title: Knockdown of Cs-Spook induces delayed larval molting in rice striped stem borer Chilo suppressalis.
abstract: Spook has essential roles in the biogenesis of the molting hormone 20-hydroxyecdysone (20-E). The function of spook in the rice striped stem borer (SSB) Chilo suppressalis remains unclear, prompting our hypothesis that it exerts actions similar to those reported for other insect species. Here we amplified the full-length transcript of spook (Cs-Spook) in SSB by 5' and 3' rapid amplification of cDNA ends. Cs-Spook has conserved P450 motifs such as Helix-C, Helix-I, Helix-K, and PERF motif (PxxFxPxRF). It was highly expressed in late instar larvae but less so in newly molted larvae. Cs-Spook was highly expressed in prothoracic glands. Cs-Spook was knocked down by dsRNA treatments. Compared with controls, the gene expression level was reduced to 9% at 24 h post injection (PI), 33% at 48 h PI, and 24% at 72 h PI. The ecdysteroid titer decreased significantly in the dsRNA-treated group (P < 0.05), resulting in delayed larval development. The delayed development in dsRNA-treatment group was rescued by treating with 20-E. Our work demonstrates that Cs-Spook participates in the biogenesis of 20-E and regulates the molt of SSB, as seen in other species.
authors.affiliation: Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
authors.forename: Muhammad Faisal
authors.initials: MF
authors.lastname: Shahzad
authors.forename: Yao
authors.initials: Y
authors.lastname: Li
authors.forename: Chang
authors.initials: C
authors.lastname: Ge
authors.forename: Yang
authors.initials: Y
authors.lastname: Sun
authors.forename: Qiupu
authors.initials: Q
authors.lastname: Yang
authors.forename: Fei
authors.initials: F
authors.lastname: Li
mesh_terms: D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D004440:Ecdysone; D004441:Ecdysterone / Q000096:biosynthesis*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D007814:Larva / Q000254:growth & development; D018978:Molting; D009036:Moths / Q000235:genetics* / Q000254:growth & development*; D016133:Polymerase Chain Reaction; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D012330:RNA, Double-Stranded; D020539:Sequence Analysis, Protein
chemical_list: D018076:DNA, Complementary; D012330:RNA, Double-Stranded; D004440:Ecdysone; D004441:Ecdysterone
keywords: Chilo suppressalis; Halloween genes; development; spook