期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：39
页码：16928-16933
DOI：10.1073/pnas.1010317107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：To study the influence of a locus control region (LCR) on the expression of a highly characterized, developmentally regulated locus, we have targeted the hCD2-LCR as a single copy into the endogenous mouse CD8 gene complex. Two knock-in mouse lines that differ in the integration site of the hCD2-LCR within the mCD8 gene complex were generated, and the influence on expression of the CD8 coreceptor was assessed. In these mice the normal developmental silencing of the CD8 genes in the CD4 lineage is deregulated, and the mice develop CD4+ cells that also express the CD8 genes. This is accompanied by the physical maintenance of the CD8 genes within an extended loop away from their subchromosomal territory. Further analysis of these mice revealed unexpected fluid chromatin dynamics, whereby the LCR can be initially dominant over the endogenous CD8 gene-repressive regulatory processes present in CD4+ cells but is continuously contested by them, resulting in the eventual inactivation of the inserted LCR, probably as a result of multiple rounds of replication.
关键词：CD8 locus ; hCD2 locus control region ; knock-in ; lymphocyte development ; chromatin structure
