Broad-complex proteins are required for puffing and transcription of salivary gland late genes during metamorphosis. Isoforms Z1 accumulate slowly in mid instar larvae salivary glands at beginning of ecdysone response (94-114 hours of development at puff stage 1) and become the predominant isoform after 6 hours. Levels diminish at puff stage 2 and are moderately abundant in late larvae from stages 3-10. In prepupae, transcripts appear at puff stage 15 onwards, reaching maximum at stages 18-20. In gut, levels remain constant between stages 1-11. In Malpighian tubules, Z1 isoforms are seen at stages 3 and 7, but not at stage 11. In fat body and wing disks, low levels increase between stages 3 and 11. Isoform Z2 accumulates to a high level at the beginning of the ecdysone response during puff stage 1 and abruptly disappears after several hours. In prepupae, transcripts are reinduced at low levels. Low levels are seen in the Malpighian Tubules, gut and fat body between stages 1-11 and high levels in the wing disk. Isoform Z3; in mid instar larval salivary gland transcript accumulates to a high level at the beginning of the ecdysone response, 94-98 hours of development in puff stage 1, and abruptly disappears after several hours. Levels increase by puff stage 3 remaining abundant in late larvae until stage 10, then diminish by stage 11. In prepupae, transcripts are abundant and increase during puff stages 11-14 and 18-20. High levels are seen in Malpighian tubules, gut and fat body between stages 1-11 and low levels in wing disk. Primary response to 20-hydroxyecdysone in third instar larval imaginal disks.