TcRtv is a conserved protein required for insect molting.

<p>(A) Expression of <i>TcRtv</i> during <i>T. castaneum</i> development. Total RNA was extracted at different stages of development: E, eggs; YL, young larvae; ML, mature larvae (last instar larvae); PP, pharate pupae; P, pupae and A, adult. RT-PCR (28 cycles) was performed using cDNA prepared from total RNA and gene-specific primers. <i>TcRpS6</i> (<i>T. castaneum ribosomal protein-S6</i>) was used as an internal loading control (24 cycles). (B) Tissue-specific expression pattern of <i>TcRtv</i> in <i>T. castaneum</i> late last instar larval midgut (M), hindgut (H) and carcass (C) (whole body minus gut) and pharate pupal elytra (E) and hindwing (W) was detected by RT-PCR using gene specific primers (28 cycles). <i>TcRpS6</i> was used as an internal loading control (24 cycles). (C) Phylogenetic analysis of Rtv orthologs from several orders of insect species was done using MEGA 4.0 neighbor joining method, with <i>Ixodes scapularis</i> included as outlier. (D) Effect of <i>TcRtv</i> dsRNA treatment on development of <i>T. castaneum</i> (n = 20). dsRNA for the <i>Vermilion</i> gene (<i>TcVer</i>) was used as a control (n = 20 each). (E) Effect of <i>TcRtv</i> dsRNA treatment on the transcript levels. RT-PCR was performed (28 cycles) to check the level of <i>TcRtv</i> transcripts using gene-specific primers. <i>TcRpS6</i> was used as a loading control (24 cycles).