Figure 2.

The catalytically dead polα (D984N) mutant complements the swi7-1 imprinting defect. (A) Southern blot analysis. polαD984N mutant complements the imprinting defect of swi7-1, but not that of the swi1 or swi3 mutant, in donor-deleted strains. Indicated strains were transformed with vector, nmtpolα and nmtpolαD984N plasmids and growth media plates containing thiamine. Asterisk (*) indicates the cross hybridization with the high copy vector pREP3. (B) DNA was prepared from the donor deleted swi7-1 mutant strains transformed with vector, nmtpolα and nmtpolαD984N plasmids and grown on selective plates containing thiamine. DNA was prepared in plugs (B) and digested with HindIII and Southern blotted followed by hybridization with radio-labelled mat1M probe (7). DNA was prepared in plugs and Southern blotted, without (left panel) or with alkali treatment (right panel), followed by hybridization.