Evidence of recombination in putative ancient asexuals.

Détails

ID Serval
serval:BIB_F812C249EEC6
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Evidence of recombination in putative ancient asexuals.
Périodique
Molecular Biology and Evolution
Auteur⸱e⸱s
Gandolfi A., Sanders I.R., Rossi V., Menozzi P.
ISSN
0737-4038[print], 0737-4038[linking]
Statut éditorial
Publié
Date de publication
2003
Volume
20
Numéro
5
Pages
754-761
Langue
anglais
Résumé
Ancient asexuals have been considered to be a contradiction of the basic tenets of evolutionary theory. Barred from rearranging genetic variation by recombination, their reduced number of gene arrangements is thought to hamper their response to changing environments. For the same reason, it should be difficult for them to avoid the build-up of deleterious mutations. Several groups of taxonomically diverse organisms are thought to be ancient asexuals, although clear evidence for or against the existence of recombination events is scarce. Several methods have recently been developed for predicting recombination events by analyzing aligned sequences of a given region of DNA that all originate from one species. The methods are based on phylogenetic, substitution, and compatibility analyses. Here we present the results of analyses of sequence data from different loci studied in several groups of evolutionarily distant species that are considered to be ancient asexuals, using seven different types of analysis. The groups of organisms were the arbuscular mycorrhizal fungi (Glomales), Darwinula stevensoni (Darwinuloidea crustacean ostracods) and the bdelloid rotifers (Bdelloidea), which are thought to have been asexual for the last 400, 25-100, and 35-40 Myr, respectively. The seven different analytical methods evaluated the evolutionary relationships among haplotypes, and these methods had previously been shown to be reliable for predicting the occurrence of recombination events. Despite the different degree of genetic variation among the different groups of organisms, at least some evidence for recombination was found in all species groups. In particular, predictions of recombination events in the arbuscular mycorrhizal fungi were frequent. Predictions of recombination were also found for sequence data that have previously been used to infer the absence of recombination in bdelloid rotifers. Although our results have to be taken with some caution because they could signal very ancient recombination events or possibly other genetic variation of nonrecombinant origin, they suggest that some cryptic recombination events may exist in these organisms.
Mots-clé
Animals, Base Sequence, Chromosome Mapping, Crustacea/genetics, Databases, Nucleic Acid, Fungi/genetics, Models, Genetic, Molecular Sequence Data, Recombination, Genetic/genetics, Reproduction, Asexual/genetics, Rotifera/genetics
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 17:38
Dernière modification de la notice
20/08/2019 16:24
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