Investment in reproduction is predicted to accelerate ageing, but the link between reproductive investment and lifespan can be sex- and context-specific. In mammals, female reproductive costs are linked to pregnancy and lactation, but in males substantial reproductive allocation is required for a range of pre- and post-copulatory reproductive traits. Such traits include male-specific increased body size, olfactory signalling and territory defence—traits often expressed under androgen-dependent control. In this experimental study, we explored how reproduction influences lifespan in male mice, contrasting this to the established lifespan costs of reproduction in females. In a 2 × 2 factorial design, we gave either castrated or intact males (factor 1) access to a female or a male cage-mate across their entire life (factor 2). Neither castration nor access to females influenced median lifespan in male mice, but maximal lifespan was increased by either castration or reproduction when compared to intact males housed in male groups (standard male housing conditions). In females, mating significantly reduced lifespan, and while both sexes had similar lifespans in non-reproductive environments, males had a much longer lifespan when allowed mating. This data highlights the sex-specific nature of social environments and reproduction on lifespan, and the role of these conditions in promoting sexual dimorphism in ageing.

生殖投资预计会加速老龄化，但生殖投资与寿命之间的联系可能因性别和环境而异。在哺乳动物中，雌性生殖成本与怀孕和哺乳有关，但在雄性中，交配前后的一系列生殖特征需要大量的生殖分配。这些特征包括男性特有的体型增大、嗅觉信号传递和领土防御——这些特征通常在雄激素依赖性控制下表现出来。在这项实验研究中，我们探讨了繁殖如何影响雄性小鼠的寿命，并将其与已确定的雌性繁殖寿命成本进行对比。在 2 × 2 因子设计中，我们让阉割的或完整的雄性（因子 1）在其整个生命周期（因子 2）与雌性或雄性笼养伴侣接触。阉割和接触雌性均不影响雄性小鼠的平均寿命，但与雄性组（标准雄性饲养条件）中的完整雄性相比，通过阉割或繁殖延长了最大寿命。在雌性中，交配显着缩短了寿命，虽然两性在非生殖环境中的寿命相似，但在允许交配的情况下，雄性的寿命要长得多。这些数据突出了社会环境和生命周期生殖的性别特异性，以及这些条件在促进衰老过程中的性别二态性中的作用。交配显着缩短了寿命，虽然两性在非生殖环境中的寿命相似，但在允许交配的情况下，雄性的寿命要长得多。这些数据突出了社会环境和生命周期生殖的性别特异性，以及这些条件在促进衰老过程中的性别二态性中的作用。交配显着缩短了寿命，虽然两性在非生殖环境中的寿命相似，但在允许交配的情况下，雄性的寿命要长得多。这些数据突出了社会环境和生命周期生殖的性别特异性，以及这些条件在促进衰老过程中的性别二态性中的作用。