Abstract
BackgroundBread wheat (Triticum aestivum L.) is one of the most important crops worldwide and its production faces pressing challenges, the solution of which demands genome information. However, the large, highly repetitive hexaploid wheat genome has been considered intractable to standard sequencing approaches. Therefore the International Wheat Genome Sequencing Consortium (IWGSC) proposes to map and sequence the genome on a chromosome-by-chromosome basis.Methodology/Principal FindingsWe have constructed a physical map of the long arm of bread wheat chromosome 1A using chromosome-specific BAC libraries by High Information Content Fingerprinting (HICF). Two alternative methods (FPC and LTC) were used to assemble the fingerprints into a high-resolution physical map of the chromosome arm. A total of 365 molecular markers were added to the map, in addition to 1122 putative unique transcripts that were identified by microarray hybridization. The final map consists of 1180 FPC-based or 583 LTC-based contigs.Conclusions/SignificanceThe physical map presented here marks an important step forward in mapping of hexaploid bread wheat. The map is orders of magnitude more detailed than previously available maps of this chromosome, and the assignment of over a thousand putative expressed gene sequences to specific map locations will greatly assist future functional studies. This map will be an essential tool for future sequencing of and positional cloning within chromosome 1A.
Highlights
It is a truth universally acknowledged that a crop as globally important as bread wheat (Triticum aestivum L.) must be one of the highest priorities for genome analysis, to facilitate development of cultivars able to meet the challenges of increasing world population and changing climate
Five short (,N50) contigs had a coverage of 206 or greater, suggesting that they may consist of large duplications that have been condensed into one contig
The construction of high-density physical maps is a major milestone in the international effort to sequence the genome of wheat, the most widely grown of the world’s food crops
Summary
It is a truth universally acknowledged that a crop as globally important as bread wheat (Triticum aestivum L.) must be one of the highest priorities for genome analysis, to facilitate development of cultivars able to meet the challenges of increasing world population and changing climate. A further confounding factor is that, as with other very large grass genomes, its majority is comprised of repetitive elements (85–90%) with only a little over 1% encoding transcribed genes [1]. Bearing these factors in mind, even though new generation sequencing technologies make it feasible to obtain reasonable coverage of such a large genome, assembling the resulting short sequence reads seems an insoluble problem. Bread wheat (Triticum aestivum L.) is one of the most important crops worldwide and its production faces pressing challenges, the solution of which demands genome information. The large, highly repetitive hexaploid wheat genome has been considered intractable to standard sequencing approaches. The International Wheat Genome Sequencing Consortium (IWGSC) proposes to map and sequence the genome on a chromosome-by-chromosome basis
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have