There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
Dramatic improvement of our understanding of the genetic basis of vision was brought
by the molecular characterization of the bovine rhodopsin gene and the human rhodopsin
and color opsin genes (Nathans and Hogness, 1983; Nathans et al., 1984, 1986a,b).
The availability of cDNA clones from these studies has facilitated the isolation of
retinal and nonretinal opsin genes and cDNA clones from a large variety of species.
Today, the number of genomic and cDNA clones of opsin genes isolated from different
vertebrate species exceeds 100 and is increasing rapidly. The opsin gene sequences
reveal the importance of the origin and differentiation of various opsins and visual
pigments. To understand the molecular genetic basis of spectral tuning of visual pigments,
it is essential to establish correlations between a series of the sequences of visual
pigments and their lambda(max) values. The potentially important amino acid changes
identified in this way have to be tested whether they are in fact responsible for
the lambda(max)-shifts using site-directed mutagenesis and cultured cells. A major
goal of molecular evolutionary genetics is to understand the molecular mechanisms
involved in functional adaptations of organisms to different environments, including
the mechanisms of the regulation of the spectral absorption. Therefore, both molecular
evolutionary analyses of visual pigments and vision science have an important common
goal.