焉耆马ACTN3基因多态性及其与耐力赛速度的关联性分析

Polymorphism of Equine ACTN3 Gene and its Association with Endurance Speed in Yanqi Horse

为探讨焉耆马ACTN3基因多态性与耐力赛速度的相关性,本研究通过直接测序法对35匹焉耆马ACTN3基因第1、15、20和21外显子进行多态性检测,并进行81 km耐力赛测试参赛马匹耐力赛速度,对各突变位点基因型与耐力赛各赛段及全程速度进行关联性分析。结果显示:参赛马匹中共检测出8个突变位点,其中2个外显子突变(C11304T和A11517G),且均为同义突变;除G9773A外其余各突变位点均为中度多态位点;2个外显子突变共有4种单倍型,其中TA为主要单倍型。G9773A突变位点AA基因型第三赛段速度显著快于AG基因型;G9789A突变位点AG基因型第一赛段速度显著低于AA基因型,第三赛段速度显著低于GG基因型;A9803G突变位点AG基因型第二赛段和全程速度均显著快于AA基因型;C11304T突变位点CC基因型第一赛段和第二赛段速度均极显著快于TT基因型,其全程速度显著快于TT基因型;A11517G突变位点AA基因型第一赛段、第二赛段及全程速度均极显著快于GG基因型,第三赛段速度显著快于GG基因型。CG/CA和CA/CA单倍型组合马匹的第一赛段、第二赛段速度及全程速度均极显著快于TG/TG单倍型组合。本研究表明,ACTN3基因为影响焉耆马耐力赛速度的重要候选基因之一,在今后耐力赛焉耆马的选育中可将C11304T和A11517G基因型作为其分子辅助标记,同时,初步确定这2个位点的优选组合为CG/CA和CA/CA基因型。

The aim of the study was to determine the ACTN3 gene polymorphisms and its association with endurance speed in Yanqi horse.The ACTN3 genes polymorphism of the exons 1,15,20 and 21 of 35 Yanqi horses was detected by sequencing.The 81 km endurance race was used to test the endurance speed of the racehorses,and the association analysis between genotype of each mutation site and the speed in three stages and whole course of endurance race was performed.The results showed that 8 mutation sites were detected in the racehorses of this study,2 of which were exon mutations(C11304T and A11517G),all of which were synonymous mutations;except for G9773A,all the mutation sites were moderately polymorphic sites;there were 4 haplotypes in 2 exons mutations,of which TA was the major haplotype.For the G9773A mutation site,the third stage speed of the AA genotype was significantly faster than AG genotype(P<0.05);for the G9789A mutation site,the first stage speed of the AG genotype was significantly lower than AA genotype(P<0.05),the speed of the third stage was significantly lower than that of the GG genotype(P<0.05);for the A9803G mutation site,the second stage and the whole course speed of the AG genotype were significantly faster than AA genotype(P<0.05);for C11304T mutation site,the first stage and the second stage speed of CC genotype were both extremely significantly faster than the TT genotype(P<0.01),and the whole course speed of CC genotype was significantly faster than the TT genotype(P<0.05);for the A11517G mutation site,the first stage,the second stage and the whole course speed of the AA genotype were significantly faster than the GG genotype(P<0.01),and the third stage speed of AA genotype was significantly faster than the GG genotype(P<0.05).The first stage,the second stage the whole course speed of the CG/CA and CA/CA haplotype combinations were significantly faster than the TG/TG haplotype combination(P<0.01).In summary,the equine ACTN3 gene is one of the candidate genes affecting the endurance speed of the Yanqi horses.The C11304T and A11517G genotypes can be used as maker-assisted selection in the future breeding of Yanqi endurance racehorse,at the same time,the preferred haplotype of these two sites can be initially determined to be CG/CA and CA/CA genotypes.