Construct: An Hsp70 promoter is fused upstream of an incomplete P-element, "BP1", which is a 2.8kb element capable of encoding a polypeptide of 717 amino acids in the germline and one of 541 amino acids in the soma. The "BP1" element has a deletion from nucleotide 578 to 684 (coordinates relative to the canonical P-element described in FBrf0038996). The intact P-element promoter is present in this fragment.