Evolution of the vertebrate DNMT3 gene family:: a possible link between existence of DNMT3L and genomic imprinting
Evolution of the vertebrate DNMT3 gene family:: a possible link between existence of DNMT3L and genomic imprinting
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DOI：
10.1159/000090817
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发表时间：
2006-01-01
影响因子：
1.7
通讯作者：
Sasaki, H.
中科院分区：
文献类型：
--
作者：
Yokomine, T.;Hata, K.;Sasaki, H.
DNA甲基化在真兽类和有袋类中观察到的基因组印记中起着至关重要的作用。在小鼠中，两种从头DNA甲基转移酶之一DNMT3A及其相关蛋白Dnmt3L已被证明是在亲代生殖系中建立印记所必需的。为了深入了解印记机制的进化，我们在其他脊椎动物物种中鉴定和表征了DNMT3家族基因。我们克隆了鸡DNMT3A和DNMT3B的基因，其蛋白产物与其小鼠同源基因的氨基酸序列同源性分别为81.5%和48.6%。利用计算机辅助数据库搜索，我们还在鱼类(河豚和斑马鱼)和有袋类动物(负鼠)中发现了DNMT3A和DNHT3B同源基因。我们发现，虽然负鼠有DNMT3L的同源基因，但鸡和鱼没有这个基因。因此，与其他DNMT3成员不同，DNMT3L仅限于发生印记的物种。真兽类和有袋类的共同祖先获得DNMT3L可能与印记的进化密切相关。版权所有(C)2006 S.Karger AG，巴塞尔。
DNA methylation plays an essential role in genomic imprinting observed in eutherian mammals and marsupials. In mouse, one of the two de novo DNA methyltransferases, Dnmt3a, and a related protein, Dnmt3L have been shown to be essential for imprint establishment in the parental germline. To gain insights into the evolution of imprinting mechanisms, we have identified and characterized the DNMT3 family genes in other vertebrate species. We cloned cDNAs for chicken DNMT3A and DNMT3B, whose putative protein products shared 81.5% and 48.6% amino acid sequence identity with their mouse orthologues. Using computer-assisted database searches, we also identified DNMT3A and DNHT3B orthologues in fish (fugu and zebrafish) and marsupials (opossum). We found that, while opossums had an orthologue for DNMT3L, chickens and fish did not have this gene. Thus, unlike the other DNMT3 members, DNMT3L was restricted to the species in which imprinting occurs. The acquisition of DNMT3L by a common ancestor of eutherians and marsupials might have been closely related to the evolution of imprinting. Copyright (c) 2006 S. Karger AG, Basel.