Jun 1, 2018

Signatures of balancing selection in toll-like receptor (TLRs) genes - novel insights from a free-living rodent

Scientific Reports
Agnieszka KlochS B Piertney


Selective pressure from pathogens is considered a key selective force driving the evolution of components of the immune system. Since single components of the immune system may interact with many pathogens, and single pathogens may be recognized by multiple components of the immune system, gaining a better understanding of the mechanisms of parasite-driven selection requires the study of multiple genes and pathogens. Toll-like receptors (TLRs) are a large gene family that code for antigen-presenting components of the innate immune response. In the present paper we characterize polymorphism and signatures of selection in seven TLRs in free-living bank voles Myodes glareolus. We report the first evidence of balancing selection in several TLR genes, supported by positive values of Fu and Li's D* in TLR2 and TLR5, and positive values of Tajima's D in LRR regions within TLR1 and TLR2. We further found significant associations between amino-acid alleles of TLR1 and TLR5 and susceptibility to infection with the blood pathogen Bartonella. Interestingly, selection patterns in TLRs presenting virus-derived motifs (TLR7 and TLR9) differed considerably from those interacting with bacterial PAMPs. In contrast to the highly variable TLRs pre...Continue Reading

Mentioned in this Paper

Gene Polymorphism
Immune Response
Immune System
TLR7 protein, human
Pathogenic Organism

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Bartonellosis is an infection caused by bacteria in the genus Bartonella and can present as a variety of diseases depending on the organism involved. While asymptomatic infection has been reported, immunocompromised individuals are more susceptible to severe infection. Find the latest research on bartonellosis here.