Changes in the cerebellar size arising from F3/Contactin developmental misexpression from the TAX-1 promoter. (A) Organization of the TAX-1 promoter/F3 cDNA construct. The F3/Contactin regulatory region, including the genomic sequences surrounding exons A1, 0, B and C1, has been replaced for by the promoter region from the human TAX-1 gene and used to drive the F3/Contactin cDNA in transgenic mice. (B) Changes in the cerebellar size arising from F3/Contactin developmental misexpression under control of the TAX-1 promoter, observed in postnatal day 6 mice. An F3/Contactin immunostaining is shown. egl, external granular layer; igl, inner granular layer; PCl, Purkinje cells layer; WM, white matter; CP, Choroid Plexus. Scale bar: 200 µm.