The rat phospholipase C beta 4 gene is expressed at high abundance in cerebellar Purkinje cells.

Inositol phospholipid-specific phospholipase C (PLC) generates two important second messengers, inositol triphosphate and diacylglycerol. The recently cloned rat PLCβ 4 cDNA is highly homologous to the norpA cDNA of Drosophila melanogaster. We have mapped the PLCβ 4 gene expression in rat brain tissue sections by in situ hybridization. The PLCβ 4 gene is expressed at high abundance in cerebellar Purkinje cells and neurones of the substantia nigra, the median geniculate bodies and the thalamic nuclei. PLCβ 4 transcripts are also detected in the mammillary nuclei, the neocortex, the habenula and the olfactory bulbs. The specific pattern of gene expression we have observed should help to clarify the relationships between the PLCβ 4 and various constituents of second-messenger systems involved in transduction mechanisms triggered by the stimulation of seven transmembrane domain receptors. The strong gene expression in Purkinje cells and retinal neurones suggests that PLCβ 4 may be involved in the pathogenesis of mouse and human neurological diseases characterized by ataxia and retinal degeneration.