title: Identification and functional analysis of chitinase 7 gene in white-backed planthopper, Sogatella furcifera.
abstract: Chitinase is used to degrade chitin in insect cuticles and the peritrophic matrix. In this study, the full-length cDNA sequence of a Cht gene (SfCht7) was identified and characterized from the white-black planthopper, Sogatella furcifera. The SfCht7 cDNA was 3148bp, contained an open reading frame of 2877bp and encoded 958 amino acids with a predicted molecular weight of 107.9kDa. Homology analysis indicated that SfCht7 has typical chitinase features include a chitin-binding domain, two catalytic domains and a signal peptide region. Phylogenetic analysis suggested that SfCht7 belonged to the group III chitinases. Quantitative real-time PCR analyses showed that SfCht7 was highly expressed before molting. After injecting SfCht7 double-stranded RNA in the nymph stage, insects exhibited phenotypes of difficulty in molting and wing development. A lethal phenotype was that nymph bodies exuviated from the head but the old cuticle did not detach completely from the body. Another lethal phenotype was that elongated distal wing pads of fifth-instar nymphs with junctions between the thorax and abdomen in the treatment group that were thinner than in the control group, giving a "wasp-waisted" appearance. In another phenotype that was not lethal, nymphs exuviated and old cuticles detached completely from the body, but the wings of adults did not stretch normally.
authors.affiliation: Institute of Entomology, Guizhou University, Guiyang, Guizhou 550025, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Institute of Entomology, Guizhou University, Guiyang, Guizhou 550025, China; College of Tobacco Science of Guizhou University, Guiyang, Guizhou 550025, China. Electronic address: agr.hyang@aliyun.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.affiliation: Hangzhou Key Laboratory of Animal Adaptation and Evolution, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China. Electronic address: tbzm611@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Tang
authors.affiliation: Key & Special Laboratory of Guizhou Education Department for Pest Control and Resource Utilization, College of Biology and Environmental Engineering, Guiyang University, Guiyang 550005, China. Electronic address: yangwenjia10@126.com.
authors.forename: Wen-Jia
authors.initials: WJ
authors.lastname: Yang
authors.affiliation: Institute of Entomology, Guizhou University, Guiyang, Guizhou 550025, China.
authors.forename: Dao-Chao
authors.initials: DC
authors.lastname: Jin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002688:Chitinases / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D006430:Hemiptera / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D009758:Nymph / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D010802:Phylogeny; D014921:Wings, Animal / Q000201:enzymology* / Q000254:growth & development
chemical_list: D019476:Insect Proteins; D002688:Chitinases
keywords: Chitinase; Eclosion; Rice planthopper; Sogatella furcifera; Wing extension