基于高通量测序的脂尾型绵羊脂肪代谢分子调控机制研究

Fat-tailed sheep is an important part of the sheep, and the presence of fat-tail results in a decrease in meat quality and production efficiency. Non-genetic measures to regulate fat metabolism have many disadvantages, and the candidate gene approach is difficult to explain the complexity and plasticity of fat metabolism. A thin-tailed population and two fat-tailed breeds with a significant difference in fat tail (Guangling Large-tailed and Small-tailed Han) are used as a reference and experimental animals, respectively. Three libraries are constructed for small RNA sequencing. Combined with high-throughput sequencing, differentially expressed miRNAs in adipose tissues are screened and validated to obtain the miRNA expression profiles at transcriptome level, and to discover novel miRNAs. The miRNA regulatory pass is analyzed by bioinformatics methods. Associations of miRNA and target mRNA with carcass and tail type traits are studied. Such research can significantly improve our understandings to the molecular mechanism of fat metabolism in fat-tailed sheep. The results will provide an important scientific basis and technical support for genomic selection to improve meat quality traits and for establishment of molecular breeding system in sheep.

脂尾型绵羊是绵羊的重要组成部分，而脂尾的存在也导致肉质品质和生产效益的降低。非遗传措施调节脂肪代谢具有很多缺点，候选基因法又难以解释脂肪代谢的复杂性和可塑性。本项目拟以瘦尾型绵羊为参照，以广灵大尾羊（长脂尾）和小尾寒羊（短脂尾）两个具有显著尾型差异的脂尾羊为对象，构建3个小RNA测序文库。结合高通量测序技术，筛选和验证脂肪组织中的差异表达miRNAs，，获得转录组水平上的miRNA表达谱，发现新的miRNAs。结合生物信息学方法，分析miRNA对靶基因的调节通路。进行关联研究，探讨miRNA和靶基因mRNA与胴体和尾型性状间的关系。由此可以显著提高我们对脂尾羊脂肪代谢分子调控机制的理解。研究结果将为绵羊肉质性状的基因组选择和分子育种体系的建立提供重要的科学依据和技术支撑。

脂尾型绵羊是绵羊的重要组成部分，而脂尾的存在也导致肉质品质和生产效益的降低。非遗传措施调节脂肪代谢具有很多缺点，候选基因法又难以解释脂肪代谢的复杂性和可塑性。. 本项目以瘦尾型绵羊（山西肉用绵羊母本品系）为参照，以广灵大尾羊（长脂尾）和小尾寒羊（短脂尾）两个具有显著尾型差异的脂尾羊为对象，构建小RNA测序文库。结合高通量测序技术，筛选和验证脂肪组织中的差异表达miRNAs，获得转录组水平上的miRNA表达谱，发现新的miRNAs。结合生物信息学方法，分析miRNA对靶基因的调节通路。进行关联研究，探讨miRNA和靶基因mRNA与胴体和尾型性状间的关系。. 通过研究，建立了3个品种皮下、肾周和尾部共8个脂肪组织小RNA文库。高通量测序获得的高质量读段介于98.82%~99.56%之间。对所有小RNA序列标签进行长度分析表明，小RNA长度集中在21~24 nt，其中长度为22 nt的小RNA出现频率最高。广灵大尾羊与小尾寒羊和山西肉用绵羊肾周脂肪中差异表达的miRNAs数分别为95和103个，皮下脂肪中分别为86和87个；广灵大尾羊与小尾寒羊尾脂中差异表达的miRNAs数为93个。与miRBase 20.0中所有物种比对，发现了351个绵羊的新miRNAs，其中194个在其他物种中也没有发现。不同脂肪组织中，可预测出靶基因的miRNA数量介于163~244个，对应的靶基因数在22900以上。对3个品种不同脂肪组织中差异表达的14个miRNAs进行了验证，结果表明，这些miRNAs在不同品种间的表达差异显著。. 研究结果为研究差异表达miRNAs的调节通路和生物学功能打下了坚实基础，有助于我们对脂尾羊脂肪代谢分子调控机制的理解。.