Transfer of genes and translocations from Neurospora crassa to N. tetrasperma. It is difficult to obtain progeny when N. crassa and N. tetrasperma are intercrossed directly.
Most ascospores are homokaryotic in the initial cross.
Homokaryotic progeny are obtained in successive generations by isolating small ascospores. A majority of ascospores are homokaryotic in crosses heterozygous for E . Small, homokaryotic ascospores can also be obtained as infrequent exceptions from crosses with wild type N. tetrasperma , where they occur even in the absence of E .