Contains (from 5' to 3'): a subfragment of the HG4-1 hb cis-regulatory sequence present in Avic\GFPhb.HG4-1, a basal Hsp70 promoter, the hb P1 5' UTR including the first intron and the P2 promoter, the GFP coding sequence, the hb 3'UTR and an SV40 transcription termination sequence.