Dr. John Taylor

Dr. John Taylor
Associate Professor
Office: PCH 012

Areas of research focus

  • Molecular evolution
  • Opsin genes
  • Phylogenetics
  • Comparative genomics

Description of Research

Nearly all life forms detect and respond to light. For animals, light detection starts with opsins.

Vertebrate visual opsins, which are expressed in the photoreceptor cells of the retina, are the focus of most opsin research, but they represent the tip of the iceberg. Our goal is to characterize connections between light sensitivity and both visual and non-visual opsin diversity. We compare vertebrate opsin repertoires to variation among species in morphology, behavior and spectral niches.

Eyeless cavefish and deep-sea fish are included to help identify opsins with roles beyond light detection. We also study opsin expression in flatfish (e.g., the starry flounder), now focussing especially on the brain. Soon we will work on Xenopus in order to study the effects of opsin gene knockouts.

Finally, we continue to use opsins as a model for extending general knowledge on the impact of duplication on gene evolution.

Select Publications

Beaudry F.E.G. et al. 2017. The non-visual opsins: eighteen in the ancestor of vertebrates, astonishing increase in ray-finned fish, and loss in amniotes. Journal of Experimental Zoology 328:685-696.

Iwanicki T.W. et al. 2017. Fine-tuning light sensitivity in the starry flounder (Platichthys stellatus) retina: regional variation in photoreceptor cell morphology and opsin gene expression. Journal of Comparative Neurology 525:2328-2342.

Marques D.A. et al. 2017. Convergent evolution of SWS2 opsin facilitates adaptive radiation of threespine stickleback into different light environments. PLoS Biology 15(4):e2001627.

Braasch I. et al. 2016. The genome of the spotted gar provides insights into vertebrate evolution and facilitates human-to-teleost comparisons.Nature Genetics 48:427-437.

Taylor J.S. 2014. Did Neanderthals and Denisovans have our de novo genes? Journal of Molecular Evolution 78:321-323.

Rennison D.J., Owens, G.K., and Taylor J.S. 2012. Opsin gene duplication and divergence in ray-finned fish. Molecular Phylogenetics and Evolution.

Owens, G.L. Rennison, D.J., Allison W.T. and Taylor J.S. 2012. Intraretinal opsin gene expression variation in the four-eyed fish (Anabelps anableps) correlates to background light properties. Biology Letters.

Churcher A.M. and Taylor J.S. 2011. The antiquity of chordate odorant receptors is revealed by the discovery of orthologs in the cnidarian Nematostella vectiensisGenome Biology and Evolution 3:36.

Taylor, J.S. and Raes, J. 2004. Duplication and divergence: The evolution of new genes and old ideas. Annual Reviews in Genetics,38:615-643.

Taylor J.S., I. Braasch, T. Frickey, A. Meyer and Y. Van de Peer, 2003. Genome duplication, a trait shared by 22,000 species of ray-finned fish. Genome Research 13:382-390.