马MxA基因第12外显子多态性检测

MxA蛋白是Ⅰ型干扰素（IFNα／β）所诱导产生的蛋白之一，属于大分子（70～80kD）GTP酶，能抵抗各种RNA病毒和部分DNA病毒。MxA蛋白结构与其抗病毒活性有直接的关系。有报道表明，MxA蛋白活性部位的一个氨基酸序列的变换，会导致其抗病毒活性的改变。MxA基因多态性分析是研究马MxA蛋白基因抗病毒作用和寻找马MxA蛋白抗性基因的基础。

Polymorphism Detection of the Twelfth Exon of Equine MxA Gene

Objective] The study aimed to establish a fast and accurate method to detect the polymorphism of the 12th exon of equine MxA gene. Method] The 12th exon of MxA gene was amplified by mismatch PCR and the products were analyzed by restriction fragment length polymorphism (RFLP) to determine the point mutation at the 1 790 nt of MxA cDNA. The sequence of the PCR products was also analyzed. Result] There were three genotypes (AA, AB and BB) in the 12th exon of equine MxA gene; the 2 081 nt of MxA cDNA mutated from G to C, correspondingly changing the 562th amino acid of the coding region of MxA protein from tryptophan to cysteine; the specific sequence of the PCR products amplified by mismatch PCR-RFLP was consistent with the analysis results of RFLP. Conclusion] The mismatch PCR-RFLP was an easy method with accurate results to detect the polymorphism of the 12th exon of equine MxA gene.