Plant Genome IV Conference Plant Genome IV Conference
A bacterial artificial chromosome (BAC) library suitable for map-based cloning and physical mapping has been constructed in soybean. The BAC vector, capable of maintaining large insert DNA, was developed by Shizuya et al. (P.N.A.S. 89:8794 1992) for use in human genome mapping. The first plant applications were by Rod Wing's laboratory at Texas A&M (Woo et al., NAR 22:4922 1994). Our soybean BAC library uses the pBeloBAC 11 vector. Large insert DNA was isolated from a HindIII partial digest of megabase DNA prepared from nuclei embedded in agarose microbeads. The nuclei were prepared from young leaves of the Williams 82 soybean cultivar. A random selection of 160 BACs generated from one ligation prepared from DNA size-selected from one partial digest ranged in size from 40 to 350 kb with an average insert size of 150 kb. A maximum of three of the 160 BACs analyzed did not appear to have an insert larger than the 7 k vector. We are currently isolating and mapping the ends of some of the BAC clones so that we will be able to establish BAC contigs for map-based cloning.