School of Biological Sciences, University of Utah, Salt Lake City, UT, USA.
Department of Human Genetics and Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, USA.
Mol Biol Evol. 2021 Dec 9;38(12):5376-5390. doi: 10.1093/molbev/msab260.
The iris of the eye shows striking color variation across vertebrate species, and may play important roles in crypsis and communication. The domestic pigeon (Columba livia) has three common iris colors, orange, pearl (white), and bull (dark brown), segregating in a single species, thereby providing a unique opportunity to identify the genetic basis of iris coloration. We used comparative genomics and genetic mapping in laboratory crosses to identify two candidate genes that control variation in iris color in domestic pigeons. We identified a nonsense mutation in the solute carrier SLC2A11B that is shared among all pigeons with pearl eye color, and a locus associated with bull eye color that includes EDNRB2, a gene involved in neural crest migration and pigment development. However, bull eye is likely controlled by a heterogeneous collection of alleles across pigeon breeds. We also found that the EDNRB2 region is associated with regionalized plumage depigmentation (piebalding). Our study identifies two candidate genes for eye colors variation, and establishes a genetic link between iris and plumage color, two traits that vary widely in the evolution of birds and other vertebrates.
眼睛的虹膜在脊椎动物物种中表现出显著的颜色变化，可能在伪装和交流中发挥重要作用。家鸽（Columba livia）有三种常见的虹膜颜色，橙色、珍珠（白色）和公牛（深褐色），在一个单一的物种中分离，从而为鉴定虹膜颜色的遗传基础提供了一个独特的机会。我们使用比较基因组学和实验室杂交中的遗传图谱来鉴定控制家鸽虹膜颜色变化的两个候选基因。我们在家鸽的珍珠眼中发现了一个 SLC2A11B 溶质载体的无义突变，这是所有珍珠眼鸽共有的，而一个与公牛眼颜色相关的基因座包括 EDNRB2，该基因参与神经嵴迁移和色素发育。然而，公牛眼可能是由鸽种之间的一系列不同等位基因控制的。我们还发现 EDNRB2 区域与羽毛区域褪色（白化）有关。我们的研究确定了两个候选基因，用于眼睛颜色的变化，并建立了虹膜和羽毛颜色之间的遗传联系，这两个特征在鸟类和其他脊椎动物的进化中变化很大。
