Department of Developmental Genetics, Institute of Cytology and Genetics, Academy of Sciences of Russia, Siberian Branch, 630090, Novosibirsk, Russia.
Transgenic Res. 2013 Oct;22(5):949-64. doi: 10.1007/s11248-013-9697-4. Epub 2013 Feb 23.
Expression of the human granulocyte-macrophage colony-stimulating factor (hGM-CSF) gene under the control of the 5'-regulatory sequence of the goat alpha-S1-casein gene with and without a matrix attachment region (MAR) element from the Drosophila histone 1 gene was studied in four and eight transgenic mouse lines, respectively. Of the four transgenic lines carrying the transgene without MAR, three had correct tissues-specific expression of the hGM-CSF gene in the mammary gland only and no signs of cell mosaicism. The concentration of hGM-CSF in the milk of transgenic females varied from 1.9 to 14 μg/ml. One line presented hGM-CSF in the blood serum, indicating ectopic expression. The values of secretion of hGM-CSF in milk of 6 transgenic lines carrying the transgene with MAR varied from 0.05 to 0.7 μg/ml, and two of these did not express hGM-CSF. Three of the four examined animals from lines of this group showed ectopic expression of the hGM-CSF gene, as determined by RT-PCR and immunofluorescence analyses, as well as the presence of hGM-CSF in the blood serum. Mosaic expression of the hGM-CSF gene in mammary epithelial cells was specific to all examined transgenic mice carrying the transgene with MAR but was never observed in the transgenic mice without MAR. The mosaic expression was not dependent on transgene copy number. Thus, the expected "protective or enhancer effect" from the MAR element on the hGM-CSF gene expression was not observed.
在含有和不含有来自果蝇组蛋白 1 基因的基质附着区 (MAR) 元件的山羊 α-S1-酪蛋白基因 5'调控序列的控制下，研究了人粒细胞-巨噬细胞集落刺激因子 (hGM-CSF) 基因在四个和八个转基因小鼠品系中的表达。在四个携带无 MAR 的转基因品系中，三个在乳腺中仅具有正确的组织特异性 hGM-CSF 基因表达，没有细胞嵌合体的迹象。转基因雌性乳汁中 hGM-CSF 的浓度为 1.9 到 14μg/ml 不等。一个品系在血清中出现 hGM-CSF，表明异位表达。在携带 MAR 的转基因品系中，六个转基因品系的 hGM-CSF 在乳汁中的分泌值从 0.05 到 0.7μg/ml 不等，其中两个没有表达 hGM-CSF。在来自该组的四个检查动物中的三个，通过 RT-PCR 和免疫荧光分析以及血清中 hGM-CSF 的存在，确定 hGM-CSF 基因发生了异位表达。在携带 MAR 的转基因小鼠的所有检查的乳腺上皮细胞中，均观察到 hGM-CSF 基因的嵌合表达，但在携带无 MAR 的转基因小鼠中从未观察到。嵌合表达与转基因拷贝数无关。因此，没有观察到 MAR 元件对 hGM-CSF 基因表达的预期“保护或增强作用”。
