Original title: Epigenetic perturbation unravels diverse origins, state conversions and de-differentiation of cortical astrocytes
Maira Mirza, Tobias Hohl, Camila Fullio, Camila Vidos +3 · September 2026
Brain development requires stem cells to become helper cells called astrocytes. Scientists know less about how chemical tags on DNA control this process. Researchers studied an epigenetic modifier, a protein that adds chemical tags to proteins around DNA, called DOT1L. They removed DOT1L in developing mouse brains from embryonic day E12.5 to P0 to see what changed. Usually, DOT1L acts as a barrier to keep cells from switching states too soon. Without it, the mice produced more astrocytes that express fewer cellular cleanup, or phagocytosis, genes. Losing DOT1L also triggered cells to de-differentiate, meaning astrocytes and stem cells moved backward toward earlier progenitor stages. The team discovered cortical astrocytes do not come from just one stem cell group. Instead, they arise from multiple sources: dorsal apical progenitors, dorsal neural stem cells, and ventral cells marked by Nkx2.1. In short, DOT1L regulates the origin paths, states, and backward development of astrocytes.
You are baking two batches of cookies from the same dough, chilling one batch and sliding the other straight into the oven. The chilled cookies keep their shape; the warm ones spread into flat discs, and if you skip the chilling step you lose the tall chewy cookies entirely. In this paper, a single enzyme is the chilling step: it keeps developing brain support cells from sliding into the wrong shape, and without it they drift back toward a flatter, less-specialized form.
Most brain-development research has focused on neurons, leaving the brain's support cells—astrocytes—comparatively unexplored. This work shows that a single epigenetic enzyme, DOT1L, acts as a barrier that stops developing astrocytes from drifting into the wrong state or reverting to a stem-like one. That matters for anyone studying brain development, repair, or developmental disorders, because it reveals that astrocyte identity is not a one-way door.
The abstract doesn't say whether the two astrocyte states have different functional roles in the living brain, or whether the same DOT1L mechanism operates outside the E12.5-to-P0 cortical window. It reports gene expression, lineage, and transcription-factor findings, but does not demonstrate direct binding or behavioral consequences.
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Epigenetic perturbation unravels diverse origins, state conversions and de-differentiation of cortical astrocytes — Maira Mirza, Tobias Hohl, Camila Fullio et al. — bioRxiv — doi:10.64898/2026.09.11.750559
Abstract licence: CC BY
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.