EJMS

Abstract

Background: Regenerating (Reg) protein was first isolated from the regenerating islets of Langerhans. Later on, studies proved that Reg proteins are involved in the proliferation and differentiation of variable cell types including the neurons. Materials and Methods: In this study, the expression pattern of Reg receptor (Reg-R) mRNA is examined in the adult and in the embryonic days at (E) 11.5, E12.5, E14.5 and E16.5 mouse brain by in situ hybridization. Results: The ventricular zone neuro-epithelial cells showed mild signal at E11.5 but the signal is intense at E12.5 for Reg-R expression. While in the cortical plate at E12.5, population of strong positive signal among population of negative neurons were observed. At E14.5, all the neocortex neurons were moderately and homogeneously stained for the gene expression. In contrast, at E16.5 the gene expression in the ventricular zone is downregulated, while in the cortical plate there was an intense and differential reaction for the gene expression. Large number of neurons were strongly labelled while moderate number was moderately stained, and few number was negatively stained for the gene at E16.5 neocortex. In the adult cerebral cortex the pyramidal neurons showed the highest gene expression among all types of neurons. Less intense signal was observe in granular neurons while the glia cells were devoid of signal for gene expression in the adult cerebral cortex. In the developing cerebellum the highest expression was detected at E16.5 while in the adult cerebellar cortex the highest expression was detected in the Purkinje cell layer. Conclusion: These data indicated that Reg-R expression is developmentally regulated and that it is important to the brain embryonic development and adult brain function.