General strategies of forward and reverse genetics

Table 14.1 Common Mutagens Used for Mutagenesis Mutagen Chemical Mutation Spectrum Mutation Rate per Locus Ethyl methanesulfonate (EMS) mostly G —> A (C —> T) transitions High Stop codons created: TGG —) TAG Splice sites destroyed: AG —> AA Allele Spectrum Usually loss-of-function (null, hypomorphic), hypermorphic (rare) Radiation Fast-neutron Rearrangements (deletions, Moderate Usually loss-of-function X-ray inversions, translocations) (often null), but can be Gamma-ray gain-of-function Insertional Transfer DNA Insertions Low Usually loss-of—function Transposons (often null)