PKC-GAMMA GENE-EXPRESSION IS DELAYED IN POSTNATAL CENTRAL-NERVOUS-SYSTEM OF MI-MI MICE

In the central nervous system (CNS), the expression of protein kinase C (PKC) genes is strictly controlled by the developmental stage. We ha ve examined the expression of PKC genes (cPKCalpha, beta, gamma, and n PKCdelta, epsilon) in the process of the postnatal development in norm al (+/+) C57BL/6 and microphthalmic (mi/mi) C57BL/6 mouse brains by No rthern blotting and in situ hybridization. By Northern blotting, the e xpression level of cPKCgamma mRNA in mi/mi mice was significantly lowe r than that in +/+ littermates at d 9,13, and 17. By in situ hybridiza tion analysis, cPKCgamma mRNA-positive cells were detected in hippocam pal and Purkinje cells in +/+ and mi/mi mice, but the magnitude of the signals in mi/mi mice was lower than that of +/+ mice, and the number of positive cells was smaller, whereas other isozymes (cPKCalpha, bet a, and nPKCdelta, epsilon) showed no significant difference between no rmal and mi/mi mice. The neuronal morphometric analysis by anti-P400 a ntibody revealed the same number and expression level of P400 protein in cerebellar Purkinje cells compared with +/+ mice. These results ind icate that the deficiency of mi gene product causes the delayed expres sion of the cPKCgamma ene.