Mating in the absence of fertilization promotes a growth-reproduction versus lifespan trade-off in female mice

Significance Pregnancy and lactation are energetically costly and can have negative effects for later-life reproduction and lifespan. To become pregnant females must mate, and these mating interactions with males could also have long-term effects on female life history. Evidence supporting this prediction has been lacking until now. Here we show that allowing female mice to mate early in life, with only sterilized males, permanently affects female life history and aging. Mated females gain and maintain body weight across life, have a greater late-life reproductive output, but suffer a shorter lifespan. These responses explain some trade-offs previously attributed to pregnancy and lactation and highlight that exposure to sexual stimuli alone can have a major effect on female life history in mammals.