0.8kb of pb transcription unit from 5' end of intron 2, in normal orientation, governing expression of lacZ.
0.8kb XhoI-EcoRI fragment (subregion of the conserved second intron sequence) of pb inserted upstream and in same orientation to lacZ.
No pairing sensitivity conferred by 0.8kb pb fragment.
No pairing sensitivity conferred by 0.8kb pb fragment.