Interaction between analogue resistance and amino acid auxotrophy in Neurospora

A new p-fluorophenylalanine resistant mutant of Neurospora (fpr-1) was isolated. It is unaffected by the suppressor of a previously described resistance mutant, mtr. The fpr-1 locus is on linkage group V, tightly linked to act-2. The expression of resistance to p-fluorophenylalanine by fpr-1 can be suppressed by genes controlling a requirement for lysine or arginine. The suppression seems to involve an increased sensitivity of the lysine and arginine auxotrophs to p-fluorophenylalanine.