Genome Size Variation and Comparative Genomics Reveal Intraspecific Diversity in Brassica rapa
2020
Boutte, Julien | Maillet, Loeiz | Chaussepied, Thomas | Letort, Sébastien | Aury, Jean-Marc | Belser, Caroline | Boideau, Franz | Brunet, Anael | Coriton, Olivier | Deniot, Gwenaëlle | Falentin, Cyril | Huteau, Virginie | Lodé-Taburel, Maryse | Morice, Jérôme | Trotoux, Gwenn | Chèvre, Anne-Marie | Rousseau-Gueutin, Mathieu | Ferreira de Carvalho, Julie | Institut de Génétique, Environnement et Protection des Plantes (IGEPP) ; Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro) | Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA) ; Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes) ; Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Bretagne Sud (UBS)-École normale supérieure - Rennes (ENS Rennes)-Institut National de Recherche en Informatique et en Automatique (Inria)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique) ; Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT) | Laboratoire de Bioinformatique pour la Génomique et la Biodiversité (LBGB) ; Génomique métabolique (UMR 8030) ; Genoscope - Centre national de séquençage [Evry] (GENOSCOPE) ; Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS)-Genoscope - Centre national de séquençage [Evry] (GENOSCOPE) ; Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS) | H2020 Marie Skłodowska-Curie Actions | Agence Nationale de la Recherche | This work was made possible by financial support of the European Union and a Marie Sklodowska-Curie grant (No. 791908) awarded to JF as well as a BOOST’EUROPE financed by the Conseil régional de Bretagne. FB was supported by a fellowship from BAP INRAE and Conseil régional de Bretagne. This work was additionally supported by the France Génomique National infrastructure, funded as part of the «Investissements d’Avenir » program managed by the Agence Nationale pour la Recherche (contract ANR-10-INBS-09 | ANR-10-INBS-0009,France Génomique,Organisation et montée en puissance d'une Infrastructure Nationale de Génomique(2010)
International audience
显示更多 [+] 显示较少 [-]英语. Traditionally, reference genomes in crop species rely on the assembly of one accession, thus occulting most of intraspecific diversity. However, rearrangements, gene duplications, and transposable element content may have a large impact on the genomic structure, which could generate new phenotypic traits. Comparing two Brassica rapa genomes recently sequenced and assembled using long-read technology and optical mapping, we investigated structural variants and repetitive content between the two accessions and genome size variation among a core collection. We explored the structural consequences of the presence of large repeated sequences in B. rapa 'Z1' genome vs. the B. rapa 'Chiifu' genome, using comparative genomics and cytogenetic approaches. First, we showed that large genomic variants on chromosomes A05, A06, A09, and A10 are due to large insertions and inversions when comparing B. rapa 'Z1' and B. rapa 'Chiifu' at the origin of important length differences in some chromosomes. For instance, lengths of 'Z1' and 'Chiifu' A06 chromosomes were estimated in silico to be 55 and 29 Mb, respectively. To validate these observations, we compared using fluorescent in situ hybridization (FISH) the two A06 chromosomes present in an F1 hybrid produced by crossing these two varieties. We confirmed a length difference of 17.6% between the A06 chromosomes of 'Z1' compared to 'Chiifu.' Alternatively, using a copy number variation approach, we were able to quantify the presence of a higher number of rDNA and gypsy elements in 'Z1' genome compared to 'Chiifu' on different chromosomes including A06. Using flow cytometry, the total genome size of 12 Brassica accessions corresponding to a B. rapa available core collection was estimated and revealed a genome size variation of up to 16% between these accessions as well as some shared inversions. This study revealed the contribution of long-read sequencing of new accessions belonging to different cultigroups of B. rapa and highlighted the potential impact of differential insertion of repeat elements and inversions of large genomic regions in genome size intraspecific variability.
显示更多 [+] 显示较少 [-]