Gene conversion and associated reciprocal recombination are separable events in vegetative cells of Saccharomyces cerevisiae.

Mitotic gene conversion occurs in both the G1 and G2 phases of cell growth. We postulate that the DNA strand or strands that connect the duplexes in G1 as a consequence of strand transfer are cleaved by an endonuclease. When this takes place in G1, crossing-over occurs in G2 at a frequency that is higher than would be expected from independent events. Conversion and associated reciprocal recombination are therefore separable with respect to the stage in the cell cycle when each occurs and possibly with respect to mechanism.