Department of Biology, Section of Ecology, University of Turku, FIN-20014, Turku, Finland.
Department of Biology, Section of Ecology, University of Turku, FIN-20014, Turku, Finland.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111133. doi: 10.1016/j.ecoenv.2020.111133. Epub 2020 Sep 4.
Anthropogenic pollution has a disadvantageous influence on various life-history traits. Although direct effects are well known, potential fitness-related trans-generational costs are less studied. Previously, empirical findings have demonstrated that environmental conditions faced by the parental generation have an effect on the traits expressed by their offspring. Here, to study this conjecture larvae of the common fruit fly (Drosophila melanogaster) were either exposed to a sub-lethal concentration of copper or reared on uncontaminated larval medium. Adult flies were kept under uncontaminated conditions. For the next generation, individuals were mated with their own group and their offspring were either exposed to copper or fed with uncontaminated larval medium. We found that in the parental generation copper exposure reduced fecundity compared with uncontaminated controls. In the progeny, females suffered impaired fecundity only if their larval condition differed from the conditions experienced by their parents. If the progeny was raised under similar conditions than the parental generation, no effect on fecundity was discovered, suggesting acclimatization to the prevailing conditions after short-time copper exposure (two generations). Our results demonstrate that exposure to an environmental stressor like heavy metals causes intra-and trans-generational fitness costs. Further, individuals may be able to acclimatize in prevailing contaminated conditions, but this might in turn debase fitness under uncontaminated conditions. Our findings are consistent with the prediction of the adaptive parental effects hypothesis which states that parents may produce offspring that are more successful under conditions faced by their parents.
人为污染对各种生活史特征都有不利影响。尽管直接影响广为人知，但潜在的与适应度相关的跨代成本研究较少。此前的实证研究结果表明，亲代所面临的环境条件会影响其后代所表现出的特征。在这里，为了研究这一假说，我们将普通果蝇（Drosophila melanogaster）的幼虫暴露于亚致死浓度的铜中或在未受污染的幼虫培养基中饲养。成年果蝇在未受污染的条件下饲养。对于下一代，个体与自己的群体交配，其后代要么暴露于铜中，要么喂食未受污染的幼虫培养基。我们发现，在亲代中，与未受污染的对照组相比，铜暴露降低了繁殖力。在后代中，如果幼虫的条件与父母所经历的条件不同，雌性的繁殖力会受到损害。如果后代在与亲代相似的条件下饲养，则不会发现繁殖力受到影响，这表明在短时间暴露于铜后（两代）对流行条件的适应。我们的研究结果表明，暴露于重金属等环境胁迫源会导致代内和跨代适应度成本。此外，个体可能能够适应流行的污染条件，但这反过来又会降低未受污染条件下的适应度。我们的发现与适应性亲代效应假说的预测一致，该假说认为，父母可能会产生在其父母所面临的条件下更成功的后代。
