Intragenic Suppression at the b2 Locus in ASCOBOLUS IMMERSUS. II. Characteristics of the Mutations in Groups A and E.

The present report is a study of 60 intragenic suppressors located in the A or E group of the b2 spore-color locus of Ascobolus immersus. The frameshift nature of the suppressors was shown by 19 combinations of plus and minus suppressor mutations. The location of the mutation sites on the genetic map of group A was defined. The conversion pattern of the frameshift suppressors is discussed according to their plus or minus phase shift and their mutagenic origin.