Effect of Rec-3 on Polarity of Recombination in the Animation-1 Locus of Neurospora Crassa

Abstract

Crosses between am-I alleles 6 and 11 produce am-I+ recombinants (proto-trophs) eightfold less frequently in the presence of rec-3+, an unlinked dominant gene. A factor also controls the relative proportions of the two classes of prototrophs with parental combinations of the flanking markers spray (5 units proximal) and histidine-I (3 units distal). Those prototrophs with the same combination as the am-16 parent are reduced from 81 to 59% of the two classes. This factor segregated in complete association with rec-3+ in 12 offspring of a rec-3 X rec-3+ cross. It is probably rec-3+ itself.