Abstract:
Eusocial insects, such as ants and termites, are characterized by high levels of coordinated social organization. This is contrasted by solitary insects that display more limited forms of collective behavior. It has been hypothesized that this gradient in sociobehavioral sophistication is positively correlated with chemical profile complexity, due to a potentially increased demand for diversity in chemical communication mechanisms in insects with higher levels of social complexity. However, this claim has rarely been assessed empirically. Here, we compare different levels of chemical and transcriptomic complexity in selected species of the order Blattodea that represent different levels of social organization, from solitary to eusocial. We primarily focus on cuticular hydrocarbon (CHC) complexity, since it has repeatedly been demonstrated that CHCs are key signaling molecules conveying a wide variety of chemical information in solitary as well as eusocial insects. We assessed CHC complexity and divergence between our studied taxa of different social complexity levels as well as the differentiation of their respective repertoires of CHC biosynthesis gene transcripts. Surprisingly, we did not find any consistent pattern of chemical complexity correlating with social complexity, nor did the overall chemical divergence or transcriptomic repertoire of CHC biosynthesis genes reflect on the levels of social organization. Our results challenge the assumption that increasing social complexity is generally reflected in more complex chemical profiles and point toward the need for a more cautious and differentiated view on correlating complexity on a chemical, genetic, and social level.
摘要:
Eusocial昆虫,比如蚂蚁和白蚁,具有高水平的协调社会组织的特点。与之形成对比的是,孤独的昆虫表现出更有限的集体行为形式。有人假设,社会行为复杂性的这种梯度与化学特征复杂性呈正相关,由于对具有较高社会复杂性的昆虫化学通讯机制多样性的潜在需求增加。然而,这一说法很少被凭经验评估。这里,我们比较了代表不同社会组织水平的Blattodea顺序的选定物种中不同水平的化学和转录组复杂性,从孤独到社会。我们主要关注表皮碳氢化合物(CHC)的复杂性,因为已经反复证明CHCs是在单性和社会性昆虫中传达各种化学信息的关键信号分子。我们评估了CHC的复杂性和我们研究的不同社会复杂性水平的分类单元之间的差异,以及它们各自的CHC生物合成基因转录本的差异。令人惊讶的是,我们没有发现任何与社会复杂性相关的化学复杂性的一致模式,CHC生物合成基因的整体化学差异或转录组库也没有反映社会组织水平。我们的结果挑战了这样一个假设,即社会复杂性的增加通常反映在更复杂的化学概况中,并指出需要对化学品的复杂性进行更谨慎和差异化的观点。遗传,社会层面。