Animal melanin has an important role in the formation of animal fur and skin, which is determined by its quantities, character, and distribution. To identify the effect of melanin on the formation of multi-colored Rex rabbits (Black, Chinchilla, Beaver, Protein cyan, Protein yellow, White), the structure of hair follicles and melanin content in multi-colored Rex rabbit skins were observed by Hematoxylin and Eosin (H&E) staining and melanin staining, respectively. The melanin granules were primarily found in the epidermis and hair follicle roots. The melanin content of skin was measured by extracting melanin from skin tissue. The results demonstrated that the melanin content was the highest in the skin of black Rex rabbit. Additionally, we measured the mRNA and protein expression levels of melanin-related key genes (MITF and TYR) in the skin of different hair color by quantitative real-time PCR and Wes assay, respectively. The results revealed that the mRNA expression levels in the skin of black Rex rabbit was highly expressed when as compared with other Rex rabbit skin (P < 0.01), and they were the lowest in the skin of white Rex rabbit. Finally, correlation analysis was conducted between melanin content and the expression levels of mRNA and protein. The results indicated a significant correlation between melanin content and the mRNA expression of MITF (P < 0.05), but it was not correlated with the mRNA expression of TYR (P > 0.05). In summary, melanin deposition has important economic value, and the coat color of fur-bearing animals is partly determined by the melanin-related genes.

中文翻译：

---

雷克斯兔黑色素色素沉着的形态学特征和基因表达模式。

动物黑色素在动物毛皮和皮肤的形成中起着重要作用，这由其数量，特征和分布决定。为了确定黑色素对多色獭兔（黑色，龙猫，海狸，蛋白蓝，蛋白黄，白色）形成的影响，通过苏木精观察了多色獭兔皮肤中的毛囊结构和黑色素含量和曙红（H＆E）染色和黑色素染色。黑色素颗粒主要存在于表皮和毛囊根部。通过从皮肤组织中提取黑色素来测量皮肤的黑色素含量。结果表明，黑獭兔皮肤中黑色素含量最高。另外，我们通过实时荧光定量PCR和Wes分析分别测量了不同发色皮肤中黑色素相关关键基因（MITF和TYR）的mRNA和蛋白质表达水平。结果显示，与其他獭兔皮肤相比，黑獭兔皮肤中的mRNA表达水平高（P  <0.01），并且是白獭兔皮肤中最低的。最后，进行了黑色素含量与mRNA和蛋白质表达水平之间的相关性分析。结果表明，黑色素含量与MITF的mRNA表达之间存在显着相关性（P  <0.05），但与TYR的mRNA表达无关（P  > 0.05）。总之，黑色素的沉积具有重要的经济价值，而带有毛皮的动物的皮毛颜色部分取决于黑色素相关的基因。