Merrill, Richard M.; Rastas, Pasi; Martin, Simon H.; Melo Hurtado, Maria CISTA; Barker, Sarah; Davey, John; Mcmillan, W. Owen; Jiggins, Chris D.
The evolution of new species is made easier when traits under divergent ecological selection are also mating cues. Such ecological mating cues are now considered more common than previously thought, but we still know little about the genetic changes underlying their evolution or more generally about the genetic basis for assortative mating behaviors. Both tight physical linkage and the existence of large-effect preference loci will strengthen genetic associations between behavioral and ecological barriers, promoting the evolution of assortative mating. The warning patterns of Heliconius melpomene and H. cydno are under disruptive selection due to increased predation of nonmimetic hybrids and are used during mate recognition. We carried out a genome-wide quantitative trait locus (QTL) analysis of preference behaviors between these species and showed that divergent male preference has a simple genetic basis. We identify three QTLs that together explain a large proportion (approximately 60%) of the difference in preference behavior observed between the parental species. One of these QTLs is just 1.2 (0-4.8) centiMorgans (cM) from the major color pattern gene optix, and, individually, all three have a large effect on the preference phenotype. Genomic divergence between H. cydno and H. melpomene is high but broadly heterogenous, and admixture is reduced at the preference-optix color pattern locus but not the other preference QTLs. The simple genetic architecture we reveal will facilitate the evolution and maintenance of new species despite ongoing gene flow by coupling behavioral and ecological aspects of reproductive isolation.
Merrill RM, Rastas P, Martin SH, et al. Genetic dissection of assortative mating behavior. PLoS Biology. 2019;17(2). doi:10.1371/journal.pbio.2005902
Merrill, R. M., Rastas, P., Martin, S. H., Melo Hurtado, M. C., Barker, S., Davey, J., … Jiggins, C. D. (2019). Genetic dissection of assortative mating behavior. PLoS Biology. Public Library of Science. https://doi.org/10.1371/journal.pbio.2005902
Merrill, Richard M., Pasi Rastas, Simon H. Martin, Maria C Melo Hurtado, Sarah Barker, John Davey, W. Owen Mcmillan, and Chris D. Jiggins. “Genetic Dissection of Assortative Mating Behavior.” PLoS Biology. Public Library of Science, 2019. https://doi.org/10.1371/journal.pbio.2005902.
R. M. Merrill et al., “Genetic dissection of assortative mating behavior,” PLoS Biology, vol. 17, no. 2. Public Library of Science, 2019.
Merrill RM, Rastas P, Martin SH, Melo Hurtado MC, Barker S, Davey J, Mcmillan WO, Jiggins CD. 2019. Genetic dissection of assortative mating behavior. PLoS Biology. 17(2), e2005902.
Merrill, Richard M., et al. “Genetic Dissection of Assortative Mating Behavior.” PLoS Biology, vol. 17, no. 2, e2005902, Public Library of Science, 2019, doi:10.1371/journal.pbio.2005902.
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