title: Allatotropin inhibits juvenile hormone biosynthesis by the corpora allata of adult Bombyx mori.
abstract: Juvenile hormone (JH) synthesis by the corpora allata (CA) does not occur during the pupal stage in both male and female Bombyx mori but begins shortly before adult ecdysis and thereafter only in females. JH biosynthesis in female adults was prevented by allatotropin (AT) through the corpora cardiaca (CC) and the tightly attached oesophagus before adult ecdysis, but after ecdysis, removal of the CC had little effect and only the oesophagus was necessary for AT to prevent JH synthesis. AT could not prevent JH synthesis by the CA alone in either stage. Short neuropeptide F (sNPF) acted directly on the CA, preventing JH biosynthesis without preventing the JH biosynthetic enzymes before adult ecdysis, but had little effect after ecdysis, indicating that the action of AT was not via sNPF. The inhibition of JH synthesis by AT was indirect. Both AT and a factor(s) from the AT-stimulated oesophagus through the CC were necessary for the inhibitory action, which was due to the prevention of some of the JH biosynthetic enzymes. These results clearly show that AT prevents JH synthesis in adult CA in B. mori, although AT stimulates JH biosynthesis by the CA in several insect species.
authors.affiliation: Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki 036-8561, Japan; Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Faculty of Agriculture and Life Sciences, Hirosaki University, Hirosaki 036-8561, Japan; Graduate School of Agricultural Sciences, Iwate University, Morioka 020-8550, Japan. Electronic address: hiruma@hirosaki-u.ac.jp.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hiruma
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D003335:Corpora Allata / Q000254:growth & development / Q000378:metabolism*; D005260:Female; D007301:Insect Hormones / Q000378:metabolism*; D007605:Juvenile Hormones / Q000096:biosynthesis*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008297:Male; D018978:Molting; D009479:Neuropeptides / Q000378:metabolism*
chemical_list: D007301:Insect Hormones; D007605:Juvenile Hormones; D009479:Neuropeptides; C050669:allatotropin
keywords: Allatotropin; Bombyx mori; Corpora allata; Juvenile hormone; Short neuropeptide F