Soma Katsunori, Shiomi Kensuke, Keino-Masu Kazuko, Masu Masayuki
Department of Molecular Neurobiology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan.
Gene Expr Patterns. 2006 Mar;6(3):325-30. doi: 10.1016/j.modgep.2005.06.013. Epub 2005 Dec 27.
Wnt signaling plays an important role in cell growth, differentiation, polarity formation, and neural development. We have recently identified the Coiled-coil-DIX1 (Ccd1) gene encoding a third type of a DIX domain-containing protein. Ccd1 forms homomeric and heteromeric complexes with Dishevelled and Axin, and positively regulates the Wnt/beta-catenin pathway. Here, we examined the spatiotemporal expression pattern of Ccd1 mRNA in mouse embryos from embryonic day 6.5 (E6.5) to E17.5 by in situ hybridization. Ccd1 expression was detected in the node region in gastrula embryos, in the cephalic mesenchyme and tail bud at E8.5, and in the branchial arch and forelimb bud at E9.5. In the central nervous system, Ccd1 expression began and persisted in the regions where the neurons differentiated, so that it was observed throughout the brain and spinal cord at E17.5. Ccd1 expression was also strong in the peripheral nervous system, including sensory cranial ganglia (trigeminal, facial, and vestibulocochlear ganglia), dorsal root ganglia, and autonomic ganglia (sympathetic ganglia, celiac ganglion, and hypogastric plexus). Ccd1 was detected in the sensory organs, such as the inner nuclear layer of the neural retina, saccule and cochlea of the inner ear, and nasal epithelium. Outside the nervous system, Ccd1 mRNA was observed in the cartilage, tongue, lung bud, stomach, and gonad at E12.5-E14.5, and in the tooth bud, bronchial epithelium, and kidney at E17.5. Taken together, these findings demonstrate that Ccd1 expression is observed in all the neurons in the nervous system, closely associated with neural crest-derived tissues, and largely overlapping with the regions where several Wnt genes are reported to play a role.
Wnt信号通路在细胞生长、分化、极性形成和神经发育中发挥着重要作用。我们最近鉴定出了编码第三种含DIX结构域蛋白的卷曲螺旋-DIX1（Ccd1）基因。Ccd1与Dishevelled和Axin形成同聚体和异聚体复合物，并正向调节Wnt/β-连环蛋白信号通路。在此，我们通过原位杂交检测了小鼠胚胎从胚胎第6.5天（E6.5）到E17.5期间Ccd1 mRNA的时空表达模式。在原肠胚胚胎的节点区域、E8.5时的头部间充质和尾芽以及E9.5时的鳃弓和前肢芽中检测到Ccd1表达。在中枢神经系统中，Ccd1表达在神经元分化的区域开始并持续存在，因此在E17.5时在整个脑和脊髓中都能观察到。Ccd1在外周神经系统中也有强烈表达，包括感觉颅神经节（三叉神经节、面神经节和前庭蜗神经节）、背根神经节和自主神经节（交感神经节、腹腔神经节和腹下丛）。在感觉器官中检测到Ccd1，如神经视网膜的内核层、内耳的球囊和耳蜗以及鼻上皮。在神经系统之外，在E12.5 - E14.5时在软骨、舌、肺芽、胃和性腺中观察到Ccd1 mRNA，在E17.5时在牙胚、支气管上皮和肾脏中观察到。综上所述，这些发现表明在神经系统的所有神经元中都观察到Ccd1表达，与神经嵴衍生组织密切相关，并且与据报道几个Wnt基因发挥作用的区域在很大程度上重叠。
