Genetic tools used for cell lineage tracing and gene manipulation in Drosophila germline stem cells

The advancement of Drosophila germline stem cell research accompanies the development of powerful new tools for genetic analysis. These include the techniques of stem cell labeling, cell lineage tracing, mosaic mutant analysis, and gene manipulation in targeted cell populations, which together constitute the critical methodologies in stem cell research. We discuss four such techniques: the tubulin-lacZ positive-labeling system; the positively marked mosaic lineage (PMML) method; the flipase/flipase recombination target (FLP/FRT)-based mosaic mutant analysis; and the GAL80-based mosaic analysis with a repressible cell marker (MARCM) system.