FIGURE 5.

WIPI1-depleted cells accumulate early stage melanosomes and atypical endosomes. A, human deeply pigmented melanocytes expressing control or WIPI1 shRNAs were fixed and imaged by TEM. Scale bar, 2 μm. The lower panel demonstrates classic stage I–IV melanosomes and atypical endosome-like vesicles that accumulate in WIPI1 shRNA-expressing cells. Scale bar, 0.1 μm. B, quantification of stage I–IV melanosomes in control and WIPI1 shRNA-expressing melanocytes. Data shown are mean ± S.D. (n = 10). **, p < 0.01 using a Student's t test versus sh control. C, photographs were taken of cell pellets from shRNA-expressing melanocytes to capture the impact of each shRNA on pigment production. Con, control.