Fiche du document
7 septembre 2021
- doi: 10.1073/pnas.2103963118
- issn: 0027-8424
Ce document est lié à :
info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.2103963118
Ce document est lié à :
info:eu-repo/semantics/altIdentifier/pmid/34465621
Ce document est lié à :
info:eu-repo/semantics/altIdentifier/eissn/1091-6490
Ce document est lié à :
info:eu-repo/grantAgreement/SNF//P2LAP3_171818///
Ce document est lié à :
info:eu-repo/grantAgreement/SNF//31003A_166323///
Ce document est lié à :
info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_390A9598B8047
info:eu-repo/semantics/openAccess , CC BY 4.0 , https://creativecommons.org/licenses/by/4.0/
Sujets proches
Units of inheritance Units of heredity Speciation (Biology)Citer ce document
C. Dufresnes et al., « Mass of genes rather than master genes underlie the genomic architecture of amphibian speciation. », Serveur académique Lausannois, ID : 10.1073/pnas.2103963118
Métriques
Partage / Export
Résumé
The genetic architecture of speciation, i.e., how intrinsic genomic incompatibilities promote reproductive isolation (RI) between diverging lineages, is one of the best-kept secrets of evolution. To directly assess whether incompatibilities arise in a limited set of large-effect speciation genes, or in a multitude of loci, we examined the geographic and genomic landscapes of introgression across the hybrid zones of 41 pairs of frog and toad lineages in the Western Palearctic region. As the divergence between lineages increases, phylogeographic transitions progressively become narrower, and larger parts of the genome resist introgression. This suggests that anuran speciation proceeds through a gradual accumulation of multiple barrier loci scattered across the genome, which ultimately deplete hybrid fitness by intrinsic postzygotic isolation, with behavioral isolation being achieved only at later stages. Moreover, these loci were disproportionately sex linked in one group (Hyla) but not in others (Rana and Bufotes), implying that large X-effects are not necessarily a rule of speciation with undifferentiated sex chromosomes. The highly polygenic nature of RI and the lack of hemizygous X/Z chromosomes could explain why the speciation clock ticks slower in amphibians compared to other vertebrates. The clock-like dynamics of speciation combined with the analytical focus on hybrid zones offer perspectives for more standardized practices of species delimitation.