REGIONAL SPECIFICITY OF TUBULIN HETEROGENEITY IN ADULT-MOUSE BRAIN

Eight alpha and twelve beta isoforms of tubulin were isolated from discrete regions of the mouse brain using high-resolution isoelectric focusing and identified by two-dimensional gel electrophoresis and immunoreactivity. In the different regions, the number of isoforms was identical, but their relatve proportion varied except for alpha 2, 3, 4, 5, 6 and beta 1 bands. The patterns of the inferior and superior colliculi was nearly similar. The cerebellum, compared with the inferior and superior colliculi is characterized by a decrease of alpha band 7 and beta bands 3 and 7 and an increase of alpha band 8 and beta bands 2, 4, 10, 11, 12. The forebrain displays an intermediate pattern between the cerebellum and the colliculi. The results suggest that in functionally different regions of the brain the number of isotypes of tubulin is identical but their relative proportion differs with an apparent correlation between the function of the neuronal subpopulations and the pattern of isotubulins.