نقش ژن Met در اووژنسیس ماده‌های بالغ Blattella germanica با استفاده از تکنیک RNAi

The German cockroach, Blattella germanica (L.) (Blattaria: Blattellidae), is an economic important pest from the perspective sanitary and agriculture in the world and Iran. Its severe economic damage is because of eating any human, animal and plant foods and transmitting important pathogens. Widespread use of chemical insecticides as the main route of control of this pest has led to the development of resistance of this species to insecticides. Nowadays, RNA interference (RNAi) technology in insects as a potential bio-insecticide that is based on IPM, is highly sequence-specific and can be designed to avoid the adverse effect on non-target species and can solve the economic and environmental problems of insecticides The Methoprene-tolerant (Met) plays as the juvenile hormone (JH) receptor and is an essential player in the JH signaling pathway in the reproduction of insects. In order to unveil the role of Met in oogenesis, Met mRNA levels were depleted using systemic RNAi. The colony of B. germanica reared on dry dog food (Panlab 125C3) and water in the dark at 30 ± 1°C and 60-70% relative humidity. A dose of 2 µg of dsMet was injected into the abdomen of freshly emerged adult females and adults were treated by dsMet on third day again. Females equivalently treated with dsMock were used as control. The dsRNA effects were examined on fifth day of adult stage. Total RNA extraction from the fat body and cDNA synthesizing were carried out. Quantitative real time PCR (qRT-PCR) reactions were carried out in triplicate by using SYBR Green. Levels of mRNA were calculated relative to BgActin-5c expression by using the iQ5 Real-Time PCR Detection System. Data were analyzed by using of T test student and Rest (2009) and Excel. The results showed that injection of dsMet in adult females knocked down Met mRNA effectively and Met expression were 67% lower in comparison with controls. Subsequently Met RNAi reduced significantly the basal oocytes growth, size of ovary, total protein content of ovary and production of ootheca compare with control. Therefore, Met is essential for transforming the oogenic signal of JH in the fat body of B. germanica. According to the key role of Met in oogenesis and fecundity of German cockroach adult female, using of biological insecticide that based on dsMet can be an appropriate approach for controlling of B. germanica in future.