Lamballe F, Smeyne R J, Barbacid M
Department of Molecular Biology, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543.
J Neurosci. 1994 Jan;14(1):14-28. doi: 10.1523/JNEUROSCI.14-01-00014.1994.
The mammalian trkC gene encodes a tyrosine protein kinase that serves as a functional receptor for neurotrophin-3 (NT-3). Here, we report that trkC is widely expressed in the developing and adult nervous system. Using in situ hybridization, we first detect trkC transcripts in the telencephalon and spinal cord of embryonic day 9.5 mouse embryos. In later embryonic development, trkC is expressed in various structures of the CNS including the caudatoputamen, septal nuclei, cerebellum, and brainstem. In the PNS, trkC hybridization appears to correlate, both temporally and spatially, with the outgrowth of axons toward their peripheral targets. trkC transcripts were also identified in the autonomous enteric nervous system as well as in some non-neural tissues such as the wall of the aorta and the acini of the submaxillary and sublingual glands. In the adult mouse, trkC gene expression is heterogeneously distributed throughout the brain, with highest levels in limbic and diencephalic structures. These results indicate that the trkC gene is widely expressed in the three identified branches of the mammalian nervous system and appears to correlate with the expression of NT-3, its cognate ligand. The apparent colocalization of trkC transcripts with NT-3 raises the possibility this neurotrophin exerts its trophic effects by a paracrine and/or autocrine mechanism.
哺乳动物的trkC基因编码一种酪氨酸蛋白激酶，它作为神经营养因子-3（NT-3）的功能性受体。在此，我们报告trkC在发育中和成年期的神经系统中广泛表达。利用原位杂交技术，我们首先在胚胎期9.5天的小鼠胚胎的端脑和脊髓中检测到trkC转录本。在随后的胚胎发育过程中，trkC在中枢神经系统的各种结构中表达，包括尾状核、隔核、小脑和脑干。在周围神经系统中，trkC杂交信号在时间和空间上似乎都与轴突向其外周靶标的生长相关。trkC转录本也在自主肠神经系统以及一些非神经组织中被鉴定出来，如主动脉壁以及颌下腺和舌下腺的腺泡。在成年小鼠中，trkC基因表达在整个大脑中呈异质性分布，在边缘系统和间脑结构中的水平最高。这些结果表明，trkC基因在哺乳动物神经系统的三个已确定分支中广泛表达，并且似乎与它的同源配体NT-3的表达相关。trkC转录本与NT-3明显的共定位增加了这种神经营养因子通过旁分泌和/或自分泌机制发挥其营养作用的可能性。
