Data from: Revealing the biochemical and genetic basis of color variation in a polymorphic lizard

Determining the mechanistic and genetic basis of animal coloration is essential to understand the costs and constraints on colour production, and the evolution and maintenance of phenotypic variation. However, genes underlying structural colour and widespread pigment classes apart from melanin remain largely uncharacterised, in part due to restricted taxonomic focus. We combined liquid chromatography-mass spectrometry and RNA-seq gene expression analyses to characterise the pigments and genes associated with skin colour in the polymorphic lizard, Ctenophorus decresii. Throat coloration in male C. decresii may be a combination of orange, yellow, grey or ultra-violet blue. We confirmed the presence of two biochemically different pigment classes, pteridines (self-synthesised) and carotenoids (acquired through the diet), in all skin colours. Orange skin had the highest levels of pteridine pigments while yellow skin tended to have higher levels of carotenoids, of which the vitamin A precursors β-carotene and β-cryptoxanthin have not been previously confirmed in reptiles. These results were confirmed by gene expression analyses, which detected 489 genes differentially expressed between the skin colours, including genes associated with pteridine production, provitamin A carotenoid metabolism, iridophore-specific synthesis, melanin synthesis and steroid hormone pathways. For the majority of these 489 genes, however, our study reveals a new association with colour production in vertebrates. These data represent a significant contribution to understanding the genetic basis of colour variation in vertebrates and a rich resource for further studies.

解析动物体色形成的机制与遗传基础，对于理解色素合成的代价与限制因素，以及表型变异的演化与维持机制至关重要。然而，除黑色素外，与结构色及广泛分布的其他色素类群相关的基因在很大程度上仍未被解析，这在一定程度上源于研究类群的局限性。我们结合液相色谱-质谱联用技术与RNA测序（RNA-seq）基因表达分析，对多态性蜥蜴德氏岩龙（Ctenophorus decresii）的体色相关色素与基因进行了表征。雄性德氏岩龙的喉部体色可呈现橙色、黄色、灰色或紫外蓝色的组合。我们在所有体色类型中均确认了两类生化特性不同的色素：蝶啶类（自身合成）与类胡萝卜素类（通过饮食获取）。橙色皮肤的蝶啶类色素含量最高，而黄色皮肤的类胡萝卜素含量通常更高；其中维生素A前体β-胡萝卜素与β-隐黄质此前尚未在爬行动物中被证实存在。基因表达分析验证了上述结果：该分析共检测到489个在不同体色皮肤间差异表达的基因，涵盖蝶啶合成、维生素A原类胡萝卜素代谢、虹彩细胞特异性合成、黑色素合成以及类固醇激素通路相关的基因。但在这489个基因中，绝大多数与脊椎动物体色形成的关联均为本次研究首次揭示。本研究数据为解析脊椎动物体色变异的遗传基础提供了重要贡献，同时也为后续相关研究提供了宝贵的资源。