TbAT1 gene and its expression in wild-type and drug-resistant trypanosome lines. (a) TbAT1 was amplified from genomic DNA prepared from T. equiperdum P, T. equiperdum PBR, STIB 247 (247), 247Mr, STIB 386 (386), and 386Mr. (b) Northern blot assay of T. equiperdum strains P and PBR, probed with the TbAT1 ORF and subsequently with a control probe for triosephosphate isomerase (TIM) as a loading control. (c) Reverse transcriptase PCR with cDNA from STIB 247 and 247Mr, confirming the lack of product in the drug-resistant derived STIB 247 line. A minus sign indicates a no-reverse-transcriptase control. TIM primers were used as positive controls.