The cattle major histocompatibility complex (MHC) class-I possesses HLA-like promoters.

To study the genetic regulation of the cattle major histocompatibility complex (MHC) class-I, a cattle MHC class-I promoter DNA fragment was isolated and characterized for the first time. Semi-degenerate PCR was performed on cattle genomic DNA and the resulting product was isolated, subcloned and sequenced. Sequence comparison of the HLA-A, -B and -C promoters to the cloned product, designated BL3-6prmtr, revealed the cattle MHC class-I promoter to have close homology to human MHC class-I promoters. To address the ability of the cattle MHC class-I promoter to initiate transcription, BL3-6prmtr was subcloned into a luciferase reporter vector and transiently transfected into cattle and human B-lymphoblastoid cell lines. A strong transcription initiation ability of BL3-6prmtr was observed, including the ability of the enhancer A and interferon response sequence (IRS) to upregulate transcription initiation.