Days weaving the lagging strand synthesis of DNA — A personal recollection of the discovery of Okazaki fragments and studies on discontinuous replication mechanism

At DNA replication forks, the overall growth of the antiparallel two daughter DNA chains appears to occur 5′-to-3′ direction in the leading-strand and 3′-to-5′ direction in the lagging-strand using enzyme system only able to elongate 5′-to-3′ direction, and I describe in this review how we have analyzed and proved the lagging strand multistep synthesis reactions, called Discontinuous Replication Mechanism, which involve short RNA primer synthesis, primer-dependent short DNA chains (Okazaki fragments) synthesis, primer removal from the Okazaki fragments and gap filling between Okazaki fragments by RNase H and DNA polymerase I, and long lagging strand formation by joining between Okazaki fragments with DNA ligase.