Genetic variation for egg-to-adult survival in Drosophila melanogaster (Diptera: Drosophilidae) in a set of recombinant inbred lines reared under heat stress in a natural thermal environment

BORDA, MIGUEL ANGEL; PABLO SAMBUCETTI; GOMEZ, FEDERICO H.; NORRY, FABIÁN MARCELO

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018

0013-8703

Quantitative trait loci (QTL) forthermotolerance were previously identified for adult flies in several mappingpopulations of Drosophila melanogaster Meigen (Diptera: Drosophilidae) inthe laboratory. However, laboratory assays may not necessarily reflect theperformance under heat stress in the field. For instance, do theheat-resistance QTL regions in the field match the QTL forthermotolerance in lab studies? To address this and other related questions weused a set of recombinant inbred lines (RIL), which were originally used to identify QTL in thelab. We tested egg-to-adult survival (EAS) QTLs in a field experiment undernaturally varying heat-stress temperatures in fly cultures reared on a rottingfruit (banana) in summer. EAS under heat stress was found to be 3 to 6 timeslower (depending on RIL) in the field than in the corresponding control atbenign temperature (25°C). Five QTL for EAS were significant in the fieldexperiment under heat stress, four of them co-located with plasticity QTL, andnone of the QTL was significant at control temperature. All significant QTLoverlapped (co-localized) with thermotolerance-QTL previously identifiedin the lab. A previously found QTL in the middle of chromosome 2 explained near30% of the phenotypic variance in EAS under heat stress in previous studies inthe lab, but this QTL explained only 8 % of the EAS variation in our fieldassay. The largest effect on EAS was found for an X-linked QTL (cytologicalrange 7B3-10C3) in the heat-stress field experiment, explaining a highproportion (14 to 45%) of the phenotypic variation in EAS. The ecologicalrelevance of QTL implicated in this study is discussed.