Heat knockdown resistance and chill‐coma recovery as correlated responses to selection on mating success at high temperature in Drosophila buzzatii

STAZIONE, LEONEL; NORRY, FABIAN M.; GOMEZ, FEDERICO H.; SAMBUCETTI, PABLO

Ecology and Evolution

Wiley

Año: 2020 vol. 10 p. 1998 - 2006

2045-7758

Reproduction and related traits such as mating success are strongly affected bythermal stress. We tested direct and correlated responses to artificial selection inreplicated lines of Drosophila buzzatii that were selected for mating success at hightemperature. Knockdown resistance at high temperature (KRHT) and chill-comarecovery (CCR) were tested as correlated selection responses. Virgin flies were allowedto mate for four hours at 33°C in three replicated lines (S lines) to obtain theselected flies and then returned at 25°C to lay eggs. Other three replicated lineswere maintained at 25°C without any selection as control (C lines). After 15 selectiongenerations, KRHT and CCR were measured. Both traits were assessed in flies thatdid not receive any hardening pretreatments as well as in flies that were either heator cold hardened. Thermotolerance traits showed significant correlated responseswith higher KRHT in S than in C lines, both with a heat-hardening pretreatment andwithout a heat-hardening pretreatment. CCR time was longer in S than in C lines bothwith a cold-hardening pretreatment and without a cold-hardening pretreatment.Hardening treatments improved both KRHT and CCR in all cases excepting KRHTin C lines. Overall, KRHT and CCR showed an antagonistic pattern of correlated responsesto our selection regime, suggesting either pleiotropy or tightly linked traitspecificgenes partially affecting KRHT and CCR.