Mm, a new factor in the porcine M blood group system

By means of a new antiserum, Mm, the Mae phenotype can be shown to be controlled by the Maem allele, the Mef phenotype by either the original Mef or a new Mefm allele, and the Mbe(f) phenotype by the Mbe(f)m allele. The complexity of the porcine M system is now extended to 13 internationally recognized blood group factors controlled by at least 19 alleles.