title: Juvenile hormone biosynthesis by corpora allata of larval tomato moth, Lacanobia oleracea, and regulation by Manduca sexta allatostatin and allatotropin.
abstract: Juvenile hormone (JH) biosynthesis and the effects of synthetic Manduca sexta allatostatin (Mas-AS) and M. sexta allatotropin (Mas-AT) were investigated in isolated corpora allata (CA) of Vth stadium larvae of the tomato moth, Lacanobia oleracea. Reversed-phase high-performance liquid chromatography (RP-HPLC) of JH extracted from CA shows that larvae produce predominantly JH II and its corresponding acid. It appears that the acid homologue is a result of JH esterase activity in the CA (and other tissues) rather than the lack of JH acid methyltransferase. Mean rates of synthesis (100-200fmol/pr/h) were inhibited ca. 70% by Mas-AS and stimulated in a dose-dependent manner up to three times by Mas-AT. However, Mas-AS had no significant effect on Mas-AT-stimulated rates of JH biosynthesis. Using RP-HPLC and an enzyme-linked immunosorbent assay (ELISA) to Mas-AT, a peak of Mas-AT-like immunoreactivity was detected in larval L. oleracea brain homogenates. Co-elution of this immunoreactive peak with synthetic Mas-AT suggests that this neuropeptide is also present in L. oleracea.
authors.affiliation: Central Science Laboratory, Sand Hutton, YO41 1LZ, York, UK. n.audsley@csl.gov.uk
authors.forename: N
authors.initials: N
authors.lastname: Audsley
authors.forename: R J
authors.initials: RJ
authors.lastname: Weaver
authors.forename: J P
authors.initials: JP
authors.lastname: Edwards
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D003335:Corpora Allata / Q000378:metabolism*; D006727:Hormone Antagonists / Q000378:metabolism*; D007301:Insect Hormones / Q000378:metabolism*; D007605:Juvenile Hormones / Q000096:biosynthesis*; D007814:Larva / Q000378:metabolism; D018551:Solanum lycopersicum; D018402:Manduca / Q000378:metabolism; D008969:Molecular Sequence Data; D009036:Moths / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D014020:Tissue Extracts / Q000378:metabolism
chemical_list: D006727:Hormone Antagonists; D007301:Insect Hormones; D007605:Juvenile Hormones; D009479:Neuropeptides; D014020:Tissue Extracts; C076523:allatostatin; C050669:allatotropin; D002265:Carboxylic Ester Hydrolases; C038003:juvenile hormone esterase