| This paper aims to explore the correlation between body size and body weight of adult horses of Jilin horses of different sexes,and the polymorphisms of high mobility group AT-hook 2(HMGA2)gene and growth hormone(GH)gene and their influence on the body size traits of Jilin horses,to screen out the molecular markers that can be used for the body height of Jilin horses,so as to provide a basis for directional selection of excellent traits in Jilin horses.In this experiment,95 healthy Jilin horses were selected as study object,including 64 adult mares and 31 adult stallions.The data of body height,body length,chest circumference and tube circumference,and body weight were measured and statistically analyzed in Jilin horse adult horses.In addition,DNA extraction,PCR amplification and gene sequencing were performed to screen the SNPs of candidate genes.At the same time,SPSS27.0 software was used to analyze the association between different genotypes of mutation sites and body size traits of Jilin horses,including body height,body length,chest circumference and tube circumference.The results were showed as follow:(1)There were significant differences in body size and weight between different sexes of adult horse breeds of Jilin horses.There were significant or extremely significant positive correlations between body weight and chest circumference,body height and body length of Jilin horses of different genders(P<0.05,P<0.01).Significant correlations were found between body height and body length,chest circumference,and body weight in adult females and males of Jilin horses.(2)One SNP(at the sixth exon C1533T)was detected in the exon of HMGA2 gene in Jilin horses,which was significantly associated with body height,body length,chest circumference and body weight in 64 adult mares.There was an InDel insertion mutation in the second intron of GH gene in Jilin horses,and the insertion length of 7bp was significantly associated with the four characters of body height,body length,chest circumference and body weight in 64 adult mares.The analysis of population genetic parameters showed that the heterozygosity of the sixth exon C1533 T mutation site of HMGA2 gene was high,indicating that alleles were distributed evenly in the population.A high number of effective alleles indicated a high degree of variation within the population.All polymorphic information contents were greater than 0.25,indicating moderate polymorphism,indicating that the loci could provide certain genetic information.Chi-square test showed that the mutation site of the sixth exon C1533 T of HMGA2 gene was not significant,which was consistent with HardyWeinberg equilibrium.The InDel site of the second intron of GH gene is significant,which accords with the Hardy-Weinberg balance.The results of this study showed that the variant site of the sixth exon C1533 T of HMGA2 gene and the InDel site of the second intron of GH gene had significant effects on the equine body ruler traits,which were important SNP sites affecting the horse body size trait in Jilin horses.The results of this study provide a reference for screening molecular markers that contribute to the height of Jilin horse body. |
