Adaptive diversity of innate immune receptor family short pentraxins in Murinae

The short pentraxins C-reactive protein (CRP) and serum amyloid P component (SAP) constitute a group of innate immune receptors that trigger immune activation by detecting molecules of the microbial cell wall. Here, we examined the evolution of short pentraxins in Murinae lineages. By molecular evolutionary analysis, CRP and SAP have been experiencing rapid diversification, driven by adaptive selection. Further, our protein modeling demonstrates that adaptively selected amino acids lie in the ligand-binding region and contact region between subunits. Our findings suggest that rapid diversification of these regions could contribute to the determinants of recognizing specificity and the interaction between subunits.

► The evolutionary patterns of short pentraxins among rat, mouse, and eight other Murinae species and within five species were analyzed.
► Adaptive selection leads to rapid diversification of short pentraxins in Murinae lineages.
► The adaptively selected amino acids lie in the ligand-binding region and contact region between subunits.