https://phys.org/news/2018-12-unravel-mystery-dna-replicates.html

David Gilbert, the J. Herbert Taylor Distinguished Professor of Molecular Biology, and doctoral student Jiao Sima published a paper today in the journal Cell that showed there are specific points along the DNA molecule that control replication.

"It's been quite a mystery," Gilbert said. "Replication seemed resilient to everything we tried to do to perturb it. We've described it in detail, shown it changes in different cell types and that it is disrupted in disease. But until now, we couldn't find that final piece, the control elements or the DNA sequences that control it."