Fig. 7. Developmental manifestation of the stria vascularis phenotype of Tbx18^-/- mice. Analyses of histology by Hematoxylin and Eosin staining (A,B) and of marker gene expression by RNA in situ hybridization (C-L) on sagittal sections of E18.5 cochleae. Figures show the basal coil (C-L) and the stria vascularis region (A,B). Arrowheads mark the lateral extension of the stria vascularis. Tbx18^-/- cochleae show normal differentiation of intermediate and marginal cell precursors of the forming stria vascularis, but lack the mesenchymal cell condensation preceding basal cell formation (arrow in B). Probes were used as indicated in the figure. For abbreviations, see Fig. 2.