Microbiome-mediated resilience and cross-generational consequences in male Drosophila exposed to combined environmental stressors Item

Environmental stressors like heat extremes and pesticide exposure can significantly threaten insect reproduction, yet the interplay of these stressors and the potential mitigating role of the gut microbiome remain poorly understood, particularly across generations. This study investigated the interactive effects of acute heat stress and sublethal imidacloprid exposure on male Drosophila melanogaster reproductive success and the subsequent fitness of their offspring. We manipulated the gut microbiome of male flies (germ-free or colonized with one or five bacterial species) and subjected them to individual or combined stress. Our findings reveal that combined stress synergistically impairs male fitness traits, an effect partially buffered by higher microbiome diversity. We further demonstrate cross-generational consequences, with paternal stress exposure also impacting offspring fitness. Our results highlight the crucial role of the gut microbiome in mediating resilience to environmental stress and underscore the importance of considering multi-stressor and intergenerational effects in ecological risk assessments.

极端高温、农药暴露等环境胁迫因子可显著威胁昆虫的生殖能力，但此类胁迫因子间的交互效应，以及肠道微生物组（gut microbiome）潜在的缓解作用，目前仍未得到充分解析，尤其在跨代际维度上。本研究以雄性黑腹果蝇（Drosophila melanogaster）为研究对象，探究了急性热胁迫与亚致死吡虫啉暴露对其生殖成功率，以及子代后续适合度的交互影响。研究中，我们对雄性果蝇的肠道微生物组进行了调控：设置无菌组，以及定殖1种或5种细菌的定殖组，并将果蝇分别暴露于单一胁迫或复合胁迫环境中。研究结果显示，复合胁迫会协同削弱雄性果蝇的适合度相关性状，而更高的微生物组多样性可部分缓解这一负面效应。本研究还证实了该胁迫存在跨代际效应：父代的胁迫暴露同样会对子代的适合度产生影响。本研究结果凸显了肠道微生物组在介导生物抵御环境胁迫抗性中的关键作用，同时强调了在生态风险评估中纳入多胁迫因子与跨代际效应的必要性。