Structures, regulatory regions, and inductive expression patterns of antimicrobial peptide genes in the silkworm Bombyx mori

Genomics. 2006 Mar;87(3):356-65. doi: 10.1016/j.ygeno.2005.11.018. Epub 2006 Jan 9.


Antimicrobial peptides (AMPs) are a group of immune proteins that protect the host from infection. In Drosophila, seven groups of inducible AMPs have been identified, with activities against fungi and gram-positive and gram-negative bacteria. On the basis of the silkworm genome sequence and expressed sequence tags, we identified 35 AMP genes, mostly belonging to the cecropin, moricin, and gloverin gene families. We predicted the core promoters required for gene transcription and the cis-regulatory elements for NF-kappaB/Rel and GATA transcription factors. The expression profiles of these genes after an immune challenge with lipopolysaccharide were examined by reverse transcription PCR. Members of the cecropin B and gloverin A subfamilies were intensely expressed in the fat body after induction. In contrast, those of the moricin B subfamily were not expressed under the same conditions. Such results suggest that these regulatory elements and their positions in the upstream regions play an important role in regulating the transcription of these defense genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antimicrobial Cationic Peptides / genetics*
  • Base Sequence
  • Binding Sites / genetics
  • Bombyx / drug effects
  • Bombyx / genetics*
  • Female
  • Gene Expression / drug effects
  • Gene Expression / genetics
  • Gene Expression Profiling*
  • Insect Proteins / genetics*
  • Intercellular Signaling Peptides and Proteins
  • Lipopolysaccharides / pharmacology
  • Male
  • Molecular Sequence Data
  • Phylogeny
  • Proteins / genetics
  • Regulatory Sequences, Nucleic Acid / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid


  • Antimicrobial Cationic Peptides
  • CecA2 protein, Bombyx mori
  • Insect Proteins
  • Intercellular Signaling Peptides and Proteins
  • Lipopolysaccharides
  • Proteins
  • gloverin
  • moricin protein, Bombyx mori