滩羊和湖羊背最长肌全基因组甲基化差异分析

本研究旨在通过不同品种绵羊背最长肌的全基因组甲基化差异分析，鉴定差异甲基化区域（DMR）和差异甲基化基因（DMG），为解析绵羊骨骼肌发育差异奠定基础。采用全基因组重亚硫酸盐测序（WGBS）技术开展了周岁龄滩羊、湖羊和滩湖F2代背最长肌全基因组DNA的甲基化水平检测和差异甲基化区域分析，探讨品种间DNA甲基化水平的差异。结果显示，全基因组范围内滩羊、湖羊和滩湖F2代胞嘧啶（C）甲基化（mC）率分别为3.55%、3.18%和3.56%，3个群体的甲基化水平基本一致。对滩羊和湖羊的甲基化水平进行比较，在不同序列环境下共检测到97 731个DMRs和10 784个DMGs。在CG、CHH、CHG序列环境下3个群体甲基化水平无显著差异。对DMGs通过基因本体（GO）和相关信号通路（KEGG）分析，共检测到419个GO条目和20个信号通路，显著富集在细胞过程、细胞组分、结合、长期抑制等相关条目中。筛选出5个与肌肉调控有关的候选基因ACTA2、ROCK1、CALD1、MYH3、MYH10。本研究绘制了滩羊、湖羊和滩湖F2代全基因组甲基化图谱，为表观遗传调控肌肉发育研究和肉质候选基因的筛选提供理论参考。

Whole Genome Methylation Variation Analysis of Longissimus Dorsi Between Tan Sheep and Hu Sheep

It aimed to identify the differential methylation region (DMR) and differential methylation gene (DMG) through the analysis of the genome-wide methylation difference of the longest muscle of the sheep's back of different breeds of sheep,and laid the foundation for the analysis of the differences in sheep skeletal muscle development.In this study,one-year-old sheep(Tan sheep and Hu sheep and Tan-Hu F2) were sanned by the whole genome bisulfite sequencing method(WGBS).The degree of methylation and differentially methylated region in the whole genome DNA of longissimus dorsi(LD) muscle were studied to explore the difference of DNA methylation in level in sheep.The results showed that the methylation (mC) rates of cytosine (C) were 3.55%,3.18% and 3.56% in Tan sheep,Hu sheep and Tan-Hu F2,respectively.A total of 97 731 DMRs and 10 784 related DMGs were detected.In CG,CHH and CHG sequences,the methylation levels of the three groups were not significantly different.419 GO terms and 20 related signal pathways were detected by GO and KEGG analysis,respectively,which were showed to be significantly enriched in cellular process,cell part,binding,long-term depression,and so on.Five candidate genes,ACTA2、ROCK1、CALD1、MYH3 and MYH10 were sreened out in muscle tissues.This study provided genome-wide methylation of pattern of three groups (Tan sheep and Hu sheep and Tan-Hu F2).The results provided reference information for the epigenetic study of Tan sheep and screened candidate genes related to muscle development and meat quality.