Fig. 1. (A) The 165 kb BAC RP11-777I19 insert. The insert contains 80 kb of the BRCA2 gene as well as 30 kb of the upstream region and 55 kb of the flanking downstream region. In addition to BRCA2, based on the sequence information (Accession Numbers Z73359 and 74739) the BAC insert is predicted to contain two novel genes of unknown function. (B) Southern analysis of EcoRV digested DNA isolated from littermates obtained from a cross between Brca2 Ko/+; Tg/+ and Brca2 Ko/+ mice. WT, wild-type allele; MT, mutant allele. Presence of a 8 kb band (lower panel) on BamHI-digested DNA shows the presence of the BAC transgene (Tg); (C) Table showing the offspring of various genotypes obtained from a cross between Brca2 Ko/+; Tg/+ and Brca2 Ko/+ mice, in expected Mendelian ratios.