Bbs5–/– mice have aberrant outer segment disk membranes. Sagittal sectioned retinas from 3-month-old WT (A, B) and Bbs5–/– (C, D) mice show aberrant outer segment membranes. In WT mice, disks are oriented parallel, whereas in Bbs5–/– mice not only are the disks oriented parallel but there is the appearance of perpendicularly oriented disks and membranous churns (indicated by arrows, < and >).