MINE transcripts observed at different stages of M. grisea life cycle. Products from nested non-quantitative RT-PCR were separated by agarose gel electrophoresis and visualized by ethidium bromide staining (negative image). Nested PCR was performed to increase the amplification specificity. Arrows on the bottom of the figure indicate primer binding sites within the MINE element. To identify transcribed chimeras, one round of nested non-quantitative RT-PCR with primer pairs 1+2 and then 3+4 was used, followed by isolation and sequencing of the resulting RT-PCR products (bands 1–5, on the middle). To further specifically amplify each individual chimeric element in quantitative reverse transcription-PCR experiments, a combination of primers q1+q2 was used. Primer q1 is specifically designed to the WEIRD-MGL junction site of the desired MINE element.