Recombinational analysis of mutations at an incompatibility locus of Schizophyllum

Strains of Schizophyllum commune carrying mutations at the Bβ incompatibility locus were crossed to wildtype strains to determine the recombinational spectra of the mutations. The results indicate a correlation between recombining ability and mating behavior which can be explained if some of the mutations are associated with deletions. The failure to recover recombinants in crosses between these mutations and certain natural Bα alleles supports the hypothesis that naturally occurring incompatibility alleles arose by deletion.