A group of scientists has reported the sequencing of large size and polyploid bread wheat genome. They have sequenced a large, 17-gigabase-pair, hexaploid genome using 454 pyrosequencing, and compared this with the sequences of diploid ancestral and progenitor genomes. They have also identified between 94,000 and 96,000 genes, and assigned two-thirds to the three component genomes (A, B and D) of hexaploid wheat. High-resolution synteny maps identified many small disruptions to conserved gene order. They observed that the hexaploid genome is highly dynamic, with significant loss of gene family members on polyploidization and domestication, and an abundance of gene fragments. Several classes of genes involved in energy harvesting, metabolism and growth are among expanded gene families that could be associated with crop productivity. Their analyses, coupled with the identification of extensive genetic variation will provide a resource for accelerating gene discovery and improving this major crop. Here it is important to mention that sequencing wheat genome was a challenge due to its polploidy nature. The bread wheat is the result of gradual and evolved hybridisation of three closely related species making its genome more complex. It is learned that the bread wheat genome is almost five times bigger than the human genome.
The research was published online in the Journal 'Nature' on wednesday 28th November 2012. It was a multi-institute project in which approximately thirty scientists were involved. DNA sequence was generated by The University of Liverpool Centre for Genomic Research (United Kingdom), 454 Life Sciences (United States), The Cold Spring Harbor Woodbury Genome Centre (United States) and The Genome Analysis Centre (United Kingdom).This work was supported by UK Biological and Biotechnological Sciences Research Council (BBSRC) and others. Scientists from MIPS/IBIS, Helmholtz- Zentrum München, 85764 Neuherberg, Germany was also the part of this project.
The full length research article is available (open access) on the Nature website.