Guglielmi Laurence, Le Bert Marc, Truffinet Véronique, Cogné Michel, Denizot Yves
UMR CNRS 6101, Faculté de Médecine, 2 rue Dr Marcland, 87025, Limoges, France.
Biochem Biophys Res Commun. 2003 Aug 1;307(3):466-71. doi: 10.1016/s0006-291x(03)01185-9.
A locus control region (LCR) containing four transcriptional enhancers lies downstream of the IgH chain locus. We studied transgenes carrying a 3(')IgH LCR-driven GFP reporter gene for expression and B cell differentiation stage specificity. We also compared transgenes that were or were not flanked by two copies of the beta-globin HS4 insulator, an element defined by its ability to protect transgenes from the influences of surrounding genes at the insertion site. Results indicate that insulators are instrumental in sustaining GFP expression in GFP-3(')LCR transgenic mice when they were included. Flow cytometry experiments reported a strictly B cell specific GFP expression from pre-B cells in bone marrow to mature B cells in spleen. Despite addition of 5(')HS4 insulators to the GFP-3(')LCR construct, complete transgene silencing occurred in some transgenic lines and was systematically observed in ageing animals from all lines.
一个包含四个转录增强子的基因座控制区（LCR）位于免疫球蛋白重链（IgH）基因座的下游。我们研究了携带由3(')IgH LCR驱动的绿色荧光蛋白（GFP）报告基因的转基因，以了解其表达情况以及B细胞分化阶段特异性。我们还比较了两侧有或没有两份β-珠蛋白HS4绝缘子的转基因，β-珠蛋白HS4绝缘子是一种因其能够保护转基因免受插入位点周围基因影响而被定义的元件。结果表明，当包含绝缘子时，它们有助于在GFP-3(')LCR转基因小鼠中维持GFP表达。流式细胞术实验报告了从骨髓中的前B细胞到脾脏中的成熟B细胞存在严格的B细胞特异性GFP表达。尽管在GFP-3(')LCR构建体中添加了5(')HS4绝缘子，但在一些转基因品系中仍发生了完全的转基因沉默，并且在所有品系的老龄动物中都系统性地观察到了这种情况。
