College of Life Science, Agricultural University of Hebei, Baoding, Hebei, China.
College of Bioscience and Bioengineering, Hebei University of Science and Technology, Shijiazhuang, Hebei, China.
Anim Genet. 2021 Feb;52(1):47-54. doi: 10.1111/age.13023. Epub 2020 Nov 17.
Genomic imprinting is a rare epigenetic process in mammalian cells that leads to monoallelic expression of a gene with a parent-specific pattern. The UBE3A (ubiquitin protein ligase E3A) gene is imprinted with maternal allelic expression in the brain but biallelically expressed in all other tissues in humans. The silencing of the paternal UBE3A allele is thought to be caused by the paternally expressed antisense RNA transcript of UBE3A-ATS. The aberrant imprinted expression of the UBE3A is associated with several neurodevelopmental syndromes and psychological disorders. Cattle are a valuable model species in determining the genetic etiology of sporadic human disorder, and maternal expression of UEB3A has been revealed by next-generation sequencing study in the bovine conceptus. In this study, we investigated the allelic expression of UBE3A and UBE3A-ATS in adult bovine somatic tissues. To confirm the splicing pattern of bovine UBE3A, five 5' alternative transcripts (MT210534-MT210538) were first obtained from bovine brain tissue by RT-PCR. Based on 10 SNP genotypes, we found that the brain-specific monoallelic expression of bovine UBE3A did not occur along the entire locus, and there was a shift from biallelic expression to monoallelic expression in exon 14 of the UBE3A gene. However, the brain-specific monoallelic expression of bovine UBE3A-ATS occurred in the entire gene. These observations demonstrated that the monoallelic expression did not occur along the bovine UBE3A entire locus and was associated with the genomic position.
基因组印迹是哺乳动物细胞中一种罕见的表观遗传过程，导致基因的单等位基因表达具有亲本特异性模式。UBE3A（泛素蛋白连接酶 E3A）基因在大脑中表现出母源等位基因表达，但在人类的所有其他组织中均表现为双等位基因表达。父本UBE3A 等位基因的沉默被认为是由 UBE3A-ATS 的父本表达反义 RNA 转录本引起的。UBE3A 的异常印迹表达与几种神经发育综合征和心理障碍有关。牛是确定散发性人类疾病遗传病因的有价值的模型物种，并且通过牛胚胎的下一代测序研究揭示了 UEB3A 的母源表达。在这项研究中，我们研究了成年牛体细胞组织中 UBE3A 和 UBE3A-ATS 的等位基因表达。为了确认牛 UBE3A 的剪接模式，首先通过 RT-PCR 从牛脑组织中获得了 5 个 5' 替代转录本（MT210534-MT210538）。基于 10 个 SNP 基因型，我们发现牛 UBE3A 的脑特异性单等位基因表达并非沿着整个基因座发生，UBE3A 基因的外显子 14 从双等位基因表达转变为单等位基因表达。然而，牛 UBE3A-ATS 的脑特异性单等位基因表达发生在整个基因中。这些观察结果表明，单等位基因表达并未沿着牛 UBE3A 的整个基因座发生，并且与基因组位置有关。
