Recent completion of the V. volvacea whole genome project (Baoet al., 2013) has greatly increased our understanding of the mating type system operative in this mushroom. V. volvacea strains V23-1 and V23-18 have the compatible bipolar mating type alleles A1 and A2, respectively, Each of these consists of a pair of mating type genes, HD1 and HD2 (Bao et al., 2013), demonstrating the possibility of mating between homokaryotic hyphae