title: Hypertrehalosaemic peptides in the honeybee (Apis mellifera): purification, identification and function.
abstract: The corpora cardiaca (CC) of the Italian race (including also the africanised variety) of the honeybee (Apis mellifera ligustica) contain approximately 3 pmol of a hypertrehalosaemic peptide. This peptide is identical in structure to the adipokinetic hormone (AKH) found in Manduca sexta, Mas-AKH. The CC of the dark European race of the honeybee (Apis mellifera carnica) contain no detectable Mas-AKH or any other adipokinetic/hypertrehalosaemic peptide. This is the first report of the occurrence of this peptide in a non-lepidopteran insect and of an intraspecific variation with regards to the presence or absence of a hypertrehalosaemic peptide in the CC of an insect. Extracts of A. m. ligustica CC elicit a strong adipokinetic/hypertrehalosaemic response when injected into crickets and cockroaches but extracts of A. m. carnica CC elicit no such responses when injected into crickets, cockroaches and butterflies. A weak hypertrehalosaemic response to injected Mas-AKH was observed in winter bees of both races, but there was no response in spring/summer bees. However, if a seasonal difference exists, it is at best minimal. Honeybees always have access to a more than adequate supply of high energy food in the form of nectar or honey stored in the hive. Thus, though A. m. ligustica CC contain a hypertrehalosaemic peptide, there is neither a glycogen-mobilising function of this hormone nor an adequate glycogen store in their fat body for its effective utilisation.
authors.affiliation: Department of Animal Ecology I, University of Bayreuth, 95440, Bayreuth, Germany
authors.forename: M W.
authors.initials: MW
authors.lastname: Lorenz
authors.forename: R
authors.initials: R
authors.lastname: Kellner
authors.forename: J
authors.initials: J
authors.lastname: Woodring
authors.forename: K H.
authors.initials: KH
authors.lastname: Hoffmann
authors.forename: G
authors.initials: G
authors.lastname: Gäde