Researchers report species- and sex-specific lifespan extension in Drosophila exposed to low temperature and darkness

A comparative study of three Drosophila species shows that while low temperature extends lifespan across all cohorts, the interactive effects of temperature and photoperiod on longevity are highly dependent on baseline lifespan, sex, and evolutionary background.

Researchers from the Institute of Biology of the Komi Scientific Centre and the Petrovsky Russian Research Centre of Surgery published a study in Biogerontology examining three Drosophila species with contrasting lifespans: D. kikkawai (short-lived), D. melanogaster (intermediate-lived), and D. virilis (long-lived).

The insects were exposed to a reduced ambient temperature of 18 °C (compared to 25 °C) and constant darkness (DD) versus a 12-hour light/dark cycle (LD).

Low temperature extended the lifespan of all three species, with the shortest-lived species (D. kikkawai males) experiencing the largest relative longevity gains, while the longest absolute lifespans were consistently maintained by the naturally long-lived D. virilis.

Constant darkness moderately increased lifespan at 25 °C, particularly in males, but acted antagonistically when combined with low temperature in D. virilis.

Gene expression analysis in D. melanogaster showed that low temperature induced a youthful metabolic and immune transcriptomic profile, which was frequently counteracted by constant darkness.

The findings do not support a simple inverse or direct relationship between an organism's baseline longevity and the efficacy of geroprotective interventions, suggesting that ecological and evolutionary history dictates the response to environmental stressors.

The research highlights that combinations of environmental interventions (such as cooling and light restriction) can have antagonistic effects depending on the genetic and sex-specific background, suggesting that multi-modal longevity protocols require careful tailoring.

By correlating longer lifespans with lower metabolic rates, greater body mass, and sustained late-life physical activity, the study provides further physiological parameters to evaluate healthy aging interventions.

For geroscience and translational drug discovery, the study underscores the risk of relying on single-strain or single-species models to validate environmental, metabolic, or physical interventions.

The antagonistic interactions observed between constant darkness and cooling highlight the necessity for rigorous, multi-variable preclinical screening in the development of lifestyle-mimetic therapies.

Future research exploring whether the identified metabolic and immune-related gene expression pathways altered by temperature in Drosophila are conserved and targetable via pharmacological means in mammalian models.