Genetic diversity of exon 13 and Intron 9 in Zfat gene and its association with height traits in crossbred horses of Golestan province

In this research, the characteristics of the distance from the withers to the ground, the back to the ground, the head to the ground, and the tail to the ground in 100 thoroughbred horses in Golestan province, which were randomly selected, and the effect of the ZFAT gene polymorphism on diversity of these traits were evaluated. To prepare blood samples, 5 to 7 ml was taken from the jugular vein of horses. DNA extraction from blood samples was done through the optimized saline method. After extracting DNA and evaluating their quantitative and qualitative characteristics, two regions of exon 13, including a fragment of 476 bp and intron 9 of ZFAT gene with a length of 457 bp, were amplified by PCR. To determine the polymorphism of PCR products, PCR-RFLP and PCR-SSCP methods were used to study regions of the gene. After identification of the genotypes, statistical analysis was performed to check the relationship between the mentioned genotypes and biometric traits, and the statistical analysis was performed with the linear GLM procedure of SAS software. The results of the present study showed that the ZFAT gene was polymorph in the intronic region and based on the number and size of digestive fragments in this gene region, three genotypes CT, TT and CC were observed with frequencies of 0.81, 0.11 and 0.08 respectively. Also, the calculations showed that the frequencies of T and C alleles are 0.86 and 0.14, respectively. The results of vertical electrophoresis of SSCP products showed three different band patterns on polyacrylamide gel, which indicated the existence of polymorphism and genetic diversity in exon 13 of ZFAT gene in thoroughbred horses. In this research, it was found that the frequency of band patterns A, B and C was 0.53, 0.40 and 0.07 respectively in the studied animals. Despite the observation of polymorphism in the above two areas, no association was observed between the studied traits and the types of genotypes, and regardless of this issue, considering the reliable reports that show the significant role of this locus on the height traits of the horse, it is suggested in the future researches, along with other gene loci, association of this gene with economic traits, including body size should be studied.