An incomplete BBSome complex is assembled in the CCT-deficient rods. Whole-eye extracts from Δ1–83PhLP-FLAG−/− and Δ1–83PhLP-FLAG± littermates at P10 were fractionated by ultracentrifugation on a 10% to 40% sucrose gradient calibrated using sedimentation (S) coefficient standards. Collected fractions were analyzed by Western blotting using specific antibodies against the indicated BBS proteins. A mature BBSome contains BBS1, -2, -4, -5, -7, -8, and -9 and migrates as a 14S complex (▴); an incomplete BBSome contains BBS1, -4, -8, -9, and migrates as a 9S complex (Δ).