Gal4, PR/Gal4 and PRm/Gal4 sequences were amplified by PCR for the production of the transient expression vectors pcDNA-Gal4, pcDNA-PR/Gal4 and pcDNA-PRm/Gal4, respectively. For this purpose, the constructs pMA236, pHP236 and pHP236m [22] were used as templates together with the Gal4 forward primer with extending HindIII and NotI sites ACGCACGCaagcttgcggccgcccaccATGAAGCTACTGTCTTCTATC and the Gal4 reverse primer with extending SalI site ATAGCTGCGTGCGTGCGTgtcgacttactctttttttgggtttgg. PCR products were digested with HindIII and SalI and ligated into pcDNA™3.1/Zeocin (Invitrogen, Carlsbad CA). pFR-eGFP, modified from pFR-Luc (Stratagene) was kindly provided by Rainer de Martin (University of Vienna).