The native bcd regulatory region drives expression of a transcript that contains the complete bcd coding sequence and native bcd 5' and 3' UTRs. An Asn to Ala amino acid substitution has been introduced at position 51 of the homeodomain, the YIRPYL motif has been mutated to AIRPYR and the PEST domain has been mutated (5 substitutions of Thr (4) or Ser (1) to Ala). An EGFP tag has been inserted at the N-terminal end of the coding sequence.