Whole genome sequencing of 76 Mexican Indigenous reveals recent selection signatures linked to pathogens and diet adaptation.

Whole genome scans for natural selection signatures across Mexican Indigenous (MI) Populations remain underrepresented in the literature. Here, we conducted the first comparative analysis of genetic adaptation in MI populations using whole genome sequencing (WGS) data from 76 individuals representing 27 different ethnic groups in Mexico. We divided the cohort into Northern, Central, and Southern populations and identified signals of natural selection within and across populations. We find evidence of adaptation to pathogenic environments in all our populations, including significant signatures in the Duffy blood group gene in Central MI populations. Despite each region exhibiting unique local adaptation profiles, selection signatures on ARHGAP15, VGLL4, LINGO2, SYNDIG1, and TFAP2B were common to all populations. Our results also suggest that selection signatures falling within enhancers or promoters are usually connected to non-coding features, with notable exceptions like ARHGAP15 and GTDC1. This paper provides new evidence on the selection landscape of Mexican Indigenous Populations and lays the foundation for additional work on Mexican phenotypic characterization. Significance statementPrevious research has identified distinct patterns of genomic adaptation across the different regions of Mexico, highlighting evidence of natural selection within metabolic and immune-related genes. However, the characterization of the Mexican selection landscape from a whole-genome perspective remains unexplored. Here, we conducted the first whole-genome scan for natural selection in 76 Mexican Indigenous individuals from 27 different ethnic groups divided into Northern, Central, and Southern populations. Our findings revealed distinct local adaptation profiles for each Mexican region, with different evidence of adaptation to pathogenic environments across these groups. In contrast, all populations had common selection signatures on ARHGAP15, VGLL4, LINGO2, SYNDIG1, and TFAP2B. This paper provides new evidence on the genetic basis of adaptation of Indigenous groups in Mexico. Moreover, it provides a foundation for additional work on Mexican phenotypic characterization.