Evolution, genetic basis and behavioural consequences of cuticular hydrocarbon diversification: the case of parabiotic ants

表皮碳氢化合物多样化的进化、遗传基础和行为后果：以共生蚂蚁为例

• 批准号: 285894508
• 负责人: Dr. Barbara Feldmeyer
• 金额: --
• 依托单位: Senckenberg Biodiversität und Klima Forschungszentrum (BiK-F)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/285894508?language=en
• 关键词: Evolution; genetic; basis; behavioural; consequences

Insect cuticles are covered with cuticular hydrocarbons (CHC). They serve two important functions: as desiccation barrier and for chemical communication. Especially in social insects, CHC profiles encode a multitude of information such as species membership, sex, reproductive caste, and colony membership. Despite their high importance, however, the evolution of CHC profiles and the underlying genetic mechanisms are little understood. Also, little is known which CHC are important for intra- and interspecific recognition.We propose to investigate a model system which is highly suited for addressing such questions. The neotropical ants Crematogaster levior and Camponotus femoratus are parabiotically associated, i.e. they share a common nest in a mutualistic way. Their CHC profiles are unusually diverse: in both taxa, multiple chemotypes exist, which have few or no compounds in common. In contrast, CHC variation in most other species is restricted to quantitative variation of the same compounds. Thus, our model system shows high chemical variability between closely related individuals, which are likely to be physiologically and ecologically similar. This unique combination opens up intriguing opportunities to investigate the evolution of cuticular hydrocarbon profiles, the causes and consequences of chemical diversification and its role for speciation. We will study the genetic basis of CHC diversity as well as the role of chemical differentiation for intra- and interspecific communication.First, we will study genetic and chemical differentiation across populations of Cr. levior in French Guiana, and elucidate population structure using genotyping by sequencing (GBS). This will allow us to investigate the relations of genetic, chemical and geographic distance to reveal the role of chemical differentiation for reproductive isolation and speciation. Second, we will study how chemical differentiation affects nestmate recognition and recognition by an associated species. Using behavioural assays with CHC fractions, we will study which CHC classes are relevant for intra- and interspecific recognition.For both Cr. levior and Ca. femoratus, we will investigate which genes are differentially expressed and/or differentially selected in different chemotypes. Our results will provide novel insights into the genetic regulation of CHC differentiation, which is still largely unknown. To verify the functionality of identified candidate loci, we will silence them via RNAi and determine the effect on CHC profiles. The biological relevance of CHC changes for nestmate and species recognition will be determined in aggression bioassays. The high CHC variation between chemotypes suggests that small changes on DNA and/or regulatory level suffice to induce large-scale changes in the CHC profile. Our project will provide a multitude of novel insights on the evolution, genetic mechanisms and behavioural consequences of cuticular hydrocarbon diversification in ants.

昆虫的角质层覆盖着角质层碳氢化合物(CHC)。它们有两个重要的功能：作为干燥屏障和化学通讯。特别是在群居昆虫中，CHC简档编码了大量信息，如物种成员身份、性别、生殖种姓和群体成员身份。然而，尽管它们非常重要，但CHC图谱的演变和潜在的遗传机制却鲜为人知。此外，对哪些CHC对于种内和种间识别是重要的知之甚少。我们建议研究一个非常适合于解决这些问题的模型系统。新热带蚂蚁Burmatogaster levior和Camponotus feoratus是寄生相关的，即它们以互惠共生的方式共享一个巢。它们的CHC谱异常不同：在两个分类群中，都存在多种化学类型，它们几乎没有共同的化合物。相比之下，大多数其他物种的CHC变化仅限于相同化合物的数量变化。因此，我们的模型系统显示了密切相关的个体之间的高度化学变异性，这些个体在生理和生态上可能是相似的。这种独特的组合为研究表层碳氢化合物剖面的演变、化学多样化的原因和后果及其对物种形成的作用提供了有趣的机会。我们将研究CHC多样性的遗传基础以及化学分化在种内和种间交流中的作用。首先，我们将研究不同种群之间的遗传和化学分化。并使用测序基因分型技术(GBS)阐明种群结构。这将使我们能够研究遗传、化学和地理距离的关系，以揭示化学分化在生殖隔离和物种形成中的作用。其次，我们将研究化学差异如何影响鸟巢伴侣的识别和相关物种的识别。通过对CHC组分的行为分析，我们将研究哪些CHC类别与种内和种间识别有关。利维和钙。我们将研究哪些基因在不同的化学类型中有差异表达和/或差异选择。我们的结果将为CHC分化的遗传调控提供新的见解，这在很大程度上仍然是未知的。为了验证已识别的候选基因座的功能，我们将通过RNAi使它们沉默，并确定对CHC图谱的影响。CHC变化对鸟巢和物种识别的生物学相关性将在攻击性生物测定中确定。不同化学类型之间的CHC差异很大，这表明DNA和/或调控水平上的微小变化足以诱导CHC谱的大规模变化。我们的项目将为蚂蚁表皮碳氢化合物多样化的进化、遗传机制和行为后果提供大量新的见解。