Temperature-sensitive mutants ofCoprinus cinereus defective in hyphal growth and stipe elongation

Temperature-sensitive variants defective in hyphal growth of the basidiomyceteCoprinus cinereus were isolated from oidia treated by UV orN-methyl-N-nitro-N-nitrosoguanidine. In 23 out of 27 variant strains isolated, the temperature-sensitive variation was shown to be due to recessive single-gene mutation. All of the 23 mutants exhibited apparent interallelic complementation with one another, with the exception of one pair. The mutants were mated with their respective progeny to construct temperature-sensitive dikaryons carrying the mutant genes homozygously. Fruiting test of the respective dikaryons showed that eight mutations reduce stipe elongation during basidiocarp maturation at a restrictive temperature (37°C).