M6P/IGF2R imprinting evolution in mammals
M6P/IGF2R imprinting evolution in mammals
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DOI：
10.1016/s1097-2765(00)80249-x
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发表时间：
2000-04-01
期刊：
影响因子：
16
通讯作者：
MacDonald, RG
中科院分区：
文献类型：
--
作者：
Killian, JK;Byrd, JC;MacDonald, RG
在动物中识别印记基因仅限于真兽类动物，这表明胎儿宫内发育在印记进化中起着重要作用。我们在此报道，M6P/IGF2R不印记在单孔动物中，也不编码与IGF2结合的受体。相反，M6P/IGF2R在双翅目有袋类负鼠中印记，但它惊人地缺乏内含子2中差异甲基化的CpG岛，推测与印记控制有关。因此，印记基因的进化不需要侵入性胎盘和妊娠胎儿生长。除非在有袋类和真兽类中存在M6P/IGF2R印记和IGF2受体结合的趋同进化，否则我们的结果也表明这两种功能是在哺乳动物分支中进化的，而不是单孔动物。
Imprinted gene identification in animals has been limited to eutherian mammals, suggesting a significant role for intrauterine fetal development in the evolution of imprinting. We report herein that M6P/IGF2R is not imprinted in monotremes and does not encode for a receptor that binds IGF2. In contrast, M6P/IGF2R is imprinted in a didelphid marsupial, the opossum, but it strikingly lacks the differentially methylated CpG island in intron 2 postulated to be involved in imprint control. Thus, invasive placentation and gestational fetal growth are not required for imprinted genes to evolve. Unless there was convergent evolution of M6P/IGF2R imprinting and receptor IGF2 binding in marsupials and eutherians, our results also demonstrate that these two functions evolved in a mammalian clade exclusive of monotremes.