Luan Yuanyuan, Wu Shangjie, Wang Mingkun, Pu Yabin, Zhao Qianjun, Ma Yuehui, Jiang Lin, He Xiaohong
Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China.
Key Laboratory of Livestock and Poultry Resources Evaluation and Utilization, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China.
Biology (Basel). 2023 Apr 13;12(4):591. doi: 10.3390/biology12040591.
Horns, also known as headgear, are a unique structure of ruminants. As ruminants are globally distributed, the study of horn formation is critical not only for increasing our understanding of natural and sexual selection but also for the breeding of polled sheep breeds to facilitate modern sheep farming. Despite this, a significant number of the underlying genetic pathways in sheep horn remain unclear. In this study, to clarify the gene expression profile of horn buds and investigate the key genes in horn bud formation, RNA-sequencing (RNA-seq) technology was utilized to investigate differential gene expression in the horn buds and adjacent forehead skin of Altay sheep fetuses. There were only 68 differentially expressed genes (DEGs) identified, consisting of 58 up-regulated genes and 10 down-regulated genes. was differentially up-regulated in the horn buds and had the highest significance (-value = 7.42 × 10). In addition, 32 DEGs were horn-related genes identified in previous studies, such as , , , , , , , and . Further, Gene Ontology (GO) analysis showed that the DEGs were mainly enriched with regard to growth, development, and cell differentiation. Pathway analysis revealed that the Wnt signaling pathway may be responsible for horn development. Further, through combining the protein-protein interaction networks of the DEGs, it was found that the top five hub genes, namely, , , , , and , were also associated with horn development. Our results suggest that only a few key genes, including , are involved in bud formation. This study not only validates the expression of candidate genes identified at the transcriptome level in previous studies but also provides new possible marker genes for horn development, which may promote our understanding of the genetic mechanisms of horn formation.
角，也被称为头部装备，是反刍动物的一种独特结构。由于反刍动物分布于全球，对角形成的研究不仅对于增进我们对自然选择和性选择的理解至关重要，而且对于无角绵羊品种的培育以促进现代养羊业也很关键。尽管如此，绵羊角形成过程中大量潜在的遗传途径仍不清楚。在本研究中，为了阐明角芽的基因表达谱并探究角芽形成中的关键基因，利用RNA测序（RNA-seq）技术研究了阿勒泰羊胎儿角芽和相邻额头皮肤中的差异基因表达。仅鉴定出68个差异表达基因（DEG），其中包括58个上调基因和10个下调基因。 在角芽中差异上调且具有最高的显著性（-值 = 7.42 × 10）。此外，32个DEG是先前研究中鉴定出的与角相关的基因，如 、 、 、 、 、 、 和 。进一步地，基因本体（GO）分析表明，DEG主要在生长、发育和细胞分化方面富集。通路分析显示Wnt信号通路可能对角的发育负责。此外，通过结合DEG的蛋白质-蛋白质相互作用网络，发现排名前五的枢纽基因，即 、 、 、 和 ，也与角的发育相关。我们的结果表明，只有少数关键基因，包括 ，参与芽的形成。本研究不仅验证了先前研究在转录组水平鉴定出的候选基因的表达，还为角的发育提供了新的可能的标记基因，这可能增进我们对角形成遗传机制的理解。
