Genetic linkage of distinct adaptive traits in sympatrically speciating crater lake cichlid fish.
Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow. Here we investigate the genomic basis of adaptive traits, focusing on a sympatrically diverging species pair of crater lake cichlid fishes. We identify the main quantitative trait loci (QTL) for two eco-morphological traits: body shape and pharyngeal jaw morphology. These traits diverge in parallel between benthic and limnetic species in the repeated adaptive radiations of this and other fish lineages. Remarkably, a single chromosomal region contains the highest effect size QTL for both traits. Transcriptomic data show that the QTL regions contain genes putatively under selection. Independent population genomic data corroborate QTL regions as areas of high differentiation between the sympatric sister species. Our results provide empirical support for current theoretical models that emphasize the importance of genetic linkage and pleiotropy in facilitating rapid divergence in sympatry.
Lehrstuhl für Zoologie and Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.|School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland 4000, Australia.
Carmelo
C
Fruciano
Lehrstuhl für Zoologie and Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
Paolo
P
Franchini
Lehrstuhl für Zoologie and Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.|Department for Plant Developmental Genetics, Institute of Biophysics, Academy of Sciences Czech Republic, Královopolská 135, 612 65 Brno, Czech Republic.
Viera
0000-0003-4581-4254
V
Kovacova
Lehrstuhl für Zoologie and Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.|Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences University of Glasgow, Glasgow G12 8QQ, UK.
Kathryn R
KR
Elmer
Lehrstuhl für Zoologie and Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
Frederico
F
Henning
Lehrstuhl für Zoologie and Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
Axel
0000-0002-0888-8193
A
Meyer
D000222:Adaptation, Physiological / Q000235:genetics*; D000818:Animals; D023681:Cichlids / Q000235:genetics* / Q000502:physiology; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D008040:Genetic Linkage; D049810:Genetic Speciation; D014644:Genetic Variation; D060106:Lakes; D040641:Quantitative Trait Loci
D004272:DNA, Mitochondrial