内蒙古绒山羊KAP9.2基因遗传多态性及其与生长性状的关联分析

【目的】 探究内蒙古绒山羊KAP基因家族角蛋白相关蛋白9.2（KAP9.2）基因插入/缺失（insertion/deletion，InDel）突变及其与生长性状的关系，以期为内蒙古绒山羊分子育种提供理论基础。【方法】 选取606只雌性阿拉善型内蒙古绒山羊为研究对象，采集耳组织提取DNA并测定其体重及体高、体长和胸围等体尺数据，利用琼脂糖凝胶电泳方法与直接测序技术检测KAP9.2基因的InDel突变，检测遗传多样性指标，利用SPSS 23.0软件分析突变位点与生长性状的关联性。【结果】 在内蒙古绒山羊KAP9.2基因外显子区存在30 bp的InDel突变，产生II、ID和DD 3种基因型。多态信息含量（PIC）显示，该位点在育成羊群体中属于中度多态（0.25<PIC<0.50），在成年羊群体中属于低度多态（PIC<0.25），且均处于哈代-温伯格平衡状态（P>0.05）；在整个群体中，属于低度多态（PIC<0.25），但偏离哈代-温伯格平衡状态（P<0.05）。关联分析结果表明，在育成羊群体中，此30 bp的InDel突变对体长和十字部高有显著影响（P<0.05），对体高、胸深和胸宽有极显著影响（P<0.01）；在成年羊群体中，此突变对管围、胸深和胸宽有极显著影响（P<0.01）。进一步的分析发现，在育成羊和成年羊全部群体中，此突变对体长和十字部高有显著影响（P<0.05），对体高、胸深和胸宽有极显著影响（P<0.01）。【结论】 KAP9.2基因InDel突变对阿拉善型内蒙古绒山羊多个生长性状有显著或极显著影响，可作为内蒙古绒山羊优良性状选育的分子标记。

The Genetic Polymorphisms of KAP9.2 Gene and Its Correlation Analysis with Growth Traits of Inner Mongolia Cashmere Goats

【Objective】 The purpose of this study was to explore the relationship between insertion/deletion (InDels) mutation of KAP gene family keratin-associated protein 9.2 (KAP9.2) gene and growth traits of Inner Mongolia cashmere goat, in order to provide a theoretical basis for molecular breeding of goats.【Method】 A total of 606 female Inner Mongolia cashmere goats were selected as the research objects, the ear tissue was collected to extract DNA, and their body weight and body size, such as body height, length and chest circumference were measured.The InDel mutation of KAP9.2 gene was detected by agarose gel electrophoresis and direct sequencing technology, and genetic diversity indicators were detected.The association between mutation locus and growth traits was analyzed by SPSS 23.0 software.【Result】 There was a 30 bp InDelmutation in the exon region of the KAP9.2 gene in Inner Mongolia cashmere goats, which produced three genotypes of II, ID and DD.The polymorphism information content (PIC) showed that the locus was moderately polymorphic (0.25<PIC<0.50) in the breeding goat population, low polymorphism (PIC<0.25) in the adult goat population, and both were in Hardy-Weinberg equilibrium (P>0.05).In the whole population, the locus was low polymorphism (PIC<0.25), but deviated from Hardy-Weinberg equilibrium (P<0.05).The results of association analysis showed that in the breeding goat population, the 30 bp InDel mutation had significant effect on body length and height at hip cross (P<0.05), and had extremely significant effect on body height, chest depth and chest width (P<0.01).In the adult goat population, this mutation had extremely significant effect on cannon circumference, chest depth and chest width (P<0.01).Further analysis found that this mutation had significant effect on body length and height at hip cross (P<0.05), and had extremely significant effect on body height, chest depth and chest width (P<0.01) in the whole population.【Conclusion】 The InDel mutation of KAP9.2 gene had significant or extremely significant effect on many growth traits of Alashan-type Inner Mongolia cashmere goat, and could be used as a molecular marker for the breeding of excellent traits of Inner Mongolia cashmere goat.