Hybridization of Saccharomyces cerevisiae with Candida utilis through protoplast fusion.

Auxotrophic mutants of Saccharomyces cerevisiae and Candida utilis were hybridized through protoplast fusion. Spontaneous, UV- and FPA-induced mitotic segregation indicated that after cell fusion, exclusion of the S. cerevisiae nucleus or nuclear fusion followed by preferential loss of S. cerevisiae chromosomes can take place. Some of the hybrids were stable. One of them, expressed mating and sporulation functions of the S. cerevisiae parent. Thus, markers from both parents could be recovered as mitotic and meiotic segregants.