Intraspecific variation in heat tolerance of Drosophila prolongata (Diptera: Drosophilidae)
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Tolerance to extreme temperatures is one of the most important components of adaptation to environments in insects. However, the genetic mechanisms of tolerance to long-term heat stress are mostly unknown. In this study, we investigated the genetic variation of susceptibility to long-term heat stress among the isofemale strains of Drosophila prolongata Singh & Gupta. High rates of pupal lethality were observed at 25 °C, showing that D. prolongata is more susceptible to heat stress than other Drosophila species. Susceptibility to heat stress was significantly different among the isofemale strains, suggesting that intraspecific genetic variation is involved in the reduced heat tolerance of D. prolongata. Unexpectedly, the tertiary sex ratio was biased to females at temperatures higher than 20 °C, indicating that the males were more susceptible to heat stress. These results demonstrated that D. prolongata is useful for genetic analysis for elucidating the molecular mechanisms of heat tolerance in insects.
KeywordsLong-term heat stress Heat-induced lethality Genetic variation Drosophila prolongata Sex ratio
This work was supported by JSPS KAKENHI Grant Number 26660263 to TM.
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