Skin transcriptional profiles in Oophaga poison frogs

Abstract Aposematic organisms advertise their defensive toxins to predators using a variety of warning signals, including bright coloration. While most Neotropical poison frogs (Dendrobatidae) rely on crypsis to avoid predators, Oophaga poison frogs from South America advertise their chemical defenses, a complex mix of diet-derived alkaloids, by using conspicuous hues. The present study aimed to characterize the skin transcriptomic profiles of South American Oophaga poison frogs. Our analyses showed very similar transcriptomic profiles for these closely related species in terms of functional annotation and relative abundance of gene ontology terms expressed. Analyses of expression profiles of Oophaga and available skin transcriptomes of cryptic anurans allowed us to propose initial hypotheses for the active sequestration of alkaloid-based chemical defenses and to highlight some genes that may be potentially involved in resistance mechanisms to avoid self-intoxication and skin coloration. In doing so, we provide an important molecular resource for the study of warning signals that will facilitate the assembly and annotation of future poison frog genomes.

摘要 警戒色生物通过各类警戒信号（包括鲜亮体色）向捕食者昭示其防御性毒素。尽管多数新热带区箭毒蛙（箭毒蛙科Dendrobatidae）依靠隐蔽拟态躲避捕食者，但来自南美洲的Oophaga属箭毒蛙则通过醒目的体色，昭示其由饮食来源生物碱混合而成的复杂化学防御体系。本研究旨在解析南美洲Oophaga属箭毒蛙的皮肤转录组谱。分析结果显示，这些亲缘关系密切的物种在基因本体（Gene Ontology，GO）注释功能与表达基因本体术语的相对丰度方面，转录组谱极为相似。通过整合分析Oophaga属箭毒蛙的表达谱与已公开的隐蔽性无尾两栖类皮肤转录组数据，我们首次提出了基于生物碱的化学防御主动储存假说，并筛选出可能参与自身中毒抗性机制与体色形成的候选基因。本研究为警戒信号相关研究提供了重要的分子资源，将助力未来箭毒蛙基因组的组装与注释工作。