The restriction of the recombination of mitochondrial DNA molecules in the zygotes of Saccharomyces cerevisiae.

Crosses were made between strains carrying a nuclear control factor (NC) and strains classified with respect to their omega allele (omega+ or omega-). The characteristic asymmetrical transmission was always observed (as was seen) in crosses not involving the omega factor. The analysis of functional recombinants in a cross involving an NC factor has indicated that the absence of the omega effect may be caused by a restriction in the zygote of the recombination of mitochondrial DNA molecules.