Deletion of the S. bayanus HMR-E resulted in loss of silencing.

Mating test of MATα strains to MATa tester strain (JRY2726). Disruption of silencing changed the mating type of the MATa strains to nonmating phenotype of a/α diploid. Two independently constructed S. bayanus hmr-e deletion strains (JRY8785, JRY8786) lost silencing to the same extent as the S. bayanus sir2Δ strain. The parental HMR-E strains (JRY8781, JRY8782) mated as efficiently as the S. cerevisiae control (JRY2728).