Daniel Vitales1, Inés Álvarez2, Sònia Garcia1, Oriane Hidalgo3,4, Gonzalo Nieto Feliner2, Jaume Pellicer4, Joan Vallès3, Teresa Garnatje1. 1. Institut Botànic de Barcelona (IBB, CSIC-ICUB), Passeig del Migdia sn, 08038 Barcelona, Catalonia, Spain. 2. Department of Biodiversity and Conservation, Real Jardín Botánico (CSIC), Plaza de Murillo 2, 28014 Madrid, Spain. 3. Laboratori de Botànica - Unitat associada CSIC, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Av. Joan XXIII 27-31, 08028 Barcelona, Catalonia, Spain. 4. Comparative Plant and Fungal Biology Department, Royal Botanic Gardens, Kew, Richmond, UK.
Abstract
BACKGROUND AND AIMS: Changes in the amount of repetitive DNA (dispersed and tandem repeats) are considered the main contributors to genome size variation across plant species in the absence of polyploidy. However, the study of repeatome dynamism in groups showing contrasting genomic features and complex evolutionary histories is needed to determine whether other processes underlying genome size variation may have been overlooked. The main aim here was to elucidate which mechanism best explains genome size evolution in Anacyclus (Asteraceae). METHODS: Using data from Illumina sequencing, we analysed the repetitive DNA in all species of Anacyclus, a genus with a reticulate evolutionary history, which displays significant genome size and karyotype diversity albeit presenting a stable chromosome number. KEY RESULTS: By reconstructing ancestral genome size values, we inferred independent episodes of genome size expansions and contractions during the evolution of the genus. However, analysis of the repeatome revealed a similar DNA repeat composition across species, both qualitative and quantitative. Using comparative methods to study repeatome dynamics in the genus, we found no evidence for repeat activity causing genome size variation among species. CONCLUSIONS: Our results, combined with previous cytogenetic data, suggest that genome size differences in Anacyclus are probably related to chromosome rearrangements involving losses or gains of chromosome fragments, possibly associated with homoploid hybridization. These could represent balanced rearrangements that do not disrupt gene dosage in merged genomes, for example via chromosome segment exchanges.
BACKGROUND AND AIMS: Changes in the amount of repetitive DNA (dispersed and tandem repeats) are considered the main contributors to genome size variation across plant species in the absence of polyploidy. However, the study of repeatome dynamism in groups showing contrasting genomic features and complex evolutionary histories is needed to determine whether other processes underlying genome size variation may have been overlooked. The main aim here was to elucidate which mechanism best explains genome size evolution in Anacyclus (Asteraceae). METHODS: Using data from Illumina sequencing, we analysed the repetitive DNA in all species of Anacyclus, a genus with a reticulate evolutionary history, which displays significant genome size and karyotype diversity albeit presenting a stable chromosome number. KEY RESULTS: By reconstructing ancestral genome size values, we inferred independent episodes of genome size expansions and contractions during the evolution of the genus. However, analysis of the repeatome revealed a similar DNA repeat composition across species, both qualitative and quantitative. Using comparative methods to study repeatome dynamics in the genus, we found no evidence for repeat activity causing genome size variation among species. CONCLUSIONS: Our results, combined with previous cytogenetic data, suggest that genome size differences in Anacyclus are probably related to chromosome rearrangements involving losses or gains of chromosome fragments, possibly associated with homoploid hybridization. These could represent balanced rearrangements that do not disrupt gene dosage in merged genomes, for example via chromosome segment exchanges.
Authors: G Nieto Feliner; I Álvarez; J Fuertes-Aguilar; M Heuertz; I Marques; F Moharrek; R Piñeiro; R Riina; J A Rosselló; P S Soltis; I Villa-Machío Journal: Heredity (Edinb) Date: 2017-03-15 Impact factor: 3.821
Authors: Laura J Kelly; Simon Renny-Byfield; Jaume Pellicer; Jiří Macas; Petr Novák; Pavel Neumann; Martin A Lysak; Peter D Day; Madeleine Berger; Michael F Fay; Richard A Nichols; Andrew R Leitch; Ilia J Leitch Journal: New Phytol Date: 2015-06-08 Impact factor: 10.151
Authors: María Fernanda Moreno-Aguilar; Luis A Inda; Aminael Sánchez-Rodríguez; Itziar Arnelas; Pilar Catalán Journal: Front Plant Sci Date: 2022-07-01 Impact factor: 6.627