本帖最后由 细胞海洋 于 2013-4-26 21:36 编辑 9 v& X1 ?9 a# B" Q& Q7 ^% X3 C
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Volume 153, Issue 3 + ?5 O( `3 Z* O: |5 ?! ZOn the cover: DNA methylation (5mC) patterns are established and maintained & c+ r2 k5 M- X0 p5 d' j7 A: ^: \by DNA methyltransferases. Removing methyl modifications requires a multistep 4 D* d+ E% U- ~( \
process. Iterative oxidation of 5mC by TET proteins generates , k7 H* N$ y1 L2 ^# T, d% g# C
5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine 0 [ n4 b$ J& G7 K
(5caC). 5fC/5caC can be excised by thymine-DNA glycosylase (TDG) and repaired to % {: z& }# d( v: Lregenerate unmodified cytosines to complete the methylation and demethylation . P9 a: @& w. H E/ q% I) \/ }' S
cycle. In this issue, Shen et al. (pp. 692–706) provide a genome-wide view of 6 V+ ?9 V7 ^7 ~3 xiterative 5mC oxidation dynamics in mouse embryonic stem cells. Their results / f8 s, f5 P7 T! j) ~
indicate that TET/TDG-dependent active DNA demethylation occurs extensively in * R3 D4 R" z8 }/ G& p8 y% cthe mammalian genome. In a related paper, Song et al. (pp. 678–691) look at the ! N5 g8 N I0 `% r8 z, ?% Q4 ]1 econtribution of 5mC oxidized states to epigenetic tuning at regulatory elements. # E! d1 y/ } {+ ]
The cyclist on the cover illustrates the cyclic change of cytosine f- }+ _0 U# R( g5 Z
modifications. Artwork by Li Shen and Yi Zhang. ( A! J; u" g' j3 L# j作者: 懵懂干细胞 时间: 2013-4-26 21:11
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