Laboratoire Évolution et Diversité Biologique, UMR5174 CNRS - Université Paul Sabatier - ENFA, Toulouse, France.
PLoS One. 2012;7(12):e50906. doi: 10.1371/journal.pone.0050906. Epub 2012 Dec 5.
The Réunion grey white-eye (Zosterops borbonicus) is a single-island endemic passerine bird that exhibits striking geographically structured melanic polymorphism at a very small spatial scale. We investigated the genetic basis of this color polymorphism by testing whether the melanocortin-1 receptor (MC1R), a gene often involved in natural melanic polymorphism in birds, was associated with the observed plumage variation. Although we found three non-synonymous mutations, we detected no association between MC1R variants and color morphs, and the main amino-acid variant found in the Réunion grey white-eye was also present at high frequency in the Mauritius grey white-eye (Zosterops mauritianus), its sister species which shows no melanic polymorphism. In addition, neutrality tests and analysis of population structure did not reveal any obvious pattern of positive or balancing selection acting on MC1R. Altogether these results indicate that MC1R does not play a role in explaining the melanic variation observed in the Réunion grey white-eye. We propose that other genes such as POMC, Agouti or any other genes involved in pigment synthesis will need to be investigated in future studies if we are to understand how selection shapes complex patterns of melanin-based plumage pigmentation.
All sequences submitted to Genbank. Accession number: JX914505 to JX914564.
留尼汪灰色白眼鸟（Zosterops borbonicus）是一种单岛特有 passerine 鸟，在非常小的空间尺度上表现出明显的地理结构黑化多态性。我们通过测试黑素皮质素 1 受体（MC1R）是否与观察到的羽毛变异有关，研究了这种颜色多态性的遗传基础。尽管我们发现了三个非同义突变，但我们没有发现 MC1R 变体与颜色形态之间的关联，并且在留尼汪灰色白眼鸟中发现的主要氨基酸变体也在其姐妹种毛里求斯灰色白眼鸟（Zosterops mauritianus）中高频出现，而毛里求斯灰色白眼鸟没有表现出黑化多态性。此外，中性检验和种群结构分析没有揭示出 MC1R 上任何明显的正选择或平衡选择模式。总的来说，这些结果表明 MC1R 不能解释留尼汪灰色白眼鸟中观察到的黑化变异。我们提出，如果我们要了解选择如何塑造黑色素为基础的羽毛色素沉着的复杂模式，那么需要在未来的研究中调查其他基因，如 POMC、Agouti 或任何其他参与色素合成的基因。
所有提交给 Genbank 的序列。注册号：JX914505 至 JX914564。
