AN ACETATE-REQUIRING MUTANT STRAIN OF NEUROSPORA CRASSA DUE TO A POSSIBLE PARACENTRIC INVERSION

Abstract
An acetate-requiring mutant strain 163 was investigated and compared with suc mutants. Growth and enzyme characteristics of the strain are similar to those of suc mutants. It is probable from genetic analyses that strain 163 carries a paracentric inversion near the mating type locus, between leu-4 and suc genes on the left arm of the 1st linkage group. The gene suc seems to be separated into 2 parts by the inversion, and this may be the reason for the acetate requirement and the similarity of strain 163 to suc mutants. Revertants were obtained from strain 163. All 6 revertants proved to be due to suppressor mutations. At least 2 different suppressor genes are involved. All the revertants produced spheroplasts and yeast-like morphology when they were cultivated with vigorous aeration in medium without acetate; they showed normal mycelial structure in medium with acetate.