[Objective] The study aimed to establish a fast and accurate method to detect the polymorphism of the 12^th exon of equine MxA gene. [Method] The 12^th 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 12^th exon of equine MxA gene; the 2 081 nt of MxA cDNA mutated from G to C, correspondingly changing the 562^th 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 12^th exon of equine MxA gene.
[Objective] To investigate the polymorphism of the thirteenth exon of MxA gene in 4 species of horse. [Method] The thirteenth exon of MxA gene fragments were amplified from genomic DNA of Sanhe horse, Xinihe horse, Wushen horse and Baerhu horse with the primers designed according to the MxA sequence announced in GenBank; the polymorphism of MxA gene was detected by PCR-SSCP and the products were sequenced. [Result] The polymorphism of the thirteenth exon of MxA gene appeared only in Wushen horse, the 2 081 nt of which mutated from guanine (G) to adenine (A) and the corresponding amino acid of which changed from glutamate (Glu) to alanine (Ala). [Conclusion] The study provided a basis for exploring the antiviral effect of MxA protein.
