Elucidation of phenotypic adaptations: Molecular analyses of dim-light vision proteins in vertebrates.

ABSTRACT: Vertebrate ancestors appeared in a uniform, shallow water environment, but modern species flourish in highly variable niches. A striking array of phenotypes exhibited by contemporary animals is assumed to have evolved by accumulating a series of selectively advantageous mutations. However, the experimental test of such adaptive events at the molecular level is remarkably difficult. One testable phenotype, dim-light vision, is mediated by rhodopsins. Here, we engineered 11 ancestral rhodopsins and show that those in early ancestors absorbed light maximally (lambda(max)) at 500 nm, from which contemporary rhodopsins with variable lambda(max)s of 480-525 nm evolved on at least 18 separate occasions. These highly environment-specific adaptations seem to have occurred largely by amino acid repl

SUBMITTER: Yokoyama S 

PROVIDER: S-EPMC2533215 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature