Eguchi Megumi, Yamaguchi Shun
Department of Physiology and Cell Biology, Division of Developmental Neurobiology, Kobe University Graduate School of Medicine, Kobe, Japan.
Neuroimage. 2009 Feb 15;44(4):1274-83. doi: 10.1016/j.neuroimage.2008.10.046. Epub 2008 Nov 12.
In vivo monitoring of gene expression using promoter-destabilized fluorescence protein constructs is a powerful method for examining the expression dynamics of immediate-early genes in the brain. However, weak fluorescence signals derived from such constructs have hampered analyses of gene expression over extensive areas of the brain. We succeeded in producing transgenic mice with brains exhibiting high level expression of the reporter gene driven by the Arc gene promoter, which is activated in association with various brain functions (reporter mRNA abundance was near 100-fold greater than endogenous Arc mRNAs). This high expression of the reporter gene enabled us to monitor Arc gene expression dynamics in vivo, over an area that included the whole of the dorsal cerebral cortex. Moreover, we were able to perform three-dimensional analyses of activated regions using paraformaldehyde-fixed brains. In addition to the visual cortex, we found that the cingulate cortex was strongly activated by light stimuli. These mice are extremely useful for the functional analysis of gene expression over extensive areas of the brains in both wild-type mice and mutants with impaired brain function.
使用启动子不稳定荧光蛋白构建体进行基因表达的体内监测是一种用于检测大脑中即刻早期基因表达动态的强大方法。然而，源自此类构建体的微弱荧光信号阻碍了对大脑广泛区域基因表达的分析。我们成功培育出转基因小鼠，其大脑中由Arc基因启动子驱动的报告基因呈现高水平表达，该启动子会随着各种脑功能的激活而被激活（报告基因mRNA丰度比内源性Arc mRNA高近100倍）。报告基因的这种高表达使我们能够在体内监测包括整个背侧大脑皮层在内区域的Arc基因表达动态。此外，我们能够使用多聚甲醛固定的大脑对激活区域进行三维分析。除了视觉皮层外，我们发现扣带回皮层也受到光刺激的强烈激活。这些小鼠对于野生型小鼠和脑功能受损突变体大脑广泛区域的基因表达功能分析极为有用。
