Which cells in the skin are responsible for producing melanin?

Melanocytes are the specialized cells in the skin responsible for producing melanin, which is the pigment that gives color to the skin, hair, and eyes. These cells are located primarily in the basal layer of the epidermis and play a crucial role in protecting the skin from ultraviolet (UV) radiation. When exposed to UV light, melanocytes increase the production of melanin as a protective mechanism against potential DNA damage caused by UV exposure. This increased melanin production leads to the darkening of the skin, commonly known as tanning.

The function of melanocytes is distinct from that of keratinocytes, which predominantly make up the outer layer of the skin and are primarily involved in forming a protective barrier. Other cells such as Langerhans cells, which are part of the immune system, and Ruffini endings, which are mechanoreceptors, serve different roles within the skin, but they do not produce melanin. Therefore, the correct choice is clearly melanocytes, as they are the only cells responsible for melanin production in the skin.