POLYMORPHISM IN EXON 14 OF ANTIVIRAL RESISTANT MX GENE IN VIETNAMESE INDIGENOUS CHICKEN BREEDS

The study was conducted to analyze the nucleotide polymorphisms of exon 14, Mx gene of seven Vietnamese indigenous chicken breedsL viz. Ac, Dong Tao, H’mong, Ho, Mia, Mong and Ri. The results revealed that the polymorphisms of exon 14 occured at two sites (2032 th and 2159 th ). The non-synonymous substitution A/G at nucleotide 2032 th of Mx gene was found in all of seven indigenous breeds used in this study. In the same breed, both of alleles A and G were present, however, allele A (viral resistance) was at a higher frequency than allele G (viral susceptiblity). Particularly, the allele A frequency of Ri and H’mong was highest among 7 breeds examined (80.91% and 74.04%, respectively). Comparative analysis of the deduced amino acids showed that 2032 A/G polymorphism altered amino acid substitution at site 631 of Mx protein of Asparagine (related to viral resistance) by Serine (lack of potent for viral resistance).