Increased thermotolerance to heat by selecting for mating

P SAMBUCETTI; STAZIONE L; NORRY F M

Foz do Iguaçu

Congreso; 2018 International Congress of Genetics; 2018

Sociedade Brasileira de Genetica

Reproductive fitness components such us mating successare strongly influenced by environmental temperature. Under the currentscenario of global warming, the knowledge about how organisms? reproduction couldbe affected by thermal stress is relevant for predicting potential evolutionaryresponses to increasing temperature. In this study, we evaluated the responsesto artificial selection on mating success at high temperature in Drosophila buzzatii and their effects onan ecologically relevant themotolerance trait, the knockdown resistance to hightemperature (KRHT). Selected lines were generated in three replicates byallowing virgin flies to mate for four hours at 33 °C. Then, females werereturned at 25 °C in empty bottles to lay eggs and obtain the next generation. Otherthree replicated lines were maintained at 25 °C as control. Once selection wasfinished, KRHT was measured as the time taken until flies were knocked down at37 °C in a glass column. After ten generations of selection, selected linesshowed higher mating success at 33 °C than control lines in a competitiveassay. Furthermore, thermotolerance was also affected by selection as KRHT washigher in selected lines than in controls. The results show that mating successcan evolve as response to sexual selection at high temperature. This responsecould be partially explained by an indirect selection on thermotolerancephenotypes. Considering that reproductive success is one of the most inclusive measuresof overall fitness, this selection response is crucial for adaption to increasingenvironmental temperature in natural populations.