Zhou Jie, Ashouian Nasrin, Delepine Marc, Matsuda Fumihiko, Chevillard Christophe, Riblet Roy, Schildkraut Carl L, Birshtein Barbara K
Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Proc Natl Acad Sci U S A. 2002 Oct 15;99(21):13693-8. doi: 10.1073/pnas.212392399. Epub 2002 Oct 7.
The 3' Ig heavy chain locus (Igh) regulatory region is the most downstream known element of the murine Igh gene cluster. We report here that the nearest non-Igh genes-Crip, Crp2, and Mta1-are located approximately 70 kb further downstream and are beyond the end of the domain of Igh transcriptional regulation. We have localized an origin of replication in MEL cells to a 3-kb segment located between the 3' Igh regulatory region and Crip. Sequences downstream of this origin are replicated by forks that move in both directions. Sequences upstream of this origin (Igh-C, -D, and -J) are replicated in a single direction through a 500-kb segment in which no active bidirectional origins can be detected. We propose that this origin may lie at or near the end of the Igh regulation domain.
3'免疫球蛋白重链基因座(Igh)调控区是小鼠Igh基因簇中已知的最下游元件。我们在此报告,最近的非Igh基因——Crip、Crp2和Mta1——位于更下游约70 kb处,且超出了Igh转录调控域的末端。我们已将MEL细胞中的一个复制起点定位到位于3'Igh调控区和Crip之间的一个3 kb片段上。该起点下游的序列由双向移动的复制叉进行复制。该起点上游的序列(Igh-C、-D和-J)通过一个500 kb的片段单向复制,在该片段中未检测到活跃的双向复制起点。我们提出,这个起点可能位于Igh调控域的末端或其附近。