Department of Zoology and Entomology, University of Pretoria, Private bag X20, Hatfield 0028, South Africa.
Department of Zoology and Entomology, University of Pretoria, Private bag X20, Hatfield 0028, South Africa.
J Insect Physiol. 2020 Aug-Sep;125:104084. doi: 10.1016/j.jinsphys.2020.104084. Epub 2020 Jul 4.
The oxidative damage caused to cells by Reactive Oxygen Species (ROS) is one of several factors implicated in causing ageing. Oxidative damage may also be a proximate cost of reproductive effort that mediates the trade-off often observed between reproduction and survival. However, how the balance between oxidative damage and antioxidant protection affects life-history strategies is not fully understood. To improve our understanding, we selected on female reproductive age in the marula fruit fly, Ceratitis cosyra, and quantified the impact of selection on female and male mortality risk, female fecundity, male sperm transfer, calling and mating. Against expectations, upward-selected lines lived shorter lives and experienced some reductions in reproductive performance. Selection affected oxidative damage to lipids and total antioxidant protection, but not in the direction predicted; longer lives were associated with elevated oxidative damage, arguing against the idea that accumulated oxidative damage reduces lifespan. Greater reproductive effort was also associated with elevated oxidative damage, suggesting that oxidative damage may be a cost of reproduction, although one that did not affect survival. Our results add to a body of data showing that the relationship between lifespan, reproduction and oxidative damage is more complex than predicted by existing theories.
活性氧(ROS)对细胞造成的氧化损伤是导致衰老的几个因素之一。氧化损伤也可能是生殖努力的一个近似代价,它介导了生殖和生存之间经常观察到的权衡。然而,氧化损伤和抗氧化保护之间的平衡如何影响生活史策略还不完全清楚。为了提高我们的认识,我们选择了马鲁拉果实蝇(Ceratitis cosyra)的雌性生殖年龄,并量化了选择对雌性和雄性死亡率风险、雌性繁殖力、雄性精子传递、求偶和交配的影响。出乎意料的是,向上选择的品系寿命较短,繁殖性能也有所下降。选择影响了脂质的氧化损伤和总抗氧化保护,但方向与预期相反;更长的寿命与更高的氧化损伤有关,这与积累的氧化损伤会降低寿命的观点相矛盾。更大的生殖努力也与更高的氧化损伤有关,这表明氧化损伤可能是生殖的代价,尽管它不会影响生存。我们的研究结果增加了一系列数据,表明寿命、繁殖和氧化损伤之间的关系比现有理论预测的更为复杂。