Results of Southern blot and RT-PCR analyses. (A) Southern blot results. Lanes: 1, AF13, XhoI; 2, Transformant O1, XhoI; 3, AF13, EcoRI; 4, O1, EcoRI; 5, AF13, HindIII; 6, O1, HindIII. (B) RT-PCR results. RT was carried out on total RNA digested with RNase-free DNase I with oligonucleotide primers specific for the coding regions of aflX and the flanking genes aflY and moxY. Lanes: 1, AF13 genomic DNA control; 2, AF13 cDNA; 3, aflX knockout transformant O1 cDNA; 4, no template negative control.