Evolutionary Fate of the Androgen Receptor-Signaling Pathway in Ray-Finned Fishes with a Special Focus on Cichlids.
The emergence of the steroid system is coupled to the evolution of multicellular animals. In vertebrates in particular, the steroid receptor repertoire has been shaped by genome duplications characteristic to this lineage. Here, we investigate for the first time the composition of the androgen receptor-signaling pathway in ray-finned fish genomes by focusing in particular on duplicates that emerged from the teleost-specific whole-genome duplication. We trace lineage- and species-specific duplications and gene losses for the genomic and nongenomic pathway of androgen signaling and subsequently investigate the sequence evolution of these genes. In one particular fish lineage, the cichlids, we find evidence for differing selection pressures acting on teleost-specific whole-genome duplication paralogs at a derived evolutionary stage. We then look into the expression of these duplicated genes in four cichlid species from Lake Tanganyika indicating, once more, rapid changes in expression patterns in closely related fish species. We focus on a particular case, the cichlid specific duplication of the rac1 GTPase, which shows possible signs of a neofunctionalization event.
ENS (Ecole Normale Supérieure de Lyon), Lyon Cedex 07, France Zoological Institute, Department of Environmental Sciences, University of Basel, 4051 Basel, Switzerland.
Thibault
T
Lorin
Zoological Institute, Department of Environmental Sciences, University of Basel, 4051 Basel, Switzerland.
Walter
http://orcid.org/0000-0002-9988-1674
W
Salzburger
Zoological Institute, Department of Environmental Sciences, University of Basel, 4051 Basel, Switzerland astrid.boehne@unibas.ch.
Astrid
http://orcid.org/0000-0002-1284-3115
A
Böhne
D000818:Animals; D023681:Cichlids / Q000235:genetics*; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020440:Gene Duplication; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D012641:Selection, Genetic; D015398:Signal Transduction
D029941:Fish Proteins; D011944:Receptors, Androgen
androgen receptor; cichlids; genome duplication; ray-finned fish; sequence evolution