a two-hour RCH pretreatment followed by a one-hour cold shock to determine the RCH and DACC responses. There was significant genetic variation among the lines for both short- and long-term acclimation responses. The phenotypic responses did not share any significant SNPs across the DGRP genomes, although RCH at 25° and DACC were phenotypically correlated among the DGRP lines. Functional mutation analysis has confirmed the functional role of several associated candidate genes in short or long-term cold acclimation responses.
