Centromeres are specialized replication domains in heterochromatin.
Centromeres are specialized replication domains in heterochromatin.
复制标题
中心粒是异染色质中的专门复制域。
DOI：
10.1083/jcb.153.1.101
复制
发表时间：
2001-04-02
影响因子：
7.8
通讯作者：
Henikoff, S
中科院分区：
文献类型：
--
作者：
Ahmad, K;Henikoff, S
The properties that define centromeres in complex eukaryotes are poorly understood because the underlying DNA is normally repetitive and indistinguishable from surrounding noncentromeric sequences. However, centromeric chromatin contains variant H3-like histones that may specify centromeric regions. Nucleosomes are normally assembled during DNA replication; therefore, we examined replication and chromatin assembly at centromeres in Drosophila cells. DNA in pericentric heterochromatin replicates late in S phase, and so centromeres are also thought to replicate late. In contrast to expectation, we show that centromeres replicate as isolated domains early in S phase. These domains do not appear to assemble conventional H3-containing nucleosomes, and deposition of the Cid centromeric H3-like variant proceeds by a replication-independent pathway. We suggest that late-replicating pericentric heterochromatin helps to maintain embedded centromeres by blocking conventional nucleosome assembly early in S phase, thereby allowing the deposition of centromeric histones.
