Molecular detection of selection across codon sites at the ELA-DRA and DQA.

Model comparisons and likelihood ratio tests (LRTs) were conducted to test for significant heterogeneity across sites (M3 v. M0) and positive selection (M1a v. M2a, M7 v. M8). Significance (p-value) of LRTs was determined by calculation of the chi-square test statistic (χ2) and degrees of freedom (df). Significant test results (pω) at each locus and population were estimated from M8 in PAML [100]. Estimates for the DQA locus are reported both excluding (DQA) and including (DQAALL) individuals with multi-locus genotypes.