Using a human interferon-α probe we have isolated recombinant phages containing murine interferon-alpha (Mu IFN-α) genes from a genomic library. One of these phages contained two complete Mu IFN-α genes and part of a third gene. The insert of a second phage held two IFN genes. This indicates that the Mu IFN-α genes are clustered in the genome as is the case for the analogous human genes. The nucleotide sequences of these 5 genes were determined. They show that the genes are all different, albeit highly homologous. The deduced amino acid sequences show that four of the five genes contain a putative glycosylation site. Three genes were transiently expressed in COS cells and they gave rise to protein products showing ant iviral properties.

The expression of the five Mu IFN-α genes and the Mu IFN-β gene was studied in virus-induced mouse L cells. The individual mRNAs were visualized in a nuclease S1 experiment, using a specific probe for each gene. In RNA preparations from induced cells mRNAs for each of the five a genes and the 13 gene were present. However, substantial differences in the amounts of the individual mRNAs were observed.