Abstract Adipose differentiation-related protein (ADRP) is a lipid droplet-associated protein that is expressed early during adipose differentiation. However, the underlying mechanism is still unclear. In this study, the porcine ADRP (pADRP) gene regulatory mechanism and its relationship to intramuscular fat (IMF) content are analysed. We investigated the characteristics of the pADRP gene prompter as well as its transcription level, core promoter and epigenetic modification status using real-time PCR, Dual-luciferase reporter assays and bisulphite sequencing. The results showed that pADRP mRNA expression in Longissimus Dorsi (LD) muscle of the low IMF (LEAN) group was lower than that in the high IMF (FAT) group (p<.01). Maximum promoter activity was found in the −926 bp to −235 bp region. The methylation level of the pADRP of this region (mainly 7th, 10th, 12th CpG sites) in the low IMF group (86.67%) was significantly higher than that in the high IMF group (46.7%) (p<.01). Our result plays an important role in pADRP transcriptional regulation and provides a good prospect for the marbling traits improvement. Highlights pADRP expression differs in divergent IMF content pigs. Promoter region located −929 to −235 bp, and its methylation contributes to gene expression.

中文翻译：

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启动子CpG甲基化状态影响猪的ADRP基因表达水平和肌内脂肪含量

摘要 脂肪分化相关蛋白（ADRP）是一种脂滴相关蛋白，在脂肪分化早期表达。然而，其潜在机制仍不清楚。本研究分析了猪ADRP（pADRP）基因调控机制及其与肌内脂肪（IMF）含量的关系。我们使用实时 PCR、双荧光素酶报告基因分析和亚硫酸氢盐测序研究了 pADRP 基因提示子的特征及其转录水平、核心启动子和表观遗传修饰状态。结果表明，低IMF（LEAN）组背最长肌（LD）的pADRP mRNA表达低于高IMF（FAT）组（p<.01）。在 -926 bp 到 -235 bp 区域发现了最大的启动子活性。低IMF组（86.67%）该区域（主要是第7、10、12位CpG位点）的pADRP甲基化水平（86.67%）显着高于高IMF组（46.7%）（p<.01）。我们的结果在 pADRP 转录调控中起着重要作用，为大理石花纹性状的改进提供了良好的前景。亮点 pADRP 表达在不同 IMF 含量的猪中不同。启动子区域位于 -929 至 -235 bp，其甲基化有助于基因表达。