MELANOCYTES AND MELANOSOMES MELANOCYTES ARE THE CELLS THAT

MELANOCYTES AND MELANOSOMES MELANOCYTES ARE THE CELLS THAT MAKE MELANOSOMES ARE MEMBRANE-BOUND ORGANELLES THAT SYNTHESIZE AND STORE MELANIN IS A COMPLEX POLYMER MADE FROM TYROSINE EUMELANIN IS BLACK BUT OTHER MELANINS CAN BE YELLOW TO RED

AFRICAN/AMERICAN ASIAN CAUCASIAN

AFRICAN/AMERICAN 11% MELANOSOMES IN MEMBRANEBOUND PACKETS ASIAN 37% MELANOSOMES IN MEMBRANEBOUND PACKETS CAUCASIAN 85% MELANOSOMES IN MEMBRANEBOUND PACKETS

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

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

INACTIVE TYROSINASE DUE TO MUTATION

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

INACTIVE TYROSINASE DUE TO MUTATION CAUSING SOME IMPROPER FOLDING THAT DOES NOT AFFECT TYROSINASE ACTIVITY. BUT GOLGI QUALITY CONTROL SENDS IT BACK TO THE RER. CORRECT SUGARS ARE NOT ADDED TO OLIGOSACCHARIDES OF TYROSINASE. SO MISDIRECTED AT TRANS-GOLGI SYSTEM MAY BE PUT INTO SECRETORY VESICLES BY MISTAKE. LACK OF TYROSINE TRANSPORT SYSTEM IN MELANOSOME MEMBRANE.

INACTIVE TYROSINASE DUE TO MUTATION CAUSING SOME IMPROPER FOLDING THAT DOES NOT AFFECT TYROSINASE ACTIVITY. BUT GOLGI QUALITY CONTROL SENDS IT BACK TO THE RER. CORRECT SUGARS ARE NOT ADDED TO OLIGOSACCHARIDES OF TYROSINASE. SO MISDIRECTED AT TRANS-GOLGI SYSTEM MAY BE PUT INTO SECRETORY VESICLES BY MISTAKE.

INACTIVE TYROSINASE DUE TO MUTATION CAUSING SOME IMPROPER FOLDING THAT DOES NOT AFFECT TYROSINASE ACTIVITY. BUT GOLGI QUALITY CONTROL SENDS IT BACK TO THE RER. CORRECT SUGARS ARE NOT ADDED TO OLIGOSACCHARIDES OF TYROSINASE. SO MISDIRECTED AT TRANS-GOLGI SYSTEM MAY BE PUT INTO SECRETORY VESICLES BY MISTAKE. LACK OF TYROSINE TRANSPORT SYTEM IN MELANOSOME MEMBRANE. LACK OF TRANSFER TO KERATINOCYTES

MELANSOMES ARE TAKEN UP BY PHAGOCYTOSIS INTO THE LOWER KERATINOCYTES

“MELANOSOME COMPLEX” IN KERATINOCYTE

MELANOCYTES BEING PHAGOCYTOSED BY A KERATINOCYTE

PHAGOCYTOSED MELANOSOMES ARE DISTRIBUTED AS A CAP AT TOP OF THE NUCLEUS

LATEX BEADS TAKEN UP BY KERATINOCYTE AND FORMING A CAP ON TOP OF THE NUCLEUS

Keratinocyte Growth Factor Promotes Melanosome Transfer to Keratinocytes

CULTURED MELANOCYTES (M) AND KERATINOCYTES (K)

MELANOSMES ARE GREEN (ANTI-TYROSINASE IMMUNOFLUORESCENCE LABELLING)

KERATINOCYTES ARE RED (ANTI-KERATIN IMMUNOFLUORESCENCE LABELLING)

CULTURED CELLS TREATED WITH KERATINOCYTE GROWTH FACTOR (KGF)

CULTURED CELLS EXPOSED TO UVB LIGHT

CULTURE TREATED WITH MELANOCYTE-STIMULATING HORMONE (MSH)

LOW POWER HIGH POWER BEGINNING OF A MALIGNANT MELANOMA (DUE TO UNCONTROLLED GROWTH OF MELANOCYTES)