Figure 3.

Choroid plexus epithelial ultrastructure is intact in BBS mutant mice. TEM micrographs of the choroid plexus epithelium from the lateral ventricles of P0 wild- type (A) and Bbs1^M390R/M390R mice (B), P9 Bbs4^−/− mice (C), and 15 week-old Bbs6^−/− mice (D). The epithelial cells appear healthy with numerous microvilli at the apical surface, intact tight junctions between cells, and an intact basolateral membrane, indicating no apparent disruption of the blood-CSF barrier at the ultrastructural level. Single asterisks (*) highlight solitary primary cilia. Double asterisks (**) indicate clusters of cilia. Arrows point to tight junctions between cells. Higher magnification of Bbs4^−/− choroid plexus solitary cilia (E) and Bbs6^−/− clustered cilia (F). FC (fenestrated capillary), LV (lateral ventricle), MV (microvilli). Bars equal 2 μm in A-D and 1 μm in E, F.