Eusocial insect reproductive females show strikingly longer life spans than nonreproductive female workers despite high genetic similarity. In the ant Harpegnathos saltator (Hsal), workers can transition to reproductive “gamergates,” acquiring a fivefold prolonged life span by mechanisms that are poorly understood. We found that gamergates have elevated expression of heat shock response (HSR) genes in the absence of heat stress and enhanced survival with heat stress. This HSR gene elevation is driven in part by gamergate-specific up-regulation of the gene encoding a truncated form of a heat shock factor most similar to mammalian HSF2 (hsalHSF2). In workers, hsalHSF2 was bound to DNA only upon heat stress. In gamergates, hsalHSF2 bound to DNA even in the absence of heat stress and was localized to gamergate-biased HSR genes. Expression of hsalHSF2 in Drosophila melanogaster led to enhanced heat shock survival and extended life span in the absence of heat stress. Molecular characterization illuminated multiple parallels between long-lived flies and gamergates, underscoring the centrality of hsalHSF2 to extended ant life span. Hence, ant caste-specific heat stress resilience and extended longevity can be transferred to flies via hsalHSF2. These findings reinforce the critical role of proteostasis in health and aging and reveal novel mechanisms underlying facultative life span extension in ants.

中文翻译：

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独特的热休克因素维持了蚂蚁的长寿命

尽管遗传相似性很高，但具有生殖能力的雌性社会性昆虫的寿命却比不具有生殖能力的雌性工蜂的寿命要长得多。在蚂蚁Harpegnathos saltator ( Hsal），工人们可以过渡到生殖“玩家门”，通过人们知之甚少的机制获得五倍的寿命延长。我们发现，在没有热应激的情况下，玩家门的热休克反应（HSR）基因表达升高，并在热应激时提高了生存率。这种 HSR 基因升高部分是由编码与哺乳动物 HSF2 (hsalHSF2) 最相似的热休克因子截短形式的基因的玩家门特异性上调驱动的。在工人中，hsalHSF2 仅在热应激时才与 DNA 结合。在玩家门中，即使在没有热应激的情况下，hsalHSF2 也会与 DNA 结合，并且定位于偏向玩家门的 HSR 基因。hsalHSF2在果蝇中的表达在没有热应激的情况下，可以提高热休克存活率并延长寿命。分子表征阐明了长寿果蝇和玩家门之间的多重相似之处，强调了 hsalHSF2 对延长蚂蚁寿命的中心作用。因此，蚂蚁种姓特有的热应激恢复能力和延长的寿命可以通过 hsalHSF2 转移到果蝇身上。这些发现强化了蛋白质稳态在健康和衰老中的关键作用，并揭示了蚂蚁兼性寿命延长的新机制。