Data from: Signatures of selection acting on the innate immunity gene Toll-like receptor 2 (TLR2) during the evolutionary history of rodents

Patterns of selection acting on immune defence genes have recently been
the focus of considerable interest. Yet, when it comes to vertebrates,
studies have mainly focused on the acquired branch of the immune system.
Consequently, the direction and strength of selection acting on genes of
the vertebrate innate immune defence remain poorly understood. Here, we
present a molecular analysis of selection on an important receptor of the
innate immune system of vertebrates, the Toll-like receptor 2 (TLR2),
across 17 rodent species. Although purifying selection was the prevalent
evolutionary force acting on most parts of the rodent TLR2, we found that
codons in close proximity to pathogen-binding and TLR2–TLR1
heterodimerization sites have been subject to positive selection. This
indicates that parasite-mediated selection is not restricted to acquired
immune system genes like the major histocompatibility complex, but also
affects innate defence genes. To obtain a comprehensive understanding of
evolutionary processes in host–parasite systems, both innate and acquired
immunity thus need to be considered.