ERM-mediated genetic screens in mammalian cells.

Genetic screens have been proven powerful for the identification of components of various signaling pathways. For mammalian cells, methods for genetic screens are limited. We have developed the ERM (enhanced retroviral mutagen) mutagenesis approach that has been shown to be efficient and amenable to genomewide genetic screens in mammalian cells without the need of cDNA library construction. The ERM method offers several advantages, including conditional gene expression and the flexibility to tag endogenous genes with different epitope-tag and marker sequences. This chapter will discuss general design, procedures, and applications of the ERM strategy.