Cloning and characterization of a male-specific defensin-like antimicrobial peptide from the tick Haemaphysalis longicornis

Dev Comp Immunol. 2012 May;37(1):207-11. doi: 10.1016/j.dci.2011.10.004. Epub 2011 Oct 19.

Abstract

A novel gene was identified from a cDNA library of the male accessory glands of Haemaphysalis longicornis. The full-length cDNA of the gene was 349bp, encoding a 79-amino acid defensin-like protein and therefore the protein was named HlMS-defensin. Reverse transcriptase-PCR results suggested that this gene was expressed exclusively in male ticks. The tissue expression pattern and the mRNA levels of HlMS-defensin during blood feeding were determined using real-time PCR. HlMS-defensin was expressed predominately in the male accessory gland and was up-regulated during blood feeding. The antimicrobial activity of a synthetic peptide based on the predicted mature portion of HlMS-defensin was examined against a variety of Gram-positive and Gram-negative bacteria and fungi. It appears that ticks use the antimicrobial peptide to protect their reproductive tracts from microbial infections. The protective role of HlMS-defensin during mating was also discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Anti-Infective Agents / pharmacology
  • Base Sequence
  • Cloning, Molecular
  • Defensins / genetics*
  • Defensins / pharmacology
  • Gene Expression Regulation
  • Genitalia / metabolism
  • Insect Proteins / genetics*
  • Insect Proteins / pharmacology
  • Ixodidae / genetics*
  • Male
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Rabbits
  • Reproduction
  • Sex Characteristics
  • Transcription, Genetic

Substances

  • Anti-Infective Agents
  • Defensins
  • Insect Proteins