A shut-down in expression of an insulin-like peptide, ILP-1, halts ovarian maturation during the overwintering diapause of the mosquito Culex pipiens
Autor(es): Sim, C.; Denlinger, D. L.
Resumo: Short day-length is used to programme adult diapause in the mosquito, Culex pipiens. The downstream endocrine event that halts ovarian maturation is a shut-down in juvenile hormone (JH) production, and recent evidence suggests that the insulin signalling pathway may be a key upstream player in executing this developmental arrest. Genes encoding insulin-like peptides-1, -2 and -5 were identified in C. pipiens, and we report that transcript levels of insulin-like peptides-1 and -5 were significantly lower in diapausing females than in their nondiapausing counterparts. Genes encoding both insulin-like peptides-1 and -5 were suppressed using RNA interference in mosquitoes programmed for nondiapause, and ovarian maturation was monitored. Knocking down insulin-like peptide-1 with RNAi in nondiapausing mosquitoes resulted in a cessation of ovarian development akin to diapause, and this arrest in development could be reversed with an application of JH. Knocking down insulin-like peptide-5 did not alter ovarian development. These results are consistent with a role for insulin-like peptide-1 in the signalling pathway leading from the perception of short day-lengths to the shut-down in JH production that characterizes adult diapause in C. pipiens.
Palavras-Chave: Insulin; Diapause; Juvenile hormone; dsRNAi
Imprenta: Insect Molecular Biology, v. 18, n. 3, p. 325-332, 2009
Identificador do objeto digital: 10.1111/j.1365-2583.2009.00872.x
Descritores: Aedes aegypti - RNA
Data de publicação: 2009
