NEW YORK, Oct 4 – The University of California, Davis said Wednesday it received a $4.4 million grant from the National Science Foundation for the mapping of wheat genomes.
" We are thrilled that NSF has funded this pioneering project because, if successful, it will demonstrate that a physical map can be constructed for the genome of any plant or animal, not just for the small-genome models such as rice and Arabidopsis ," Jan Dvorak, a UC Davis agronomy and range science professor, said in a statement.
Scientists from Kansas State and Texas A&M universities and at the US Department of Agriculture's Agricultural Research Service will collaborate on the project.
This is one of 16 new NSF grants totaling more than $48 million that will support research projects in plant genomics during the next five years. It is the fourth NSF plant genome grant awarded to UC Davis as the lead institution since the inception of the NSF Plant Genome program three years ago.
Because common wheat, Triticum aestivum , originated by hybridization of three different plant species, its nucleus contains three separate genomes -- the total collection of genes passed on from generation to generation -- designated A, B and D.
Wheat genomes are quite large, compared to the genomes of plant species such as arabidopsis and rice, commonly studied by plant researchers as model systems. The D genome, the smallest of the three wheat genomes, is roughly two and a half times the size of the maize genome and 10 times the size of the rice genome.
The goal of the newly funded project is to construct a physical map of the wheat D genome. A physical map of a genome finds the order of cloned DNA fragments covering the entire genome so that the order corresponds to the order of DNA in chromosomes.
To obtain a detailed picture of gene distribution in the wheat D genome, the researchers will clone and order 300,000 DNA fragments isolated from Aegilops tauschii -- one of the three wheat ancestors -- whose genome is equivalent to the wheat D genome.
Each of the 300,000 clones will be characterized by an automated DNA fingerprinting process. Computers then will be used to order the cloned DNA fragments as they are found in the wheat chromosomes into groups known as " contigs."
The position of each contig on the chromosome will be determined and neighboring contigs will be identified and linked to generate a physical map of each of the seven chromosomes of the wheat D genome.
With an integrated wheat physical map at hand, researchers will be able to compare the positions of corresponding genes on the physical maps of the wheat D genome with those of maize's medium- sized genome and rice's small genome. These comparisons will provide information on changes in genome architecture that have accompanied increases in genome size among plants in the grass family, to which wheat belongs.
Mapping of wheat genes on the physical map will have also great practical significance in discovery and isolation of genes. Identification of gene-rich regions in the genome will make it possible to eventually sequence the most genetically relevant parts of the wheat genomes.