STRUCTURE OF AN INTERFERON-ALPHA-2 GENE EXPRESSED IN THE BOVINE CONCEPTUS EARLY IN GESTATION

Genomic and cDNA clones for bovine trophoblast interferon (IFN) have been isolated by probing a bovine genomic library and a bovine embryonic (day-18 post coitus) cDNA library respectively with the ovine trophoblast IFN cDNA. The two DNA sequences were identical; sequence analysis demonstrated 80% identity between the amino acid sequence of bovine trophoblast IFN and ovine trophoblast IFN, and 70% identity with a previously identified bovine IFN-α2. Southern blotting of bovine genomic DNA indicated the presence of a minimum of three trophoblast IFN genes. Primer extension analysis identified the transcription start site in the 5' flanking region of the bovine IFN gene. Computer-aided analysis of the 5' flanking sequence demonstrated a similarity with that of bovine IFN-α2 and the existence of a possible viral induction sequence.