Involvement of and in JH-Mediated Reproduction of Female (Hendel).

Juvenile hormone (JH) prevents metamorphosis during insect larval stages and promotes adult reproductive processes. Krüppel-homolog 1 (Kr-h1), a zinc finger transcription factor assumed to be induced by JH via the JH receptor methoprene-tolerant (Met), mediates the antimetamorphic effect of JH in insects, but its function in JH-mediated reproductive processes has not been fully explored. In this study, and involved in the JH signaling pathway were first cloned and identified from the oriental fruit fly, , an important pest infesting fruit and vegetables worldwide. Subsequent spatiotemporal expression analysis revealed that and were both highly expressed in 7-day-old adults and fat body of female adults, respectively. Treatment with a JH analog (methoprene) significantly induced the expression of JH signaling and () genes and accelerated ovary development. RNA interference (RNAi) further revealed that either or depletion at the adult stage of impeded ovary development, with significantly lower egg production noted as well. In addition, rescue through methoprene application after RNAi stimulated the expression of JH signaling and genes. Although there were still differences in ovary phenotype between rescued insects and the pre-RNAi control, ovary redevelopment with a larger surface area was observed, consistent with the spatiotemporal expression and phenotypes recorded in the original methoprene experiment. Our data reveal the involvement of Met and in insect vitellogenesis and egg production, thus indicating the crucial role of the JH signaling pathway in insect reproduction.