Epigenetic regulation of social and behavioral plasticity in ants

摘要 这项提议的目标是确定表观遗传途径如何调节社会行为的可塑性。 使用模型蚂蚁Harpegnathos跳跃。具体地说，我们将测试外部社交线索的假设 通过调节下游转录因子和相关的神经肽传递到染色质 使社会行为发生稳定变化的表观遗传途径。 在神经发育和行为障碍中，表观遗传通路经常被破坏。哈佩格纳托斯 蚂蚁是研究大脑表观遗传学的理想模型系统，因为工蚁和蚁后拥有相同的基因 但表现出明显的社会行为。此外，成年的哈佩格纳托斯工蚁可以通过 显著的表型转变，包括生殖、新陈代谢和行为的可塑性变化。 我们发现，人类促性腺激素释放激素神经肽的蚂蚁同源物 随着Harpegnathos工人成为女王，它被下调了，并表明它是必要的和 足以刺激工人的狩猎。我们的初步数据显示，加压素是一种具有 在哺乳动物中保守的社会角色，也优先在工作者的大脑中表达，特别是在那些 不要表现出高水平的科拉西林。在目标1中，我们将确定这两个神经肽是否作用于 不同或重叠的神经元、分子和表观遗传途径，以及它们是否驱动不同的社会 行为。 我们之前的工作还发现，由Corazine诱导的转录因子Kr-H1可以防止程序外 激活大脑中“不适合社交的”基因，从而维持两人适当的社交行为 工人和游戏机门。初步研究发现，另一种转录因子Fd3F被抑制 这可能会促进与Kr-H1相反的社会可塑性。Fd3F与先锋有相同之处 其他物种中的转录因子，这表明重新编程染色质状态的能力可能是 它在行为重新编程中的作用。在目标2中，我们将确定转录和染色质的变化 这些转录因子通过什么来调节成年种姓转变过程中的大脑和行为可塑性 哈佩格纳托斯。 拟议的实验将利用我们之前在体内操纵基因表达的经验 在蚂蚁大脑中进行了行为和功能基因组分析。鉴于神经肽， 转录因子和表观遗传调节因子在这项研究中是非常保守的，我们的结果 应该对我们理解这些分子过程如何调节社会行为产生广泛的影响。

ABSTRACT The goal of this proposal is to determine how epigenetic pathways regulate plasticity in social behaviors using the model ant Harpegnathos saltator. Specifically, we will test the hypothesis that external social cues are conveyed to chromatin by neuropeptides that regulate downstream transcription factors and associated epigenetic pathways to enable stable changes in social behavior. Epigenetic pathways are often disrupted in neurodevelopmental and behavioral disorders. Harpegnathos ants are an ideal model system to study brain epigenetics because workers and queens have the same genes but display distinct social behaviors. Furthermore, adult Harpegnathos workers can become queens via a remarkable phenotypic transition that involves plastic changes in reproduction, metabolism, and behavior. We have discovered that the ant homolog of the human gonadotropin-releasing hormone, the neuropeptide corazonin, is downregulated as Harpegnathos workers become queens and showed that it is necessary and sufficient to stimulate hunting in workers. Our preliminary data show that vasopressin, a neuropeptide with conserved social roles in mammals, is also preferentially expressed in worker brains, especially in those who do not express high levels of corazonin. In Aim 1, we will determine whether these two neuropeptides act on distinct or overlapping neuronal, molecular, and epigenetic pathways and whether they drive distinct social behaviors. Our previous work also revealed that Kr-h1, a transcription factor induced by corazonin, prevents unscheduled activation of “socially inappropriate” genes in the brain, thereby maintaining proper social behavior in both workers and gamergates. Preliminary studies identified another transcription factor, Fd3F, which is repressed by corazonin and might promote social plasticity in opposition to Kr-h1. Fd3F shares homology with pioneer transcription factors in other species, suggesting that an ability to reprogram chromatin states might underpin its function in behavioral reprogramming. In Aim 2, we will identify the changes on transcription and chromatin by which these transcription factors regulate brain and behavioral plasticity during adult caste transitions in Harpegnathos. The proposed experiments will leverage our previous experience with in vivo manipulation of gene expression in ant brains followed by behavioral and functional genomics analyses. Given that the neuropeptides, transcription factors, and epigenetic regulators investigated in this proposal are deeply conserved, our results should have broad impact on our understanding of how these molecular processes regulate social behavior.