Heat-induced hormesis in longevity as correlated response to thermal -stress selection in Drosophila buzzatii

FEDERICO H. GOMEZ; CARLOS I. BERTOLI; PABLO SAMBUCETTI; ALEJANDRA C. SCANNAPIECO; FABIAN M. NORRY

JOURNAL OF THERMAL BIOLOGY

Elsevier

Año: 2008 vol. 34 p. 17 - 22

0306-4565

a b s t r a c tHormesis in longevity is a widespread phenomenon across the animal kingdom. It takes place whenlongevity is improved as an indirect effect of mild stress. We explored some possible evolutionarytrajectories of hormesis in longevity in artificially selected lines of Drosophila buzzatii. The lines were bidirectionallyselected for either knockdown resistance to heat stress (K-, K+) or chill-coma recovery(CCR-, CCR+, with the + and – signs indicating selection for decreased and increased tolerance,respectively). All K and CCR lines successfully diverged due to thermal-stress selection. The heatinduciblehormesis in longevity was substantial in both K- and CCR- females, whereas no hormesis wasapparent for females in CCR+, K+ and control lines. Among-line differences in longevity of non-heattreatedfemales disappeared after a heat-hardening treatment. Hormesis effects on the demographicsenescence rate were sex-specific and consistently higher in the shorter-lived than in the longer-livedlines. Hormesis is an adaptive response, as its magnitude can evolutionary increase with stresssensitivity.& 2008 Elsevier Ltd. All rights reserved.