Avian influenza (high pathogenicity) is a major concern
to the global poultry industry. Also, human health concerns
are mounting over the highly virulent H5N1 influenza
strain. To date, the H5N1 virus strain has not been detected
in the USA but much effort is devoted to being prepared.
The Mx gene exists in a wide variety of species, from yeast
to most animals. It has been documented that in chickens,
certain Mx alleles have more antiviral function, including
resistance to Influenza A. Additionally, commercial traits
such as egg and meat production, as well as immune
functions, have been reportedly linked to the Mx gene in
Genomic DNA containing the first four exons and upstream sequences of the interferon (IFN)-inducible chicken Mx gene was cloned and sequenced. The exon/intron structure of the chicken Mx gene resembles that of the mouse Mx1 gene: exon 1 is very small, the first intron contains a noncoding exon 1′ that is alternatively spliced in different chicken breeds and exon 2 harbors the ATG initiation codon. Exons 3 and 4 of the chicken and mouse Mx genes have identical lengths and the encoded polypeptides show a high degree of homology. Sequences upstream of the transcription start site functioned as an IFN-inducible promoter in chick and monkey cells when cloned in front of a promoterless luciferase reporter gene. Deletion analysis suggested that the sequence 5′AGTTTCGTTTCT3′ is of critical importance for inducibility. It conforms to the consensus sequence of the IFN stimulated response element (ISRE) present in Mx and other IFN-α/β-inducible promoters of mammals These results suggest that the ISRE motif has been conserved and that it regulates expression of IFN-inducible genes in both mammals and birds