Reversal of the fecundity / longevity trade-off across social transitions in ants

调查社会性昆虫生殖力/寿命权衡的逆转将提供重要的见解衰老的调制。到目前为止，研究未能在社会昆虫中找到共同的衰老分子调节因子，这可能是因为典型研究物种之间不受控制的生态变化已经涵盖了调节衰老的关键因素。我们建议解决这个问题，通过使用一个比较的方法集中在蚂蚁，以确定衰老调节是独立于任何模式物种的特定生态或系统发育的位置。理论工作，从我们的研究单位的第一个资助阶段预测，任何社会昆虫工作者的生殖潜力，应选择更长的预期寿命。在大多数蚂蚁物种中，工蚁可以产生单倍体雄性。它们通常在蚁后死后这样做，以获得直接的适应力。然而，工蜂通常不能完全取代蜂王，因为它们缺乏产生二倍体蜂王和工蜂的能力。有趣的是，两种可供选择的工蚁类型在蚂蚁中反复进化：全能工蚁可以产生雄性和雌性，不育工蚁不能产生任何可行的后代。除了这些生理上的限制，工人的直接繁殖的机会也取决于殖民地水平的生活史参数，如殖民地的大小和女王的数量，这将进一步影响工人的老化mechanism.We将调查种姓（女王或工人），繁殖力（产卵或不），年龄（年轻或年老）如何影响15种蚂蚁的基因表达。我们仔细选择了不同的殖民地大小和女王数量的物种，量化的影响，工人的生殖潜力衰老的物种的生态和系统发育的位置。许多物种延长生命的两个因素是对氧化应激和病原体暴露的适应能力。有人提出，社会昆虫女王寿命更长，因为工人保护他们免受这些环境压力和/或为他们提供足够的资源，以保持积极的修复和防御机制更长的时间。在建议的项目中，我们将通过实验研究具有不同生殖潜力的工蚁（在15个物种之间和之内）对氧化应激和免疫挑战的适应能力是否也存在差异。从野外收集蚂蚁并在实验室进行实验的工作量需要三位经验丰富的蚂蚁研究人员的共同努力和专业知识。总的来说，这个比较项目在15个蚂蚁物种将提供有价值的信息的分子和生理机制老化的蚂蚁，繁殖力是如何与长寿的皇后和工人，以及我们的一般理解的逆转的繁殖力/长寿权衡的背景下，在先进的社会进化的过渡。

Investigating the reversal of the fecundity/longevity trade-off in social insects will provide important insights into the modulation of senescence. So far, studies have failed to find common molecular regulators of ageing across the social insects, possibly because uncontrolled ecological variation between the typical study species has covered key factors regulating ageing. We propose to tackle this problem by using a comparative approach focussed on ants, to identify senescence regulators that are independent of any model species' specific ecology or phylogenetic position.Theoretical work from the 1st funding phase of our research unit predicts that any reproductive potential of social insect workers should select for longer life expectancy. In most ant species, workers can produce haploid males. They usually do so when the queen dies, to gain direct fitness. However, workers typically cannot fully replace the queen because they lack the ability to produce diploid queens and workers. Interestingly, two alternative worker types have evolved repeatedly in ants: totipotent workers that can produce both males and females, and sterile workers that cannot produce any viable offspring. In addition to these physiological constraints, a worker's chance for direct reproduction also depends on colony-level life-history parameters, such as colony size and queen number, which should further affect worker ageing mechanisms.We will investigate how caste (queen or worker), fecundity (egg-laying or not), and age (young or old) affect gene expression in 15 species of ants. We carefully selected species with varying colony size and queen number, to quantify the effect of worker reproductive potential on senescence independent of the species' ecology and phylogenetic position. Two factors that prolong lives in many species are the resilience to oxidative stress and pathogen exposure. It has been proposed that social insect queens live longer because workers protect them against these environmental stressors and/or provide them with enough resources to maintain active repair and defence mechanisms for a longer time. In the proposed project, we will experimentally investigate whether ant workers with different reproductive potential (across and within 15 species) also differ in their resilience to oxidative stress and immune challenge.The workload of collecting the ants from the field and conducting the experiments in the laboratory will require the combined force and expertise of three experienced ant researchers. Overall, this comparative project across 15 ant species will provide valuable information on the molecular and physiological mechanisms underlying ageing in ants, how fecundity is linked to longevity in both queens and workers, and our general understanding of the reversal of the fecundity/longevity trade-off on the background of transitions in advanced social evolution.