Quantification of TYRP1 immunogold labeling in BLOC-2− and BLOC-2R melanocytes
| Cell | Golgi | TGN | Vac. End. | TVEs/End. | MVBs | Mels. | TVEs/Mel. | Lys. | Ves. |
| BLOC-2− | 19.6 | 7.7 | 7.0 | 10.8 | 6.7 | 31.1 | 9.1 | 4.0 | 4.0 |
| BLOC-2R | 3.0 | 1.3 | 4.8 | 5.0 | 3.0 | 74.2 | 7.0 | 1.5 | 0.2 |
| Cell | Golgi | TGN | Vac. End. | TVEs/End. | MVBs | Mels. | TVEs/Mel. | Lys. | Ves. |
| BLOC-2− | 19.6 | 7.7 | 7.0 | 10.8 | 6.7 | 31.1 | 9.1 | 4.0 | 4.0 |
| BLOC-2R | 3.0 | 1.3 | 4.8 | 5.0 | 3.0 | 74.2 | 7.0 | 1.5 | 0.2 |
Ultrathin cryosections of BLOC-2− or BLOC-2R cells were labeled with antibodies to TYRP1 and ATP7A and protein A conjugated to 10- and 15-nm gold particles, respectively. Gold particles decorating each indicated compartment were counted in ≥30 cell profiles each. Values are based on 1,278 gold particles counted in BLOC-2− cells and 1,430 in BLOC-2R cells. Vac. End., vacuolar endosomes; TVEs, tubulovesicular endosomes near vacuolar endosomes or the Golgi (TVEs/End.) or near melanosomes (TVEs/Mel.); MVBs, multivesicular bodies; Mels, melanosome stages II, III, or IV; Lys., lysosomes; Ves., vesicles of undefined origin. Compartments with the most dramatic differences between cell lines are indicated in bold.