ABSTRACT

The B incompatibility factor of the fungus Schizophyllum commune having allelic specificity α2–β6 was subjected to mutagenesis by X-irradiation. Five types of mutations were recovered, four of them new types previously unreported. All lead to loss of the B-factor regulatory function; three of the five have retained their allelic specificity. The mutations map in three closely linked sites: Bα, Bβ, and between Bα and Bβ.