GENETIC ANALYSES OF THE GREEN VISUAL PIGMENTS OF RABBIT (ORYCTOLAGUS-CUNICULUS) AND RAT (RATTUS-NORVEGICUS)

We have cloned and sequenced the green opsin genes of rabbit and rat. When these genes are expressed in cultured cells and reconstituted wit h Il-cis retinal, the resulting visual pigments have wavelengths of ma ximal absorption (lambda(max)) of 509 nm. These blue-shifted lambda(ma x) values are fully explained by their aa composition A, Y, Y, T, and S at sites 180, 197, 277, 285, and 308, respectively. The inference on the ancestral pigment sequences strongly suggests that the rabbit and rat (and mouse) green pigments attained the extant lambda(max) values independently, mainly by the single aa replacement A308S. (C) 1998 El sevier Science B.V. All rights reserved.