The Steroid Hormone Receptor EcR Finely Modulates Drosophila Lifespan During Adulthood in a Sex-specific Manner

The steroid hormone ecdysone influences Drosophila lifespan. Longevity is extended in mutants deficient for ecdysone synthesis or mutants of the ecdysone receptor (EcR). However, the underlying mechanisms remain unclear. Here we conditionally inactivated EcR by RNA interference or expression of dominant negative forms, using the RU486 inducible system. A mild ubiquitous inactivation of EcR during adulthood was sufficient to slow the aging of male flies, whereas a stronger EcR inactivation decreased longevity. Surprisingly, ubiquitous inactivation of EcR strongly decreased female lifespan. This deleterious effect was suppressed in sterile ovo(D1) mutant females, suggesting that EcR represses a negative signal for lifespan produced in ovaries. These results reveal a complex adult and sex-specific control of lifespan by steroid signalling in Drosophila.