Bartolomei M S, Zemel S, Tilghman S M
Howard Hughes Medical Institute, Princeton University, New Jersey 08544.
Nature. 1991 May 9;351(6322):153-5. doi: 10.1038/351153a0.
THE mouse H19 gene encodes one of the most abundant RNAs in the developing mouse embryo. It is expressed at the blastocyst stage of development, and accumulates to high levels in tissues of endodermal and mesodermal origin (H. Kim, unpublished result). After birth the gene is expressed in all tissues except skeletal muscle. It lacks a common open reading frame in the 2.5-kilobase RNA, but has considerable nucleotide sequence similarity between the genes of rodents and humans. Expression of the gene in transgenic mice results in late prenatal lethality, suggesting that the dosage of its gene product is strictly controlled. The H19 gene maps to the distal segment of mouse chromosome 7, in a region that is parentally imprinted, a process by which genes are differentially expressed on the maternal and paternal chromosomes. We have now used an RNase protection assay that can distinguish between H19 alleles in four subspecies of Mus, to demonstrate that the H19 gene is parentally imprinted, with the active copy derived from the mother. This assay will be of general use in assaying allele-specific gene expression.
小鼠H19基因编码发育中小鼠胚胎中最丰富的RNA之一。它在发育的囊胚阶段表达，并在内胚层和中胚层来源的组织中积累到高水平（H. Kim，未发表结果）。出生后，该基因在除骨骼肌外的所有组织中表达。它在2.5千碱基的RNA中缺乏常见的开放阅读框，但在啮齿动物和人类的基因之间具有相当大的核苷酸序列相似性。该基因在转基因小鼠中的表达导致产前晚期致死，这表明其基因产物的剂量受到严格控制。H19基因定位于小鼠7号染色体的远端区域，该区域是亲本印记的，即基因在母本和父本染色体上差异表达的过程。我们现在使用了一种核糖核酸酶保护试验，该试验可以区分小家鼠四个亚种中的H19等位基因，以证明H19基因是亲本印记的，活性拷贝来自母亲。该试验将普遍用于检测等位基因特异性基因表达。
