The NTN2L Gene Encoding a Novel Human Netrin Maps to the Autosomal Dominant Polycystic Kidney Disease Region on Chromosome 16p13.3

The netrins define a family of chemotropic factors that have been shown to play a central role in axon guidance. We identified two exon traps encoding netrin-like sequences during the assembly of a transcriptional map for the genomic interval surrounding the polycystic kidney disease type 1 and tuberous sclerosis type 2 genes. We describe the characterization of a novel human netrin-2-like gene, designated NTN2L, and its transcript. The genomic interval containing the NTN2L gene was sequenced, and the coding region was predicted based on computer analysis. The structure of the NTN2L gene has been confirmed utilizing nested RT-PCR. The NTN2L gene is predicted to encode a 580-amino-acid protein having homology to the chicken and Drosophila netrins and to Caenorhabditis elegans UNC-6. The NTN2L gene has a restricted pattern of expression; its transcript is undetectable by Northern analysis in all tissues examined, but can be recovered from spinal cord RNA by RT-PCR. This report represents the first description and characterization of a human netrin.