ARS | Publication request: CHARACTERIZATION AND PHYSICAL MAPPING OF MAIZE BAC LIBRARIES USING HIGH DENSITY BAC FILTER HYBRIDIZATION

Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 14, 2002
Publication Date: March 14, 2002

Technical Abstract: High-density filter sets from two maize B73 libraries containing 6X (HindIII) and 7X (EcoRI) haploid genome equivalents, respectively, were evaluated with a set of complex probes. The complex probes will provide information on chromosome architecture and organellar DNA content. A second set of probes containing 90 maize RFLP core markers were hybridized to the HindIII BAC filters. These markers will be used to facilitate the anchoring process of the genetic to physical map. The core markers have been extensively used to generate genetic maps in maize, to provide a framework to anchor BAC contigs with the IBM map, and to function as bin delimiters. After accounting for the clones with no inserts and organellar contaminants 98.6% of the HindIII BACs remain that can be used for physical mapping. The four centromeric repeat probes had similar hybridization trends in both libraries. The number of positive telomeric repeat sequences and rDNA were increased in the EcoRI library by four- and seven-fold compared to the HindIII library. Twenty-three of the single-copy core markers identified an average of 7.2 positive clones with a standard deviation of 3.10 and a range of 3 to 15 positives clones. Forty-two markers with two to three copies based on RFLP mapping data had 3 to 23 positive BAC clones following hybridization experiments. Seven core markers are suspected to contain repetitive elements based on the high number of positive clones obtained from hybridizations. The wide range of positive signals identified by the maize core markers may be indicative of the effects of preferential cloning caused by use of the HindIII restriction enzyme.