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

GOMEZ FEDERICO; NORRY FABIAN M; SAMBUCETTI PABLO; BORDA, MIGUEL ANGEL

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018

0013-8703

Quantitative trait loci (QTL) for thermotolerance were previously identified for adult flies in several mapping populations of Drosophila melanogaster Meigen (Diptera: Drosophilidae) in the laboratory. However, laboratory assays may not necessarily reflect the performance under heat stress in the field. For instance, do the heat-resistance QTL regions in the field match the QTL for thermotolerance in lab studies? To address this and other related questions we used a set of recombinant inbred lines (RIL), which were originally used to identify QTL in the lab. We tested egg-to-adult survival (EAS) QTLs in a field experiment under naturally varying heat-stress temperatures in fly cultures reared on a rotting fruit (banana) in summer. EAS under heat stress was found to be 3 to 6 times lower (depending on RIL) in the field than in the corresponding control at benign temperature (25°C). Five QTL for EAS were significant in the field experiment under heat stress, four of them co-located with plasticity QTL, and none of the QTL was significant at control temperature. All significant QTL overlapped (co-localized) with thermotolerance-QTL previously identified in the lab. A previously found QTL in the middle of chromosome 2 explained near 30% of the phenotypic variance in EAS under heat stress in previous studies in the lab, but this QTL explained only 8 % of the EAS variation in our field assay. The18 largest effect on EAS was found for an X-linked QTL (cytological range 7B3 ? 10C3) in the heat-stress field experiment, explaining a high proportion (14 to 45%) of the phenotypic variation in EAS. The ecological relevance of QTL implicated in this study is discussed.