A ~2.2kb fragment of the ftz upstream region, which contains the neurogenic element extending from the XbaI to BalI restriction sites is inserted into pCasper4, followed by the ftz basal promoter (~40bp upstream of the transcription start site) and 5'UTR is cloned upstream of Antp coding sequences. This is fused to the ftz 3'UTR, and 200bp from downstream of the polyA signal.