Expression of Cdk5 activator -p39 mRNA during rat brain development

Abstract

Objective To detect the different distribution of Cdk5 two activators, p35 and p39, throughout brain development. Methods We examined the spatial and temporal expression of p39 in the developing rat brains by Northern blot analysis and in situ hybridization. Results Northern blot analysis showed that p39 expression was low in 15-day old fetuses and newborns, and was most prominent in the 1-3 week-old rat brains. In the adult rat brains, expression declined to the same level as in newborn rat brains. In situ hybridization showed that p39 mRNA was weakly expressed in all neurons of all regions in the newborn rat brains and the transcriptional level was highest in all regions in the 3 week-old rat brains. In the adult rat brains, the expression was decreased in most neurons, except Purkinje and granule cells in the cerebellum which retained high levels. Conclusion The expression of p39 varies spatially and temporally along with rat brain development, and its subcellular location is related with the activation of Cdk5 function. Key words: Cyclin-dependent kinase5; p39; p35