The genetic and evolutionary drives behind primate color vision

摘要: Primate color vision is based on two to three cone types in the retina, each expressing a different class of visual pigment, making them only mammals that possess trichromacy. These pigment classes are short wavelength-sensitive (SWS1) and long (LWS) orthologues same pigments found many other vertebrates, as well middle (MWS) paralogue LWS pigment. Trichromacy was achieved differently Old World New primates. In primates, duplication opsin gene occurred giving rise “red-sensitive” or L “green-sensitive” M Their corresponding genes adjacent X chromosome which, together with their high sequence homology, underlying cause for frequency red-green blindness seen humans. primates prosimians, however, mechanism leading trichromacy, one exception, single polymorphic gene, from which allelic variants encode differing spectral peaks. inactivation limits expression just per photoreceptor meaning trichromacy females; while all male blind. Despite several hypothesis, reasons evolutionary paths taken by still unclear remain be confirmed.