title: Characterization and expression profiling of serine protease inhibitors in the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae).
abstract: Serine protease inhibitors (SPIs) have been found in all living organisms and play significant roles in digestion, development and innate immunity. In this study, we present a genome-wide identification and expression profiling of SPI genes in the diamondback moth, Plutella xylostella (L.), a major pest of cruciferous crops with global distribution and broad resistance to different types of insecticides.
  
  
  
  A total of 61 potential SPI genes were identified in the P. xylostella genome, and these SPIs were classified into serpins, canonical inhibitors, and alpha-2-macroglobulins based on their modes of action. Sequence alignments showed that amino acid residues in the hinge region of known inhibitory serpins from other insect species were conserved in most P. xylostella serpins, suggesting that these P. xylostella serpins may be functionally active. Phylogenetic analysis confirmed that P. xylostella inhibitory serpins were clustered with known inhibitory serpins from six other insect species. More interestingly, nine serpins were highly similar to the orthologues in Manduca sexta which have been demonstrated to participate in regulating the prophenoloxidase activation cascade, an important innate immune response in insects. Of the 61 P.xylostella SPI genes, 33 were canonical SPIs containing seven types of inhibitor domains, including Kunitz, Kazal, TIL, amfpi, Antistasin, WAP and Pacifastin. Moreover, some SPIs contained additional non-inhibitor domains, including spondin_N, reeler, and other modules, which may be involved in protein-protein interactions. Gene expression profiling showed gene-differential, stage- and sex-specific expression patterns of SPIs, suggesting that SPIs may be involved in multiple physiological processes in P. xylostella.
  
  
  
  This is the most comprehensive investigation so far on SPI genes in P. xylostella. The characterized features and expression patterns of P. xylostella SPIs indicate that the SPI family genes may be involved in innate immunity of this species. Our findings provide valuable information for uncovering further biological roles of SPI genes in P. xylostella.
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Key Laboratory of Integrated Pest Management of Fujian and Taiwan, China Ministry of Agriculture, Fuzhou, 350002, China.
authors.forename: Hailan
authors.initials: H
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Key Laboratory of Integrated Pest Management of Fujian and Taiwan, China Ministry of Agriculture, Fuzhou, 350002, China.
authors.forename: Xijian
authors.initials: X
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Key Laboratory of Integrated Pest Management of Fujian and Taiwan, China Ministry of Agriculture, Fuzhou, 350002, China.
authors.forename: Jiwei
authors.initials: J
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|School of Biological Sciences, University of Missouri, Kansas City, MO, 64110-2499, USA.
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Key Laboratory of Integrated Pest Management of Fujian and Taiwan, China Ministry of Agriculture, Fuzhou, 350002, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Xia
authors.affiliation: Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350013, China.
authors.forename: Fengluan
authors.initials: F
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.|Key Laboratory of Integrated Pest Management of Fujian and Taiwan, China Ministry of Agriculture, Fuzhou, 350002, China.
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, and College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. msyou@iae.fjau.edu.cn.|Institute of Applied Ecology and Research Centre for Biodiversity and Eco-Safety, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. msyou@iae.fjau.edu.cn.|Fujian-Taiwan Joint Innovation Centre for Ecological Control of Crop Pests, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. msyou@iae.fjau.edu.cn.|Key Laboratory of Integrated Pest Management of Fujian and Taiwan, China Ministry of Agriculture, Fuzhou, 350002, China. msyou@iae.fjau.edu.cn.
authors.forename: Minsheng
authors.initials: M
authors.lastname: You
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016000:Cluster Analysis; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics; D008018:Life Cycle Stages / Q000235:genetics; D009036:Moths / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development; D010802:Phylogeny; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D015843:Serpins / Q000737:chemistry / Q000235:genetics; D059467:Transcriptome
chemical_list: D019476:Insect Proteins; D015842:Serine Proteinase Inhibitors; D015843:Serpins
keywords: Canonical inhibitor; Expression pattern; Lepidoptera; Phylogenetic analysis; Serpin