ACTN3/ EXON-19 GENE POLYMORPHISM AND ASSOCIATION WITH THOROUGHBRED HORSES PERFORMANCE IN IRAQ

Abstract

The research was conducted in the Iraqi Equestrian Club (15 km west of Baghdad city center) for the period from 10/1/2021 to 11/30/2022, with the aim of revealing the ACTN3 gene/ EXON-19 region polymorphism and its relationship to the performance of Thoroughbred horses. British in Iraq. It was found that there are 3 variants (3 SNPs) in the ACTN3 gene with respect to exon 19 and in different sites , which are rs1143578253, their polymorphism are TT, TA, and AA and their distribution ratios were 15.38, 56.41 and 28.21%, and that the non-significant difference, and the frequency of the allele was 0.44 and 0.56 for the two alleles C and T, respectively, and the heterogeneity rs1141508235. It appeared that there were two genotypes of the studied piece in the ACTN3/ EXON19 gene in the thoroughbred horses, CC and CT genotype, with the absence of the TT structure, and the highly significant differences (P≤0.01) between the distribution ratios of the combinations in the British thoroughbred, as the two ratios were 87.18 and 12.82% for the two genotypes CC and TC, and the allelic frequencies for the C and T alleles were 0.94 and 0.06, respectively. The distribution percentages of ACTN3/EXON19 gene polymorphism at position rs1146645613/SNP for the horse sample in this study had high significant differences (P≤0.01) between the genotype's distribution percentages in the British thoroughbred, and the percentages were 87.18 and 12.82% for the two genotypes TT and TC, and the mutant structure did not appear. CC and the frequencies for the T and C alleles were 0.94 and 0.06, respectively. There was a significant variation (P≤0.05) in the depth of respiration after exercise according to the different polymorphism of the rs1143578253 hetero, and the highest rate was for the TT combination (84.80 ± 5.13 seconds) as well as the number of respiration times after exercise, but for the hybrid genotype TA (59.16 ± 1.81 times/min), there was There was a highly significant variation (P≤0.01) in the rate of speed according to the genotype of the thoroughbred horses, and the highest rate of speed was for horses with the mutant genotype AA and the lowest for their counterparts with the wild genotype TT. It is concluded from the study that the ACTN3 gene has a distinct role in some of the traits studied on British terrier horses in Iraq, especially the number and depth of respiration after exercise, rate of speed, and some body measurements, specifically body length, chest circumference, and frontal height, as it varied significantly with the difference in the polymorphism of some variations.