Figure 2

Electron micrographs of WT and rd1 mice. (A) Morphological defects in mitochondrial cristae structure (red arrows) at P3 in rd1 retinas. Abnormal mitochondria (red arrows) became more widespread in rd1 rod photoreceptor inner segments from P7. The Golgi apparatus (blue triangles) emerged within the inner segments at P7 and showed extensive at P14 in WT mice. In rd1 mice, the Golgi apparatus was scarcely observed from P7. Image scale bar: 1000 nm; 500 μm (magnified graphs). (B) Through TEM, a group of rod terminals was observed at P14 in the OPL of wild-type mice, with synaptic ribbons marked by red arrows. In the OPL of rd1 mice, the terminals contained vesicles and a possible invagination accompanied by postsynaptic structures. Image scale bar: 500 nm. (C) Quantification of abnormal mitochondria, the number of Golgi apparatus and ribbon indication showed that mitochondria cristae structure defected as early as P3, few Golgi apparatus were seen from P7 and few ribbons at P14 in the rd1 retina. (N = 3 eyes from 3 different mice, n = 6 images from each eye). **P < 0.01, *P < 0.05 compared with rd1 mice by an independent two-sample t-test.