Characterization of a 5-formylcytosine chromocenter in Xenopus embryos

DNA甲基化是一种表观遗传标记，在发育和疾病中起重要作用。现在普遍认为DNA甲基化是动态的，并且受到酶促去甲基化的影响。甲基胞嘧啶双加氧酶的泰特家族将5-甲基胞嘧啶转化为氧化衍生物，其是活性DNA去甲基化的中间体，但其本身也可以作为表观遗传标记起作用。然而，很少有人知道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。我们已经发现，早期非洲爪蟾胚胎显示5-甲酰胞嘧啶（5 fC）的单核灶在中囊胚过渡。我们有证据表明，这些5 fC色心是由位于不同染色体上的重复DNA序列组成的，这些序列在界面期间合并。我们现在提出的性质，功能，和一个可能的生物学作用，这5 fC色心在非洲爪蟾的发展。

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.