Effect of <i>TcKnk2</i> dsRNA-treatment on the development of <i>T. castaneum</i>.

<p>(A) Injection of dsRNA for <i>TcKnk2</i> into penultimate instar larvae, last instar larvae and pharate pupae (n = 60) led to lethal phenotype at pupal-adult molt (∼55%) and ∼15% adult hypomorphic phenotype with split elytra. (B) Specific down-regulation of <i>TcKnk2</i> transcripts by RNAi. dsRNAs (200 ng per insect) for <i>TcKnk2</i> were injected into pharate pupae. Three days after injection, total RNA was extracted from whole insects of at pupal stage day 3 (n = 3) and used for cDNA synthesis. (C) Specificity of <i>TcKnk2</i> dsRNA-treatment. Effect of <i>TcKnk2</i> dsRNA-treatment on transcripts for <i>TcKnk</i>, <i>TcKnk3</i> and other genes involved in chitin metabolism such as <i>TcChs-A</i> and <i>TcCht5</i> was checked by RT-PCR. <i>T. castaneum ribosomal protein-S6</i> (<i>TcRPS6</i>) was used as internal loading control. dsRNA for <i>T. castaneum Vermilion</i> (<i>TcVer</i>) and <i>TcKnk</i> was injected as a control.