How a Cell Prepares for Division
At this scale, the cell does not appear to be reacting.
It appears to be operating with a framework in which
structure, timing, and function are tightly integrated.
Cell Division Starts Before It Starts
by John D. Wise, PhD
Cells do not simply copy their DNA in advance of mitosis. They must first make it possible to do so. A recent paper explains how a cell prepares for this elaborate operation.
Dbf4-dependent kinase finetunes Ino80 function at chromosome replication origins (Nature Communications, 28 March 2026). Every time a cell divides, it must duplicate its entire genome. In human cells, that means copying 6.4 billion base pairs of DNA across 46 chromosomes with extraordinary precision. This process, called DNA replication, begins at specific sites along the chromosomes known as “origins.”* From these starting points, molecular machines move outward, unwinding the DNA and building new strands.
*Pro-Tip: the term “origin” is an important technical point in this paper. Rather than copying each chromosome in a single pass, the cell initiates replication at thousands of these origins simultaneously, with replication proceeding outward from each site until the entire chromosome is duplicated.
The summary on Phys.org, “Precision work prior to cell division: How enzymes optimize DNA structure,” (April 1, 2026), says concerning these origin* sites:
“It is precisely here that a piece of DNA has to be exposed and flanked by regularly spaced nucleosome arrays. This particular arrangement is essential, as the cellular replication machinery can only begin copying the genetic material when the DNA is correctly organized here.”
Precision Prior to Action
DNA wrapping around histones. (Credit: Illustra Media)
But there is a complication. DNA is not lying around loose and accessible. It is tightly packaged into chromatin, wrapped around histone spools called nucleosomes. This packaging is essential for genomic stability and organization, but it also creates a physical barrier. Replication machinery must gain access to DNA that is hidden by this packing architecture.
For years, scientists have understood that specialized enzymes control when replication begins. One of the most important of these is a protein complex known as Dbf4-dependent kinase,[1] or DDK. Its established role has been to activate the core replication machinery, particularly the helicase that unzips the DNA double helix.
As the new study explains:
“The highly conserved Dbf4-Dependent Kinase (DDK) plays a pivotal role during S phase. It phosphorylates the replicative helicase … which leads to the initiation of replication.”
In other words, DDK has been understood primarily as a trigger. When it acts, replication begins. But new research reveals something unexpected. DDK is not just triggering replication.
It is preparing the DNA for replication before the process even starts.
The researchers discovered that DDK modifies not only the replication machinery, but also a large chromatin remodeler (INO80). This complex is responsible for arranging nucleosomes, the “spools” around which DNA is wound, into specific, regular patterns along the genome.
This matters because replication does not begin randomly on DNA. Replication origins must be located within a very particular structural environment. Each origin contains a short stretch of relatively open DNA,[2] flanked by precisely positioned and evenly spaced nucleosomes. This arrangement allows the replication machinery to assemble while maintaining the surrounding chromatin structure. As the paper explains, DNA replication is not just a matter of activating enzymes, but of preparing the chromatin landscape itself:
“The origin function has to be viewed as an interplay of classical replication machinery as well as chromatin factors.”
The new finding is that DDK directly controls this structural preparation. It does so by phosphorylating a specific component of the Chromatin Remodeler (INO80), a subunit called Arp8.
This modification acts as a fine-tuning mechanism, enabling the remodeler to establish the precise nucleosome spacing required at replication origins. When this phosphorylation is disrupted, the consequences are immediate: nucleosomes are incorrectly spaced, and the cell struggles to copy its DNA.
In the authors’ summary:
“DDK not only regulates the core replication machinery but also regulates a factor that generates replication-conducive chromatin architecture at replication origins.”
This is the key shift from this research.
Replication is not simply triggered; the cell must arrange its DNA into the correct structural configuration before the machinery can even engage.
The implications extend further.
“Nucleosome architecture at replication origins is established during the G1 phase, prior to replication initiation.”
This means that the cell is not reacting to the moment of replication. It is preparing for it in advance, establishing the physical conditions that will later allow replication to occur.
Even more striking, replication across the genome is not simultaneous. Different regions begin copying at different times, following a coordinated schedule:
“Origins do not fire simultaneously. Rather, they follow a temporal programme of early- versus late-firing origins.”
