How long do melanocytes and melanosomes continue to protect DNA after UV exposure? Basically, if skin is tanned, then over the next month it is shed, will melanocytes continue to produce high levels of melanin to keep the new skin tanned without requiring more UV exposure? The cells react by producing more melanin after exposure but will they continue to do this in new skin cells?
The tanning response to UV occurs in two phases:
Both processes are influenced by genetic factors.
Source for the initial points, which also contains interesting details on the enzymes involved in these processes.