scholarly journals Visual Pigment Molecular Evolution in the Trinidadian Pike Cichlid (Crenicichla frenata): A Less Colorful World for Neotropical Cichlids?

2012 ◽  
Vol 29 (10) ◽  
pp. 3045-3060 ◽  
Author(s):  
Cameron J. Weadick ◽  
Ellis R. Loew ◽  
F. Helen Rodd ◽  
Belinda S. W. Chang
Keyword(s):  
Molecular Evolution ◽  
Visual Pigment ◽  
Neotropical Cichlids

scholarly journals Out of the blue: adaptive visual pigment evolution accompanies Amazon invasion

2015 ◽  
Vol 11 (7) ◽  
pp. 20150349 ◽  
Author(s):  
Alexander Van Nynatten ◽  
Devin Bloom ◽  
Belinda S. W. Chang ◽  
Nathan R. Lovejoy
Keyword(s):  
Molecular Evolution ◽  
Positive Selection ◽  
Visual Pigment ◽  
Large Scale ◽  
Marine Species ◽  
South American ◽  
Sequence Analyses ◽  
Freshwater Habitats ◽  
Varying Environments ◽  
Visual Pigment Evolution

Incursions of marine water into South America during the Miocene prompted colonization of freshwater habitats by ancestrally marine species and present a unique opportunity to study the molecular evolution of adaptations to varying environments. Freshwater and marine environments are distinct in both spectra and average intensities of available light. Here, we investigate the molecular evolution of rhodopsin, the photosensitive pigment in the eye that activates in response to light, in a clade of South American freshwater anchovies derived from a marine ancestral lineage. Using likelihood-based comparative sequence analyses, we found evidence for positive selection in the rhodopsin of freshwater anchovy lineages at sites known to be important for aspects of rhodopsin function such as spectral tuning. No evidence was found for positive selection in marine lineages, nor in three other genes not involved in vision. Our results suggest that an increased rate of rhodopsin evolution was driven by diversification into freshwater habitats, thereby constituting a rare example of molecular evolution mirroring large-scale palaeogeographic events.

scholarly journals To see or not to see: molecular evolution of the rhodopsin visual pigment in neotropical electric fishes

2019 ◽  
Vol 286 (1906) ◽  
pp. 20191182 ◽  
Author(s):  
Alexander Van Nynatten ◽  
Francesco H. Janzen ◽  
Kristen Brochu ◽  
Javier A. Maldonado-Ocampo ◽  
William G. R. Crampton ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Visual Pigment ◽  
Sensory System ◽  
Selective Constraint ◽  
South American ◽  
Functional Variation ◽  
Photon Detection ◽  
Poor Vision ◽  
Deep Channel ◽  
Dim Light

Functional variation in rhodopsin, the dim-light-specialized visual pigment, frequently occurs in species inhabiting light-limited environments. Variation in visual function can arise through two processes: relaxation of selection or adaptive evolution improving photon detection in a given environment. Here, we investigate the molecular evolution of rhodopsin in Gymnotiformes, an order of mostly nocturnal South American fishes that evolved sophisticated electrosensory capabilities. Our initial sequencing revealed a mutation associated with visual disease in humans. As these fishes are thought to have poor vision, this would be consistent with a possible sensory trade-off between the visual system and a novel electrosensory system. To investigate this, we surveyed rhodopsin from 147 gymnotiform species, spanning the order, and analysed patterns of molecular evolution. In contrast with our expectation, we detected strong selective constraint in gymnotiform rhodopsin, with rates of non-synonymous to synonymous substitutions lower in gymnotiforms than in other vertebrate lineages. In addition, we found evidence for positive selection on the branch leading to gymnotiforms and on a branch leading to a clade of deep-channel specialized gymnotiform species. We also found evidence that deleterious effects of a human disease-associated substitution are likely to be masked by epistatic substitutions at nearby sites. Our results suggest that rhodopsin remains an important component of the gymnotiform sensory system alongside electrolocation, and that photosensitivity of rhodopsin is well adapted for vision in dim-light environments.

Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher
Keyword(s):  
Cytochrome P450 ◽  
Molecular Evolution ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase ◽  
Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

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