The Mouse Neuronal Protein 15.6 Gene Family

During the course of reviewing the results of automatic annotation of 1989 clusters derived from 16,078 sequences of an adult mouse testis cDNA library, we found a cluster of 24 cDNA clones showing similarity to the mouse neuronal protein 15.6 (NP15.6) gene and named it the NP15.6-like gene. This NP15.6-like gene corresponded to an intronless gene, mapped to chromosome 15, and was expressed predominantly in the testes. Interestingly, the mouse NP15.6 gene itself is a split gene consisting of three exons, mapped to chromosome X, and was expressed at high levels in various tissues and organs. We found two more intronless NP15.6-like genes; one was mapped to chromosome 5, and the other to chromosome X. These two intronless genes were probably processed-type pseudogenes. Our present observations support the idea that NP15.6 family proteins have a shorter half-life and span a membrane.