Liu J W, Tabe L M
CSIRO Division of Plant Industry, Canberra, Australia.
Plant Cell Physiol. 1998 Jan;39(1):115-23. doi: 10.1093/oxfordjournals.pcp.a029282.
Nuclear matrix attachment regions (MARs) are thought to influence gene expression by anchoring active chromatin to the proteinaceous nuclear matrix. In this study, two plant DNA fragments with strong MAR activity were selected and tested for their effects on expression of a linked reporter gene in transgenic tobacco. One MAR was isolated from the 5' flanking region of a pea vicilin gene previously reported to be expressed in a copy number-dependent manner in transgenic tobacco. A second MAR was isolated from the genome of Arabidopsis thaliana by preselection for autonomously replicating sequence (ARS) activity in yeast. Flanking copies of the A. thaliana MAR stimulated median reporter gene expression in transgenic plants by five to ten fold. Neither MAR significantly reduced the variation in transgene expression between individual transformants, or conferred copy number-dependence in gene expression.
核基质附着区（MARs）被认为通过将活性染色质锚定到蛋白质性核基质上来影响基因表达。在本研究中，选择了两个具有强MAR活性的植物DNA片段，并测试了它们对转基因烟草中连接的报告基因表达的影响。一个MAR是从豌豆伴球蛋白基因的5'侧翼区域分离出来的，该基因先前报道在转基因烟草中以拷贝数依赖的方式表达。第二个MAR是通过在酵母中对自主复制序列（ARS）活性进行预选，从拟南芥基因组中分离出来的。拟南芥MAR的侧翼拷贝使转基因植物中的报告基因表达中位数提高了五到十倍。两个MAR均未显著降低单个转化体之间转基因表达的差异，也未赋予基因表达的拷贝数依赖性。
