7 Ty Mutagenesis

Abstract

Publisher Summary This chapter presents an overview of Ty mutagenesis. The use of transposable elements as insertional mutagens is a powerful tool for genetic analysis. This approach, first developed in bacteria, has also proved to be an effective technique for tagging genes in nematodes, Drosophila , mice, and higher plants. Using the retrotransposons, Ty1 and Ty2, which are native to Saccharomyces cerevisiae , methods for transposon mutagenesis have been developed over the past 10 years. The chapter presents three recent improvements made in Ty mutagenesis. First, markers have been developed that only function after transposition; thus, cells that have had a transposition event can be directly selected. Second, an I-DmoI restriction site, which is unique to the yeast genome, has been engineered adjacent to the Ty1 marker gene. This restriction site can be used in a variety of manipulations that simplify physical mapping and identifying sequences adjacent to the Ty insertion. Third, a technique called “genetic footprinting” has been developed that allows the identification and phenotypic analysis of Ty1-induced mutations within essentially any gene in a population of cells.