Identification of Marsupial-Specific Genomic Imprinting Loci

基因组印迹是一种独特的基因表达调控机制，通过沉默来自双亲的两个基因中的一个而导致单等位基因的表达。在高等脊椎动物中，只有哺乳动物才有基因组印记，这对正常的胚胎发育是必不可少的。然而，单等位基因表达有一个严重的缺点，即只有一次隐性突变可能会立即导致异常表型。在这项研究中，我们开发了一种从有袋类动物基因组DNA中识别印记基因座的新方法，作为研究基因组印记在哺乳动物进化中为什么以及如何产生的第一步。

Genomic imprinting is a unique regulatory mechanism of gene expression, causes monoallelic gene expression by silencing of one of two genes derived from both parents. In higher vertebrates, only mammals have genomic imprinting and it is essential for normal embryonic development. However, monoallelic gene expression has a critical demerit in that only one hit of recessive mutations could lead abnormal phenotypes immediately. In this research, we have developed the novel approach identifying imprinted loci from marsupial genomic DNA as the first step to investigate why and how genomic imprinting arose in mammalian evolution.