Читать книгу Horse Economics - Vera Kurskaya - Страница 24

Once I was asked why in horses pigment is frequently located on the periphery of the body. Apparently, it can be explained by the lower body temperature in these areas. An illustrative example is the color pattern in Siamese cats, which is characterized by a dark nose, ears, paws, and tail. The reason for this distribution of pigment is a temperature-sensitive form of tyrosinase, which facilitates the synthesis of dark pigment in the sections of the body with a reduced temperature. In horses, the existence of such a form of tyrosinase and its effect on the color has not yet been proven. However, Bowling and Ruvinski (2000) suggested that the reason for the outlying distribution of pigment in horses is indeed a biochemical mechanism, connected with a reduced temperature on the periphery of the body.