Martin S C, Sandell J H, Heinrich G
Evans Department of Clinical Research and Medicine, Boston University Medical Center Hospital, Boston, Massachusetts.
Dev Biol. 1998 Mar 15;195(2):114-30. doi: 10.1006/dbio.1997.8839.
We identified previously five distinct trk genes in the zebrafish. The structures of two of these, TrkC1 and TrkC2, are most similar to mammalian TrkC. Detailed sequence comparisons reported here indicate that although the similarities to TrkC are greatest in those regions of the extracellular domain implicated in ligand binding, the two sequences also differ significantly in these regions. Whole-mount in situ hybridization experiments in the early embryo revealed full-length trkC1 but no trkC2 transcripts in the cranial ganglia and in a subset of Rohon-Beard neurons. At the same time, full-length trkC2 but no trkC1 transcripts were detected laterally in the spinal cord, in the caudal hindbrain, in reticulospinal neurons of rhombomeres 4, 5, and 6, and in the midbrain. Both types of transcripts were expressed in clusters of cells in the dorsal telencephalon and the nucleus of the tract of the postoptic commissure. These results suggest distinct functions of trkC1 and trkC2 in nervous system development. The expression patterns define two different neuronal populations in the zebrafish.
我们之前在斑马鱼中鉴定出了五个不同的trk基因。其中两个基因，TrkC1和TrkC2，其结构与哺乳动物的TrkC最为相似。此处报道的详细序列比较表明，尽管在与配体结合相关的细胞外结构域区域与TrkC的相似性最大，但这两个序列在这些区域也存在显著差异。早期胚胎的整体原位杂交实验显示，在颅神经节和一部分罗霍恩-比尔兹神经元中存在全长trkC1转录本，但没有trkC2转录本。与此同时，在脊髓外侧、尾侧后脑、菱脑节4、5和6的网状脊髓神经元以及中脑中检测到全长trkC2转录本，但没有trkC1转录本。两种类型的转录本都在背侧端脑的细胞簇和视交叉后连合束核中表达。这些结果表明trkC1和trkC2在神经系统发育中具有不同的功能。这些表达模式定义了斑马鱼中两种不同的神经元群体。
