Figure 7.

EM localization of Rab 27a, myosin VIIa, and myosin Va. Cryosections of wild-type RPE were labeled with 4B12 mouse anti-Rab27a (A and C), and Q142 rabbit anti-Rab27a antibody (B), anti-myosin VIIa (D and E), or antimyosin Va (F and G). Protein A gold particles (10 nm) are indicated in the lower magnification panels by arrowheads. Rab27a is found on the perimeter membrane of most melanosomes, whether elliptical or spherical or in the cell body or the apical processes. Rab27a is also sometimes found within the lumen of the melanosome (B). Myosin VIIa is found on some melanosomes and in the cytoplasm, whereas myosin V is not found on melanosomes but strongly labels the plasma membrane of rod outer segments. Bar, 200 nm.