Several FGF5 mutations are associated with hair length variation in many domestic animals, including New World camelids. The dromedary was investigated in the present study with breeds exhibiting marked variations in hair length. This study aimed to: (1) identify the molecular variation(s) in the three exons of FGF5 of a diverse group of breeds (Mejaheem, Shaele, Sofor, Waddah and Omani; n = 28); (2) examine the association of the identified variants with hair length; (3) validate the association via genotyping the polymorphism in a large population of diverse camels (n = 113); and (4) test the segregation of the identified variant with hair length in a pedigree. A non-synonymous mutation (c.779 C > T) was identified that changes the amino acid from proline to leucine and was found to be associated with different hair length in dromedaries. The variants at c.779 displayed a co-dominance mode of inheritance and three hair length phenotypes: short (C/C), intermediate (C/T) and long (T/T). Across the examined dromedary breeds, both alleles were present, which is probably due to the breeders’ preference for an intermediate hair length. When compared with other camelids, the identified variant was found exclusively in dromedaries with the ancestral allele at c.779 being ‘C’. This study constitutes the first thorough exploration of the FGF5 gene in dromedaries.

中文翻译：

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FGF5错义突变与单峰驼毛长度变异有关

一些FGF5突变与许多家养动物（包括新世界骆驼科动物）的毛发长度变化有关。在本研究中对单峰骆驼进行了调查，品种的毛发长度有显着差异。本研究旨在：(1) 确定不同品种群（Mejaheem、Shaele、Sofor、Waddah 和 Omani；n  = 28）的FGF5三个外显子的分子变异；(2) 检查已识别变异与头发长度的关联；(3) 通过对大量不同骆驼的多态性进行基因分型来验证关联 ( n = 113); (4) 测试鉴定的变异与系谱中头发长度的分离。鉴定了一种非同义突变（c.779 C > T），该突变将氨基酸从脯氨酸变为亮氨酸，并被发现与单峰骆驼的不同毛发长度有关。c.779 处的变体显示出共显性遗传模式和三种头发长度表型：短 (C/C)、中间 (C/T) 和长 (T/T)。在所检查的单峰骆驼品种中，两个等位基因都存在，这可能是由于饲养员偏爱中等长度的毛发。与其他骆驼科动物相比，所鉴定的变异仅在单峰骆驼中发现，其祖先等位基因在 c.779 为“C”。这项研究是对单峰骆驼FGF5基因的首次彻底探索。