Plant & Animal Genomes XIII Conference Plant & Animal Genomes XIII ConferenceJanuary 15-19, 2005
Town & Country Convention Center
San Diego, CA
M. Shields , Qian Zhang , Thomas M. Davis
We are developing large- and medium-insert (BAC and fosmid, respectively) genome libraries for the diploid strawberry, Fragaria vesca, a putative A genome donor to the octoploid cultivated strawberry, F. x ananassa. These resources will provide the platform for direct and positional cloning, and for whole genome sequencing. BAC library construction has been hampered by difficulties in isolating sufficiently pure, high molecular weight (>100Kb) DNA. Such difficulties have also been encountered by other labs working with Fragaria, suggesting that alternative DNA isolation techniques must be developed to obtain the desired high molecular weight DNA. We are testing methods for overcoming this challenge. Meanwhile, we have constructed a fosmid library that has proven to be of high quality. The library was constructed from randomly sheared DNA and consists of 33,000 clones with an average insert size of 40,000 Kb, representing approximately 8 genome equivalents. The clones have been spotted onto two high-density filters, and duplicate copies have been made available to other researchers as a genomic tool. Hybridization screening has been conducted with several probes, including a heterologous probe (from peach), and at least one positive clone has been detected for each probe. Further characterization of the library with chloroplast and mitochondrial DNA-specific probes is in progress. Methods, analysis and clone fingerprinting results will be presented. Library filters are available upon request.