2025/06/12 by Léa Torcq, Catherine Vivier, Sandrine Schmutz +2 · 1 voice
Biochemistry, Genetics and Molecular Biology · Immunology and Microbiology · Medicine · #Hematopoietic Stem Cell Transplantation #Immune responses and vaccinations #Single-cell and spatial transcriptomics
paper · doi:10.1242/dev.204454
openalex publication_date 2025/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Hematopoietic stem cells and more committed progenitors (collectively referred to as HSPCs) emerge from vessels during development, via endothelial-to-hematopoietic transition (EHT). Recently, using the zebrafish embryo, we showed that two EHT cell types emerge from the dorsal aorta, raising the question of their subsequent fate. To address this issue, we established a complex pipeline based on single-cell photoconversion and transgenic lines to characterize the abilities of EHT cell progenies to conquer hematopoietic organs and to obtain their transcriptomic profiles. We show that the two EHT cell types lead to partly differentially fated cells, with significant differences in thymus colonization and T-lymphoid lineage commitment. In addition, we investigated implantation of HSPCs in niches, with the support of HSPC signatures (gata2b and cd34/podocalyxin), retrieved from our single-cell datasets. This revealed, at unprecedented resolution, the homing of HSPCs in niches of entire early larvae, including the pronephros, the sub-aortic and caudal regions, as well as the area contacting the supra-intestinal artery. Our work provides new insights into fundamental aspects of HSPC fate acquisition, from their emergence to their homing in specific niches.