PUBLICATION
Positive selection rather than relaxation of functional constraint drives the evolution of vision during chicken domestication
- Authors
- Wang, M.S., Zhang, R.W., Su, L.Y., Li, Y., Peng, M.S., Liu, H.Q., Zeng, L., Irwin, D.M., Du, J.L., Yao, Y.G., Wu, D.D., Zhang, Y.P.
- ID
- ZDB-PUB-171205-16
- Date
- 2016
- Source
- Cell Research 26: 556-73 (Journal)
- Registered Authors
- Du, Jiu Lin, Rong-Wei, Zhang
- Keywords
- none
- MeSH Terms
-
- Animals
- Animals, Domestic/genetics*
- Biological Evolution*
- Chickens/genetics*
- Domestication*
- Gene Knockdown Techniques
- Genome
- Mice
- Morpholinos/pharmacology
- Poultry/genetics*
- Selection, Genetic*
- Vision, Ocular/genetics*
- Zebrafish/genetics
- PubMed
- 27033669 Full text @ Cell Res.
Citation
Wang, M.S., Zhang, R.W., Su, L.Y., Li, Y., Peng, M.S., Liu, H.Q., Zeng, L., Irwin, D.M., Du, J.L., Yao, Y.G., Wu, D.D., Zhang, Y.P. (2016) Positive selection rather than relaxation of functional constraint drives the evolution of vision during chicken domestication. Cell Research. 26:556-73.
Abstract
As noted by Darwin, chickens have the greatest phenotypic diversity of all birds, but an interesting evolutionary difference between domestic chickens and their wild ancestor, the Red Junglefowl, is their comparatively weaker vision. Existing theories suggest that diminished visual prowess among domestic chickens reflect changes driven by the relaxation of functional constraints on vision, but the evidence identifying the underlying genetic mechanisms responsible for this change has not been definitively characterized. Here, a genome-wide analysis of the domestic chicken and Red Junglefowl genomes showed significant enrichment for positively selected genes involved in the development of vision. There were significant differences between domestic chickens and their wild ancestors regarding the level of mRNA expression for these genes in the retina. Numerous additional genes involved in the development of vision also showed significant differences in mRNA expression between domestic chickens and their wild ancestors, particularly for genes associated with phototransduction and photoreceptor development, such as RHO (rhodopsin), GUCA1A, PDE6B and NR2E3. Finally, we characterized the potential role of the VIT gene in vision, which experienced positive selection and downregulated expression in the retina of the village chicken. Overall, our results suggest that positive selection, rather than relaxation of purifying selection, contributed to the evolution of vision in domestic chickens. The progenitors of domestic chickens harboring weaker vision may have showed a reduced fear response and vigilance, making them easier to be unconsciously selected and/or domesticated.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping