Institute of Biology, University of Graz, Universitätsplatz 2, A-8010 Graz, Austria.
Department of Comparative Physiology, Uppsala University, Norbyvägen 18A, SE-75 236 Uppsala, Sweden.
Biol Lett. 2020 Nov;16(11):20200629. doi: 10.1098/rsbl.2020.0629. Epub 2020 Nov 25.
Carotenoid pigments play a major role in animal body colouration, generating strong interest in the genes involved in the metabolic processes that lead from their dietary uptake to their storage in the integument. Here, we used RNA sequencing (RNA-Seq) to test for differentially expressed genes in a taxonomically replicated design using three pairs of related cichlid fish taxa from the genera and . Within each pair, taxa differed in terms of red and yellow body colouration, and high-performance liquid chromatography (HPLC) analyses of skin extracts revealed different carotenoid profiles and concentrations across the studied taxa. Five genes were differentially expressed in all three yellow-red skin contrasts (, , , and ), but only the tetratricopeptide repeat protein-coding gene , whose gene product is linked to mammalian lipid metabolism, was consistently expressed more highly in the red skin samples. The RNA-Seq results were confirmed by quantitative PCR. We propose as a compelling candidate gene for variation in animal carotenoid colouration. Since differential expression of was correlated with the presence/absence of yellow carotenoids in a previous study, we suggest that is more likely associated with the concentration of total carotenoids than with the metabolic formation of red carotenoids.
类胡萝卜素色素在动物体色形成中起着重要作用，因此人们对参与代谢过程的基因产生了浓厚的兴趣，这些基因将类胡萝卜素从饮食摄入引导到在表皮中的储存。在这里，我们使用 RNA 测序 (RNA-Seq) 在使用来自属和的三个相关慈鲷鱼类对的分类复制设计中测试差异表达基因。在每对中，类群在体色上存在红色和黄色差异，并且对皮肤提取物的高效液相色谱 (HPLC) 分析显示，在所研究的类群中存在不同的类胡萝卜素谱和浓度。五个基因在所有三种黄色-红色皮肤对比中都有差异表达（、、、和），但只有 tetratricopeptide repeat 蛋白编码基因，其基因产物与哺乳动物脂质代谢有关，在红色皮肤样本中始终表达更高。RNA-Seq 结果通过定量 PCR 得到了证实。我们提出作为动物类胡萝卜素颜色变化的一个有说服力的候选基因。由于在之前的研究中，的差异表达与黄色类胡萝卜素的存在/不存在相关，因此我们认为与总类胡萝卜素的浓度相关，而不是与红色类胡萝卜素的代谢形成相关。
