Sociosexual exposure has opposing effects on male and female actuarial senescence in the fruit fly Drosophila melanogaster

Wayne G. Rostant, Janet S. Mason, Nicholas West, Alexei A. Maklakov, Tracey Chapman

Research output: Contribution to journalArticlepeer-review

Abstract

Males and females rarely express the same length of life. Here, we studied how sociosexual exposure shapes male and female age-specific mortality rates in Drosophila melanogaster. We maintained focal females and males within large, replicated cohorts throughout life with individuals of the same or opposite sex. Consistent with previous works, we found that females kept throughout their lives with males had only half the lifespan of those maintained throughout life at the same density in same-sex cohorts. In contrast, only a small lifespan decrease was observed in the corresponding male treatments and the reduction in male lifespan following exposure throughout life to other males or females was similar. Deconvolution of underlying aging parameters revealed that changes in lifespan were underpinned by opposing effects on actuarial aging in males versus females. Exposure to the opposite or same sex increased initial mortality rate in both sexes. However, in females, increasing exposure to males increased the rate of aging, while increasing exposure to females actually decreased it. The effects were in the opposite direction in males and were much smaller in magnitude. Overall, the findings were consistent with reports suggesting that exposure to the same versus opposite sex can affect survival differently in males and females. However, they also reveal a new insight—that overall lifespan can be underpinned by key differences in actuarial senescence in each sex. The findings suggest that responses to same or opposite sex exposure may have fundamentally and qualitatively different physiological consequences for health in males and females.

Original languageEnglish
Pages (from-to)2230-2239
Number of pages10
JournalJournals of Gerontology - Series A Biological Sciences and Medical Sciences
Volume78
Issue number12
Early online date11 Sep 2023
DOIs
Publication statusPublished - Dec 2023

Keywords

  • Lifespan
  • Mortality
  • Reproductive costs

Cite this