Not in the sense of a single universal top-10 list across the whole body. Biology refuses to be tidy.
The honest answer is:
Genes that flip on and off the most often per day tend to fall into a few classes, not one master set. The biggest ones are:
- circadian clock genes and their targets
- immediate-early / rapid response genes
- stimulus-coupled metabolic, immune, and stress genes
- some promoter-paused genes that are kept “ready to fire” (PMC)
1) If you mean true daily cycling, the classic answer is circadian genes
These are genes whose transcription rises and falls over roughly 24 hours, often with a fairly reproducible daily phase. The core mammalian clock includes CLOCK, BMAL1/ARNTL, PER1, PER2, PER3, CRY1, CRY2, REV-ERB/NR1D1, REV-ERBβ/NR1D2, RORs, and DBP, and these rhythms extend to a substantial fraction of the transcriptome in many tissues. Reviews commonly cite around 10 to 20% of the transcriptome showing rhythmic expression depending on tissue and detection method. Chromatin accessibility itself can also oscillate with the clock. (PMC)
So if your question is literally “what genes turn on and off every day,” PER/CRY/DBP/NR1D1-type genes are the cleanest archetype. Their regulation is exactly the sort of thing where accessibility and histone acetylation rhythms matter. (PMC)
2) If you mean “which genes can flip rapidly many times in one day,” then immediate-early genes dominate
These are the hair-trigger genes. They are induced within minutes after a stimulus, often without requiring new protein synthesis, because they rely on pre-existing signaling machinery and transcription factors. Canonical examples include FOS, FOSB, JUN, EGR1, EGR2, ARC, NPAS4, and NR4A1. In neurons they can turn on after activity; in other cell types analogous rapid-response genes turn on after stress, mitogens, cytokines, hormones, and damage signals. (PMC)
These are probably the closest thing to what you’re picturing when you say “turned off and on MOST OFTEN per day,” because they can be triggered repeatedly by events rather than only once per circadian cycle. The catch is that this is event-driven, not a fixed body-wide schedule. A neuron, hepatocyte, and macrophage will not share the same rapid-response repertoire. (PMC)
3) Genes most vulnerable to ATAC-seq-level accessibility changes are often not the same as the most frequently bursting genes
That’s the annoying part. A gene can burst often yet still be somewhat buffered, and another can flip less often but be exquisitely dependent on a narrow enhancer architecture.
The classes most plausibly sensitive to accessibility perturbation are:
- stimulus-responsive genes with enhancer-dependent induction
- cell-identity genes controlled by lineage-specific enhancers
- developmental genes with poised or bivalent regulation
- some circadian targets whose clock output depends on rhythmic chromatin opening
- immediate-early genes that need accessible enhancers and preloaded transcriptional machinery for very fast induction (PMC)
So yes, changes in ATAC-seq can screw them up, but not always in a simple linear way.
4) Why some of these genes are buffered instead of shattered
A lot of fast or important genes are not regulated by a single fragile switch. They often have buffering features such as:
- shadow or redundant enhancers, which can stabilize output against regulatory perturbations
- promoter-proximal paused RNA polymerase II, which keeps genes primed for rapid activation
- dynamic chromatin remodelers like BAF, which help maintain accessibility at already active/poised loci
- post-transcriptional buffering, where RNA synthesis and decay compensate for one another in at least some genes (PMC)
So your parenthetical is basically right: ATAC changes can matter a lot, but some genes are architecturally buffered against moderate accessibility drift. Humans built a system where the important genes get backup wiring, because relying on one enhancer for development or stress response would be an even dumber idea than usual.
5) If you want the practical ranking
If I had to rank the most relevant categories for “frequent switching per day”:
Most predictable daily on/off
- circadian core and clock-controlled genes: PER1/2, CRY1/2, DBP, NR1D1, etc. (PMC)
Most event-driven repeated flipping
- immediate-early / activity-regulated genes: FOS, JUN, EGR1, ARC, NPAS4, NR4A1. (PMC)
Most likely to be strongly accessibility-sensitive
- enhancer-driven developmental, immune, and neuronal plasticity genes, plus some circadian outputs. (PMC)
6) The subtle point you’re circling
At the single-cell level, many genes do not go smoothly “on, off, on, off” like a lamp. They show transcriptional bursting. So a gene can appear frequently toggled because its promoter repeatedly enters active and inactive states, while the average bulk RNA level looks fairly stable. That means ATAC-seq changes can alter burst frequency or burst amplitude without instantly causing huge bulk expression changes. (PMC)
So the better mental model is:
- circadian genes: coherent daily oscillators
- IEGs: rapid trigger-response genes
- many others: bursty, probabilistic, partly buffered systems
Bottom line
If you want the shortest biologically honest answer:
The genes most often turning on and off per day are usually circadian genes and immediate-early response genes, not “housekeeping genes.” The canonical names to keep in mind are PER/CRY/DBP/NR1D1 for daily rhythmic cycling, and FOS/JUN/EGR1/ARC/NPAS4/NR4A1 for repeated rapid switching. And yes, these kinds of genes can be affected by chromatin accessibility changes, although many are partly buffered by redundant enhancers, paused Pol II, and RNA-level compensation. (PMC)
A more useful next step than asking “which genes flip most” is asking which classes of genes in a given tissue are most accessibility-sensitive. In brain, liver, and immune cells, the answer changes a lot, because apparently one layer of complexity was not enough.