Revealing The Genetic Basis Of Heterosis In F1 Hybrids Between Small-ear Spotted And Duroc Through Additive And Dominance Models

To explore the potential genes associated with growth traits in the hybrid F1 generation of Duroc(♂)and Small-Ear Spotted Pig(♀),and unravel the molecular genetic basis of hybrid vigor,this study employed SNPs chip data of the F1 generation for analysis in order to identify associated genes and elucidate the molecular genetic basis of hybrid vigor in the hybrid F1 generation.Initially,whole-genome association analyses were performed for the additive and dominance genetic components using qualitycontrolled SNPs data and growth trait data,including four original phenotypes,two adjusted phenotypes,and twelve novel phenotypes-breeding values.Considering the limited sample size of the F1 population,which may result in many significant signals falling below the significance threshold of traditional models,this study employed a chromosome-wise threshold of 1E-6 to search for significant signals within each chromosome.To enhance the reliability of the significant loci identified by the wholegenome association analysis,permutation tests were conducted to assess the significance of the identified loci,with 10,000 permutations and a significance level of 0.01.Subsequently,the genes associated with the significant loci identified through permutation tests were annotated,and the growth-related tissues associated with the expression of these genes were determined.Finally,the identified genes were compared with relevant published literature to further validate their functional relevance.The results of this study are as follows:1.By analyzing the genomic data of the hybrid F1 generation using different genetic components and phenotypes,this study systematically revealed the genomic architecture of hybrid vigor.The significant loci were further screened and confirmed by permutation test.2.This study grouped the F1 generation based on parental information and calculated the hybrid vigor of six paternal lineages using the information from both maternal and offspring populations.The F1 generation exhibited the manifestation of hybrid vigor.Additionally,the expression of the genes MAP7D1,FHL3,and CDH13,among others,which were found also in the final analysis,was shown to be associated with the development of muscle and fat,providing initial evidence for the molecular genetic basis of hybrid vigor in the offspring of Duroc(♂)and Small-Ear Spotted Pig(♀).To sum up,this research contributes to a better understanding of the mechanisms underlying hybrid vigor at the genomic level.The findings provide valuable insights and references for the development and utilization of hybrid vigor.