Casting a Genetic Light on the Evolution of Eyes

@article{Fernald2006CastingAG,
  title={Casting a Genetic Light on the Evolution of Eyes},
  author={Russell D. Fernald},
  journal={Science},
  year={2006},
  volume={313},
  pages={1914 - 1918}
}
  • R. Fernald
  • Published 29 September 2006
  • Biology
  • Science
Light has been exploited for information by organisms through the evolution of photoreceptors and, ultimately, eyes in animals. Only a handful of eye types exist because the physics of light constrains photodetection. In the past few years, genetic tools have revealed several parallel pathways through which light guides behavior and have provided insights into the convergent evolution of eyes. The gene encoding opsin (the primary phototransduction protein) and some developmental genes had very… 
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References

SHOWING 1-10 OF 38 REFERENCES
Evolution of eyes
  • R. Fernald
  • Biology
    Current Opinion in Neurobiology
  • 2000
Evolution of eyes and photoreceptor cell types.
  • D. Arendt
  • Biology
    The International journal of developmental biology
  • 2003
TLDR
It is proposed that the retinal ganglion, amacrine and horizontal cells are evolutionary sister cell types that evolved from a common rhabdomeric photoreceptor cell precursor, the proto-eye.
Signalling pathways in Drosophila and vertebrate retinal development
  • J. Kumar
  • Biology
    Nature Reviews Genetics
  • 2001
TLDR
New insights into the roles that signal-transduction cascades might have in determining the Drosophila melanogaster eye indicate that, like many developmental processes, eye specification is an inductive process.
Ciliary Photoreceptors with a Vertebrate-Type Opsin in an Invertebrate Brain
TLDR
Comparative analysis indicates that both types of photoreceptors, with distinct opsins, coexisted in Urbilateria, the last common ancestor of insects and vertebrates, and sheds new light on vertebrate eye evolution.
Parietal-Eye Phototransduction Components and Their Potential Evolutionary Implications
TLDR
The discovery of two opsins in the same cell: the blue-sensitive pinopsin and a previously unidentified green-sensitive opsin, which is named parietopsin provides clues about how rod and cone phototransduction might have evolved.
Comparative analysis of gene expression for convergent evolution of camera eye between octopus and human.
TLDR
A comparative analysis of gene expression in octopus and human camera eyes suggests that a larger number of conserved genes and their similar gene expression may be responsible for the convergent evolution of the camera eye.
Evolution of the cichlid visual palette through ontogenetic subfunctionalization of the opsin gene arrays.
TLDR
Subfunctionalization through differential ontogenetic expression may be a key mechanism for preservation of opsin genes and provide a palette from which selection creates the diverse visual sensitivities found among the cichlid species of the lacustrine adaptive radiations.
Photoreceptor sectral sensitivities in terrestrial animals: adaptations for luminance and colour vision
TLDR
This review outlines how eyes of terrestrial vertebrates and insects meet the competing requirements of coding both spatial and spectral information, and looks at spectral tuning and diversification among ‘long-wavelength’ receptors (sensitivity maxima at greater than 500 nm), which play a primary role in luminance vision.
Phototransduction in primate cones and blowfly photoreceptors: different mechanisms, different algorithms, similar response
TLDR
A direct comparison of the responses to a natural time series of intensities, simulated in the cone and measured in the blowfly photoreceptor, shows that the responses are quite similar.
...
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