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Developmental arrest induced by juvenile hormone in larvae of Bombyx mori
Author(s) -
Sakurai Sho,
Imokawa Hiroshi
Publication year - 1988
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940080403
Subject(s) - prothoracic gland , juvenile hormone , ecdysteroid , biology , corpus allatum , hemolymph , methoprene , ecdysone , medicine , moulting , bombyx mori , endocrinology , bombycidae , larva , instar , hormone , biochemistry , botany , gene
Injection of the juvenile hormone analog (JHA) methoprene into day 3, fifthinstar larvae of Bombyx mori induced developmental arrest. Feeding activity declined, and the larvae remained as larvae for more than 2 weeks, after which they died. After JHA 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 (PTTH) in vitro, indicating that JHA did not inhibit the competence of the glands to respond to PTTH. 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 PTTH 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.