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 andnamedit the NP15.6-like gene. This NP15.6-like gene correspondedto an intronless gene, mappedto chromosome 15, andwas expressedpredominantly in the testes. Interestingly, the mouse NP15.6 gene itself is a split gene consisting of three exons, mappedto chromosome X, andwas expressedat high levels in various tissues andorgans. We foundtwo more intronless NP15.6-like genes; one was mappedto chromosome 5, andthe 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 andspan a membrane.