Inferring the degree of incipient speciation in secondary contact zones of closely related lineages of Palearctic green toads (Bufo viridis subgroup).

Détails

ID Serval
serval:BIB_660BA661766C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Inferring the degree of incipient speciation in secondary contact zones of closely related lineages of Palearctic green toads (Bufo viridis subgroup).
Périodique
Heredity
Auteur(s)
Dufresnes C., Bonato L., Novarini N., Betto-Colliard C., Perrin N., Stöck M.
ISSN
1365-2540 (Electronic)
ISSN-L
0018-067X
Statut éditorial
Publié
Date de publication
2014
Peer-reviewed
Oui
Volume
113
Numéro
1
Pages
9-20
Langue
anglais
Résumé
Reproductive isolation between lineages is expected to accumulate with divergence time, but the time taken to speciate may strongly vary between different groups of organisms. In anuran amphibians, laboratory crosses can still produce viable hybrid offspring >20 My after separation, but the speed of speciation in closely related anuran lineages under natural conditions is poorly studied. Palearctic green toads (Bufo viridis subgroup) offer an excellent system to address this question, comprising several lineages that arose at different times and form secondary contact zones. Using mitochondrial and nuclear markers, we previously demonstrated that in Sicily, B. siculus and B. balearicus developed advanced reproductive isolation after Plio-Pleistocene divergence (2.6 My, 3.3-1.9), with limited historic mtDNA introgression, scarce nuclear admixture, but low, if any, current gene flow. Here, we study genetic interactions between younger lineages of early Pleistocene divergence (1.9 My, 2.5-1.3) in northeastern Italy (B. balearicus, B. viridis). We find significantly more, asymmetric nuclear and wider, differential mtDNA introgression. The population structure seems to be molded by geographic distance and barriers (rivers), much more than by intrinsic genomic incompatibilities. These differences of hybridization between zones may be partly explained by differences in the duration of previous isolation. Scattered research on other anurans suggests that wide hybrid zones with strong introgression may develop when secondary contacts occur <2 My after divergence, whereas narrower zones with restricted gene flow form when divergence exceeds 3 My. Our study strengthens support for this rule of thumb by comparing lineages with different divergence times within the same radiation.
Mots-clé
Incipient speciation, secondary contact, hybridization, dispersal, selection, clines, Anura, microsatellites, mitochondrial DNA.
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/02/2014 13:42
Dernière modification de la notice
08/05/2019 19:41
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