Sequence encoding a QF driver is recombineered into a construct carrying an 85 kb genomic fragment that includes the 31 kb transcription unit of Tbh and 14 kb genomic DNA upstream and 71 kb downstream of the Oct-TyrR transcription start site extending into one or more adjacent genes on each side. Ncra\QF is inserted into the position of the first ATG of Tbh in such a way that it is presumably expressed under the control of Tbh regulatory sequences.