Genomic imprinting of IGF2, p57KIP2 and PEG1/MEST in a marsupial, the tammar wallaby
Genomic imprinting of IGF2, p57KIP2 and PEG1/MEST in a marsupial, the tammar wallaby
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DOI：
10.1016/j.mod.2004.10.003
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发表时间：
2005-02-01
影响因子：
2.6
通讯作者：
Ishino, F
中科院分区：
文献类型：
--
作者：
Suzuki, S;Renfree, MB;Ishino, F
基因组印记在哺乳动物中广泛存在，但尚未在鸟类中发现。为了获得更广泛的理解印迹的起源和意义，我们已经表征了三个基因，从三个独立的印迹集群在真兽目哺乳动物在发育中的胎儿和胎盘的澳大利亚有袋动物，tammar小袋鼠Macropus eugenii。分离人和小鼠p57（KIP 2）、IGF 2和PEG 1/MEST基因的印记基因直向同源物。p57（KIP 2）没有显示稳定的单等位基因表达，这表明它在有袋动物中没有印记。与此相反，有父亲特异性表达的IGF 2在几乎所有的组织，但偏父亲表达的IGF 2在胎儿头部和胎盘，证明了组织特异性印迹的发生，发生在小鼠和人类。PEG 1/MEST α的表达也存在父系偏好。人和小鼠PEG 1/MEST启动子的差异甲基化区域（DMR）在小袋鼠中不存在。这些数据证实了真兽目和有袋类动物在发育过程中存在共同的印记区域，但表明控制印记基因表达的调控机制在这两组哺乳动物之间存在差异。(C)2004爱思唯尔爱尔兰有限公司保留所有权利。
Genomic imprinting is widespread amongst mammals, but has not yet been found in birds. To gain a broader understanding of the origin and significance of imprinting, we have characterized three genes, from three separate imprinted clusters in eutherian mammals in the developing fetus and placenta of an Australian marsupial, the tammar wallaby Macropus eugenii. Imprinted gene orthologues of human and mouse p57(KIP2), IGF2 and PEG1/MEST genes were isolated. p57(KIP2) did not show stable monoallelic expression suggesting that it is not imprinted in marsupials. In contrast, there was paternal-specific expression of IGF2 in almost all tissues, but the biased paternal expression of IGF2 in the fetal head and placenta, demonstrates the occurrence of tissue-specific imprinting, as occurs in mice and humans. There was also paternal-biased expression of PEG1/MESTalpha. The differentially methylated region (DMR) of the human and mouse PEG1/MEST promoter is absent in the wallaby. These data confirm the existence of common imprinted regions in eutherians and marsupials during development, but suggest that the regulatory mechanisms that control imprinted gene expression differ between these two groups of mammals. (C) 2004 Elsevier Ireland Ltd. All rights reserved.