Stabilization of the Human DMC1 Nucleoprotein Filament.

The meiosis-specific recombinase, DMC1, is important for the generation of haploids during meiosis. DMC1 forms a helical nucleoprotein filament on ssDNA overhangs located at the processed double-stranded DNA break. The DMC1 filament performs a search for homology in homologous chromosome. Once homology is located, the DMC1 filament strand invades the homologous chromosome forming a displacement loop (D-loop). These connections are needed for accurate segregation to occur later in meiosis. Because DMC1 requires numerous accessory factors and specific ionic conditions to participate in this DNA repair process, in vitro assays were developed to understand how these accessory factors influence the biochemical properties of hDMC1. This chapter describes a method that can be used to investigate the stability of the human DMC1 nucleoprotein filament under various conditions and provides insight into an important early stage in DNA double-strand break repair by homologous recombination during meiosis.