A zebrafish homologue of deleted in colorectal cancer (zdcc) is expressed in the first neuronal clusters of the developing brain

DCC (deleted in colon cancer), Neogenin and UNC-5 are all members of the im munoglobulin superfamily of transmembrane receptors which are believed to p lay a role in axon guidance by binding to their ligands, the Netrin/UNC-40 family of secreted molecules (Cell. Mol. Life Sci. 56 (1999) 62; Curr. Opin . Genet. Dev. 7 (1997) 87). Although zebrafish homologues of the Netrin fam ily of secreted molecules have been reported, to date there has been no pub lished description of zebrafish DCC homologues (Mol. Cell. Neurosci. 9 (199 7) 293., Mol. Cell. Neurosci. I I ( 1998) 194; Mech. Dev. 62 (1997) 147). W e report here the expression pattern of a zebrafish dcc (zdcc) homologue du ring the initial period of neurogenesis and axon tract formation within the developing central nervous system. Between 12 and 33 h post-fertilisation zdcc is expressed in a dynamic spatiotemporal pattern in all major subdivis ions of the central nervous system. Double-labelling for zdcc and the post- mitotic neuronal marker HNK-1 revealed that subpopulations of neurons withi n the first nuclei of the zebrafish brain express zdcc. These results suppo rt our previous observation that patterning of neuronal clusters in the zeb rafish brain occurs early in development (Dev. Bioi, 229 (2001) 271). (C) 2 001 Elsevier Science Ireland Ltd. All rights reserved.