Khillan J S, Schmidt A, Overbeek P A, de Crombrugghe B, Westphal H
Proc Natl Acad Sci U S A. 1986 Feb;83(3):725-9. doi: 10.1073/pnas.83.3.725.
Eight transgenic mice were generated in which the promoter of the mouse alpha 2(I) collagen gene (nucleotides -2000 to +54), linked to the bacterial gene for chloramphenicol acetyltransferase (CAT), is stably integrated in the germ line. These strains contain from 1 to 20 copies of the alpha 2(I) collagen-CAT chimeric gene per haploid genome. In seven of the eight strains, the CAT gene is expressed, although the levels of CAT enzyme activity vary considerably from one strain to the other. In six of these strains, the expression of the CAT gene follows the expected tissue distribution pattern of expression of the alpha 2(I) collagen gene. In these six strains, the level of CAT activity is much higher in extracts of tail, a tissue that is very rich in tendons, than in any other tissue that was tested. This distribution parallels the much higher levels of alpha 2(I) collagen RNA that are found in the tail as compared to other tissues. Expression of the chimeric gene is detected in the embryo after 8.5 days of gestation, at approximately the same time that the endogenous type I genes become active. We conclude that the alpha 2(I) collagen promoter sequences present in the recombinant plasmid used for our experiments contain sufficient information to ensure stage- and tissue-specific activity of this promoter.
我们培育了8只转基因小鼠，其中小鼠α2（I）型胶原基因的启动子（核苷酸-2000至+54）与氯霉素乙酰转移酶（CAT）的细菌基因相连，并稳定整合到种系中。这些品系每个单倍体基因组含有1至20个α2（I）型胶原-CAT嵌合基因拷贝。在8个品系中的7个品系中，CAT基因表达，尽管不同品系间CAT酶活性水平差异很大。在其中6个品系中，CAT基因的表达遵循α2（I）型胶原基因预期的组织分布表达模式。在这6个品系中，尾巴提取物中的CAT活性水平比任何其他测试组织都高得多，尾巴是富含肌腱的组织。这种分布与尾巴中与其他组织相比发现的α2（I）型胶原RNA的高水平相平行。在妊娠8.5天后的胚胎中检测到嵌合基因的表达，大约与内源性I型基因开始活跃的时间相同。我们得出结论，用于我们实验的重组质粒中存在的α2（I）型胶原启动子序列包含足够的信息来确保该启动子的阶段和组织特异性活性。
