Abstract: 【Aim】 To assess the silence efficiency of Knickkopf (Knk) gene at the mRNA and protein levels in the migratory locust, Locusta migratoria, by doublestranded RNA (dsRNA), so as to provide basic information for the gene function analysis in the migratory locust by using RNAi technology.【Methods】 dsRNA was synthesized and injected into the body cavity of the day-1 2nd instar nymphs, and the integuments of abdomen were dissected after dsRNA injection into the locusts at 48, 72 and 96 h, respectively. Half of abdomen integuments were collected and used for the mRNA expression detection by RT-qPCR, while the other half were prepared and used for the protein expression detection by Western blotting. 【Results】 Compared with the control, the relative expression level of Knk mRNA in the treatment group decreased by 78.3%, 96.2% and 95.1%, respectively, while the relative expression level of Knk protein decreased by 61.2%, 33.3% and 52.9%, respectively, at 48, 72 and 96 h after dsRNA injection into the locusts. 【Conclusion】 The Knk expression can be significantly suppressed at both mRNA and protein levels in the migratory locust after dsKnk injection. However, the silence efficiency at the mRNA level is much stronger than that at protein level.

Key words: Locusta migratoria, gene silence, RNA interference, dsRNA, Western blot, RT-qPCR