title: Identification and expression profile analysis of antimicrobial peptide/protein in Asian corn borer, Ostrinia furnacalis (Guenée).
abstract: Antimicrobial peptides/proteins (AMPs) are a group of immune proteins that exhibit strong antibiotic properties against numerous infectious bacterial strains. They are evolutionarily conserved and present in every kingdom and phylum, ranging from prokaryotes to humans. We analyzed the transciptome from the larvae of Asian corn borer, Ostrinia furnacalis (Guenée), and identified several putative AMP transcripts, OfgLys5, OfgLys6, OfgLys10, OfgAtt, and OfgIID. OfgLys5, OfgLys6, and OfgLys10 are all highly homologous with c-type lysozymes, and OfgAtt shows significant identities with Lepidoptera attacin. The amino acid sequence of OfgLys5 and OfgLys6 possessed all conserved features critical for fundamental structure and function of c-type lysozyme, including the two catalytic sites, Glu(32) and Asp(50). OfgAtt is a typical glycine-rich protein. The antimicrobial activity of O. furnacalis hemolymph increased significantly after injection with Escherichia coli, Micrococcus luteus, or Beauveria bassiana. OfgAtt, IDD, and Lys6 are expressed at low level prior to the challenge, but strongly induced against Gram-positive and negative bacteria, and fungi. Under the same inducement conditions, the transcripts of these three genes elevated most when fifth instar larvae were injected. Therefore, O. furnacalis larvae are induced to produce antimicrobial materials in the hemolymph after the infection, and increase of lysozyme and attacin may contribute to the antimicrobial activity.
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, P. R. China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Zhang
authors.forename: Fan
authors.initials: F
authors.lastname: Zhou
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chu
authors.forename: Zhangwu
authors.initials: Z
authors.lastname: Zhao
authors.forename: Chunju
authors.initials: C
authors.lastname: An
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D052982:Beauveria; D004926:Escherichia coli; D006458:Hemolymph / Q000737:chemistry; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D007915:Lepidoptera / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D016982:Micrococcus luteus; D009113:Muramidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D059467:Transcriptome
chemical_list: D000890:Anti-Infective Agents; D019476:Insect Proteins; C039711:attacin antibacterial protein, insect; D009113:Muramidase
keywords: Attacin; Lysozyme; Ostrinia furnacalis Guenée; antimicrobial peptide