GENETIC FACTORS AFFECTING ALLELIC RECOMBINATION AT HISTIDINE-3 LOCUS OF NEUROSPORA CRASSA

In addition to the gene rec-4, other genetic factors affect the frequency of allelic recombination in the his-3 locus. One dominant factor, designated as rec-6+, in association with rec-4+ causes greater reduction in prototrophic frequency than obtained with rec-4+ alone. The action of rec 6+ in crosses recessive homozygous for rec-4 is not established at the present. The effect of rec-6+ is recognised only with one his-3 allele but not with another. Interaction of rec-4+ or rec-4 with other genetic factors can give approximately ten fold variation in the prototrophic frequencies obtained with a pair of alleles. It is suggested that the control of the rate of mutations during meiosis might be one of the roles of the recombination genes. © 1969 Springer-Verlag.