Anello M, Daverio M S, Silbestro M B, Vidal-Rioja L, Di Rocco F
Laboratorio de Genética Molecular, Instituto Multidisciplinario de Biología Celular (IMBICE), CONICET-UNLP-CIC, Calle 526 e/10 y 11, La Plata, 1900, Buenos Aires, Argentina.
Anim Genet. 2019 Apr;50(2):143-149. doi: 10.1111/age.12769. Epub 2019 Feb 7.
The llama (Lama glama) is a fiber-producing species that presents a wide range of coat colors, among which white is one of the most important for the textile industry. However, there is little information about the molecular mechanisms that control the white phenotype in this species. In domestic mammals, a white coat is usually produced by mutations in the KIT proto-oncogene receptor tyrosine kinase (KIT) and microphthalmia-associated transcription factor (MITF) genes. In this work we have sequenced and described the coding regions of KIT and MITF-M, the melanocyte-specific isoform, and the two transcriptional variants MITF-M(-) and MITF-M(+). Moreover, we studied the expression of these genes in the skin of white and colored llamas. Although no variants were revealed to be associated with white coat color, significant differences between phenotypes were observed in the expression levels of KIT and MITF-M. Interestingly, white llamas expressed less MITF-M(+) than did colored ones, which is consistent with a consequent reduction in the synthesis of melanin. Even though our results indicate that downregulation of KIT and MITF-M expression is involved in white phenotype production in llamas, the causative gene of white coat color remains unknown.
羊驼（Lama glama）是一种产毛动物，其毛色种类繁多，其中白色对纺织业来说是最重要的颜色之一。然而，关于该物种中控制白色表型的分子机制的信息却很少。在家养哺乳动物中，白色皮毛通常是由原癌基因受体酪氨酸激酶（KIT）和小眼相关转录因子（MITF）基因的突变产生的。在这项研究中，我们对KIT和MITF-M（黑素细胞特异性异构体）以及两种转录变体MITF-M(-)和MITF-M(+)的编码区进行了测序和描述。此外，我们研究了这些基因在白色和有色羊驼皮肤中的表达情况。虽然没有发现与白色毛色相关的变体，但在KIT和MITF-M的表达水平上观察到了表型之间的显著差异。有趣的是，白色羊驼表达的MITF-M(+)比有色羊驼少，这与黑色素合成的相应减少是一致的。尽管我们的结果表明KIT和MITF-M表达的下调与羊驼白色表型的产生有关，但白色皮毛颜色的致病基因仍然未知。
