Developmental Gfi1 Dynamics Define Hematopoietic Emergenceand Adult Hematopoietic Stem Cell Potency

Yabushita, T.; Tanaka, Y.; Ideue, T.; Wakahashi, K.; Tsuruda, M.; Morino-Koga, S.; Yokomizo, T.; Noda, T.; Nishiyama, A.; Kurotaki, D.; Umemoto, T.; Yamazaki, S.; Takizawa, H.; Tamura, T.; Ogawa, M.; Suda, T.

doi:10.64898/2026.07.28.741133

bioRxiv · 10.64898/2026.07.28.741133

Developmental Gfi1 Dynamics Define Hematopoietic Emergenceand Adult Hematopoietic Stem Cell Potency

Yabushita, T.·Tanaka, Y.·Ideue, T.·Wakahashi, K.·Tsuruda, M.·Morino-Koga, S.·Yokomizo, T.·Noda, T.·Nishiyama, A.·Kurotaki, D.·Umemoto, T.·Yamazaki, S.·Takizawa, H.·Tamura, T.·Ogawa, M.·Suda, T.

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Abstract

Gfi1 regulates endothelial-to-hematopoietic transition (EHT) and hematopoietic stem cell (HSC) maintenance; however, its expression dynamics remain unclear. We generated a non-disruptive Gfi1-T2A-mScarlet reporter to track Gfi1 expression. At E10.5, reporter selectively marked EHT in the dorsal aorta, umbilical artery, and vitelline artery. At E9.5, mScarlet-positive endothelial cells were present in the umbilical and vitelline arteries but were scarce in the dorsal aorta, indicating vascular-bed-specific differences in hemogenic activation. Gfi1 was broadly expressed in fetal liver HSCs, while higher expression levels identified HSCs with enhanced multilineage reconstitution and preferential T-cell output. Although Gfi1 expression declined during fetal-to-adult maturation, a subset of adult bone marrow HSCs retained expression and exhibited superior repopulating and self-renewal capacity. Bulk and single-cell transcriptomic analyses linked this subset to dormant and fetal-associated programs, including imprinted genes. Reduced chromatin accessibility at a conserved Gfi1 +26.5kb putative enhancer correlated with developmental Gfi1 downregulation. Thus, Gfi1 dynamics define EHT onset and functionally distinct HSC stemness.

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Yabushita, T., Tanaka, Y., Ideue, T., Wakahashi, K., Tsuruda, M., Morino-Koga, S., Yokomizo, T., Noda, T., Nishiyama, A., Kurotaki, D., Umemoto, T., Yamazaki, S., Takizawa, H., Tamura, T., Ogawa, M., Suda, T.. 2026-07-29. Developmental Gfi1 Dynamics Define Hematopoietic Emergenceand Adult Hematopoietic Stem Cell Potency. https://doi.org/10.64898/2026.07.28.741133

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