种公鸡精液抗冻性状的全基因组关联分析OA

Based on genome-wide association study(GWAS)technology,this research aimed to identify single nucleotide polymorphisms(SNPs)and candidate genes associated with semen cryotolerance traits in roosters,in order to provide reference information for molecular breeding aimed at improving semen cryotolerance of roosters.A total of 215 healthy 65-week-old White Leghorn breeding roosters were selected as the experimental population.Fresh semen and frozen-thawed semen samples were collected,and freeze-tolerance indexes including variations in sperm motility,sperm viability and sperm abnormality rate were determined and calculated,with 3 biological replicates.Heritability was estimated using DMUAI software.Genomic DNA was extracted from wing vein blood samples,and genotyping was performed using the chicken 55K SNP array.After quality control with Plink v1.9 software,GWAS was conducted using the BLINK model embedded in GAPIT,and genetic effect analysis was carried out for SNP-linked candidate genes.The variation values of sperm motility and sperm viability presented low heritability ranging from 0.070 to 0.154,while the variation of sperm abnormality rate showed moderate heritability of 0.397.A total of 7 significant SNP loci were identified by GWAS.Three significant SNPs(chr6:31460756,chr24:4865901,chr24:5049139)associated with sperm viability variation were annotated to 3 candidate genes,namely CADM1,APOC3 and APOA1.Four significant SNPs(chr6:4901210,chr6:4902911,chr7:15775500,chr7:26741761)related to sperm abnormality rate variation corresponded to 4 candidate genes including DYDC2,MTX2,ADCY5 and MYLK.This GWAS on semen cryotolerance in White Leghorn roosters identified 7 key candidate genes,including APOA1,MTX2,and APOC3.The results provide valuable information for marker-assisted selection breeding aimed at improving semen cryotolerance in roosters.