Homologous recombination in eukaryotes.

Homologous recombination (HR) is a mechanistically conserved pathway that ensures maintenance of genomic integrity. During meiosis, HR results in DNA crossover events between homologous chromosomes that produce the genetic diversity inherent in germ cells. The physical connection established between homologs during the crossover event is essential to facilitate correct chromosome segregation. HR is also involved in maintenance of somatic cell genomic stability by restoring replication after a stalled replication fork has encountered a DNA lesion or strand break, as well as following exogenous stresses such as ionizing radiation that induce DNA double-strand breaks. The importance of HR can be gauged by the conservation of HR genes and functions from bacteria to man. Here we review the players and mechanics of eukaryotic HR.