马(Equus caballus)的性格行为直接决定其是否或如何被调教训练,蒙古马是受外血影响较小的自然品种,因此,蒙古马是研究马性格行为相关多态位点的最适合的品种。本研究旨在识别脑源性神经营养因子基因(brain derived neurotrophic factor, BDNF)、多巴胺-β-羟化酶基因(dopamine beta-hydroxylase, DBH)、5-羟色胺转运体基因(solute carrier family 6 member 4 gene, SLC6A4)和儿茶酚-O-甲基转移酶基因(catechol-O-methyltransferase, COMT)片段的多态性,并分析其与蒙古马性格行为的相关性。选用饲养环境和受调教均相同的60匹蒙古马,编号和颈静脉采血。以实地问卷调查的方法,对能反应马匹性格行为的28个表型性状,进行统计学描述。采用单链构象多态性检测(single strand conformational polymorphism, SSCP)和测序的方法,分析4个性格候选基因的多态性;并进行基因分型,分析其与蒙古马性格性状的相关性。结果表明,蒙古马BDNF基因的222 bp (C→T)和261 bp (G→C)位点均有一个突变,且与咬人行为显著相关;DBH基因的第758 bp处有一个(G→A)突变,与对其他马友好和忍耐力行为显著相关,且与理解力、过河、游泳和沙浴等行为相关极显著;SLC6A4基因的第1 362 bp处有一个(T→C)突变,与神经质、恐慌性、对马具的反应和胆怯性等行为相关,与独立性行为相关极显著;COMT基因的第217 bp处有一个(G→A)突变,显著影响蒙古马的竞争性行为。这些数据说明,BDNF、DBH、SLC6A4和COMT基因与蒙古马的性格行为性状相关,而且SLC6A4基因的多态位点在蒙古马以后的进化过程中会稳定遗传。本研究为建立蒙古马性格行为性状的分子标记辅助选择提供了理论依据。
The horse (Equus caballus) temperament traits directly determines whether or how it is trained. Mongolian horse is a natural species, mixes with fewer external genome, which makes it as the most suitable species for researching the association of the polymorphism of candidate genes with the phenotype of temperament traits. The aim of this study was to identify the polymorphisms of the solute carrier family 6 member 4 gene (SLC6A4), dopamine beta-hydroxylase gene (DBH), brain derived neurotrophic factor gene (BDNF) and catechol-O-methyltransferase gene(COMT) and provide insight into the association with the Mongolian horse temperament behavior. The research animals were consisted with 60 Mongolian horses, with the same breeding and training situation, which were numbered and collected peripheral blood, respectively. The 28 temperament behavioral characteristics were described with the questionnaire survey method. The SNP analysis for 4 candidate genes was performed using the single strand conformational polymorphism (SSCP) and gene sequencing. Further, the statistical analysis system (SAS) software was used to analyze the genotype and the association. For BDNF gene, the SNPs in 222 bp (C→T) and 261 bp (G→C) were identified, and the association analysis showed that the biting behavior was significant affected by BDNF genes as C222T and G261C. For DBH gene, the SNP was identified in 758 bp (G→A), and DBH gene (G758A) was significant associated with endurance and on other horse-friendly behavior, which also had remarkable influence on such behaviors as comprehension ability, crossing the river and swimming, sand bath et al. For SLC6A4 gene, the SNP was identified in 1 362 bp (T→C), and gene (T1362C) significantly affected the behavior such as nervousness, panic, the reaction to harness and timid, et al. SLC6A4 gene (T1362C) was remarkable associated with the independence acts else. For COMT gene, the SNP was identified in 217 bp (G→A) and COMT gene