Thermal‐specific patterns of longevity and fecundity in a set of heat‐sensitive and heat‐resistant genotypes of Drosophila melanogaster

Abstract

AbstractFitness‐related traits are often affected by temperature. Heat‐resistant genotypes could influence the dependence of fitness traits on temperature, which should be important in adaptation to directional changes in temperature including global warming. Here, we tested temperature‐dependent variation in longevity and fecundity between Drosophila melanogaster Meigen (Diptera: Drosophilidae) genotypes that differ in heat‐resistance QTL. Longevity and fecundity were affected by heat‐resistance genotypes at constant moderate and high temperature. However, these differences between heat‐resistant and heat‐sensitive genotypes disappeared in a cyclic thermal regime. Analysis with the logistic mortality function indicated that mortality patterns are dependent on temperature and genotype. The results suggest that genotype*temperature interactions are substantial for senescence‐related traits. In particular, fluctuating temperatures can drastically reduce any differences in life‐history traits between heat‐resistance genotypes, even if such genotypes differentially affect the traits at constant temperatures.