THE CONTROL OF ALLELIC RECOMBINATION AT HISTIDINE LOCI IN NEUROSPORA CRASSA

Abstract

The gene rec‐1 + which reduces allelic recombination at the his‐1 locus by a factor of between 15 and 30 has no effect upon allelic recombination at the his‐2, his‐3, his‐5, his‐6 and his‐7 loci. Other genes controlling recombination at two of these loci, namely rec‐x at his‐2 and rec‐w at his‐3 , have been found. There is a strong possibility that rec‐x may be identical with rec‐3 , so far known to regulate recombination only at the am‐1 locus. It is probable that the stocks used all carry a rec + gene which regulates recombination at the his‐6 locus, since all prototroph frequencies are low, but no regulatory gene active at the his‐5 and his‐7 loci.