Some Strategies for Finding Mutants

"You get what you select for, but you don't know what you are selecting for until you get it." Tom Silhavy

Isolation of mutants in catabolic pathways

Selection for resistance to a toxic substrate analog
Selection for increased expression (e.g. faster growth on limiting substrate)
Screen for failure to grow on a particular carbon or nitrogen source

Isolation of mutants in biosynthetic pathways

Penicillin enrichment
Screen for failure to grow without a particular nutritional supplement

Isolation of mutants in essential genes

Screen for conditional lethal mutants
Brute force screen for loss of an enzymatic activity

Isolation of mutants in defined loci or regions of the chromosome

Localized mutagenesis
Allele replacement
Subtractive mutagenesis
Select or screen for mutants in essential genes in diploids

Isolation of mutations that affect complex interactions

Selection for suppressor mutations
Screen for synthetic mutations
Selection or screen for increased or decreased expression of reporter genes

REFERENCES:

Beckwith, J. 1991. Strategies for finding mutants. Methods Enzymol. 204: 1-18.
Shuman H., and T. Silhavy. 2003. The art and design of genetic screens: Escherichia coli. Nat Rev Genet. 4: 419-431.

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Please send comments, suggestions, or questions to smaloy@sciences.sdsu.edu
Last modified July 2, 2004