The Multinational Brassica Genome Project
The cultivated Brassica species are grown in many countries and include important oil, vegetable and condiment crops. They contribute to the world economy, health (the vegetables contain vitamins and anti-carcinogenic compounds; rapeseed oil contains an excellent balance of polyunsaturated fatty acids) and the environment (rapeseed oil can serve as a biofuel or a renewable resource for industrial applications). However, considerable improvement in yield, quality, robustness, range and input efficiencies is required if the full potential benefits of Brassica crops are to be realized.
Due to their close phylogenetic relationship with the important model species Arabidopsis thaliana, for which the entire genome sequence has been available since 2000, it was anticipated that knowledge transfer for Brassica crop improvement would be straightforward. However, although the physiology and developmental biology of Arabidopsis and Brassica are very similar, the genomes of Brassica species are very much more complex than that of A. thaliana, as a result of multiple rounds of polyploidy during their ancestry. For example, B. napus may contain over 100,000 genes, compared to ca. 28,000 in A. thaliana. This makes the identification of orthology relationships of genes extremely difficult, and the presence in Brassica of multiple homologues of each gene in A. thaliana provides ample opportunity for divergence of gene function.
The genomes of Brassica species, although 4 to 10 times larger than that of A. thaliana, are still of a tractable size for genomic technologies. Physical maps are being constructed for the Brassica A genome in Korea and for both the A and C genomes in the UK. Partial physical mapping of the genome of B. napus is being conducted in Canada and in the EU. Although such physical maps will be of great value for the identification of specific regions of the genomes of these important crops, they will not permit the detailed analysis of the entire Brassica genome, the preparation of microarrays to analyse the transcriptome, or the efficient design of markers associated with the sequences of specific genes for use in breeding programmes. To achieve these things, the complete sequence of at least one of the Brassica genomes will be required. It is necessary to sequence only one Brassica genome initially as both the macrostucture (chromosome level) and the microstructure (gene-by-gene level) of Brassica genomes show extensive, though imperfect, collinearity.
The international Brassica research community is working together to establish communal genomic resources; also at brassica.info. A steering group has been formed for the Multinational Brassica Genome Project (details of the present membership are shown below). This steering group represents the international Brassica research community and has the roles of promoting international cooperation and helping to defining the strategic goals of the community in the area of Brassica genomics. The steering group recently agreed that these goals should include the genetic anchoring of the BAC-based physical maps being constructed for Brassica genomes, and that the 500Mb Brassica A genome should be sequenced by an international consortium, with a target completion date of the end of 2007. A concept note describing the strategy for the genome sequencing project, that can succeed only with the active participation of the many countries for which Brassica species represent important crops and/or research tools, has been published.
Scientists wishing to participate in the Multinational Brassica Genome Project should contact their national (or regional) representative on the steering group for more information.
|Prepared by the Steering Group for the Multinational Brassica Genome Project:|
|Ian Bancroft||John Innes Centre, UK|
|Derek Lydiate||Agriculture and Agri-Food, Canada|
|Tom Osborn||University of Wisconsin, USA|
|Michel Renard||INRA Rennes, France|
|Wolfgang Friedt||University of Giessen, Germany|
|Yong-Pyo Lim||Chungnam National University, S. Korea|
|Jan Sadowski||Adam Mickiewicz University, Poland|
|Jinling Meng||Huazhong Argricultural University, China|
|David Edwards||Agriculture Victoria, Australia|
|Graham King||Horticulture Research International, UK|