A measured mark-transmission result at replication
Alabert and colleagues used nascent chromatin capture, isotope labeling and mass spectrometry in cultured human cells to distinguish parental and newly synthesized histones. Modified parental histones were recovered on replicated DNA, while new histones initially diluted modification levels. This is biochemical transmission and recovery evidence at the population level. It is not a genomic-address map, a single-nucleosome neighbor-copying movie or a test showing that a liquid compartment survives cell division. Alabert et al., 2015.
Total recovery differs from immediate copying
Many newly deposited histone profiles approached parental profiles during maturation, whereas H3K9me3 and H3K27me3 accumulated progressively on both old and new histones. Total recovery can therefore occur without every new histone immediately matching a marked parent. The result constrains a simple instantaneous copying story, but does not rank all enzymatic, spatial and phase models of cellular memory. Persistence of mark abundance is also distinct from persistence of a measured cell phenotype. Alabert et al., 2015.
An H1 perturbation adds regional information
Liu and colleagues followed H3K27me3 recovery after replication in mouse embryonic stem cells using ChOR-seq. Recovery varied across genomic regions and was delayed by selected H1 depletion in chronic and inducible comparisons. This supports an H1 contribution in that system. Other H1 variants remained, and the readout does not directly track nucleosome contacts or isolate physical compaction from every H1 function. It neither tests liquid-phase inheritance nor demonstrates that mark recovery alone preserves cell identity. Liu et al., 2023.
HP1 assembly capacity differs from the tested cellular state
Erdel and colleagues observed purified mouse HP1α droplets with DNA under the examined in-vitro conditions. In mouse fibroblasts, chromocenters persisted after Suv39h1/2 loss removed strong H3K9me3/HP1 enrichment. In a separate engineered U2OS reporter system, tethered HP1 repressed expression without a detected droplet assembly. These comparisons show why enrichment, repression and purified droplet capacity cannot be equated with phase-based memory. They are not complete HP1 deletion or multi-generation natural-locus inheritance experiments, and they do not exclude every phase process in other heterochromatin systems. Erdel et al., 2020.
A transmission mechanism with a silencing phenotype — 12 October 2026
Charlton and colleagues connected parental histone handling to inheritance of a measured silencing state in fission yeast. Mrc1 connector-domain and Mcm2 histone-binding mutants disrupted lagging-strand recycling and produced asymmetric loss of H3K9me-associated reporter silencing in daughter lineages. Their biochemical and genetic comparisons support a recycling mechanism in that organism. This supplies a cellular inheritance readout beyond total mark recovery; it does not establish human transgenerational inheritance or a requirement for a liquid chromatin compartment. Charlton et al. (2024).
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
- Alabert et al. (2015), Genes & Development 29:585–590. Two distinct modes for propagation of histone PTMs across the cell cycle. DOI: 10.1101/gad.256354.114. Primary research.
- Liu et al. (2023), Nature Communications 14:4081. Histone H1 facilitates restoration of H3K27me3 during DNA replication by chromatin compaction. DOI: 10.1038/s41467-023-39846-y. Primary research.
- Erdel et al. (2020), Molecular Cell 78:236–249.e7. Mouse Heterochromatin Adopts Digital Compaction States without Showing Hallmarks of HP1-Driven Liquid-Liquid Phase Separation. DOI: 10.1016/j.molcel.2020.02.005. Primary research.
- Charlton SJ, Flury V, Kanoh Y, et al. (2024). The fork protection complex promotes parental histone recycling and epigenetic memory. Cell 187:5029–5047.e21. DOI: 10.1016/j.cell.2024.07.017. Primary research.
Independent update access: Consensus fetched primary abstract; Scite Introduction, main-text study summary, Figure 1 caption and initial Results inspected. Supplementary validation and raw data not reanalyzed. 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.