1. MOVEMENT OF MELANOSOMES

5. FORMATION OF MELANOSOMES

9. MELANOSOMES (GREEN) MICROTUBULES (RED) F-ACTIN (BLUE)

11. HUMAN SKIN

17. MELANOBLASTS MIGRATE FROM THE NEURAL CREST DURING EMBRYOGENESIS
MELANOBLASTS DIVIDE TO FORM MELANOCYTES

18. AN AUTO - IMMUNE DISEASE IN WHICH SOME MELANOCYTES ARE DESTROYED BY THE IMMUNE SYSTEM

19. MELANSOMES ARE TAKEN UP BY PHAGOCYTOSIS INTO THE LOWER KERATINOCYTES

21. INACTIVE TYROSINASE DUE TO MUTATION

22. MUTATION CAUSING SOME IMPROPER FOLDING THAT DOES NOT AFFECT TYROSINASE ACTIVITY.
BUT GOLGI QUALITY CONTROL SENDS IT BACK TO THE RER.

23. CORRECT SUGARS ARE NOT ADDED TO OLIGOSACCHARIDES OF TYROSINASE.
SO MISDIRECTED AT TRANS-GOLGI SYSTEM
MAY BE PUT INTO SECRETORY VESICLES BY MISTAKE.

24. LACK OF TYROSINE TRANSPORT SYTEM IN MELANOSOME MEMBRANE.

25. LACK OF FUNCTIONAL TYROSINASE

26. LACK OF TRANSFER TO KERATINOCYTES