Separating multiple sources of variation on heat resistance in Drosophila hydei.
While numerous insect studies have demonstrated the effects environmental conditions, genetic variation and other factors have on thermal resistance, often showing patterns consistent with adaptive plasticity and local adaptation, few experiments have considered the effects of multiple factors simultaneously. Here however, we have investigated the impact of sex, rearing conditions, hardening, population, and laboratory rearing period on adult heat resistance in stocks of Drosophila hydei, a cosmopolitan species that occurs across a range of climatic zones. We show that population and putative laboratory adaptation effects are larger than those associated with rearing temperature and hardening, although there was also a notable interaction between hardening and sex, in that females showed a cost of hardening that was not present in males. In separate experiments, we found that environmental effects across a generation were small and similar in magnitude to those within a generation. These findings suggest multiple sources of variation on heat resistance and place potential genetic versus environmental sources in context.
School of BioSciences, Bio21 Institute, The University of Melbourne, Victoria 3010, Australia.
Michele
M
Johnstone
School of BioSciences, Bio21 Institute, The University of Melbourne, Victoria 3010, Australia; Daintree Rainforest Observatory, Division of Research and Innovation, James Cook University, Cairns, Queensland 4878, Australia.
Michele
M
Schiffer
School of BioSciences, Bio21 Institute, The University of Melbourne, Victoria 3010, Australia. Electronic address: ary@unimelb.edu.au.
Ary A
AA
Hoffmann
D000064:Acclimatization; D000818:Animals; D004330:Drosophila / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D004777:Environment; D005260:Female; D014644:Genetic Variation; D006358:Hot Temperature; D008297:Male; D011157:Population Dynamics; D012737:Sex Factors; D000071436:Thermotolerance
Acclimation; Adaptation; Domestication; Drosophila; Maternal; Resistance