Defensins are important antimicrobial peptides found in numerous vertebrate and invertebrate species. This study addresses the question of the secretion and transcriptional kinetics of defensin in tick hemolymph following challenge with the Lyme disease spirochete Borrelia burgdorferi. SDS-PAGE of cell-free plasma from ticks inoculated along a time line shows that defensin appears to fluctuate with peak intensity at 18 hours post-inoculation. The discovery of abundant defensin in hemocyte lysates from unstimulated ticks suggests its storage in secretory vesicles. A time line study suggests defensin transcription takes place either constitutively at low levels or with high activity between 6 and 18 hours post-infection. Identifying the actual time and site of transcription by protein and molecular methods will facilitate the characterization of this important gene and the conditions that stimulate induction of defensin biosynthesis.
Species 1: Parasitiformes Ixodidae Dermacentor variabilis (American dog tick)
Keywords: defensin, hemocytes
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