A comparison of vertebrate interferon gene families detected by hybridization with human interferon DNA

Cloned human interferon complementary DNAs were used as hybridization probes to detect interferon α and β gene families in restriction endonuclease digests of total genomic DNA isolated from a wide range of vertebrates and invertebrates. A complex interferon-α multigene family was detected in all mammals examined, whereas there was little or no cross-hybridization of human interferon-α complementary DNA to non-mammalian vertebrates or invertebrates. In contrast, human interferon- β complementary DNA detected one or two interferon- β genes in all mammals tested, with the exception of the cow and the blackbuck, both of which possessed a complex interferon- β multigene family which has presumably arisen by a recent series of gene duplications. Interferon- β sequences could also be detected in non-mammalian vertebrates ranging from birds to bony fish. Detailed restriction endonuclease mapping of DNA sequences neighbouring the interferon- β gene in a variety of primates indicated a strong evolutionary conservation of flanking sequences, particularly on the 3′ side of the gene.