In Developmental Cell, Vijaykumar et al. map the fetal liver microenvironment at tissue scale and identify hepatoblasts as central regulators of hematopoietic stem cell expansion . Using 3D microscopy, transcriptomics, and genetic models, the study charts the dynamic remodeling of hematopoietic niches during development.
Hepatoblasts pervasively express KIT ligand and other supportive cytokines at peak hematopoiesis. Hepatoblast-specific deletion of Kitl suppresses stem cell expansion and impairs fetal erythropoiesis, demonstrating their functional relevance in vivo.
As hepatoblasts differentiate, niche activity contracts and hematopoiesis declines, highlighting a tightly timed transition from a pro-hematopoietic to a metabolic organ.
https://doi.org/10.1016/j.devcel.2026.01.011