We describe the isolation and expression of a murine homologue of the Phospholipase C beta3 Neighboring Gene (PNG), located in the MEN1 region on chromosome 11q13. The PNG cDNA was isolated using a human PNG cDNA clone (SOM172). Human and mouse PNG do not have any marked similarity to other known genes on the DNA level, but the predicted protein display similarity to the C-terminal part of Phospholipase C beta2. Northern blots with mouse PNG probes revealed expression of a 1 kb message in multiple tissues, and an additional 2.3 kb band in testis. The predicted murine protein contains 203 amino acids. In situ hybridization histochemistry displayed png mRNA expression in several tissues of the midstage mouse embryo, including the central nervous system. In late stage embryos, png was highly expressed in skeletal muscle, retina and neocortex. In the adult animal, expression was restricted to testis and thymus.