Population genomics of an exceptional hybridogenetic system of Pelophylax water frogs.

Détails

ID Serval
serval:BIB_1DBBF2AFDCA6
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Population genomics of an exceptional hybridogenetic system of Pelophylax water frogs.
Périodique
BMC evolutionary biology
Auteur(s)
Dubey S., Maddalena T., Bonny L., Jeffries D.L., Dufresnes C.
ISSN
1471-2148 (Electronic)
ISSN-L
1471-2148
Statut éditorial
Publié
Date de publication
05/08/2019
Peer-reviewed
Oui
Volume
19
Numéro
1
Pages
164
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: epublish
Résumé
Hybridogenesis can represent the first stage towards hybrid speciation where the hybrid taxon eventually weans off its parental species. In hybridogenetic water frogs, the hybrid Pelophylax kl. esculentus (genomes RL) usually eliminates one genome from its germline and relies on its parental species P. lessonae (genomes LL) or P. ridibundus (genomes RR) to perpetuate in so-called L-E and R-E systems. But not exclusively: some all-hybrid populations (E-E system) bypass the need for their parental species and fulfill their sexual cycle via triploid hybrid frogs. Genetic surveys are essential to understand the great diversity of these hybridogenetic dynamics and their evolution. Here we conducted such study using RAD-sequencing on Pelophylax from southern Switzerland (Ticino), a geographically-isolated region featuring different assemblages of parental P. lessonae and hybrid P. kl. esculentus.
We found two types of hybridogenetic systems in Ticino: an L-E system in northern populations and a presumably all-hybrid E-E system in the closely-related southern populations, where P. lessonae was not detected. In the latter, we did not find evidence for triploid individuals from the population genomic data, but identified a few P. ridibundus (RR) as offspring from interhybrid crosses (LR × LR).
Assuming P. lessonae is truly absent from southern Ticino, the putative maintenance of all-hybrid populations without triploid individuals would require an unusual lability of genome elimination, namely that P. kl. esculentus from both sexes are capable of producing gametes with either L or R genomes. This could be achieved by the co-existence of L- and R- eliminating lineages or by "hybrid amphigamy", i. e. males and females producing sperm and eggs among which both genomes are represented. These hypotheses imply that polyploidy is not the exclusive evolutionary pathway for hybrids to become reproductively independent, and challenge the classical view that hybridogenetic taxa are necessarily sexual parasites.
Mots-clé
Ecology, Evolution, Behavior and Systematics, Amphibians, Hybrid amphigamy, Hybrid amphispermy, Hybrid speciation, P. lessonae, Pelophylax kl. esculentus, Polyploidization, RAD-sequencing, Sex chromosomes, Water frogs
Pubmed
Web of science
Open Access
Oui
Création de la notice
09/08/2019 13:23
Dernière modification de la notice
21/08/2019 6:33
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