Adaptive Evolution as a Predictor of Species-Specific Innate Immune Response

Area of Science:

• Evolutionary biology
• Genomics
• Immunology

Background:

• Positive selection is linked to protein functional changes, influencing species-specific traits like HIV response.
• Understanding the genotype-phenotype correlation requires large-scale studies to identify evolutionary patterns.
• Innate immune genes are crucial for host defense and are subject to evolutionary pressures.

Purpose of the Study:

• To investigate species-specific positive selection in human and mouse innate immune genes.
• To identify genes under positive selection and their functional clustering.
• To correlate evolutionary selection with functional and phenotypic outcomes.

Main Methods:

• Analyzed 456 innate immune genes using codon-based models of evolution across human, mouse, and 19 other vertebrate species.
• Utilized population genomic data from Neanderthal, 1000 Genomes, and 17 mouse genome projects.
• Examined fixation or variability of positively selected residues in human and mouse populations.

Main Results:

• Found evidence of species-specific positive selection on both human and mouse evolutionary branches.
• Identified that genes under positive selection cluster by function and interaction pathways.
• Determined whether positively selected residues are fixed or variable in human and mouse populations.

Conclusions:

• Species-specific positive selection acts on innate immune genes in both humans and mice.
• Functional clustering of selected genes provides targets for studying selection's role in protein function.
• This research aids in understanding the relationship between positive selection and discordant phenotypes.