■皮毛颜色是家养绵羊的重要特征和经济性状。在这项研究中,我们探索了绵羊毛色调节的潜在机制和信号通路。
■用于相对和绝对定量的等压标签(iTRAQ)技术用于对具有黑色与白色外套颜色的绵羊皮肤中的全局蛋白质表达谱进行分类。免疫荧光法观察差异蛋白的表达定位。Westernblot和定量实时聚合酶链反应(qRT-PCR)用于评估它们在绵羊皮毛颜色形成中的作用。
■总共获得了136种不同外壳颜色的差异蛋白,包括101个上调和35个下调。通过GO注释丰富色素沉着功能条目。通过KEGG分析提取酪氨酸代谢和血小板活化信号通路。通过直接相互作用网络图中差异蛋白的相互作用,发现APOA1(载脂蛋白A-1)和FGA(纤维蛋白原α链)是关键差异蛋白。引人注目的是,筛选了20种候选差异蛋白,其中ACTB(β-肌动蛋白)蛋白在白绵羊皮肤中表达较高,而ALB(白蛋白),APOA1MAOA(胺氧化酶)和FGA蛋白在黑羊皮肤中表达较高,通过免疫荧光验证,蛋白质印迹和qRT-PCR。
■我们的研究发现了几种可能参与绵羊皮毛颜色形成的新型蛋白质。获得的白色和黑色绵羊皮肤蛋白质组图谱为未来研究提供了宝贵的资源,以了解控制绵羊皮肤生理和黑素生成的蛋白质表达网络。
OBJECTIVE: Coat color is an important characteristic and economic trait in domestic sheep. In this study, we explored the potential mechanisms and the signaling pathways involved in coat color regulation for sheep.
METHODS: Isobaric tags for relative and absolute quantification (iTRAQ) technology was used to catalog global protein expression profiles in skin of sheep with black versus white coat color. Immunofluorescence was used to observe the expression localization of differential protein. Western blot and quantitative real time polymerase chain reaction (qRT-PCR) were used to evaluate their role in the coat color formation of sheep.
RESULTS: A total of 136 differential proteins were obtained in different coat colors, including 101 up-regulated and 35 down-regulated. Pigmentation function entries were enriched through gene ontology annotation. Tyrosine metabolism and platelet activation signaling pathway were extracted by Kyoto encyclopedia of genes and genomes analysis. Apolipoprotein A-1 (APOA1) and fibrinogen alpha chain (FGA) were found to be critical differential proteins by the interaction of differential proteins in the direct-interaction network diagram. Strikingly, twenty candidate differential proteins were screened, from which beta-actin (ACTB) protein showed higher expression in white sheep skin, while albumin (ALB), APOA1, MAOA (amine oxidase) and FGA proteins showed higher expression in black sheep skin, which was validated by immunofluorescence, western blot, and qRT-PCR.
CONCLUSIONS: This study identified several novel proteins that may be involved in the coat color formation of sheep. The white and black sheep skin proteome profiles obtained provide a valuable resource for future research to understand the network of protein expression controlling skin physiology and melanogenesis in sheep.