The epigenetic mechanisms underlying genomic imprinting include DNA methylation and monoallelic expression of genes in close proximity. Although genes imprinted in humans and mice have been widely characterized, there is a lack of detailed and comprehensive studies in livestock species including pigs. The purpose of this study was to investigate a detailed methylation status and parent-of-origin-specific gene expression within the genomic region containing an underexamined porcine DIRAS3 locus. Through whole-genome bisulfite sequencing (WGBS) and RNA sequencing (RNA-seq) of porcine parthenogenetic embryos and analyses of public RNA-seq data from adult pigs, DNA methylation and monoallelic expression pattern were investigated. As a result, maternal hypermethylation at the DIRAS3 locus and hypothalamus-specific and monoallelic expression of the DIRAS3 gene were found in pigs. In conclusion, the findings from this study suggest that the presence of maternal hypermethylation, or imprints, might be maintained and related to monoallelic expression of DIRAS3 during pig development.

中文翻译：

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猪DIRAS3基因座的基因组印迹

基因组印记的表观遗传机制包括DNA甲基化和紧密接近的基因的单等位基因表达。尽管已经广泛地刻印在人和小鼠中的基因具有广泛的特征，但是在包括猪在内的牲畜物种中仍缺乏详细而全面的研究。这项研究的目的是调查包含未充分检查的猪DIRAS3基因座的基因组区域内详细的甲基化状态和母本特异性基因表达。通过对猪孤雌生殖胚胎的全基因组亚硫酸氢盐测序（WGBS）和RNA测序（RNA-seq）以及对成年猪的公共RNA-seq数据进行分析，研究了DNA甲基化和单等位基因表达模式。结果，DIRAS3处的母亲超甲基化在猪中发现了DIRAS3基因的基因座和下丘脑特异性和单等位基因表达。总之，这项研究的发现表明，可能会维持母体高甲基化或印迹，并与猪发育过程中DIRAS3的单等位基因表达有关。