Loading...
Thumbnail Image
Publication

Euarchontan opsin variation brings new focus to Primate origins

Amanda D. Melin
Wells, Konstans
Moritz, Gillian L.
Kistler, Logan
Orkin, Joseph D.
Timm, Robert M.
Bernard, Henry
Lakim, Maklarin B.
Perry, George H.
Kawamura, Shoji
... show 1 more
Citations
Altmetric:
Abstract
Debate on the adaptive origins of primates has long focused on the functional ecology of the primate visual system. For example, it is hypothesized that variable expression of short- (SWS1) and middle-to-long-wavelength sensitive (M/LWS) opsins, which confer color vision, can be used to infer ancestral activity patterns and therefore selective ecological pressures. A problem with this approach is that opsin gene variation is incompletely known in the grandorder Euarchonta, i.e., the orders Scandentia (treeshrews), Dermoptera (colugos), and Primates. The ancestral state of primate color vision is therefore uncertain. Here we report on the genes (OPN1SW and OPN1LW) that encode SWS1 and M/LWS opsins in seven species of treeshrew, including the sole nocturnal scandentian Ptilocercus lowii. In addition, we examined the opsin genes of the Central American woolly opossum (Caluromys derbianus), an enduring ecological analogue in the debate on primate origins. Our results indicate: 1) retention of ultraviolet (UV) sensitivity in C. derbianus and a shift from UV to blue spectral sensitivities at the base of Euarchonta; 2) ancient pseudogenization of OPN1SW in the ancestors of P. lowii, but a signature of purifying selection in those of C. derbianus; and, 3) the absence of OPN1LW polymorphism among diurnal treeshrews. These findings suggest functional variation in color vision of nocturnal mammals and a distinctive visual ecology of early primates, perhaps one that demanded greater spatial resolution under light levels that could support cone-mediated color discrimination.
Description
Date
2016-04
Journal Title
Journal ISSN
Volume Title
Publisher
Molecular Biology and Evolution
Research Projects
Organizational Units
Journal Issue
Keywords
Color vision, Sensory ecology, Caluromys, Dendrogale, Euarchonta, Ptilocercus, Tupaia
Citation
Melin, A. D. et al. 2016. Euarchontan opsin variation brings new focus to Primate origins. Molecular Biology and Evolution, 33(4):1029–1041.
DOI
Embedded videos