Selective distribution of a novel tubulin in the developing and mature rat brain

A monoclonal antibody, G8, was isolated which recognizes a form of tubulin (G8-tubulin) with a novel distribution in the rat brain. Immunoblots of rat brain homogenates and immunohistochemical staining of rat brain sections of various ages with G8 revealed a restricted and developmentally regulated distribution of the G8-tubulin. G8 staining was primarily found in granule cell dendrites in the dentate gyrus, in pyramidal cell apical dendrites in the hippocampus, and in Purkinje cell dendrites in the cerebellum. This pattern was much more selective than that observed with three other anti-tubulin antibodies. Relative abundance of G8-tubulin in the brain increases with age between postnatal day 1 (P1) and adulthood. The results suggest that G8 is specific for a novel tubulin form which shows a characteristic distribution in the rat brain. This distribution may indicate that the G8-tubulin possesses functional specificity.