Regulation of juvenile hormone biosynthesis in Heliothis virescens by Manduca sexta allatotropin.
In Heliothis virescens, reproduction is strictly dependent on juvenile hormone (JH). In females, mating induces a sharp increase in JH titers, which stimulates increased vitellogenin biosynthesis and higher rates of egg production. JH biosynthesis is presumably stimulated by production and/or release of stimulatory neuropeptides such as allatotropins. There is evidence that allatotropin of H. virescens may be structurally related to Manduca sexta allatotropin (Manse-AT). In a radiochemical in vitro assay, synthetic Manse-AT stimulated JH biosynthesis by corpora allata (CA) of virgin H. virescens females in a dose-dependent manner, but had no effect on CA activity in H. virescens males. In females, the CA showed a transient increase in sensitivity to Manse-AT shortly after mating. Several structurally related peptides stimulated CA activity to a similar extent as Manse-AT. Corpora allata activity was stimulated by a Ca2+ ionophore, A23187. A membrane-permeable Ca2+ chelator, BAPTA/AM, antagonized the stimulatory effects of Manse-AT, suggesting that Manse-AT may enhance CA activity by increasing intracellular Ca2+ concentration.
Rachinsky
Anna
A
Department of Entomology, Kansas State University, Manhattan, Kansas, USA. arachins@d.umn.edu
Srinivasan
Asoka
A
Ramaswamy
Sonny B
SB
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000502:physiology; D005260:Female; D007301:Insect Hormones / Q000502:physiology*; D007605:Juvenile Hormones / Q000096:biosynthesis*; D018402:Manduca / Q000502:physiology*; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000502:physiology*; D017386:Sequence Homology, Amino Acid
D007301:Insect Hormones; D007605:Juvenile Hormones; D009479:Neuropeptides; C050669:allatotropin; D002118:Calcium