Genetic Quality Affects the Rate of Male and Female Reproductive Aging Differently in Drosophila melanogaster

Abstract

Dryad data: https://dx.doi.org/10.5061/dryad.5089j74.abstract: Males and females often maximize fitness by pursuing different reproductive strategies, with males commonly assumed to benefit more from increased resource allocation into current reproduction. Such investment should trade off with somatic maintenance and may explain why males frequently live shorter than females. It also predicts that males should experience faster reproductive aging. Here we investigate whether reproductive aging and life span respond to condition differently in male and female Drosophila melanogaster, as predicted if sexual selection has shaped male and female resourceallocation patterns. We manipulate condition through genetic quality by comparing individuals inbred or outbred for a major autosome. While genetic quality had a similar effect on condition in both sexes, condition had a much larger general effect on male reproductive output than on female reproductive output, as expected when sexual selection on vigor acts more strongly on males. We find no differences in reproductive aging between the sexes in low condition, but in high condition reproductive aging is relatively faster in males. No corresponding sex-specific change was found for life span. The sex difference in reproductive aging appearing in high condition was specifically due to a decreased aging rate in females rather than any change in males. Our results suggest that females age slower than males in high condition primarily because sexual selection has favored sex differences in resource allocation under high condition, with females allocating relatively more toward somatic maintenance than males.

Social behavior and aging: A fly model

“…As in other animals, sex differences in aging, lifespan, 14,88 reproductive traits, [108][109][110][111][112] and transgenerational effects have been reported in D. melanogaster. 111,113,114 Like other animals, rapid reproduction in early life reduces longevity in D. melanogaster, as resources invested in reproduction can come at the cost of organismal longevity.…”

The hidden ageing costs of sperm competition

“…Lemaître et al ., 2020) and reproduction (e.g. Brengdahl et al ., 2018) can differ widely between males and females across species strongly emphasises that we need to investigate how both natural and sexual selection interact to shape male ageing patterns. Such studies could reveal new insights about the evolutionary roots of the sex‐specific decline in physiological performance and health issues at late ages (Marais et al ., 2018).…”

Sex ratio at mating does not modulate age fitness effects in Drosophila melanogaster

“…More recent studies have further investigated how female and male age can decrease offspring viability by focusing on underlying pre‐ and postmeiotic aging processes (Firman, Young, Rowe, Duong, & Gasparini, ; Pizzari et al, ; Tan, Pizzari, & Wigby, ). In short, the effects of age on reproductive success have been relatively well explored, yet most available studies have overlooked how socio‐sexual factors such as density or sex ratio might modulate reproductive senescence across the sexes (Brengdahl, Kimber, Maguire‐Baxter, Malacrinò, & Friberg, ; Carazo, Molina‐Vila, & Font, ; Fricke, Green, Mills, & Chapman, ; Ruhmann, Koppik, Wolfner, & Fricke, ; Tan et al, ; Zhao, Xuan, Li, & Xi, ).…”