Asymmetric evolution in two fish-specifically duplicated receptor tyrosine kinase paralogons involved in teleost coloration.

@article{citeulike:781129, abstract = {The occurrence of a fish-specific genome duplication (FSGD) in the lineage leading to teleost fishes is widely accepted, but the consequences of this event remain elusive. Teleosts, and the cichlid fishes from the species flocks in the East African Great Lakes in particular, evolved a unique complexity and diversity of body coloration and color patterning. Several genes involved in pigment cell development have been retained in duplicate copies in the teleost genome after the FSGD. Here we investigate the evolutionary fate of one of these genes, the type III receptor tyrosine kinase (RTK) colony-stimulating factor 1 receptor (csf1r). We isolated and shotgun sequenced two paralogous csf1r genes from a bacterial artificial chromosome library of the cichlid fish Astatotilapia burtoni that are both linked to paralogs of the pdgfr beta gene, another type III RTK. Two pdgfr beta-csf1r paralogons were also identified in the genomes of pufferfishes and medaka, and our phylogenetic analyses suggest that the pdgfr beta-csf1r locus was duplicated during the course of the FSGD. Comparisons of teleosts and tetrapods suggest asymmetrical divergence at different levels of genomic organization between the teleost-specific pdgfr beta-csf1r paralogons, which seem to have evolved as coevolutionary units. The high-evolutionary rate in the teleost B-paralogon, consisting of csf1rb and pdgfr betab, further suggests neofunctionalization by functional divergence of the extracellular, ligand-binding region of these cell-surface receptors. Finally, we hypothesize that genome duplications and the associated expansion of the RTK family might be causally linked to the evolution of coloration in vertebrates and teleost fishes in particular.}, address = {Lehrstuhl f\"{u}r Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Konstanz, Germany.}, author = {Braasch, I. and Salzburger, W. and Meyer, A. }, citeulike-article-id = {781129}, issn = {0737-4038}, journal = {Mol Biol Evol}, keywords = {cichlid, colorgene, fish}, month = {June}, number = {6}, pages = {1192--1202}, posted-at = {2006-07-31 21:16:17}, priority = {2}, title = {Asymmetric evolution in two fish-specifically duplicated receptor tyrosine kinase paralogons involved in teleost coloration.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/16547150}, volume = {23}, year = {2006} }

TY - JOUR ID - citeulike:781129 L3 - citeulike-article-id:781129 TI - Asymmetric evolution in two fish-specifically duplicated receptor tyrosine kinase paralogons involved in teleost coloration. JF - Mol Biol Evol VL - 23 IS - 6 SP - 1192 EP - 1202 AD - Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Konstanz, Germany. SN - 0737-4038 N2 - The occurrence of a fish-specific genome duplication (FSGD) in the lineage leading to teleost fishes is widely accepted, but the consequences of this event remain elusive. Teleosts, and the cichlid fishes from the species flocks in the East African Great Lakes in particular, evolved a unique complexity and diversity of body coloration and color patterning. Several genes involved in pigment cell development have been retained in duplicate copies in the teleost genome after the FSGD. Here we investigate the evolutionary fate of one of these genes, the type III receptor tyrosine kinase (RTK) colony-stimulating factor 1 receptor (csf1r). We isolated and shotgun sequenced two paralogous csf1r genes from a bacterial artificial chromosome library of the cichlid fish Astatotilapia burtoni that are both linked to paralogs of the pdgfr beta gene, another type III RTK. Two pdgfr beta-csf1r paralogons were also identified in the genomes of pufferfishes and medaka, and our phylogenetic analyses suggest that the pdgfr beta-csf1r locus was duplicated during the course of the FSGD. Comparisons of teleosts and tetrapods suggest asymmetrical divergence at different levels of genomic organization between the teleost-specific pdgfr beta-csf1r paralogons, which seem to have evolved as coevolutionary units. The high-evolutionary rate in the teleost B-paralogon, consisting of csf1rb and pdgfr betab, further suggests neofunctionalization by functional divergence of the extracellular, ligand-binding region of these cell-surface receptors. Finally, we hypothesize that genome duplications and the associated expansion of the RTK family might be causally linked to the evolution of coloration in vertebrates and teleost fishes in particular. KW - cichlid KW - colorgene KW - fish AU - Braasch, I AU - Salzburger, W AU - Meyer, A PY - 2006/06// UR - http://view.ncbi.nlm.nih.gov/pubmed/16547150 ER -