The evolution of altruistic workers in termites and their molecular underpinnings

白蚁利他工蚁的进化及其分子基础

• 批准号: 501764160
• 负责人: Professorin Dr. Judith Korb
• 金额: --
• 依托单位: Abteilung Evolutionsbiologie und Ökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/501764160?language=en
• 关键词: evolution; altruistic; workers; termites; their

Eusocial insects, like honeybees and ants, are textbook examples of social evolution. They are characterized by reproductive division of labour with a one or a few reproducing individuals, while the other colony members perform all other tasks such as brood care and defence. This resembles division of labour in multicellular organisms with cells specialized in reproduction (germline) and somatic tissues performing all other tasks. Accordingly, social insects have been called ‘superorganisms’ and the evolution of eusociality has be classified as a major evolutionary transition.Termites, the second major lineage of social insects, are less studied. They are all eusocial insects because of the presence of queens and kings and sterile soldiers. Yet, the degree of worker altruism varies profoundly between lineages. It ranges from (i) totipotent ‘false workers’ which develop in reproductives and (ii) non-sterile ‘true workers’ with reduced reproductive options, to (iii) sterile ‘true workers’. Only the third type qualifies as having passed a major evolutionary transition. The occurrence of these worker types aligns with the social complexity and ecology of the species. Yet the evolutionary history of worker altruism is unclear. Phylogenetic reconstructions provide an ambiguous signal of two alternative, equally parsimonious hypotheses. Also other traits, like development, do not yield clear answers. Thus, there is a nearly 40 years’ debate on the evolutionary history of termite sociality centring on these hypotheses.We aim to uncover the molecular underpinnings of worker development using genomic and transcriptomic approaches. By studying crucial species of different degrees of worker altruism across the termites’ phylogeny, we will identify homologous gene regulatory networks. They will allow us to deduce the evolutionary history of worker altruism, test the two alternative hypotheses, and thus solve a long-standing controversy. Our study also offers a rare opportunity to track the history of a major evolutionary transition. Finally, it will allow future studies to map ecological traits to transitions and infer potential driving forces of social evolution.

真社会性昆虫，如蜜蜂和蚂蚁，是社会进化的教科书例子。它们的特点是与一个或几个繁殖个体进行生殖分工，而其他群体成员则执行所有其他任务，如育雏和防御。这类似于多细胞生物中的劳动分工，细胞专门从事生殖（生殖细胞）和体细胞组织执行所有其他任务。因此，社会性昆虫被称为“超级有机体”，真社会性的进化被归类为一个主要的进化转变。白蚁是社会性昆虫的第二大谱系，但研究较少。它们都是真社会性昆虫，因为有女王、国王和不育的士兵。然而，工人利他主义的程度在不同的血统之间有很大的差异。它的范围从（i）全能的“假工人”，在生殖和（ii）非不育的“真正的工人”减少生殖选择，（iii）不育的“真正的工人”。只有第三种类型才有资格通过一个主要的进化过渡。这些工蚁的出现与物种的社会复杂性和生态学相一致。然而，工人利他主义的进化史尚不清楚。系统发育重建提供了两个可供选择的模糊信号，同样简约的假设。其他的特征，比如发展，也不能给出明确的答案。因此，围绕这些假说，白蚁社会性的进化史已经有近40年的争论。我们的目标是利用基因组和转录组学方法揭示工蚁发育的分子基础。通过研究不同程度的工人利他主义在白蚁的进化过程中的关键物种，我们将确定同源基因调控网络。它们将使我们能够推断出工人利他主义的进化历史，检验两种替代假设，从而解决一个长期存在的争议。我们的研究还提供了一个难得的机会来追踪一个重大进化转变的历史。最后，它将允许未来的研究映射生态特征的过渡和推断社会进化的潜在驱动力。