title: Identification, characterization and functional analysis of a chitin synthase gene in the brown citrus aphid, Toxoptera citricida (Hemiptera, Aphididae).
abstract: Chitin synthase (CHS) is a crucial enzyme involved in the final step of the insect chitin biosynthetic pathway. In this study, we cloned the full-length cDNA sequence of a chitin synthase gene (TCiCHS) from the brown citrus aphid, Toxoptera citricida, an important citrus pest and the main vector of citrus tristeza virus worldwide. TCiCHS was expressed during the entire lifecycle and in all insect tissues examined. Expression was highest in first-second-instar nymphs, nymph-adult transitions and in the abdomen (6.7-fold higher than head). Embryos had a higher expression level than the integument. Fourth-instar nymphs were exposed to 5 and 500 mg/l concentrations of the chitin synthesis inhibitor diflubenzuron (DFB) for 48 h and had the highest mortality at the 500 mg/l concentration. The mRNA expression levels of TCiCHS were significantly enhanced upon the exposure of nymphs to both low and high DFB concentrations. Silencing of TCiCHS occurred through plant-mediated double-stranded RNA (dsRNA) feeding. Most dsRNA-fed nymphs were unable to moult to the next stage, and the expression of TCiCHS decreased 48% compared with controls. These results demonstrate that TCiCHS plays an important role in nymph to adult development, is possibly help identify molecular targets for To. citricida control.
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.
authors.forename: F
authors.initials: F
authors.lastname: Shang
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.|Zhaotong City Branch of Yunnan Provincial Tobacco Corporation, Zhaotong, China.
authors.forename: W-K
authors.initials: WK
authors.lastname: Xia
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.
authors.forename: D-D
authors.initials: DD
authors.lastname: Wei
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.
authors.forename: D
authors.initials: D
authors.lastname: Wei
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, China.
authors.forename: J-J
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D001042:Aphids / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D002687:Chitin Synthase / Q000235:genetics*; D004132:Diflubenzuron / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D019476:Insect Proteins / Q000235:genetics*; D007605:Juvenile Hormones / Q000494:pharmacology; D018978:Molting / Q000187:drug effects; D009758:Nymph / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D016366:Open Reading Frames; D010802:Phylogeny; D034622:RNA Interference; D017422:Sequence Analysis, DNA
chemical_list: D019476:Insect Proteins; D007605:Juvenile Hormones; D002687:Chitin Synthase; D004132:Diflubenzuron
keywords: RNA interference; Toxoptera citricida; chitin synthase; diflubenzuron