Balancing selection in Pattern Recognition Receptor signalling pathways is associated with gene function and...

Area of Science:

• Evolutionary genetics
• Immunology
• Genomics

Background:

• Pathogen-mediated balancing selection is crucial for maintaining genetic diversity in immune genes.
• Factors influencing selection targets within immune gene families remain largely unexplored.

Purpose of the Study:

• To investigate the influence of gene function and pleiotropy on balancing selection in Pattern Recognition Receptor (PRR) signaling pathways.
• To identify specific PRR gene types that are preferentially targeted by balancing selection.

Main Methods:

• Whole-genome resequencing data from bank voles (Myodes glareolus) were analyzed.
• 123 PRR signaling pathway genes were examined for associations between balancing selection, pleiotropy, and function.
• Comparisons were made between receptors for microbial ligands versus downstream signaling proteins, and receptors for cell wall/capsid components versus nucleic acid components.

Main Results:

• Balancing selection predominantly targeted PRR receptor genes with low pleiotropy.
• Receptors recognizing microbial cell wall components were stronger targets of balancing selection than those recognizing nucleic acids.
• Localized signatures of balancing selection were mainly found in introns and distributed across functional categories.

Conclusions:

• Balancing selection on immune genes, especially PRR receptors for microbial components, is significantly influenced by pleiotropy and gene function.
• Host-pathogen coevolution is a key driver of balancing selection and genetic diversity in innate immunity.