University of California, Davis researchers have caught single DNA strands on video in the act of replicating, Newsweek reports. It adds that their analysis indicates that there's a lot of randomness in the process.
Davis' Stephen Kowalczykowski and his colleagues attached a circular piece of DNA from E. coli to a glass slide via a short tail and, as replication occurs, that tail gets longer. They further added a fluorescent dye to label the DNA as it replicates.
As they report in Cell, the researchers found that the replisome polymerases act autonomously in time and stochastically.
"We've shown that there is no coordination between synthesis of the two strands. They are completely autonomous," Kowalczykowski says in a statement.
He further likens the starting and stopping of replication to driving on the highway. "Sometimes the traffic in the next lane is moving faster and passing you, and then you pass it," he adds. "But if you travel far enough you get to the same place at the same time."