太阳花马基因流模式与适应性渗入特征分析OA

To systematically identify the gene flow patterns and adaptive introgression regions of Taiyanghua Horses during crossbreeding,an integrated analysis of population genetic structure,gene flow(f3-statistic,D-statistic,windowed D-statistic)and selection signatures(Fst,πratio,XP-CLR,iHS,XP-EHH)was performed based on genome-wide SNP data from whole-genome resequencing in Taiyanghua Horses(TYH,n=31),Mongolian Horses(MON,n=31)and Thoroughbred Horses(TB,n=32).The results showed that:1)The genetic differentiation(Fst=0.040 7)between TYH and TB was significantly lower than that between TYH and MON(Fst=0.068 5),and ADMIXTURE analysis revealed a mean Thoroughbred ancestry proportion of 76.5％.The D-statistic confirmed significant gene flow from TB to TYH(D=0.221 6,Z=29.1),with introgression signals dispersedly distributed across the whole genome.2)The introgression-selection co-localization integrated analysis identified 168 windows(covering 126 genes)in putative selected TB introgression regions,which were functionally enriched in immune regulation(IL-17 signaling pathway)and neural signaling pathways.3)It was estimated that 841 windows(covering 441 genes)were detected in putative selected regions with retained Mongolian horses ancestry,which were enriched in locomotor gait and neuromuscular function,including DMRT3,the key gene regulating equine gait.This study achieves the systematic integration of gene flow scanning and multi-method selection signature analysis in TYH,and reveals the coexisting molecular adaptive characteristics of Thoroughbred introgression and Mongolian horses ancestry retention during crossbreeding.