Song Junghun, Xu Yuanzhong, Hu Xiaoxia, Choi Brian, Tong Qingchun
Genesis. 2010 Nov;48(11):628-34. doi: 10.1002/dvg.20672. Epub 2010 Oct 19.
Cre-loxP technology enables specific examination of the function and development of individual nuclei in the complex brain network. However, for most brain regions, the utilization of this technique has been hindered by the lack of mouse lines with Cre expression restricted to these regions. Here, we identified brain expressions of three transgenic Cre lines previously thought to be pancreas-specific. Cre expression driven by the rat-insulin promoter (Rip-Cre) was found mainly in the arcuate nucleus, and to a lesser degree in other hypothalamic regions. Cre expression driven by the neurogenin 3 promoter (Ngn3-Cre mice) was found in the ventromedial hypothalamus. Cre expression driven by the pancreas-duodenum homeobox 1 promoter (Pdx1-Cre) was found in several hypothalamic nuclei, the dorsal raphe and inferior olivary nuclei. Interestingly, Pdx1-Cre mediated deletion of vesicular GABA transporter led to postnatal growth retardation while Ngn3-Cre mediated deletion had no effects, suggesting a role for Pdx1-Cre neurons, but not pancreas, in the regulation of postnatal growth. These results demonstrate the potential for these Cre lines to study the function and development of brain neurons.
Cre-loxP技术能够对复杂脑网络中单个核团的功能和发育进行特异性检测。然而，对于大多数脑区而言，由于缺乏Cre表达局限于这些区域的小鼠品系，该技术的应用受到了阻碍。在此，我们鉴定出了三种先前被认为是胰腺特异性的转基因Cre品系在脑中的表达情况。由大鼠胰岛素启动子驱动的Cre表达（Rip-Cre）主要在弓状核中被发现，在下丘脑的其他区域也有较少程度的表达。由神经生成素3启动子驱动的Cre表达（Ngn3-Cre小鼠）在腹内侧下丘脑被发现。由胰腺十二指肠同源框1启动子驱动的Cre表达（Pdx1-Cre）在多个下丘脑核团、中缝背核和下橄榄核中被发现。有趣的是，Pdx1-Cre介导的囊泡GABA转运体缺失导致出生后生长迟缓，而Ngn3-Cre介导的缺失则没有影响，这表明Pdx1-Cre神经元而非胰腺在出生后生长调节中发挥作用。这些结果证明了这些Cre品系在研究脑神经元功能和发育方面的潜力。
