Answer
The percentage of melanin is 8% in control cells, 6% in rapamycin-treated cells, and 12% in HCQ-treated cells. When autophagy is induced by rapamycin, the percent of melanin is reduced significantly
$(P<0.05)$
and skin color appeared lighter than the control. When cells are treated with HCQ (inhibits autophagy), the percent of melanin increases, and skin color appears darker. The difference between HCQ-treated cells and control is highly significant
$(P<0.01)$
Based on these results, it can be concluded that autophagy influences the amount of melanin in skin cells and therefore skin color.
Work Step by Step
Autophagy is a type of cellular degradation, where internal components of the cell are packaged into membrane vesicles degraded by fusing with lysosomes. Lysosomes contain hydrolytic enzymes that can break down the vesicle contents.
Autophagy can also degrade melanosomes, organelles that contain melanin. If the concentration of melanin is high (i.e. melanosomes are not degraded), the skin color is dark. If the concentration of melanin is low (i.e. melanosomes are degraded), the skin is light in color.
