Odorant and gustatory receptor diversity and evolution in the stinging wasps, ants, and bees (Hymenoptera: Aculeata)

有关环境化学成分的信息对任何生物体都是至关重要的。例如，化学感官能够定位和评估食物来源、产卵地点和生殖伙伴的质量。群居昆虫，如蚂蚁，进一步利用化学因素(信息素)来建立它们的群居行为。昆虫依靠三种类型的化学感受器来感知它们所处的化学环境：嗅觉(ORS)、味觉(GRS)和亲离子受体。虽然后者通常在拷贝数和氨基酸序列上都是保守的，但一些昆虫具有显著的或和Gr谱系扩展，最明显的是蚂蚁和蜜蜂。这些扩展与蚂蚁和蜜蜂的社会生活以及相关的区分各种不同化学因素(如痕迹信息素)的必要性有关。然而，一些非社会性黄蜂的化学感受器的特征表明，具有寄生生活方式的物种也可以表现出大量的化学感受器。由于膜翅目中与真社会性蚂蚁和蜜蜂的亲缘关系较近的任何一个谱系中的化学受体都没有被研究过，所以目前还不清楚蚂蚁和蜜蜂中化学受体的异常多样性是否是这两个群体的衍生特征。我们的研究项目旨在首次全面推断膜翅目蚂蚁和蜜蜂起源的类群的or和Gr多样性的进化：刺蜂(刺蜂)。预期结果将告知生活方式变化的时间和背景，或GR曲目的扩展。此外，它们将为9-外显子亚组的ORS是否可能参与角质层碳氢化合物的感知提供新的见解。我们将研究总共23只刺蜂的化学感受器(代表所有主要的针叶目，包括。那些具有寄生生活方式的黄蜂)，以及与针叶蜂类密切相关的黄蜂物种。为了回答我们的研究问题，我们将比较研究化学感觉组织的基因转录数据和基因组数据。我们比较的基础将是11种独居黄蜂的基因组组合草图，我们为这一项目做准备时对其进行了测序。为了编制相应的或和Gr编码基因的基因组序列数据，也在其基因组到目前为止尚未测序的物种中，我们将应用目标DNA富集法。这种方法有望促进未来对那些由于基因组巨大而无法经济地对其基因组进行测序的物种的基因库进行比较分析。因此，从我们的研究项目中获得的见解将不仅对进化生物学家以及进化和化学生态学家产生重大兴趣，而且对在比较基因组学领域的各个领域工作的科学家也是如此。

Information about the chemical composition of the environment is of critical importance for any organism. Chemical senses enable, for example, localizing and assessing the quality of food sources, oviposition sites, and reproductive partners. Social insects, such as ants, further utilize chemical factors (pheromones) to establish their social behaviors. Insects rely on three types of chemosensory receptors to perceive their chemical environment: olfactory (Ors), gustatory (Grs), and ionotropic receptors. While the latter are typically conserved in both their copy number and amino acid sequence, some insects feature remarkable Or and Gr repertoire expansions, most notably ants and bees. These expansions have been linked with the ants' and bees' eusocial life and the associated necessity to discriminate between various different chemical factors (e.g., trail pheromones). The characterization of the chemoreceptors in some non-eusocial wasps revealed, however, that species with a parasitoid lifestyle can also exhibit large chemoreceptor repertoires. Since chemoreceptors have not been studied in any lineage of Hymenoptera comparatively closely related to eusocial ants and bees, it remains unclear whether or not the extraordinary diversity of chemoreceptors in ants and bees is a derived feature of these two groups at all. Our research project aims at comprehensively inferring for the first time the evolution of Or and Gr diversity in the group of Hymenoptera from within which ants and bees arose: the stinging wasps (Aculeata). The expected results will inform both about when and in what context of lifestyle changes Or and Gr repertoire expansions occurred. Furthermore, they will provide new insights into whether or not Ors of the 9-exon subgroup are likely involved in the perception of cuticular hydrocarbons. We will study the chemoreceptors in a total of 23 stinging wasps (representing all major lineages of Aculeata, incl. those with parasitoid lifestyles) and in a wasp species closely related to the aculeates. To answer our research questions, we will compare gene transcript data from studying chemosensory tissues with genomic data. The foundation for our comparisons will be, among others, draft genome assemblies of eleven species of solitary wasps that we sequenced in preparation for this project. To compile corresponding genomic sequence data of Or- and Gr-coding genes also in species whose genomes have not been sequenced so far, we will apply a target DNA enrichment approach. The approach promises to foster future comparative analyses of gene repertoires in species whose genomes cannot be sequenced economically due to the huge size of the genomes. The insights gained from our research project will thus not only be of major interest for evolutionary biologists as well as evolutionary and chemical ecologists, but also for scientists working in various areas in the field of comparative genomics.