Abstract
Human head and body lice are obligatory hematophagous ectoparasites that belong to a single species, Pediculus humanus. Only body lice, however, are vectors of the infectious Gram-negative bacterium Bartonella quintana. Because of their near identical genomes, yet differential vector competence, head and body lice provide a unique model system to study the gain or loss of vector competence. Using our in vitro louse-rearing system, we infected head and body lice with blood containing B. quintana in order to detect both differences in the proliferation of B. quintana and transcriptional differences of immune-related genes in the lice. B. quintana proliferated rapidly in body lice at 6 days post-infection, but plateaued in head lice at 4 days post-infection. RNAseq and quantitative real-time PCR validation analyses determined gene expression differences. Eight immunoresponse genes were observed to be significantly different with many associated with the Toll pathway: Fibrinogen-like protein, Spaetzle, Defensin 1, Serpin, Scavenger receptor A and Apolipoporhrin 2. Our findings support the hypothesis that body lice, unlike head lice, fight infection from B. quintana only at the later stages of its proliferation.
Original language | English (US) |
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Pages (from-to) | 244-254 |
Number of pages | 11 |
Journal | Insect Molecular Biology |
Volume | 23 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2014 |
Keywords
- Pediculus humanus capitis
- Pediculus humanus humanus
- disease vector
- ectoparasite
- insect
- trench fever
ASJC Scopus subject areas
- Molecular Biology
- Genetics
- Insect Science