In Genetic Analysis 14.1 we designed a screen to identify conditional mutants of S. cerevisiae in which the secretory system was defective. Suppose we were successful in identifying 12 mutants. Describe the crosses you would perform to determine the number of different genes represented by the 12 mutations.

Key Concepts

Mutant Analysis

Mutant analysis involves studying organisms with specific mutations to understand gene function. In this context, identifying conditional mutants of S. cerevisiae helps researchers determine how these mutations affect the secretory system. By analyzing the phenotypes of these mutants, scientists can infer the roles of the affected genes in cellular processes.

Genetic Crosses

Genetic crosses are experimental breeding techniques used to study inheritance patterns and gene interactions. To determine the number of different genes represented by the 12 mutations, one would perform crosses between the mutants and analyze the offspring's phenotypes. This can reveal whether the mutations are in the same gene (allelic) or in different genes (non-allelic).

Complementation Test

A complementation test is a method used to determine if two mutations that produce similar phenotypes are in the same gene or in different genes. By crossing two mutants and observing the phenotype of the offspring, researchers can assess whether the mutations complement each other. If the offspring display a wild-type phenotype, the mutations are in different genes; if they show the mutant phenotype, they are likely in the same gene.