A1 Journal article (refereed)
Genome‐phenotype‐environment associations identify signatures of selection in a panmictic population of threespine stickleback (2023)

Strickland, K., Räsänen, K., Kristjánsson, B. K., Phillips, J. S., Einarsson, A., Snorradóttir, R. G., Bartrons, M., & Jónsson, Z. O. (2023). Genome‐phenotype‐environment associations identify signatures of selection in a panmictic population of threespine stickleback. Molecular Ecology, 32(7), 1708-1725. https://doi.org/10.1111/mec.16845

JYU authors or editors

Publication details

All authors or editors: Strickland, K.; Räsänen, K.; Kristjánsson, B. K.; Phillips, J. S.; Einarsson, A.; Snorradóttir, R. G.; Bartrons, M.; Jónsson, Z. O.

Journal or series: Molecular Ecology

ISSN: 0962-1083

eISSN: 1365-294X

Publication year: 2023

Publication date: 10/01/2023

Volume: 32

Issue number: 7

Pages range: 1708-1725

Publisher: Wiley-Blackwell

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1111/mec.16845

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/86292

Abstract

Adaptive genetic divergence occurs when selection imposed by the environment causes the genomic component of the phenotype to differentiate. However, genomic signatures of natural selection are usually identified without information on which trait is responding to selection by which selective agent(s). Here we integrate whole-genome-sequencing with phenomics and measures of putative selective agents to assess the extent of adaptive divergence in threespine stickleback occupying the highly heterogeneous lake Mývatn, NE Iceland. We find negligible genome wide divergence, yet multiple traits (body size, gill raker structure and defence traits) were divergent along known ecological gradients (temperature, predatory bird densities and water depth). SNP based heritability of all measured traits was high (h2 = 0.42 – 0.65), indicating adaptive potential for all traits. Environment-association analyses further identified thousands of loci putatively involved in selection, related to genes linked to, for instance, neuron development and protein phosphorylation. Finally, we found that loci linked to water depth were concurrently associated with pelvic spine length variation - supporting the conclusion that divergence in pelvic spine length occurred in face of gene flow. Our results suggest that whilst there is substantial genetic variation in the traits measured, phenotypic divergence of Mývatn stickleback is mostly weakly associated with environmental gradients, potentially as a result of substantial gene flow. Our study illustrates the value of integrative studies that combine genomic assays of multivariate trait variation with landscape genomics.

Keywords: genome; genes; properties; structure (properties); DNA; heritability; phenotype; population genetics

Free keywords: adaptive divergence; gene flow; environmental gradients; genome scans; landscape genomics; gasterosteus aculeatus

Contributing organizations

Ministry reporting: Yes

VIRTA submission year: 2023

JUFO rating: 3