Identification of an imprinted gene, Meg3/Gtl2 and its human homologue MEG3, first mapped on mouse distal chromosome 12 and human chromosome 14q
Identification of an imprinted gene, Meg3/Gtl2 and its human homologue MEG3, first mapped on mouse distal chromosome 12 and human chromosome 14q
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DOI：
10.1046/j.1365-2443.2000.00320.x
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发表时间：
2000-03-01
期刊：
影响因子：
2.1
通讯作者：
Ishino, F
中科院分区：
文献类型：
--
作者：
Miyoshi, N;Wagatsuma, H;Ishino, F
背景：小鼠远端12号染色体父本复制导致胚胎晚期/新生儿死亡和生长促进，而母本复制导致胚胎晚期死亡和生长迟缓。与小鼠远端12号染色体同源的人类父系或母系14q染色体的单染色体二体也被报道对生长、智力活动和肌肉骨骼形态表现出一些印记效应。为了分离该区域的印迹基因，我们利用雄激素胚胎和正常受精胚胎，采用减法杂交的方法对母系表达基因（Megs）进行了系统筛选。结果：分离出小鼠Meg基因的7个候选克隆。其中，我们在小鼠远端12号染色体上发现了一个新的母系表达的印迹基因Meg3，并表明其与Gtl2基因相同。我们还发现14q染色体上的人类同系物MEG3也是单等位表达的。结论：这是首次在小鼠远端12号染色体和人类14q号染色体上分别发现印迹基因。由于在小鼠Meg3/Gtl2和人类Meg3中都没有明显的开放阅读框，这些基因的功能尚不清楚。然而，这一结果将为进一步研究该染色体区域的几个重要印迹基因提供良好的基础。
Background: The paternal duplication of mouse distal chromosome 12 leads to late embryonal/neonatal lethality and growth promotion, whereas maternal duplication leads to late embryonal lethality and growth retardation. Human paternal or maternal uniparental disomies of chromosome 14q that are syntenic to mouse distal chromosome 12 have also been reported to show some imprinting effects on growth, mental activity and musculoskeletal morphology. For the isolation of imprinted genes in this region, a systematic screen of maternally expressed genes (Megs) was carried out by our subtraction-hybridization method using androgenetic and normally fertilized embryos.Results: We have isolated seven candidate clones of the mouse Meg gene. Among them, we identified a novel maternally expressed imprinted gene, Meg3, on mouse distal chromosome 12 and showed that it was identical to the Gtl2 gene. We also found that the human homologue MEG3 on chromosome 14q was also monoallelically expressed.Conclusions: This is the first identification of the imprinting gene, both on mouse distal chromosome 12 and on human chromosome 14q, respectively. Because there are no obvious open reading frames in either the mouse Meg3/Gtl2 or human MEG3, the function of these genes remains unclear. However, this result will provide a good basis for the further investigation of several important imprinted genes in this chromosomal region.