Transmission electron micrographs of rod photoreceptor cells in retinas of 4 week old mice.

<p>A. Structural organization at the base of the outer segment in wild type mice (+/+) B. Structural organization at the base of the outer segment in Q344X-hRho-GFP heterozygous mice (Q344X/+). In A and B, typical stacks of membranes disks are attached to the connecting cilium. C. Abnormal ultrastructure of rod cells in retinas from Q344X-hRho-GFP homozygous mouse (Q344X/Q344X). Isolated connecting cilia (asterisks) and disorganized membranes (indicated by arrows) are apparent, but no discernible rod-like structures are visible.