Biochemical and histochemical analysis of 71 kDa dystrophin isoform (Dp71f) in rat brain

Dp71 is a member of the dystrophin family and the most abundant dmd gene pr oduct in the brain. In the present study, we focused on a short dystrophin transcript named Dp71f, which is alternatively spliced when exon 78 is abse nt The topographic localization of this protein in the encephalon has not b een properly described yet, nor its cellular or subcellular localization, a nd even less its functions. Dp71f was found to be a cytoplasmic 70 kDa prot ein and localized in all encephalon regions studied. Double labeling using specific markers for various cell types confirmed Dp71f distribution in the cytoplasm of all cell types studied. Labeling was more conspicuous near th e nucleus and diminished towards the periphery of cells. In some cases, we observed cells that were positive for actin and Dp71f in regions correspond ing to lamellipodia-like structures. Dp71f and Dp71d isoforms were differen tly distributed. Our study is the first specific and unambiguous descriptio n of the topography and cellular localization patterns of Dp71f in brain, s uggesting that Dp71f is a ubiquitous protein.