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.
AvicGFPhb.HG4-3-RNA is detected in neuroblasts at embryonic stages 9 and 10. At embryonic stage 11 labeling is seen in ganglion mother cells. AvicGFPhb.HG4-3-protein is detected in earlier born neuroblasts of the ventral nerve cord at embryonic stage 11. At embryonic stage 16 both AvicGFPhb.HG4-3-RNA and -protein label early-born neurons in the deepest layers of the embryonic CNS.