Modifications of the high reversion frequency in the nic-2 mutant of Coprinus radiatus. 1. Evidence for the existence of three strain types with more or less elevated reversion frequencies

Summary In Coprinus radiatus, a cross homozygous for nic-2 mutation yields two types of nic-strains. The first one (nic-2F) retains the character of the original mutant, reverting at meiosis with a frequency of 20 to 30%. All crosses with the second type (nic-2 fa) show a sharply reduced reversion rate.The analysis of the progeny of crosses involving a nic-2 fa strain show the appearance of a third type of strains (nic-2 fn). The reversion of nic-2 fn strain is low, but this character is not imposed to the partner in a cross with a nic-2F strain.