From ScienceDaily:
Gilbert and Sima examined a single segment of the DNA in the highest possible 3D resolution and saw three sequences along the DNA molecule touching each other frequently. The researchers then used CRISPR, a sophisticated gene editing technology, to remove these three areas simultaneously.
And with that, they found that these three elements together were the key to DNA replication.
“Removing these elements shifted the segment’s replication time from the very beginning to the very end of the process,” Gilbert said. “This was one of those moments where just one result knocks your socks off.”
In addition to the effect on replication timing, the removal of the three elements caused the 3D structure of the DNA molecule to change dramatically.
“We have for the first time pinpointed specific DNA sequences in the genome that regulate chromatin structure and replication timing,” Sima said. “These results reflect one possible model of how DNA folds inside cells and how these folding patterns could impact the hereditary materials’ function.” …
“If you duplicate at a different place and time, you might assemble a completely different structure,” Gilbert said. “A cell has different things available to it at different times. Changing when something replicates changes the packaging of the genetic information.”
Paper. (paywall) – Jiao Sima, Abhijit Chakraborty, Vishnu Dileep, Marco Michalski, Kyle N. Klein, Nicolas P. Holcomb, Jesse L. Turner, Michelle T. Paulsen, Juan Carlos Rivera-Mulia, Claudia Trevilla-Garcia, Daniel A. Bartlett, Peiyao A. Zhao, Brian K. Washburn, Elphège P. Nora, Katerina Kraft, Stefan Mundlos, Benoit G. Bruneau, Mats Ljungman, Peter Fraser, Ferhat Ay, David M. Gilbert. Identifying cis Elements for Spatiotemporal Control of Mammalian DNA Replication. Cell, 2018; DOI: 10.1016/j.cell.2018.11.036 More.
Note this:
“If you duplicate at a different place and time, you might assemble a completely different structure,” Gilbert said. “A cell has different things available to it at different times. Changing when something replicates changes the packaging of the genetic information.”
Huh? Some of us remember when heredity was a lockstep, diagrammable process, and not the least bit plastic.
See also: Remarkable Vid Of A Mouse Embryo Developing
and
Quantum Biology: Did Researchers Produce Quantum Entanglement In Living Organisms?
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