Sex pheromones in Neotropical tree frogs (Hylidae) - Insights into an under-studied communication mode in anurans

化学交流是动物界进化中最古老的交流系统，对许多物种的性行为尤为重要。与其他动物相比，关于无尾两栖动物中信息素的研究极其稀少，尽管许多无尾两栖动物拥有被认为含有性信息素的生殖腺。以五种新热带树蛙为例，它们在身体的不同区域显示出雄性生殖腺，我想要调查这个世界上最大的青蛙家族(海蛙科)中性信息素的使用。为此，我计划1)在墨西哥和秘鲁的原生栖息地对这些青蛙进行采样，2)对它们的繁殖腺体进行组织学检查，并在3D模型中将它们可视化，3)使用遗传和化学方法(下一代测序和高效液相色谱)分离和鉴定信息素内容物，4)在野外行为分析中测试性信息素在求偶过程中的重要性。通过这项研究，我计划扩大到目前为止关于无尾两栖动物求偶信息素的使用和结构的非常有限的知识。对同一科内不同物种和属之间的信息素进行比较，以及与迄今已发现的其他两栖物种(特别是火蜥蜴)的化合物进行比较，可能有助于进一步了解两栖动物特别是无尾两栖动物中求偶信息素的进化。

Chemical communication is the evolutionary oldest communication system in the animal kingdom and it is especially important for the sexual behaviour in many species. Compared to other animals, studies regarding pheromones in anurans are extremely scarce, although many anuran species possess breeding glands which are suggested to contain sex pheromones. On the example of five Neotropical tree frog species that exhibit male breeding glands in different regions of the body, I want to investigate the use of sex pheromones in this worldwide biggest frog family (Hylidae). For this purpose I plan to 1) sample these frogs in their native habitats in Mexico and Peru, 2) histologically examine their breeding glands and visualize them in 3D-models, 3) isolate and identify the pheromonal gland contents using genetical and chemical methods (next generation sequencing and HPLC) and 4) test the significance of the sex pheromones during courtship in behavioural assays in the field. With this study I plan to expand the so far very restricted knowledge of the usage and structure of courtship pheromones in anurans. A comparison of the pheromones between the different species and genera within the same family as well as with so far identified chemical compounds of other amphibian species (especially salamanders) might lead to a further understanding of the evolution of courtship pheromones in amphibians generally and in anurans in particular.