Characterization of a 5-formylcytosine chromocenter in Xenopus embryos

DNA甲基化是一种表观遗传标记，在发育和疾病中起着重要作用。现在人们普遍认为DNA甲基化是动态的，并受到酶去甲基化的影响。Tet家族的甲基胞嘧啶双加氧酶将5-甲基胞嘧啶转化为氧化的衍生物，这些氧化的衍生物是通往活跃的DNA去甲基化的中间产物，但它们本身也可以作为表观遗传标记。然而，关于氧化胞嘧啶衍生物作为表观遗传标记的功能以及它们在脊椎动物发育中的作用，人们知之甚少。我们发现，非洲爪哇早期胚胎在中期囊胚过渡过程中显示出单一的5-甲酰胞嘧啶(5fC)核。我们有证据表明，这些5fC染色中心是由位于不同染色体上的重复DNA序列组成的，这些DNA序列在界面上结合在一起。我们现在建议对这个5fC染色中心的性质、功能和在非洲爪哇发育中可能的生物学作用进行表征。

DNA methylation is an epigenetic mark, which plays important roles in development and disease. It is now widely accepted that DNA methylation is dynamic and is subject to enzymatic demethylation. The Tet family of methylcytosine dioxygenases convert 5-methylcytosine to oxidized derivatives, which are intermediates towards active DNA demethylation, but which may also function as epigenetic marks in their own right. However, little is known about the function of oxidized cytosine derivatives as epigenetic marks and as to their role in vertebrate development. We have discovered that early Xenopus embryos display single nuclear foci of 5-formylcytosine (5fC) during the midblastula transition. We have evidence that these 5fC chromocenters are made up of repetitive DNA sequences residing on different chromosomes, which coalesce during interface. We now propose to characterize the nature, the function, and a possible biological role of this 5fC chromocenter in Xenopus development.