Context-dependent candidate genes : a test of within-population genetic variation for photoperiodic plasticity

• Components of the circadian clock have been implicated as involved in photoperiodic regulation of diapause across various insect groups, hence contributing to adaptation to adverse seasonal conditions. Such studies typically involve either characterization of nondiapause mutants, or comparisons of populations differing in diapause induction thresholds, leaving within-population variation unexplored. Here, we present a test of the effects on diapause induction of within-population variation at two circadian loci, timeless and period, in the butterfly Pararge aegeria. Variation at both loci has previously shown to be associated with diapause induction on an interpopulation level. However, in the present study, no effect on induction was found of either locus at a within-population level. Examination of sequence data revealed novel variation at both timeless and period in the studied population. We hypothesize that selection for a northern-type life cycle may have promoted compensatory variants, ensuring a high rate of diapause induction despite the presence of southern, diapause-averting SNP alleles. Additionally, both timeless and period showed considerable variation across Scandinavian populations, with an unusually high rate of nonsynonymous substitutions compared to the rest of the genome, raising new questions about the fine-scale adaptive dynamics of circadian genes.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

zoologisk ekologi

Animal Ecology

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)