| Title | Integrative Taxonomy Recognizes Evolutionary Units Despite Widespread Mitonuclear Discordance: Evidence from a Rotifer Cryptic Species Complex |
| Abstract | Mitonuclear discordance across taxa is increasingly recognized as posing a major challenge to species delimitation based on DNA sequence data. Integrative taxonomy has been proposed as a promising framework to help address this problem. However, we still lack compelling empirical evidence scrutinizing the efficacy of integrative taxonomy in relation to, for instance, complex introgression scenarios involving many species. Here, we report remarkably widespread mitonuclear discordance between about 15 mitochondrial and 4 nuclear Brachionus calyciflorus groups identified using different species delimitation approaches. Using coalescent-, Bayesian admixture-, and allele sharing-based methods with DNA sequence or microsatellite data, we provide strong evidence in support of hybridization as a driver of the observed discordance. We then describe our combined molecular, morphological, and ecological approaches to resolving phylogenetic conflict and inferring species boundaries. Species delimitations based on the ITS1 and 28S nuclear DNA markers proved a more reliable predictor of morphological variation than delimitations using the mitochondrial COI gene. A short-term competition experiment further revealed systematic differences in the competitive ability between two of the nuclear-delimited species under six different growth conditions, independent of COI delimitations; hybrids were also observed. In light of these findings, we discuss the failure of the COI marker to estimate morphological stasis and morphological plasticity in the B. calyciflorus complex. By using B. calyciflorus as a representative case, we demonstrate the potential of integrative taxonomy to guide species delimitation in the presence of mitonuclear phylogenetic conflicts. |
| Source | Systematic biology (Print) 65 (3), pp. 508–524 |
| Keywords | 18S and 28S ribosomal RNA genescyclical parthenogenscytochrome c oxidase subunit IDNA barcodingGMYChaplowebinternal transcribed spacer Ireticulate evolution |
| Journal | Systematic biology (Print) |
| Editor | Oxford University Press, Oxford, Regno Unito |
| Year | 2016 |
| Type | Articolo in rivista |
| DOI | 10.1093/sysbio/syw016 |
| Authors | Papakostas, Spiros; Michaloudi, Evangelia; Proios, Konstantinos; Brehm, Michaela; Verhage, Laurens; Rota, Jadranka; Pena, Carlos; Stamou, Georgia; Pritchard, Victoria L.; Fontaneto, Diego; Declerck, Steven A. J. |
| Text | 355893 2016 10.1093/sysbio/syw016 ISI Web of Science WOS 000375210300012 Scopus 2 s2.0 84978829373 18S and 28S ribosomal RNA genes cyclical parthenogens cytochrome c oxidase subunit I DNA barcoding GMYC haploweb internal transcribed spacer I reticulate evolution Integrative Taxonomy Recognizes Evolutionary Units Despite Widespread Mitonuclear Discordance Evidence from a Rotifer Cryptic Species Complex Papakostas, Spiros; Michaloudi, Evangelia; Proios, Konstantinos; Brehm, Michaela; Verhage, Laurens; Rota, Jadranka; Pena, Carlos; Stamou, Georgia; Pritchard, Victoria L.; Fontaneto, Diego; Declerck, Steven A. J. object Object ; object Object ; object Object ; object Object ; object Object Mitonuclear discordance across taxa is increasingly recognized as posing a major challenge to species delimitation based on DNA sequence data. Integrative taxonomy has been proposed as a promising framework to help address this problem. However, we still lack compelling empirical evidence scrutinizing the efficacy of integrative taxonomy in relation to, for instance, complex introgression scenarios involving many species. Here, we report remarkably widespread mitonuclear discordance between about 15 mitochondrial and 4 nuclear Brachionus calyciflorus groups identified using different species delimitation approaches. Using coalescent , Bayesian admixture , and allele sharing based methods with DNA sequence or microsatellite data, we provide strong evidence in support of hybridization as a driver of the observed discordance. We then describe our combined molecular, morphological, and ecological approaches to resolving phylogenetic conflict and inferring species boundaries. Species delimitations based on the ITS1 and 28S nuclear DNA markers proved a more reliable predictor of morphological variation than delimitations using the mitochondrial COI gene. A short term competition experiment further revealed systematic differences in the competitive ability between two of the nuclear delimited species under six different growth conditions, independent of COI delimitations; hybrids were also observed. In light of these findings, we discuss the failure of the COI marker to estimate morphological stasis and morphological plasticity in the B. calyciflorus complex. By using B. calyciflorus as a representative case, we demonstrate the potential of integrative taxonomy to guide species delimitation in the presence of mitonuclear phylogenetic conflicts. 65 Published version http //sysbio.oxfordjournals.org/content/65/3/508.short papakostas 2016_SystBiol_Papakostas_et_al.pdf Articolo in rivista Oxford University Press 1063 5157 Systematic biology Print Systematic biology Print Syst. biol. Print Systematic biology. Print diego.fontaneto FONTANETO DIEGO |
