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. Based on your knowledge of the genetic tools for studying baker's yeast, how would you clone the genes that are mutated in your respective yeast strains? What is an approach to cloning the human orthologs (see Genetic Analysis 14.2 for definition) of the yeast genes?

Key Concepts

Gene Cloning Techniques

Gene cloning involves isolating and amplifying a specific gene of interest. Common techniques include using restriction enzymes to cut DNA, ligating the gene into a vector, and transforming the vector into host cells, such as bacteria or yeast. This allows for the replication and study of the gene, facilitating the identification of mutations in the yeast strains.

Conditional Mutants

Conditional mutants are organisms that exhibit a mutant phenotype only under certain environmental conditions, such as temperature or nutrient availability. In the context of S. cerevisiae, these mutants can help identify essential genes involved in specific cellular processes, like the secretory system, by allowing researchers to observe the effects of mutations under controlled conditions.

Orthologs and Functional Conservation

Orthologs are genes in different species that evolved from a common ancestral gene and typically retain the same function. Cloning human orthologs of yeast genes involves identifying these conserved genes through sequence similarity and functional studies, which can provide insights into gene function and disease mechanisms in humans based on findings from yeast models.