A 2kb bcd promoter fragment is fused upstream of a bcd cDNA sequence, followed by the bcd 3' UTR.
bcdTN3 rescues bcd6
One copy of P{bcdTN3} in bcd6 embryos expands and shifts the bcd expression domain slightly more anterior towards the gnathal and thoracic regions. Two copies rescues the bcd6 mutant phenotype completely.