Functional Duplication of the Short-Wavelength-Sensitive Opsin in Sea Snakes: Evidence for Reexpanded Color Sensitivity Following Ancestral Regression.
Genome Biol Evol
; 15(7)2023 07 03.
Article
en En
| MEDLINE
| ID: mdl-37434309
Color vision is mediated by ancient and spectrally distinct cone opsins. Yet, while there have been multiple losses of opsin genes during the evolution of tetrapods, evidence for opsin gains via functional duplication is extremely scarce. Previous studies have shown that some secondarily marine elapid snakes have acquired expanded "UV-blue" sensitivity via changes at key spectral tuning amino acid sites of the Short-Wavelength Opsin 1 (SWS1) gene. Here, we use elapid reference genomes to show that the molecular origin of this adaptation involved repeated, proximal duplications of the SWS1 gene in the fully marine Hydrophis cyanocinctus. This species possesses four intact SWS1 genes; two of these genes have the ancestral UV sensitivity, and two have a derived sensitivity to the longer wavelengths that dominate marine habitats. We suggest that this remarkable expansion of the opsin repertoire of sea snakes functionally compensates for the ancestral losses of two middle-wavelength opsins in the earliest (dim-light adapted) snakes. This provides a striking contrast to the evolution of opsins during ecological transitions in mammals. Like snakes, early mammals lost two cone photopigments; however, lineages such as bats and cetaceans underwent further opsin losses during their adaptation to dim-light environments.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Quirópteros
/
Hydrophiidae
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Genome Biol Evol
Asunto de la revista:
BIOLOGIA
/
BIOLOGIA MOLECULAR
Año:
2023
Tipo del documento:
Article
País de afiliación:
Australia
Pais de publicación:
Reino Unido