Southern analysis of A. thaliana genomic DNA. A Southern blot of genomic DNA digested with restriction enzymes EcoRI (RI) and EcoRV (RV) was hybridised with the labelled ARA1 (A) and GAL1 (B) cDNA clones, respectively, under low-stringency (right) and high-stringency (left) conditions. The positions of size markers (kb) are indicated. In (A), bands corresponding to fragment sizes predicted from the genomic DNA sequence are indicated (*). In the EcoRV digest an additional fragment of 0.3 kb is expected (not shown) and in the EcoRI digest a fragment of 5.6 kb is expected but not observed. This difference may arise from RFLP differences between strains.[from Sherson et al. 1999]