Aging and rejuvenation: An ant model to study the regulation of longevity

项目总结： 蚂蚁是一种群居昆虫，可以发展为实验上易于驯化的有机体，用于探测动态 控制包括衰老在内的一系列过程的表观遗传程序的变化。衰老是一个过程 内在生理功能的进行性衰退。在寿命之间有一个公认的权衡 而生殖作为女性较高的生殖活动与较短的寿命有关。但是，在 在群居昆虫中，繁殖蚁后的寿命比非繁殖蚁长10倍。在蚂蚁身上 Harpegnathos saltator，未接触蜂王信息素的成年个体可以经历可逆的 从非生殖工作者转变为表现出充分发育的生殖假女王(配偶门) 卵巢，更重要的是，寿命延长了5倍，这表明衰老是可逆的。寿命再次缩短 当玩家门回复到工人(回复者)的时候。因此，Harpegnathos提供了一个有效的系统来 研究衰老和返老还童的表观遗传调控，因为成体的可塑性允许在 种姓。 我们已经对长寿调节组织：脂肪体、卵巢和大脑进行了转录组分析。 工人VS游戏门VS复原者。我们已经确定了一组差异表达基因(Deg)， 其中一些与长寿的调节有关，例如IIS(胰岛素和IGF信号转导)途径 组件。为了进一步分析蚂蚁长寿的遗传和表观遗传调控，我们将首先比较 年轻与老年配子门的生理学、寿命、转录组和组蛋白修饰 工人们来确定衰老的表观遗传调控，最有趣的是，恢复活力。蜂窝手机 重点部门的定位和功能将进一步分析。第二，我们将利用我们新的 已建立的遗传工具-蚂蚁的CRISPR-在卵巢的两个部位产生敲除(KO)蚂蚁，HS ImpL2和HS-ALS，它们可能是蚂蚁IIS的抑制剂。这些KO蚂蚁将被用来描述 IIS在游戏门显著延长寿命中的作用。第三，HS-ILP1(胰岛素样肽1)是 在脑中差异表达，在卵巢中差异表达。而HS-ILP1和HS-ILP2都很强 与工蚁相比，智商增加，脂肪体和卵巢中的IIS减少。要解决这个问题 悖论，我们将分析(A)HS-ILP1和-ILP2在调节IIS的两个分支：AKT和 MAPK；(B)HS-ImpL2和HS-ALS在调节HS-ILPS活性中的作用；以及(C)两个胰岛素受体如何 (INRs)介导HS-ILPS在差异调节IIS中的作用。

Project summary: Ants are social insects that can be developed as experimentally tractable organisms for probing the dynamic changes in the epigenetic programs that control an array of processes, including aging. Aging is a process of progressive decline in intrinsic physiological functions. There is a well-established trade-off between lifespan and reproduction as higher reproductive activity in females is associated with shorter lifespan. However, in social insects, the reproductive queen has up to 10X longer lifespan than non-reproductive workers. In the ant Harpegnathos saltator, adult individuals that are not exposed to queen pheromones can undergo a reversible switch from non-reproductive workers to reproductive pseudo-queens (gamergates) that exhibit fully developed ovary and, importantly, a 5X increase in lifespan, showing that aging is reversible. Lifespan is shortened again when gamergates are reverted to workers (revertants). Thus, Harpegnathos provides an effective system to study epigenetic regulation of aging and rejuvenation given the adult plasticity that allows switching between castes. We have performed transcriptome analysis of the longevity-regulatory tissues: the fat body, ovary and brain, in workers vs. gamergates vs. revertants. We have identified a group of differentially expressed genes (DEGs), some of which have been implicated in the regulation of longevity, e.g. IIS (insulin and IGF signaling) pathway components. To further analyze the genetic and epigenetic regulation of longevity in ants, we will first compare physiology, lifespan, transcriptome and histone modifications in gamergates derived from young vs. old workers to ascertain the epigenetic regulation of aging and, most intriguingly, rejuvenation. The cellular localization and functions of important DEGs will be further analyzed. Second, we will utilize our newly established genetic tool – CRISPR in ants – to generate knockout (KO) ants in the two DEGs in the ovary, Hs- IMPL2 and Hs-ALS, which likely act as inhibitors of IIS in ants. These KO ants will be used to characterize the role of IIS in the dramatically extended lifespan in gamergates. Third, Hs-ILP1 (insulin-like peptide 1) is differentially expressed in the brain and Hs-ILP2 in the ovary. While both Hs-ILP1 and Hs-ILP2 are strongly increased in gamergates compared to workers, IIS is decreased in the fat body and ovary. To address this paradox, we will analyze (a) the role of Hs-ILP1 and -ILP2 in regulating the two branches of IIS: AKT and MAPK; (b) the role of Hs-ImpL2 and Hs-ALS in regulating activity of Hs-ILPs; and (c) how two insulin receptors (InRs) mediate the role of Hs-ILPs in differentially regulating IIS.