Historical overview: Searching for replication help in all of the rec places

For several decades, research into the mechanisms of genetic recombination proceeded without a complete understanding of its cellular function or its place in DNA metabolism. Many lines of research recently have coalesced to reveal a thorough integration of most aspects of DNA metabolism, including recombination. In bacteria, the primary function of homologous genetic reco mbination is the repair of stalled or collapsed replication forks. Recombin ational DNA repair of replication forks is a surprisingly common process, e ven under normal growth conditions. The new results feature multiple pathwa ys for repair and the involvement of many enzymatic systems. The long-recog nized integration of replication and recombination in the DNA metabolism of bacteriophage T4 has moved into the spotlight with its clear mechanistic p recedents. In eukaryotes, a similar integration of replication and recombin ation is seen in meiotic recombination as well as in the repair of replicat ion forks and double-strand breaks generated by environmental abuse. Basic mechanisms for replication fork repair can now inform continued research in to other aspects of recombination. This overview attempts to trace the hist ory of the search for recombination function in bacteria and their bacterio phages, as well as some of the parallel paths taken in eukaryotic recombina tion research.