Submitted to: Wheat Genetics International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2003
Publication Date: 9/1/2003
Citation: Gill, B.S., Qi, L.L., Echalier, B., Chao, S., Lazo, G.R., Anderson, O.D., Akhunov, E.D., Dvorak, J., Linkiewicz, A.M., Dubcovsky, J. 2003. A transcriptome map of wheat. Wheat Genetics International Symposium Proceedings. 1:261-264. Interpretive Summary: Recent findings about the placement of genes expressed in wheat are providing an insight into the organization of the wheat genome. Genes in wheat were tentatively placed on genetic maps constructed from a complex series of screenings against mapping lines. The Genes are represented by expressed sequence tags (ESTs), also know as cloned nucleic acid fractions of the expressed portion of the genome, or transcriptome. 16,099 loci were assessed, being placed into 159 different bin locations of the wheat map. Most agronomic genes were located in the EST-dense bins located in distal portions of the chromosomes. It is estimated that on average, about 1 EST locus can be found every 1 Mb of wheat DNA. The wheat transcriptome map, together with the draft sequence of the rice genome, now provides unique opportunities for gene discovery in wheat. More importantly, this wheat bin map will be a resource for markers for breeding and framework for constructing a more detailed map of the wheat genome.
Technical Abstract: A transcriptome map of wheat genome with 16,099 EST loci spanning the 21 chromosomes of bread wheat (Triticum aestivum L.) or an average of 766 loci per chromosome, has been developed. Of the 16,099 EST loci, 14,051 were allocated to 159 bins using a set of nullisomic-tetrasomic, ditelosomic, and deletion lines providing an expected average of 95 loci per chromosome bin or 1 EST locus per 1 Mb of wheat DNA. Observed EST distribution was non-random with 40% of the EST loci mapping in the bins located in the distal 20% of the chromosomes. Most agronomic genes were located in the EST-dense distal bins. The wheat transcriptome map, together with the draft sequence of the rice genome, now provides unique opportunities for gene discovery in wheat. More importantly, this wheat bin map will be a resource for markers for breeding and framework for constructing a sequence-ready BAC-contig map of the wheat genome.