Autor(es): Abdel-latief, Mohatmed; Hoffmann, Klaus H.

Resumo: The genome of Tribolium castaneum encodes two allatostatin [AS type B; W(X)6Wamide and AS type C; PISCF-OH] and one allatotropin (AT) precursor, but no AS type A (FGLamide) (Tribolium Genome Sequencing Consortium, 2008: Nature 452:949?955). Here we studied the activity (in vitro) of peptides derived from these precursors on the synthesis/release of juvenile hormone (JH) III. The corpora cardiaca-corpora allata (CC-CA) complexes of adult females of another tenebrionid beetle, the mealworm Tenebrio molitor, were used. Incubating the gland complexes in a medium containing Trica-AS B3 peptide, we showed that the peptide has allatostatic function in T. molitor. The activity of the type C AS depended on the age of the test animals and their intrinsic rate of JH III biosynthesis. The Trica-AS C peptide inhibited the JH release from CA of 3-day-old females with a high intrinsic rate of JH synthesis, but activated JH release from the CA of 7-day-old females with a lower intrinsic rate of JH production. The allatotropin peptide (Trica-AT) also activated the JH release from the CA of 7-day-old females in a dose-dependent and reversible manner. Unexpectedly, a type A AS derived from the precursor of the American cockroach Periplaneta americana (Peram-AS A2b) inhibited the JH release from the CA of younger and older females in the concentration range of 10?8 to 10?4? M, and the effects were fully reversible in the absence of peptide. These data suggest a complex role of allatoactive neuropeptides in the regulation of JH III biosynthesis in beetles. ¸ 2010 Wiley Periodicals, Inc.

Palavras-Chave: Coleoptera; Tenebrio molitor; Tribolium castaneum; Juvenile hormone biosynthesis; Corpora allata; Allatostatin; Allatotropin

Imprenta: Archives of Insect Biochemistry and Physiology , v. 74, n. 3, p. 135-146, 2010

Identificador do objeto digital: 10.1002/arch.20359

Descritores: Aedes aegypti - Biosynthesis

Data de publicação: 2010

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