Leech Thomas, Sait Steven M, Bretman Amanda
School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
J Insect Physiol. 2017 Oct;102:12-17. doi: 10.1016/j.jinsphys.2017.08.008. Epub 2017 Aug 19.
Social environments can have a major impact on ageing profiles in many animals. However, such patterns in variation in ageing and their underlying mechanisms are not well understood, particularly because both social contact and isolation can be stressful. Here, we use Drosophila melanogaster fruitflies to examine sex-specific effects of social contact. We kept flies in isolation versus same-sex pairing throughout life, and measured actuarial (lifespan) and functional senescence (declines in climbing ability). To investigate underlying mechanisms, we determined whether an immune stress (wounding) interacted with effects of social contact, and assessed behaviours that could contribute to differences in ageing rates. Pairing reduced lifespan for both sexes, but the effect was greater for males. In contrast, pairing reduced the rate of decline in climbing ability for females, whereas for males, pairing caused more rapid declines with age. Wounding reduced lifespan for both sexes, but doubled the negative effect of pairing on male lifespan. We found no evidence that these effects are driven by behavioural interactions. These findings suggest that males and females are differentially sensitive to social contact, that environmental stressors can impact actuarial and functional senescence differently, and that these effects can interact with environmental stressors, such as immune challenges.
社会环境会对许多动物的衰老模式产生重大影响。然而，衰老变化的这种模式及其潜在机制尚未得到充分理解，特别是因为社交接触和隔离都可能带来压力。在这里，我们利用黑腹果蝇来研究社交接触的性别特异性影响。我们让果蝇一生都处于隔离状态或同性配对状态，并测量了实际寿命（寿命）和功能衰老（攀爬能力下降）。为了探究潜在机制，我们确定免疫应激（受伤）是否与社交接触的影响相互作用，并评估了可能导致衰老速度差异的行为。配对缩短了两性的寿命，但对雄性的影响更大。相比之下，配对减缓了雌性攀爬能力的下降速度，而对于雄性，配对导致随着年龄增长下降速度更快。受伤缩短了两性的寿命，但使配对对雄性寿命的负面影响加倍。我们没有发现证据表明这些影响是由行为相互作用驱动的。这些发现表明，雄性和雌性对社交接触的敏感度不同，环境压力源对实际寿命和功能衰老的影响也不同，而且这些影响可能与环境压力源相互作用，如免疫挑战。
