[Mutagenesis modified of Mx gene from chicken and identification of its antiviral specificity]

To study whether the antiviral specificity of chicken Mx protein is determined by an amino acid substitution at position 631.

We used PCR site-directed mutagenesis technique by which a single amino acid was reciprocally substituted G with A at position 2032bp of chicken Mx cDNA. Sequence analysis confirmed successful mutation from G to A at 2032bp of chicken Mx cDNA. The fragments amplified by PCR containing the mutation site were subcloned into a enteukaryotic expression vector. Then the recombinant vector was transfected into COS-I cell, Mx gene and Mx protein in the transfected COS-I cell were detected by RT-PCR and indirect fluorescence assay.

The results showed that COS- I cell transfected the recombinant plasmid could stably express the Mx protein. The antivirus assay showed that Mx protein had characteristics of resistance to infection of Newcastle Disease Virus.

This study may provide a basis of the virus-resistant mechanism of Mx protein and production of virus-resistant transgenic chicken.