B. napus Genome Sequence

Within the family of Brassicaceae, the genus Brassica includes species which genomes are highly duplicated by frequent polyploidy that occurred during their evolution. Among these, oilseed rape (B. napus) has been formed relatively-recently through a further allotetraploidization event between B. oleracea and B. rapa. It represents an important crop that provides about ~13% of edible vegetable oil world-wide. Sequence the B. napus genome would provide an invaluable basis to address together sequencing a genome of an important crop with a high potentiality for improvement and of a recent polyploid species to understand consequences on its genome evolution through recurrent polyploidizations. Having the advantage of relatively small genome size (1150 Mb) and the progress in international initiatives for sequencing of its parental species, we initiated in 2010 sequencing of a winter cultivar of B. napus, through the Seq-Poly-Nap (Sequencing the highly duplicated and recent polyploid genome of oilseed rape (Brassica napus) _ ANR-2009*) project. In order to resolve the two A and C constituting subgenomes with the least ambiguity, we used combination of different sequencing technologies (Sanger, 454 and Illumina), together with the development of tools for adequate annotation, bioinformatics, bioanalysis, modeling and integration of data. The ‘resequencing’ of other B. napus genotypes and the development of a high throughput genotyping chip will anchor the contig sequences and resolve the complexity of this highly duplicated genome. Progress in our project and integration with different sequencing initiatives will be presented. * The French oilseed rape sequencing project; Teams involved:  CEA/IG/CNS, INRA-URGV, INRA-EPGV, INRA-APBV-Rennes.