Somatic recombination in the common-AB diploid of Schizophyllum commune

Summary A recessive suppressor, su-1, of arg-2 was used to detect somatic recombination in common-AB diploids of S. commune. Recombinants were recovered from dense, fastgrowing sectors on arginine-deficient medium. The majority of spontaneous recombinants (129/154) recovered in this study were apparently haploid. Strains which scored as aneuploid and diploid were also recovered and analyzed. Genetic analysis of spontaneous recombinants indicated that crossing over is rare and that haploidization very likely proceeds via stages of aneuploidy. No increase in the frequency of crossing over was detected in recombinants derived following treatment with UV light. The preliminary results favor a parasexual mechanism of recombination in common-AB diploids.Journal Article No. 5126, Michigan Agricultural Experiment Station. This resarch was supported in part by Contract AT-(11-1) 1301 from the United States Atomic Energy Commission and Grant No. GB-13654 from the National Science Foundation.