(a) Single-plane confocal microscopy images of MBds within LC3-positive autophagosomes in MEFs expressing GFP-LC3 (left) and in hRPE-1 cells stained for endogenous LC3 (right). MBd markers: Cep55, MKLP1 or MgcRacGAP. Autophagosomes: GFP-LC3 or LC3. Note that MKLP1 (blue) and MgcRacGAP (red) are co-localized (magenta) in the autophagosome (green), indicating that MBds are sorted into autophagosomes. Scale bars, 2 μm. 