Genetic recombination inNeurospora crassaandN. sitophila

Abstract

Mutant genes in linkage groups I (mating-type chromosome), VI and VII have been transferred fromNeurospora crassatoN. sitophilaby hybridization and repeated backcrossing. Recombination between these genes has been studied from five-point crosses involving linkage group I and three-point crosses involving linkage groups VI and VII of the two species.The results show significant differences in the amount of recombination between some of the genes in the proximal regions of the mating-type chromosomes of the two species. They indicate proximal localization of crossovers in the mating-type chromosome ofN. sitophila. The results also show significant differences in recombination frequency between the genes in linkage group VI and a close similarity in linkage group VII. They further show that the centromere in the two species may not be interfering with crossing-over in its vicinity to such an extent as to be of any evolutionary significance.