FIB-SEM 3D reconstructions of two representative mouse P14 CPECs, with one forming a single multicilia cluster with closely aggregated basal bodies (CEPC #1) and the other forming multiple subclusters of multicilia with more dispersed basal bodies (CEPC #2). Orange, axoneme; blue-green, basal body; blue arrowheads, aggregated tip of clustered cilia; yellow arrowheads, DAs; red arrowheads, basal body connections via SDA-SDA or SDA-basal body contact. 3D axes, x (red), y (green), and z (white). Bounding box dimensions: CPEC#1, top, 3.224 x 2.824 x 2.904 μm; bottom, 1.856 x 2.56 x 1.664 μm. CPEC#2, top, 3.144 x 4.456 x 2.776 μm; bottom, 1.288 x 1.328 x 1.024 μm.
