AdmixLD: fast genome-scale inference of ancestry disequilibrium in hybrid zones

Abstract

Abstract Summary Hybrid zones represent powerful natural systems for studying reproductive isolation and speciation. One key genomic signature of genetic incompatibilities and epistatic interactions is linkage disequilibrium (LD)—non-random associations between loci from different lineage backgrounds, generated by selection against maladaptive allele combinations. However, admixture alone induces strong genome-wide LD in hybrid populations, obscuring selection-driven signals. Here, we present AdmixLD, a fast, scalable C++ tool for genome-wide LD scanning in hybrid zones that estimates LD using partial correlation to control for individual hybrid index. By removing admixture-driven covariance, AdmixLD enhances detection of locus-specific associations and enables genome-scale identification of candidate barrier loci and interacting genomic regions. Availability The software and its code source are available at https://github.com/yzfranci/AdmixLD, and scripts for the data analysis are available at https://github.com/yzfranci/AdmixLDAnalysis.