Abstract
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.
Highlights
Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow
From high-coverage sequencing of double-digest restriction site-associated DNA, we constructed a genetic map of 495 single-nucleotide polymorphisms (SNPs) resolving 24 linkage group (LG) with an average marker spacing of 2.65 cM
We found highly supported quantitative trait loci (QTL) for both shape traits
Summary
Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow. 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. The sympatric speciation and the well-studied traits involved in ecological divergence make the Midas cichlid species flock an ideal system to clarify the genetic basis of ecologically relevant traits and how selective pressures can translate into important genomic differences in the face of ongoing gene flow.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
