Jeong Young Sun, Oh Keon Bong, Park Jung Sun, Kim Ji-Su, Kang Yong-Kook
Development and Differentiation Research Center, KRIBB, Yuseong-gu, Daejeon, Korea.
Dev Dyn. 2009 Jul;238(7):1666-73. doi: 10.1002/dvdy.21975.
DNA methyltransferase-1 (Dnmt1) is involved in the maintenance of genomic methylation patterns. Rather than full-length Dnmt1, mouse oocytes have a truncated variant called Dnmt1o. Immunofluorescence data showed that Dnmt1o localized to the cytoplasm, but this has not been confirmed using more direct methods. The cytoplasmic localization of Dnmt1o has been assigned to the main cause of global DNA demethylation in early mouse embryos. We studied localization of Dnmt1o in mouse and pig embryos. We identified pig Dnmt1o protein and its transcript with unique 5'-end sequence. Physically separating mouse and pig 2-cell embryos into their nuclear and cytoplasmic components demonstrated that Dnmt1o of both species localized to the cytoplasm. Cloned pig embryos had Dnmt1o as the main form, with no indication of somatic Dnmt1. These findings indicate that Dnmt1o is cytoplasmic during early development; its presence in both pig and mouse embryos further suggests that Dnmt1o is conserved in mammals.
DNA甲基转移酶-1（Dnmt1）参与基因组甲基化模式的维持。与全长Dnmt1不同，小鼠卵母细胞有一种名为Dnmt1o的截短变体。免疫荧光数据显示Dnmt1o定位于细胞质，但尚未使用更直接的方法进行证实。Dnmt1o的细胞质定位被认为是早期小鼠胚胎中全基因组DNA去甲基化的主要原因。我们研究了Dnmt1o在小鼠和猪胚胎中的定位。我们鉴定出具有独特5'端序列的猪Dnmt1o蛋白及其转录本。将小鼠和猪的2细胞胚胎物理分离为细胞核和细胞质成分，结果表明这两个物种的Dnmt1o都定位于细胞质。克隆猪胚胎以Dnmt1o为主要形式，未显示出体细胞Dnmt1的迹象。这些发现表明Dnmt1o在早期发育过程中位于细胞质中；它在猪和小鼠胚胎中的存在进一步表明Dnmt1o在哺乳动物中是保守的。