Taken together, these findings point to a deeper level of organization than is often assumed. The cell is not merely activating molecular machinery on demand. It is arranging structure, timing, and function in a coordinated sequence, ensuring that when replication begins, the necessary conditions are already in place.
The Illusion of Reactive Assembly
What looks like a small refinement to a known enzyme begins to reveal a larger pattern. Cells don’t simply react.
They prepare.
The discovery that DDK helps arrange nucleosomes before replication begins means that the process is not assembled in real time. Necessary conditions are established in advance. Structure is set so that function can occur.
And this preparation is not isolated to a single step.
As replication proceeds, the DNA is continuously unwound, copied, and then repackaged. Nucleosomes are removed ahead of the replication machinery and reassembled behind it. Chromatin structure is not static. It is constantly being taken apart and rebuilt, even as the genome is being duplicated.
At the same time, replication does not occur everywhere at once. Tens of thousands of origins across the genome are activated in a coordinated temporal sequence, with some regions replicating early and others later. Each of these sites must be properly prepared, correctly timed, and successfully completed.
What emerges is not a simple mechanical process, but a layered system:
- preparation before replication
- coordinated execution during replication
- reconstruction after replication
The genome is not merely copied. It is continuously and purposefully reorganized.
This is why researchers increasingly speak of the “4D genome,” not only the three-dimensional arrangement of DNA in space, but its dynamic reconfiguration through time. The genome operates within a framework of rigid constraint, within which remarkable flexibility routinely plays out. This flexible rigidity is maintained through an ongoing process of change. (See “Genome Shows Design in 4 Dimensions, 12 Jan 2026).
And yet, through all of this change, the system preserves stability. The same genome is copied in every cell, each time it divides. The same cellular identity is maintained. The same patterns of gene activity are re-established.
This is the tension now coming into focus.
The system behaves as if future requirements are already taken into account. The chromatin must be properly arranged before replication can begin. The replication must proceed in a coordinated sequence. The structure must be restored after disruption.
Each layer moves the system further away from reactive assembly, and deeper into pre-structured coordination.
At this scale, the cell does not appear to be reacting. It appears to be operating with a framework in which structure, timing, and function are tightly integrated.
This is why evolutionary biology is reaching a crisis point.
When Foresight Enters the Lab: The “As if” Crisis
The system behaves as if future requirements are already taken into account. The traditional bottom-up narrative has unraveled. In a purely reactive, stochastic system, we would expect to see real-time improvisation; instead, we find a coordinated sequence where the end is known from the beginning.
It is no accident that modern biology has been forced to retreat into the language of Systems Biology. This shift was a surrender to the data. Systems biology is the tacit admission that reductionism fails to explain the cell; you cannot understand the 4D nucleome by looking at isolated parts any more than you can understand a symphony by analyzing a single note.
By capitulating to this framework, the scientific establishment has inadvertently invited the Design foot into the lab.
Footnotes
[1] A kinase is a type of enzyme that regulates other proteins by attaching a phosphate group to them, a process called phosphorylation. This chemical modification can change a protein’s shape, activity, or interactions, allowing kinases to act as key control points in cellular processes.
[2] These open segments are called “nucleosome free regions” (NFR’s).
Recommended Resource: Documentary film Origin by Illustra Media.
John Wise received his PhD in philosophy from the University of CA, Irvine in 2004. His dissertation was titled Sartre’s Phenomenological Ontology and the German Idealist Tradition. His area of specialization is 19th to early 20th century continental philosophy.
He tells the story of his 25-year odyssey from atheism to Christianity in the book, Through the Looking Glass: The Imploding of an Atheist Professor’s Worldview (available on Amazon). Since his return to Christ, his research interests include developing a Christian (YEC) philosophy of science and the integration of all human knowledge with God’s word.
He has taught philosophy for the University of CA, Irvine, East Stroudsburg University of PA, Grand Canyon University, American Intercontinental University, and Ashford University. He currently teaches online for the University of Arizona, Global Campus, and is a member of the Heterodox Academy. He and his wife Jenny are known online as The Christian Atheist with a podcast of that name, in addition to a YouTube channel: John and Jenny Wise.