Genome-Wide Analysis Identifies Heat Stress Resistance Selection Signatures in Pakistani Indigenous Chickens

The chicken genome has evolved under natural and artificial selection for thousands of years, resulting in substantial genetic diversity among populations worldwide. This diversity allows the investigation of ge-nomic regions under selection and provides valuable insights into mechanisms of adaptation. In this study, we analyzed genomic data using various statistical approaches including fixation index (Fst), nucleotide diversity (π), and Tajima’s D were applied to identify selective signatures in indigenous chickens from Pakistan in comparison to White Leghorn chickens. We identified, 34 candidate genes associated with heat tolerance were identified, including well known stress related genes such as HSF3, HSF4, and RPTOR. These genes were significantly enriched in gene ontology (GO) terms related to stress response, protein folding, and cellular homeostasis .These findings highlight the important role of selection in shaping ge-nomic differentiation among chicken populations and provide a deeper understanding of the genetic basis of adaptation to environmental stress.