Two breakpoint clusters at fragile site FRA3B form phased nucleosomes.
Two breakpoint clusters at fragile site FRA3B form phased nucleosomes.
复制标题
脆弱位点 FRA3B 处的两个断点簇形成定相核小体。
DOI：
10.1101/gr.2304404
复制
发表时间：
2004
期刊：
影响因子：
7
通讯作者：
Wang,Yuh-Hwa
中科院分区：
文献类型：
--
作者：
Mulvihill,DavidJ;Wang,Yuh-Hwa
Fragile sites are gaps and breaks in metaphase chromosomes generated by specific culture conditions. Fragile site FRA3B is the most unstable site and is directly involved in the breakpoints of deletion and translocation in a wide spectrum of cancers. To learn about the general characteristics of common fragile sites, we investigated the chromatin structure of the FRA3B site. Because FRA3B spans several hundred kilobases, we focused our study on two breakpoint clusters found in FRA3B. Using various nucleases, we demonstrated that these two regions contain phased nucleosomes, regardless of treatment with aphidicolin. Because these regions are located in intron 4 of theFHITgene, it is very interesting to observe phased nucleosomes over these regions, which are several hundred kilobases downstream from the promoter. Further, by using nucleosome assembly assays, we demonstrate that these two regions do not contain strong nucleosome positioning elements. These results suggest that other factors appear to cooperate with the DNA sequence of these regions to impart nucleosome phasing. This study provides the first information on the chromatin structure of breakpoint regions in a common fragile site. The observation of phased nucleosomes over these breakpoint regions could offer a foundation to understand the expression of fragile sites.
