Measuring UV-induced Mutagenesis at the Locus in .

There are several methods to measure the capacity of yeast cell to respond to environmental impacts on their genome by mutating it. One frequently used method involves the detection of forward mutations in the gene. The gene encodes for an arginine permease that is responsible for the uptake of arginine and it can also transport the toxic analog of arginine, canavanine (Whelan , 1979). When cells are grown on a media containing canavanine but lacking arginine, the cells die because of the uptake of the toxic canavanine. However, if a mutation in the gene inactivates the permease, that cell survives and forms a colony on the plate. The following protocol describes the measurement of UV-induced mutagenesis at the locus.