Direct and correlated responses to chill-coma recovery selection in Drosophila buzzatii

CARLOS I. BERTOLI; ALEJANDRA C. SCANNAPIECO; PABLO SAMBUCETTI; F.M. NORRY

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA

Wiley-Blackwell

Lugar: Holanda; Año: 2010 vol. 134 p. 154 - 159

0013-8703

Chill-coma recovery (CCR) is an important trait for thermal adaptation in insects. Multiple phenotypescould be affected by selection on CCR if the trait is genetically correlated with other adaptivetraits. To test for heritable (co-)variation in CCR, we examined direct and correlated responses tobi-directional selection on CCR. Drosophila buzzatii Patterson & Wheeler (Diptera: Drosophilidae)was artificially selected for decreased and increased recovery time following exposure to 0 C. After18 selected generations, the selection response in CCR was significant but qualitatively asymmetric,with replicated lines for slow CCR showing the highest response. Knockdown resistance to high temperaturewas not affected by CCR selection. Starvation resistance in the adult fly showed no clear patternof correlated responses to CCR selection. Selection on CCR had no impact on developmentaltime and body size. Chill-coma recovery shows no apparent genetic trade-offs with any of the multipletraits included in this study. These results are largely consistent with recent studies on clines inD. buzzatii, which showed that CCR is not across-population correlated with other clinally varyingtraits of thermal adaptation. Cold adaptation may evolve toward increased cold resistance independentof upper thermal limits.