1. Turn a framework into measured questions
A dynamic-genome proposal needs to specify what changes: population contact frequencies, the separation of particular loci, or the persistence of an inferred loop. These are different measurements. Lieberman-Aiden and colleagues' human-cell Hi-C maps revealed chromosome and A/B compartment patterns, but each map is an ensemble of fixed cells. It does not by itself show how any one chromosome moves through time. [1]
2. Population ordering after mitosis
In highly purified synchronous mouse erythroid cells, Zhang and colleagues used Hi-C to follow mitotic exit. A/B compartments emerged rapidly and then strengthened and expanded, while smaller domains coalesced into larger domains. The earlier recovery of CTCF binding and slower focal return of cohesin distinguished molecular occupancy from structural-loop recovery. These observations reject an automatic assumption that all domain structures must appear before compartments. [2]
The study orders events among populations sampled at successive stages. It cannot establish identical timing in every cell, tissue or developmental process. The original appraisal used the publisher abstract and extended-data descriptions. The independent recheck also inspected selected primary main-text passages; full-method and supplementary validation are not claimed. Architectural and transcriptional recovery occurring together would still require a targeted intervention to distinguish causal direction. [2]
3. A living locus rather than a static boundary loop
At the 505-kb Fbn2 domain in mouse embryonic stem cells, live labeled-anchor tracking showed fluctuating distances in G1/early S. CTCF, RAD21 and WAPL perturbations and Micro-C controls supported an architectural contribution. A Bayesian model inferred that fully boundary-bridged loops were infrequent and transient, rather than permanently closed in every observed cell. [3]
This experiment does not directly watch cohesin moving along DNA; it tracks two genomic labels and infers states from their separation. The silent Fbn2 gene provides no direct transcription-output test. Model-dependent loop lifetimes at this single locus cannot set a universal seconds-to-days hierarchy for the entire nucleus. [3]
4. Evidence assessment
Genome dynamics are directly supported in the measured settings, while a claim that temporal folding is a universal upstream regulatory program is not established by these examples. The useful distinction is between a changing physical or statistical readout and a demonstrated change in gene regulation caused by that readout. Contact mapping, live imaging and targeted perturbation address complementary parts of that problem; agreement among them strengthens a specific interpretation without making it universal. [1] [2] [3]
Dynamics beyond one mouse locus — 12 October 2026
Sabaté and colleagues extended live anchor tracking to three endogenous TADs in human HCT116 cells, alongside Capture Micro-C, cohesin perturbation and polymer modeling. The sampled domains showed dynamic anchor proximity and were interpreted as being continuously extruded by multiple cohesin complexes. This extends the earlier single-locus evidence, while retaining locus-label, cell-line and model limits; the paper’s inferred uniform cohesin dynamics across its sampled regions is not a measured universal constant for every tissue or locus. Sabaté et al. (2025).
This addition uses primary studies. Access depth and claim limits are recorded with each added reference; it is a dated literature appraisal, not independent experimental replication.
Primary studies and review scope
- Lieberman-Aiden et al. (2009), Science 326:289–293. Comprehensive mapping of long-range interactions reveals folding principles of the human genome. DOI: 10.1126/science.1181369. Primary research.
- Zhang et al. (2019), Nature 576:158–162. Chromatin structure dynamics during the mitosis-to-G1 phase transition. DOI: 10.1038/s41586-019-1778-y. Primary research.
- Gabriele et al. (2022), Science 376:496–501. Dynamics of CTCF- and cohesin-mediated chromatin looping revealed by live-cell imaging. DOI: 10.1126/science.abn6583. Primary research.
- Sabaté T, Lelandais B, Robert MC, et al. (2025). Uniform dynamics of cohesin-mediated loop extrusion in living human cells. Nature Genetics 57:3152–3164. DOI: 10.1038/s41588-025-02406-9. Primary research.
Independent update access: Consensus fetched primary abstract and Scite selected main-text passages, including study design and initial Results; not every supplementary analysis inspected. Primary source.
The retained scientific text and the identity and fit of these references were checked on 3 October 2026. The discussion covers these experiments rather than an exhaustive literature search. Source-access limitations and outstanding work remain.