Reverse genetic techniques will be necessary to take full advantage of the
genomic sequence data for Drosophila and other experimental organisms. To d
evelop a method for the targeted recovery of mutations, we combined an EMS
chemical mutagenesis regimen with mutation detection by denaturing high per
formance liquid chromatography (DHPLC). We recovered mutant strains at the
high rate of similar to4.8 mutations/kb for every 1000 mutagenized chromoso
mes from a screen for new mutations in the Drosophila and gene. Furthermore
, we observed that the EMS mutational spectrum in Drosophila germ cells sho
ws a strong preference for 5'-PuG-3' sites, and for G/C within a stretch of
three or more G/C base pairs. Our method should prove useful for targeted
mutagenesis screens in Drosophila and other genetically tractable organisms
and for more precise studies of mutagenesis and DNA repair mechanisms.