Losses of functional opsin genes, short-wavelength cone photopigments, and color vision—A significant trend in the evolution of mammalian vision

All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wave...

Celý popis

Uloženo v:

Podrobná bibliografie
Vydáno v:	Visual neuroscience Ročník 30; číslo 1-2; s. 39 - 53
Hlavní autor:	JACOBS, GERALD H.
Médium:	Journal Article
Jazyk:	angličtina
Vydáno:	New York, USA Cambridge University Press 01.03.2013
Témata:	Animals Biological Evolution Color Perception - genetics Evolution Genes Genetics Humans Mammals Opsins - classification Opsins - genetics Phylogeny Pigments Primates Retinal Cone Photoreceptor Cells - physiology Review Article Vision Disorders - genetics Vision, Ocular - genetics Eutherian evolution SWS1 opsin genes Pseudogenes Mammalian color vision Cone pigments Visual adaptations
ISSN:	0952-5238, 1469-8714, 1469-8714
On-line přístup:	Získat plný text
Tagy:	Přidat tag Žádné tagy, Buďte první, kdo vytvoří štítek k tomuto záznamu!

Popis
Shrnutí:	All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wavelengths. With the exception of a number of primate taxa, the modal pattern for mammals is to have two types of cone photopigment, one drawn from each of the gene families. In recent years, it has been discovered that the SWS1 opsin genes of a widely divergent collection of eutherian mammals have accumulated mutational changes that render them nonfunctional. This alteration reduces the retinal complements of these species to a single cone type, thus rendering ordinary color vision impossible. At present, several dozen species from five mammalian orders have been identified as falling into this category, but the total number of mammalian species that have lost short-wavelength cones in this way is certain to be much larger, perhaps reaching as high as 10% of all species. A number of circumstances that might be used to explain this widespread cone loss can be identified. Among these, the single consistent fact is that the species so affected are nocturnal or, if they are not technically nocturnal, they at least feature retinal organizations that are typically associated with that lifestyle. At the same time, however, there are many nocturnal mammals that retain functional short-wavelength cones. Nocturnality thus appears to set the stage for loss of functional SWS1 opsin genes in mammals, but it cannot be the sole circumstance.
Bibliografie:	ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 14 ObjectType-Article-1 ObjectType-Feature-2 ObjectType-Review-3 content type line 23
ISSN:	0952-5238 1469-8714 1469-8714
DOI:	10.1017/S0952523812000429