title: Sexual selection against natural hybrids may contribute to reinforcement in a house mouse hybrid zone.
abstract: Sexual selection may hinder gene flow across contact zones when hybrid recognition signals are discriminated against. We tested this hypothesis in a unimodal hybrid zone between Mus musculus musculus and Mus musculus domesticus where a pattern of reinforcement was described and lower hybrid fitness documented. We presented mice from the border of the hybrid zone with a choice between opposite sex urine from the same subspecies versus hybrids sampled in different locations across the zone. While no preference was evidenced in domesticus mice, musculus males discriminated in favour of musculus signals and against hybrid signals. Remarkably, the pattern of hybrid unattractiveness did not vary across the hybrid zone. Moreover, allopatric populations tested in the same conditions did not discriminate against hybrid signals, indicating character displacement for signal perception or preference. Finally, habituation-discrimination tests assessing similarities between signals pointed out that hybrid signals differed from the parental ones. Overall, our results suggest that perception of hybrids as unattractive has evolved in border populations of musculus after the secondary contact with domesticus. We discuss the mechanisms involved in hybrid unattractiveness, and the potential impact of asymmetric sexual selection on the hybrid zone dynamics and gene flow between the two subspecies.
authors.affiliation: CNRS, Institut des Sciences de l'Evolution de Montpellier, UMR5554, , Université Montpellier 2, Montpellier, France.
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Latour
authors.forename: Marco
authors.initials: M
authors.lastname: Perriat-Sanguinet
authors.forename: Pierre
authors.initials: P
authors.lastname: Caminade
authors.forename: Pierre
authors.initials: P
authors.lastname: Boursot
authors.forename: Carole M
authors.initials: CM
authors.lastname: Smadja
authors.forename: Guila
authors.initials: G
authors.lastname: Ganem
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D051456:Gene Flow / Q000235:genetics*; D005828:Genetics, Population; D006824:Hybridization, Genetic / Q000235:genetics* / Q000502:physiology; D008297:Male; D052586:Mating Preference, Animal / Q000502:physiology*; D051379:Mice; D060047:Reproductive Isolation; D012903:Smell / Q000502:physiology; D013045:Species Specificity; D014556:Urine / Q000737:chemistry
keywords: hybrid signal; mate recognition; reproductive character displacement; speciation; urinary cues