We previously reported the generation of a IP3R1 promoter-lacZ transgenic mouse line (1NM13) whose cerebellar Purkinje cells were symmetrically stained as bands in the parasagittal direction with X-gal, a chromogenic substrate for lacZ (1997 SFN Meeting Abstract 349.9). Uneven transgene expression was detected in a subset of post-mitotic immature Purkinje cells as far as E14. The parasagittal banding became clear during the early postnatal development and was almost disappeared by the postnatal 3rd week because of the transgene expression in all Purkinje cells. Zebrin II/aldolase C is the best-understood marker for adult parasagittal molecular compartments, and the parasagittal bands appear by P14. We have compared the parasagittal organization of the lacZ banding with that of zebrin II immunoreactivity in P12-14 transgenic mouse cerebella. Both parasagittal banding patterns were not completely matched (lacZ+/zebrin+, lacZ+/zebrin-, lacZ-/zebrin+, lacZ-/zebrin-), indicating that there are multipe molecular...