McKnight R A, Shamay A, Sankaran L, Wall R J, Hennighausen L
Laboratory of Biochemistry and Metabolism, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20982.
Proc Natl Acad Sci U S A. 1992 Aug 1;89(15):6943-7. doi: 10.1073/pnas.89.15.6943.
Matrix-attachment regions (MARs) may function as domain boundaries and partition chromosomes into independently regulated units. We have tested whether MAR sequences from the chicken lysozyme locus, the so-called A-elements, can confer position-independent regulation to a whey acidic protein (WAP) transgene in mammary tissue of mice. In the absence of MARs, expression of WAP transgenes was observed in 50% of the lines, and regulation during pregnancy, during lactation, and upon hormonal induction did not mimic that of the endogenous WAP gene and varied with the integration site. In contrast, all 11 lines in which WAP transgenes were juxtaposed to MAR elements showed expression. Accurate position-independent hormonal and developmental regulation was seen in four out of the five lines analyzed. These results indicate that MARs can establish independent genetic domains in transgenic mice.
基质附着区域（MARs）可能作为结构域边界发挥作用，并将染色体划分为独立调控的单元。我们已经测试了来自鸡溶菌酶基因座的MAR序列，即所谓的A元件，是否能够赋予小鼠乳腺组织中乳清酸性蛋白（WAP）转基因位置独立的调控。在没有MARs的情况下，50%的品系中观察到了WAP转基因的表达，并且在怀孕期、哺乳期以及激素诱导时的调控并不模仿内源性WAP基因的调控，且随整合位点而变化。相比之下，所有11个将WAP转基因与MAR元件并列的品系均表现出表达。在分析的5个品系中的4个中观察到了准确的位置独立的激素和发育调控。这些结果表明MARs能够在转基因小鼠中建立独立的遗传结构域。
