[Mitochondrial marker recombination in yeasts. II. Crosses of isochromosomal and anisomitochondrial strains].

Mitochondrial markers of resistance to antibiotics erythromycin and neomycin were used to study mitochondrial recombination in Saccharomyces cerevisiae bifactorial crosses both in cis and trans configurations of markers. The following parameters of mitochondrial recombination have been examined: a) the asymmetrical transmission of parental classes, b) the frequency and the polarity of recombination and c) the effect of cell mating type on above listed parameters. The counting of results was carried out among random samples of zygotic diploid daughter colonies. The data obtained revealed the following features of mitochondrial recombination: 1. The origin of mitochondria controls all the parameters of mitochondrial recombination. 2. There are discovered two classes of mitochondrial crosses in relation to the polarity of recombination--a) a low polarity as "homosexual" (with types of mitochondria omega- X omega-) and b) a high polarity crosses as (heterosexual) (omega+ X omega+) 3. The linear arrangement of mitochondrial markers of the resistance to erythromycin and neomycin in relation to omega factor is suggested as omega-N-E. 4. The effect of cell mating type on the asymmetrical transmission of parental classes, frequency and polarity of recombination is established. 5. A new class of mitochondria is discovered that can transmit (or recombinate) with very high efficiency by ER-markers, but cannot transmit (or recombinate with) NR-markers.