The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins
To evaluate how terrestrially descended, marine-living tetrapods have adapted their vision for life in the ocean environment, the rod and cone visual pigments of diving turtles, birds, and mammals were examined. Genetics was used primarily. When possible, in situ electroretinography (ERG) was also u...
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ftcdlib:qt6wn46905 2023-05-15T16:05:18+02:00 The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins Levenson, David H. 2004-01-01 application/pdf http://www.escholarship.org/uc/item/6wn46905 english eng eScholarship, University of California qt6wn46905 http://www.escholarship.org/uc/item/6wn46905 public Levenson, David H.(2004). The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins. California Sea Grant College Program. UC San Diego: California Sea Grant College Program. Retrieved from: http://www.escholarship.org/uc/item/6wn46905 visual pigments electroretinography cone visual pigments pinnipeds cetaceans S cones Physical Sciences and Mathematics article 2004 ftcdlib 2016-04-02T18:29:44Z To evaluate how terrestrially descended, marine-living tetrapods have adapted their vision for life in the ocean environment, the rod and cone visual pigments of diving turtles, birds, and mammals were examined. Genetics was used primarily. When possible, in situ electroretinography (ERG) was also used. Of the three visual pigments possessed by most mammals, cetacean rod and middle/long-wavelength sensitive (M/L) cone visual pigments had previously been shown to be shifted towards the wavelengths (λ) of light that predominant in marine habits, λ~475 nm. The genetic sequences of the short-wavelength sensitive (S) cones of numerous cetaceans were examined from nuclear DNA. The distribution of mis-sense mutations found in their S cone opsin genes indicates that all members ofthe cetacean order lack S cones. Genetic evaluation of the retinal mRNA of seven pinniped species revealed that these mammals also lack S cones. The convergent loss of S cones in pinnipeds and cetaceans suggests that this loss may be adaptive for vision in the marine environment. Rod and M/L cone pigments of pinnipeds were also examined. In contrast to the cetaceans, one pinniped, the deep-diving northern elephant seal was found to possess a short-wavelength-shifted visual pigment, its rod pigment. The rod and M/L cone visual pigments of the other pinnipeds were similar to those of terrestrial carnivores. An ERG investigation of three pinnipeds including the elephant seal supported the genetic results. Finally, the rod visual pigments of five sea turtle and three penguin species were examined with genetics. None was found to be markedly marine-adapted. Additional examination of cone sensitivity in sea turtles with ERG indicated limited departure from the terrestrial condition. Clearly, the cetaceans are the most marine adapted ofthe groups examined. The pinnipeds and sea turtles showed limited adaptation, and the penguins were not apparently different from terrestrial birds. As the cetaceans are the only completely aquatic lineage among these groups, it seems that the terrestrial life-stage may still be of selective significance to some or all of the other groups. Particularly in the case of the sea turtles and penguins, which are highly photopic by ancestry, phylogenetic inertia may also limit the plasticity of the visual systems in adapting for vision in the marine environment. XIV Article in Journal/Newspaper Elephant Seal University of California: eScholarship Cones The ENVELOPE(78.344,78.344,-68.635,-68.635) Cones, The ENVELOPE(78.344,78.344,-68.635,-68.635) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
visual pigments electroretinography cone visual pigments pinnipeds cetaceans S cones Physical Sciences and Mathematics |
spellingShingle |
visual pigments electroretinography cone visual pigments pinnipeds cetaceans S cones Physical Sciences and Mathematics Levenson, David H. The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins |
topic_facet |
visual pigments electroretinography cone visual pigments pinnipeds cetaceans S cones Physical Sciences and Mathematics |
description |
To evaluate how terrestrially descended, marine-living tetrapods have adapted their vision for life in the ocean environment, the rod and cone visual pigments of diving turtles, birds, and mammals were examined. Genetics was used primarily. When possible, in situ electroretinography (ERG) was also used. Of the three visual pigments possessed by most mammals, cetacean rod and middle/long-wavelength sensitive (M/L) cone visual pigments had previously been shown to be shifted towards the wavelengths (λ) of light that predominant in marine habits, λ~475 nm. The genetic sequences of the short-wavelength sensitive (S) cones of numerous cetaceans were examined from nuclear DNA. The distribution of mis-sense mutations found in their S cone opsin genes indicates that all members ofthe cetacean order lack S cones. Genetic evaluation of the retinal mRNA of seven pinniped species revealed that these mammals also lack S cones. The convergent loss of S cones in pinnipeds and cetaceans suggests that this loss may be adaptive for vision in the marine environment. Rod and M/L cone pigments of pinnipeds were also examined. In contrast to the cetaceans, one pinniped, the deep-diving northern elephant seal was found to possess a short-wavelength-shifted visual pigment, its rod pigment. The rod and M/L cone visual pigments of the other pinnipeds were similar to those of terrestrial carnivores. An ERG investigation of three pinnipeds including the elephant seal supported the genetic results. Finally, the rod visual pigments of five sea turtle and three penguin species were examined with genetics. None was found to be markedly marine-adapted. Additional examination of cone sensitivity in sea turtles with ERG indicated limited departure from the terrestrial condition. Clearly, the cetaceans are the most marine adapted ofthe groups examined. The pinnipeds and sea turtles showed limited adaptation, and the penguins were not apparently different from terrestrial birds. As the cetaceans are the only completely aquatic lineage among these groups, it seems that the terrestrial life-stage may still be of selective significance to some or all of the other groups. Particularly in the case of the sea turtles and penguins, which are highly photopic by ancestry, phylogenetic inertia may also limit the plasticity of the visual systems in adapting for vision in the marine environment. XIV |
format |
Article in Journal/Newspaper |
author |
Levenson, David H. |
author_facet |
Levenson, David H. |
author_sort |
Levenson, David H. |
title |
The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins |
title_short |
The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins |
title_full |
The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins |
title_fullStr |
The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins |
title_full_unstemmed |
The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins |
title_sort |
visual pigments of diving tetrapods: genetic and electroretinographic investigations of pinnipeds, cetaceans, sea turtles, and penguins |
publisher |
eScholarship, University of California |
publishDate |
2004 |
url |
http://www.escholarship.org/uc/item/6wn46905 |
long_lat |
ENVELOPE(78.344,78.344,-68.635,-68.635) ENVELOPE(78.344,78.344,-68.635,-68.635) |
geographic |
Cones The Cones, The |
geographic_facet |
Cones The Cones, The |
genre |
Elephant Seal |
genre_facet |
Elephant Seal |
op_source |
Levenson, David H.(2004). The Visual Pigments of Diving Tetrapods: Genetic and Electroretinographic Investigations of Pinnipeds, Cetaceans, Sea Turtles, and Penguins. California Sea Grant College Program. UC San Diego: California Sea Grant College Program. Retrieved from: http://www.escholarship.org/uc/item/6wn46905 |
op_relation |
qt6wn46905 http://www.escholarship.org/uc/item/6wn46905 |
op_rights |
public |
_version_ |
1766401200568139776 |