Autophagosomes with recognizable cargo are rare in cells. (A) To assess relative rates of autophagosome formation, the fusion inhibitor bafilomycin A1 (10 nM) was applied for 2 h prior to fixation with 2% glutaraldehyde in order to trap newly formed autophagosomes. Two different PINK1 shRNA lines (A14 and D14) exhibit increased AV formation over 2 h compared to the control shRNA line. *, p < 0.05 vs. Control. (B) Autophagosomes in bafilomycin A1-treated control cells contain a variety of cytoplasmic structures (left, arrow), while mitochondria comprise a prominent component of autophagosomes in bafilomycin A1-treated (PINK1 shRNA) cells (right, arrow). Scale bar: 500 nm. These data indicate induction of selective mitophagy in PINK1-deficient cells. This figure was modified from Figure 2 published in ref. 1951, Chu CT. A pivotal role for PINK1 and autophagy in mitochondrial quality control: implications for Parkinson disease. Human Molecular Genetics 2010; 19:R28-R37.