Genetic approaches to targeting multiple PARP genes in a mammalian genome

The aim of this chapter is to present feasible strategies for producing novel Parp knock out mice as well multiple knock outs utilizing genetrap and specifically gene targeted ES cell clones publically available through international programs such as KOMP and IGTC. Specifically, we first describe general considerations and strategic decisions that precede the generation of knock out mice using these available materials, and an overview over clones relevant to the PARP family is provided. Detailed protocols for splice variant analysis of the gene of interest, to determine what to expect from a given gene trap clone, are presented. Furthermore, we provide a detailed and widely applicable step by step method to fine-map genomic genetrap insertion sites once targeted clones have been obtained. This is a prerequisite for development of feasible genotyping methods that usually have to be developed by the user.