Scheme of Neurospora rDNA cluster. Scheme of ribosomal DNA tandem repeat locus in N. crassa. Details of the rDNA repeat are shown including the non-transcribed sequences (NTS) and the units that produce the mature 17S, 5.8S and 25S rRNA. H is the HindIII restriction enzyme site. The bar corresponds to the probe used to detected siRNAs. RRT and FRT are the oligos used for RT reaction to detect reverse and forward transcripts respectively, and P1 and P2 the primers used for amplification RT-PCR. The scheme is not to scale.