COMPLEMENTATION BETWEEN ALLELES OF THE Td LOCUS IN NEUROSPORA CRASSA

Abstract
The complementation characteristic of 75 Td mutants of Neurospora crassa have been examined. These mutants were found to comprise 5 complementation groups. These mutants may also be divided into 5 generally corresponding groups on the basis of previously determined functional characteristics, suggesting a relationship between functional alterations and ability to complement in a heterocaryon. It was also noted that the ability to form a CRM, a protein immunologically related to the enzyme, appears to be a prerequistite for complementation in the Td system. The significance of these observations was discussed in terms of possible mechanisms of complementation and of the relationship between structure and function of the region controlling the formation of tryptophan synthetase in N. crassa.