DPP-mediated TGFβ signaling regulates juvenile hormone biosynthesis by activating the expression of juvenile hormone acid methyltransferase

Citations Over TimeTop 10% of 2011 papers

Abstract

Juvenile hormone (JH) biosynthesis in the corpus allatum (CA) is regulated by neuropeptides and neurotransmitters produced in the brain. However, little is known about how these neural signals induce changes in JH biosynthesis. Here, we report a novel function of TGFβ signaling in transferring brain signals into transcriptional changes of JH acid methyltransferase (jhamt), a key regulatory enzyme of JH biosynthesis. A Drosophila genetic screen identified that Tkv and Mad are required for JH-mediated suppression of broad (br) expression in young larvae. Further investigation demonstrated that TGFβ signaling stimulates JH biosynthesis by upregulating jhamt expression. Moreover, dpp hypomorphic mutants also induced precocious br expression. The pupal lethality of these dpp mutants was partially rescued by an exogenous JH agonist. Finally, dpp was specifically expressed in the CA cells of ring glands, and its expression profile in the CA correlated with that of jhamt and matched JH levels in the hemolymph. Reduced dpp expression was detected in larvae mutant for Nmdar1, a CA-expressed glutamate receptor. Taken together, we conclude that the neurotransmitter glutamate promotes dpp expression in the CA, which stimulates JH biosynthesis through Tkv and Mad by upregulating jhamt transcription at the early larval stages to prevent premature metamorphosis.

Related Papers

• → Vitellogenesis induced by Juvenile Hormone in the Female Sterile Mutant apterous-four in Drosophila melanogaster(1973)106 cited
• → 4′-OH-JH-III: an additional hydroxylated juvenile hormone produced by locust corpora allata in vitro(1999)23 cited
• → Adaptation of a radiochemical assay for juvenile hormone biosynthesis to study caste differentiation in a primitive termite(1985)36 cited
• → Effects of decapitation and ovariectomy on the regulation of juvenile hormone synthesis in the cockroach, Diploptera punctata(1983)37 cited
• → Activite de l'hormone juvenile en C17 (JH-II) chez Locusta migratoria(1976)4 cited