Developmental arrest induced by juvenile hormone in larvae of Bombyx mori

✍ Scribed by Sho Sakurai; Hiroshi Imokawa

• Book ID: 102745761
• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 600 KB
• Volume: 8
• Category: Article
• ISSN: 0739-4462
• DOI: 10.1002/arch.940080403

✦ Synopsis

Injection of the juvenile hormone analog UHA) methoprene into day 3, fifthinstar larvae of Bornbyx mori induced developmental arrest. Feeding activity declined, and the larvae remained as larvae for more than 2 weeks, after which they died. After ]HA injection, the hemolymph ecdysteroid titer was low, and the prothoracic glands were almost inactive for 7 days. During this period, prothoracic glands were stimulated by prothoracicotropic hormone (PlTH) in vitro, indicating that JHA did not inhibit the competence of the glands to respond to PlTH. When brain-corpora cardiaca-corpora allata complexes were removed from intact fifth-instar larvae on day 4, the prothoracic glands became autonomously active and produced enough ecdysone for pupation. When PlTH injections were given to larvae previously injected with JHA (7 days before), the larvae recovered feeding activity, purged their guts, and pupated. Injections of 20-hydroxyecdysone into larvae that had been injected with JHA 7 days earlier induced larval molting. These results suggest that JHA affects both the brain and the prothoracic gland.