Juvenile hormone regulates the steroidogenic competence of Manduca sexta prothoracic glands

Academic Article

Abstract

  • The acquisition of steroidogenic competence by prothoracic glands of last instar Manduca sexta larvae is regulated by juvenile hormone (JH). Topical treatment of pre-commitment larvae with JH I or (7S)-hydroprene (a JH analog) delays development by increasing the time to pupal commitment and wandering. Prothoracic gland competence is suppressed in JH-treated larvae: Unstimulated and prothoracicotropic hormone (PTTH)-stimulated rates of in vitro ecdysone secretion are decreased relative to rates of secretion by competent glands. (7S)-Hydroprene also suppresses the competence of glands in head-ligated pre-commitment larvae, suggesting the hormone acts directly on the glands. Two results indicate PTTH plays a role in controlling competence, and that JH regulates competence indirectly by inhibiting PTTH release: (1) head-ligation prevents the acquisition of full competence, and (2) cAMP levels are elevated in glands from JH-treated larvae. Thus, the decrease in the JH titer that precedes pupal commitment in Manduca is permissive for the acquisition by prothoracic glands of steroidogenic competence. © 1988.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Watson RD; Bollenbacher WE
  • Start Page

  • 251
  • End Page

  • 259
  • Volume

  • 57
  • Issue

  • 3