UAS sequences upstream of an Hsp70 minimal promoter are ligated to a truncated minigene-like version of pb : fusion of Hsp70 to the first exon of pb, the first intron of pb, the second exon of pb, ~2kb of intron two fused just upstream of exon four in intron three and from there the normal genomic sequence of pb.
In a pb5 background, pbScer\UAS.hs shows only weak or partial rescue of the mutant phenotype, less than for pbΔKpn. Flies exhibit some of the characteristic of the pb null homeotic labial-to-leg transformation. Partial labial palps form, as evidenced by the presence of some pseudotracheal rows, but distinctive preothoracic leg tissues are present on the labial palps.
Partial pb regulatory sequences are retained and the construct is driven in a partial pb pattern.