If the pathway being dissected genetically contains

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: If the pathway being dissected genetically contains genes that are essential for cell viability, the isolation of mutants in a diploid becomes essential. For example, a diploid containing a mutation in a DNA replication gene yields two live spores and two dead spores after sporulation (Fig. A.7b). A lethal phenotype informs us that there is a mutation in an essential gene in the diploid, but it is not useful for further studies. To study an essential gene, it is more useful to isolate conditional mutants that express the mutant phenotype under restrictive conditions but not at permissive temperatures. Temperature-sensitive and coldsensitive mutations are examples of conditional mutations. Yeast is ideal for isolating this type of mutation because it (a) Mutation in Non-essential Gene grows at temperatures from 15°C to 37°C. A screen for conditional mutants was the starting point for isolation of cell division cycle mutations (cdc) that led to an understanding of cancer biology (see Chapter 19 of the main textbook...
View Full Document

This note was uploaded on 10/03/2013 for the course BI 206 taught by Professor Celenza during the Spring '08 term at BU.

Ask a homework question - tutors are online