sustentacular cell

Agouti gene has many alleles and its expression can cause the production of phaeomelanin, otherwise cause the production of eumelanin.

Agouti基因的表达会引起棕黑素的产生，而Agouti不表达时则会引起真黑素的表达，从而调节色素合成的真黑素和棕黑素之间的转换。

These granules consist of the actual pigments: eumelanin and phaeomelanin.

正是这些小颗粒组成了二种色素: 真黑素和棕黑素.

this gene acts in the hair follicles where the melanocyte can switch between eumelanin and phaeomelanin (dark pigment and tan pigment).

此基因作用于毛囊中，也就是黑色素细胞内分化为真黑素还是棕黑素的地方。

Eumelanin is responsible for the darker colours such as black, blue, chocolate brown and phaeomelanin causes the lighter yellow/ red colours such as tan, red, yellow.

真黑素决定了深色系，如黑、、克力色；棕黑素则影响浅色的红黄系，如茶色、色、色。