Phenotypic novelty in experimental hybrids is predicted by the genetic distance between species of cichlid fish.

Détails

Ressource 1Télécharger: BIB_53D0CA6612A8.P001.pdf (890.91 [Ko])
Etat: Public
Version: Final published version
ID Serval
serval:BIB_53D0CA6612A8
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Phenotypic novelty in experimental hybrids is predicted by the genetic distance between species of cichlid fish.
Périodique
BMC Evolutionary Biology
Auteur(s)
Stelkens R.B., Schmid C., Selz O., Seehausen O.
ISSN
1471-2148[electronic], 1471-2148[linking]
Statut éditorial
Publié
Date de publication
2009
Peer-reviewed
Oui
Volume
9
Numéro
283
Pages
283
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: epublish
Résumé
BACKGROUND: Transgressive segregation describes the occurrence of novel phenotypes in hybrids with extreme trait values not observed in either parental species. A previously experimentally untested prediction is that the amount of transgression increases with the genetic distance between hybridizing species. This follows from QTL studies suggesting that transgression is most commonly due to complementary gene action or epistasis, which become more frequent at larger genetic distances. This is because the number of QTLs fixed for alleles with opposing signs in different species should increase with time since speciation provided that speciation is not driven by disruptive selection. We measured the amount of transgression occurring in hybrids of cichlid fish bred from species pairs with gradually increasing genetic distances and varying phenotypic similarity. Transgression in multi-trait shape phenotypes was quantified using landmark-based geometric morphometric methods. RESULTS: We found that genetic distance explained 52% and 78% of the variation in transgression frequency in F1 and F2 hybrids, respectively. Confirming theoretical predictions, transgression when measured in F2 hybrids, increased linearly with genetic distance between hybridizing species. Phenotypic similarity of species on the other hand was not related to the amount of transgression. CONCLUSION: The commonness and ease with which novel phenotypes are produced in cichlid hybrids between unrelated species has important implications for the interaction of hybridization with adaptation and speciation. Hybridization may generate new genotypes with adaptive potential that did not reside as standing genetic variation in either parental population, potentially enhancing a population's responsiveness to selection. Our results make it conceivable that hybridization contributed to the rapid rates of phenotypic evolution in the large and rapid adaptive radiations of haplochromine cichlids.
Mots-clé
Animals, Cichlids/genetics, Evolution, Genetic Speciation, Hybridization, Genetic, Phenotype
Pubmed
Web of science
Open Access
Oui
Création de la notice
22/06/2009 12:12
Dernière modification de la notice
20/08/2019 14:08
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