The method of obtaining the bovine γ-interferon gene by means of simultaneous multidirected mutagenesis of the human γ-interferon gene is presented. The first strand of the bovine γ-interferon gene was obtained by ligation of synthetic oligonucleotides, using the cDNA of human γ-interferon, cloned in the single-stranded phage M13mpl9 as a template. The second strand was synthesized using a large fragment of E. coli DNA-polymerase 1. The double-stranded gene was then treated by restriction nucleases and cloned in a pUC- 18 derived vector. The primary structure was confirmed by sequencing. © 1989.