Genetics of adaptation in colourful poison frogs

哺乳动物、鸟类、鱼类和爬行动物对着色的遗传学进行了研究，但对两栖动物的研究很少。除了颜色模式的广泛变异性外，关于在两栖动物物种内部和之间创造颜色多样性的潜在遗传成分，我们一无所知。在这种背景下，新热带毒蛙与捕食者避免策略有关的色彩模式的多样性是研究生态适应遗传学的一个令人兴奋的机会。不同种群的毒蛙的颜色模式不同，有强有力的证据表明，颜色是适应性的，可能是由捕食者的选择驱动的。在适应性着色、行为和毒性方面的差异，再加上分类交配(通过颜色)，很可能是颜色变体之间形成前合子隔离机制的原因。这项建议的目的是对颜色极其多态的新热带草莓毒蛙Oophaga的着色基因进行表征。普米利奥。这种蛙在不同的巴拿马种群中既有明亮的异形体，也有较暗的隐晦的颜色变形体。对于这个项目，我将从三个不同颜色模式的人群中收集皮肤样本：一个红色的，一个绿色的和一个蓝色的。我将进行RNAseq分析，以获得背部皮肤来源的cDNA。CDNA样本将被送往测序服务，该服务将执行下一代测序，以分析涉及着色的基因表达水平的差异。我预计参与类胡萝卜素/蝶呤吸收、合成或储存的基因在不同的颜色变体中的表达水平不同。我将通过执行实时定量RT-PCR(RT=反转录)来确认有显著表达差异的基因座的结果。因此，我将确定该物种颜色变异背后的关键基因表达差异。这一关键信息本身将具有重大意义，因为它将识别色素形成的分子途径的哪些部分在该物种中适应性地进化。它还将为未来的研究开辟许多有趣的途径，从而更好地理解自适应着色的原因和后果。

The genetics of colouration has been studied in mammals, birds, fish and reptiles but studies on amphibians are scarce. Besides extensive variability in colour pattern nothing is known about the underlying genetic components involved in creating colour diversity within and among amphibian species. In this context the diversity of colouration patterns linked to predator avoidance strategies in Neotropical poison frogs is an exciting opportunity to study the genetics of ecological adaptation. Poison frogs differ in colouration patterns among populations and strong evidence exists that colouration is adaptive, probably driven by predator selection. Divergence in adaptive colouration, behaviour and toxicity in combination with assortative mating (by colour) very likely contributes to the formation of prezygotic isolation mechanisms among colour morphs. The objective of this proposal is to characterize the colouration genes for the extremely colour polymorphic Neotropical strawberry poison frog Oophaga. pumilio. In this frog bright aposematic as well as duller cryptic colour morphs are present in different Panamanian populations. For this project I will collect skin samples from three populations diverged in colour patterns: a red one, a green one and a blue one. I will perform RNAseq analysis to obtain dorsal skin-derived cDNA. cDNA samples will be send to a sequencing service that will perform next generation sequencing to analyse differences in expression levels in genes involved in colouration. I expect that genes involved in the carotenoid /pteridine uptake, synthesis or storage differ in their expression level among colour morphs. I will confirm results for loci with significant expression differences by performing quantitative Real time-RT-PCR (RT=reverse transcription). Thus, I will determine the key gene expression differences underlying colour variation in this species. This critical information will be of major interest in its own right, as it will identify which parts of the molecular pathways to pigment formation are evolving adaptively in this species. It will also open up many interesting avenues for future investigation that will lead to a better understanding of causes and consequences of adaptive colouration.