An apparent connection between histidine, recombination, and repair in Neurospora.

Two mutants of Neurospora crassa, uvs-3 and mei-3, share four properties--UV sensitivity, inhibition by histidine, meiotic blockage when homozygous, and increased duplication instability (due to mitotic crossing over, to deletions or to both). The present paper shows that a third nonallelic mutant, uvs-6, exhibits the same four properties.--Also, the instability of duplications in the absence of any UV-sensitive mutant is increased by the presence of histidine in the growth medium.