Detection of MR1 splice variants. (a) Agarose gel showing bands representing different splice variants of MR1 detected via PCR on cDNA from bovine and ovine PBMC (upper panel) and a variety of ovine Theileria-infected cell-lines (lower panel): two B-cell lines (B), two monocyte lines (M), and three T-cell lines (T). (b) Structure of MR1 splice variants detected in bovine and ovine PBMC. The α2 region is preserved in all variants identified.