Fig. S5

Ciliary and microvillar defects in the pronephros of 6 dpf pam^-/- embryos

Upper panels - Electron micrographs of the anterior-posterior regions of the pronephros of 6 dpf pam^+/+ (A-E) and pam^-/- (F-J) embryos. The entire pronephros was examined using alternating 0.5  μm thick sections for ~ 50  μm followed by several ultrathin sections examined by EM. Although microvilli and cilia were present in the most anterior segment of the pronephros of both wildtype and Pam-null embryos, cilia were much reduced, and microvilli were essentially absent in other pronephric regions of the mutant; only the very posterior pronephros lacked microvilli in the wildtype embryo. Bars = 2  μm (A, E, F, J) and 1  μm (B, C, D, G, H, I).

Lower panels – Bright-field micrographs of toluidine blue-stained transverse thick sections through wildtype (K, L) and Pam-null (M, N) 6 dpf embryos; the vastly different appearance of the mutant embryos is due to the massive edema. Higher magnification images of the pronephric region (L, N) revealed that the pronephros lumen (white arrows in L) in the pam^+/+ embryo was almost occluded, whereas it was more open in the pam^-/- animals. Bars = 10 (K, M) and 5 (L, N) μm.