Distinctive higher-order chromatin structure at mammalian centromeres
Distinctive higher-order chromatin structure at mammalian centromeres
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DOI：
10.1073/pnas.211322798
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发表时间：
2001-10-09
影响因子：
11.1
通讯作者：
Allan, J
中科院分区：
文献类型：
--
作者：
Gilbert, N;Allan, J
高级染色质纤维的结构还没有被详细定义。我们已经使用了一种新的方法，基于蔗糖梯度离心比较构象的着丝粒卫星DNA含有高阶染色质纤维与散装染色质纤维从相同的小鼠成纤维细胞。我们的数据表明，来自染色体的着丝粒结构域的染色质纤维存在于一个更密集的结构比散装染色质，而pericentromeric染色质纤维有一个中间构象。从目前的模型的角度来看，我们的数据被解释为表明，卫星染色质采用一个规则的螺旋构象兼容的典型的30纳米染色质纤维，而散装染色质纤维出现不太经常折叠，也许是间歇性中断变形。哺乳动物染色体的着丝粒结构域中的高级染色质纤维的这种独特构象可以在异染色质的形成和着丝粒身份的确定中发挥作用。
The structure of the higher-order chromatin fiber has not been defined in detail. We have used a novel approach based on sucrose gradient centrifugation to compare the conformation of centromeric satellite DNA-containing higher-order chromatin fibers with bulk chromatin fibers obtained from the same mouse fibroblast cells. Our data show that chromatin fibers derived from the centromeric domain of a chromosome exist in a more condensed structure than bulk chromatin whereas pericentromeric chromatin fibers have an intermediate conformation. From the standpoint of current models, our data are interpreted to suggest that satellite chromatin adopts a regular helical conformation compatible with the canonical 30-nm chromatin fiber whereas bulk chromatin fibers appear less regularly folded and are perhaps intermittently interrupted by deformations. This distinctive conformation of the higher-order chromatin fiber in the centromeric domain of the mammalian chromosome could play a role in the formation of heterochromatin and in the determination of centromere identity.