Poster: Genomic & proteomic resources

Abs # 885: Unraveling the Barley Genome Using an Ac/Ds Transposon Tool

Presenter:	Singh, Jaswinder , jsingh@nature.berkeley.edu
Authors	Singh, Jaswinder  (A)   Zhang, Shibo  (A)   Cooper, Lol  (B)   East, Greg  (A)   Gates, Chris  (A)   Kaur, Rajvinder  (A)   Lowe, Chris  (A)   Sturbaum, Anne  (C)   Bregitzer, Phil  (C)   Hayes, Patrick  (B)   Lemaux, Peggy  (A)
Affiliations:	(A): University of California (B): Oregon State University (C): National Small Grains Germplasm Research Facility USDA ARS, Aberdeen

The maize Ac/Ds transposon system has been successfully utilized for insertional mutagenesis in heterologous plant species. Using this system, single-copy Ds insertion lines (TNP) were generated in barley in order to conduct functional genomic studies. Thirty such lines were analyzed using inverse PCR to determine the flanking sequences adjacent to Ds. BLAST searches of the flanking sequences were performed against DNA and protein databases, including gene prediction programs. The results indicated that ~82% of flanking sequences are from either known or putative genes, which include those for wall-associated kinases, ubiquitin-conjugating enzyme, cytochrome P450 and several ESTs from barley and wheat. This confirms the preferential insertion of Ds into gene-rich regions, a critical factor in conducting functional genomics in species, like barley and wheat, with large genomes. To date Ds elements have been mapped to six of seven barley chromosomes at 20 different loci and BAC addresses determined to integrate barley genetic and physical maps. Mapping information provides the location of Ds insertions relative to potentially important traits, and the information needed to select candidates for future saturation mutagenesis, accomplished by the re-activation of Ds elements. Therefore, factors influencing re-activation of Ds elements, such as status of the terminal inverted repeats and the 8 bp duplications, were studied in detail. Since to date no observable morphological phenotype was observed in Ds insertion lines, several TNP lines are being analyzed for biochemical phenotype using proteomics tools, such as 2- dimensional electrophoresis. These data have important implications for saturation mutagenesis and functional genomics efforts in cereals.