Differential introgression reveals candidate genes for selection across a spruce (Picea sitchensis × P. glauca) hybrid zone
Article first published online: 10 DEC 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 197, Issue 3, pages 927–938, February 2013
How to Cite
Hamilton, J. A., Lexer, C. and Aitken, S. N. (2013), Differential introgression reveals candidate genes for selection across a spruce (Picea sitchensis × P. glauca) hybrid zone. New Phytologist, 197: 927–938. doi: 10.1111/nph.12055
- Issue published online: 7 JAN 2013
- Article first published online: 10 DEC 2012
- Manuscript Accepted: 18 OCT 2012
- Manuscript Received: 7 SEP 2012
- Genome British Columbia, Genome Canada and the Province of British Columbia
- the Natural Science and Engineering Research Council of Canada
- NSERC Canada Graduate Scholarship
- ecological gradient;
- genomic cline;
- geographic cline;
- hybrid zone;
- single nucleotide polymorphisms (SNPs);
- Differential patterns of introgression between species across ecological gradients provide a fine-scale depiction of extrinsic and intrinsic factors that contribute to the maintenance of species barriers and adaptation across heterogeneous environments.
- Introgression was examined for 721 individuals collected from the ecological transition zone spanning maritime to continental climates within the Picea sitchensis–Picea glauca contact zone using a panel of 268 candidate gene single nucleotide polymorphisms.
- Geographic clines showed a strong spatial relationship between allele frequencies and both distance from the ocean along major rivers and mean annual precipitation, indicating a strong role for environmental selection. Interspecific patterns of differentiation using outlier tests revealed three candidate genes that may be targets of long-term divergent selection between the parental species, although contemporary genomic clines within the hybrid zone suggested neutral patterns of introgression for these genes.
- This study provides a fine-scale analysis of locus-specific introgression, identifying a suite of candidate loci that may be targets of extrinsic or intrinsic selection, with broad application in understanding local adaptation to climate.