Transcriptional analysis of the recombinant H. jecorina strains was done by RT-qPCR to compare expression of both inserted genes using sar1 (SAR/ARF-type small GTPase) as a stable reference gene [25] . Furthermore, the copy numbers of both genes was measured by qPCR of genomic DNA using pki as a reference, which in the native H. jecorina genome is present as a single copy gene. Based on these analyses a strain (termed PEC/PSC1) was chosen for further investigations because it showed the highest equal expression of both inserted genes. This was confirmed by the finding that this strain bears two copies of each recombinant gene in the genome. These data were also supported using Southern blot analysis (data not shown).