The agouti signaling protein (ASIP) gene has a crucial role in pigmentation by encoding a protein that binds the melanocortin 1 receptor and stimulates the synthesis of pheomelanin rather than eumelanin. Several studies have suggested that an increased copy number of the ASIP gene might explain the white pigmentation of certain goat breeds, as previously demonstrated in sheep. In the current work, we have identified the segregation of the ASIP CNV in Murciano-Granadina (black or brown coat), Malagueña (brown, blond or white coat) and Saanen (white coat) goats with available Illumina Goat SNP50 BeadChip (Illumina Inc., San Diego, CA) data by using the PennCNV v1.0.5 and QuantiSNP v2 tools. This result shows that the ASIP CNV segregates in non-white breeds. To gain new insights into this issue, we have estimated the copy number of the ASIP gene in 83 goats from 8 breeds with different coloration patterns using a real-time quantitative PCR approach. Our results showed an increased ASIP copy number not only in Saanen (3.50 ± 0.23 copies relative to the calibrator) and white Malagueña (3.51 ± 0.51 copies) goats, but also in the Murciano-Granadina breed (3.33 ± 0.58 copies) as well as in blond/brown individuals from the Malagueña (3.58 ± 0.73 copies) breed. The number of ASIP copies was not significantly different in these four caprine populations (P > 0.05). Moreover, we did not observe a trend towards increased ASIP copy number in breeds with predominantly white colors, such as Maltese (2.85 ± 0.28 copies), Jonica (2.82 ± 0.39 copies) and Blanca de Rasquera (2.37 ± 0.33 copies). Our results, combined with recent findings demonstrating the high structural complexity of the ASIP locus, indicate that additional functional and expression studies should be performed in order to fully understand the role of ASIP structural variation in goat pigmentation.

刺豚鼠信号蛋白（ASIP）基因在色素沉着中起着至关重要的作用，其编码的蛋白与melanocortin 1受体结合，并刺激苯丙氨酸而不是Eumelanin的合成。多项研究表明，ASIP基因拷贝数的增加可能解释了某些山羊品种的白色色素沉着，如先前在绵羊中所证明的。在当前的工作中，我们已经确定了ASIP CNV在Murciano-Granadina（黑色或棕色外套），Malagueña（棕色，金色或白色外套）和Saanen（白色外套）山羊中的分离，以及可用的Illumina山羊SNP50 BeadChip（Illumina Inc. （加利福尼亚州圣地亚哥）数据使用PennCNV v1.0.5和QuantiSNP v2工具。此结果表明，ASIPCNV隔离在非白色品种中。为了获得对该问题的新见解，我们使用实时定量PCR方法，估计了来自8种颜色不同的品种的83只山羊的ASIP基因的拷贝数。我们的结果表明，不仅Saanen（相对于校准品，3.50±0.23份）和白色Malagueña（3.51±0.51份）山羊，而且Murciano-Granadina品种（3.33±0.58份）以及ASIP拷贝数均增加。来自Malagueña（3.58±0.73份）品种的金发/棕色个体。在这四个山羊种群中，ASIP拷贝数没有显着差异（P > 0.05）。而且，我们没有观察到ASIP增加的趋势白色为主的品种，例如马耳他（2.85±0.28份），乔尼卡（2.82±0.39份）和布朗卡·拉斯奎拉（2.37±0.33份）。我们的研究结果与最近发现的ASIP基因座结构高度复杂性相结合，表明应进行其他功能和表达研究，以充分了解ASIP结构变异在山羊色素沉着中的作用。