To investigate whether ocular albinism type 1 (OA1) is differentially expressed in the skin of mice with different coat colors and to determine its correlation with coat color establishment in mouse, the expression patterns and tissue distribution characterization of OA1 in the skin of mice with different coat colors were qualitatively and quantitatively analyzed by real-time quantitative PCR (qRT-PCR), immunofluorescence staining and Western blot. The qRT-PCR analysis revealed that OA1 mRNA was expressed in all mice skin samples tested, with the highest expression level in brown skin, a moderate expression level in black skin and the lowest expression level in gray skin. Positive OA1 protein bands were also detected in all skin samples by Western blot analysis. The relative expression levels of OA1 protein in both black and brown skin were significantly higher than that in gray skin, but there was no significant difference between black and brown mice. Immunofluorescence assays revealed that OA1 was mainly expressed in the hair follicle matrix, the inner and outer root sheath in the skin tissues with different coat colors. To get further insight into the important role of OA1 in the melanocytes' pigmentation, we transfected the OA1 into mouse melanocytes and then detected the relative expression levels of pigmentation-related gene. Simultaneously, we tested the melanin content of melanocytes. As a result, the overexpression of OA1 significantly increased the expression levels of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein 1 (TRP1) and premelanosome protein (PMEL). However, the tyrosinase-related protein 2 (TRP2) level was attenuated. By contrast, the level of glycoprotein non-metastatic melanoma protein b (GPNMB) was unaffected by OA1 overexpression. Furthermore, we observed a significant increase in melanin content in mouse melanocyte transfected OA1. Therefore, we propose that OA1 may participate in the formation of coat color by regulating the level of MITF and the number, size, motility and maturation of melanosome.

中文翻译：

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1型眼白化病调节小鼠黑素细胞的黑素生成。

为了研究1型白化病（OA1）在不同毛色的小鼠皮肤中是否差异表达，并确定其与毛色建立在小鼠中的相关性，OA1在不同毛色的小鼠皮肤中的表达模式和组织分布特征通过实时定量PCR（qRT-PCR），免疫荧光染色和Western印迹对毛色进行定性和定量分析。qRT-PCR分析显示，OA1 mRNA在所有测试的小鼠皮肤样品中表达，棕色皮肤中的表达水平最高，黑色皮肤中的表达水平，灰色皮肤中的最低表达水平。通过蛋白质印迹分析在所有皮肤样品中也检测到了阳性OA1蛋白带。黑色和棕色皮肤中OA1蛋白的相对表达水平显着高于灰色皮肤，但是黑色和棕色小鼠之间没有显着差异。免疫荧光分析表明，OA1主要在毛囊基质，皮肤组织的内外根鞘中以不同的被毛颜色表达。为了进一步了解OA1在黑素细胞色素沉着中的重要作用，我们将OA1转染到小鼠黑素细胞中，然后检测色素沉着相关基因的相对表达水平。同时，我们测试了黑色素细胞的黑色素含量。结果，OA1的过表达显着增加了小眼科相关转录因子（MITF），酪氨酸酶（TYR），酪氨酸酶相关蛋白1（TRP1）和黑素体前蛋白（PMEL）。但是，酪氨酸酶相关蛋白2（TRP2）的水平减弱。相比之下，糖蛋白非转移性黑色素瘤蛋白b（GPNMB）的水平不受OA1过表达的影响。此外，我们观察到小鼠黑素细胞转染的OA1中黑色素含量显着增加。因此，我们建议OA1可以通过调节MITF的水平以及黑素体的数量，大小，运动性和成熟度来参与外套颜色的形成。