Sun Min-Yu, Yetman Michael J, Lee Tang-Cheng, Chen Yuqing, Jankowsky Joanna L
Department of Neuroscience, Baylor College of Medicine, Houston, Texas, 77030.
J Comp Neurol. 2014 Apr 1;522(5):1191-208. doi: 10.1002/cne.23497.
Transgenic lines expressing a controllable form of Cre recombinase have become valuable tools for manipulating gene expression in adult neural progenitors and their progeny. Neural progenitors express several proteins that distinguish them from mature neurons, and the promoters for these genes have been co-opted to produce selective transgene expression within this population. To date, nine CreER(T2) transgenic lines have been designed using the nestin promoter; however, only a subset are capable of eliciting expression within both neurogenic zones of the adult brain. Here we compare three such nestin-CreER(T2) lines to evaluate specificity of expression and efficiency of recombination. Each line was examined by using three different Cre reporter strains that varied in sensitivity. We found that all three nestin-CreER(T2) strains induced reporter expression within the main neurogenic areas, albeit to varying degrees depending on the reporter. Unexpectedly, we found that two of the three lines induced substantial reporter expression outside of neurogenic areas. These lines produced strong labeling in cerebellar granule neurons, with additional expression in the cortex, hippocampus, striatum, and thalamus. Reporter expression in the third nestin-CreER(T2) line was considerably more specific, but was also less efficient, labeling a smaller percentage of the target population than the other two drivers. Our findings suggest that each nestin-CreER(T2) line may best serve different experimental needs, depending on whether specificity or efficiency is of greatest concern. Our study further demonstrates that each new pair of driver and responder lines should be evaluated independently, as both components can significantly influence the resulting expression pattern.
表达可调控形式的Cre重组酶的转基因品系已成为在成年神经祖细胞及其子代中操纵基因表达的宝贵工具。神经祖细胞表达几种使其与成熟神经元区分开来的蛋白质，并且这些基因的启动子已被用于在该群体中产生选择性转基因表达。迄今为止，已经使用巢蛋白启动子设计了9种CreER(T2)转基因品系；然而，只有一部分能够在成年大脑的两个神经发生区域内引发表达。在这里，我们比较了三种这样的巢蛋白-CreER(T2)品系，以评估表达的特异性和重组效率。每个品系都使用三种敏感性不同的Cre报告菌株进行检测。我们发现，所有三种巢蛋白-CreER(T2)菌株都在主要神经发生区域内诱导了报告基因的表达，尽管根据报告基因的不同程度有所差异。出乎意料的是，我们发现这三个品系中的两个在神经发生区域之外诱导了大量的报告基因表达。这些品系在小脑颗粒神经元中产生了强烈的标记，并在皮质、海马体、纹状体和丘脑中额外表达。第三个巢蛋白-CreER(T2)品系中的报告基因表达明显更具特异性，但效率也较低，标记的目标群体百分比低于其他两个驱动品系。我们的研究结果表明，每个巢蛋白-CreER(T2)品系可能最适合不同的实验需求，这取决于特异性或效率是否是最值得关注的。我们的研究进一步表明，每一对新的驱动和应答品系都应该独立评估，因为这两个组件都可以显著影响最终的表达模式。
