Functions of DNA repair genes during meiosis

One of the most basic functions in any organism is DNA repair. In addition, programmed DNA "damage," in the form of DNA double-strand breaks (DSBs), is a regular part of the physiology of most organisms. There are three main types of DSB repair: homologous recombination; single-strand annealing; and nonhomologous end joining. The gene products known to be required for these repair processes are conserved in evolution, but the relative dependence on different pathways for DSB repair is different when systems are compared. In the yeast Saccharomyces cerevisiae, the formation and repair of DNA double-strand breaks (DSBs) is apparently an essential feature of meiotic recombination. However, it is not clear whether DSBs are a conserved feature of meiotic recombination in eukaryotes. The basidiomycete Coprinus cinereus presents an experimental system which is amenable to genetic analysis, processes DSBs in a manner similar to complex eukaryotes, and has a naturally synchronous meiosis. An understanding of the functions of conserved genes in DSB repair in C. cinereus and other similar systems will help to determine whether DSB repair is a unifying theme in meiotic recombination or whether conserved gene products have other essential functions that tie together DNA repair and meiosis.