Sclerotomal hematopoiesis in vertebrate embryos contributes to robustness of the blood system

Zheng Jiang; Tianqi Li; Yixiao Song; Luxi Chen; Juhui Qiu; Fan Zhou; Xiaotong Wu; Jianbin Wang; Anming Meng

doi:10.1093/nsr/nwag035

Sclerotomal hematopoiesis in vertebrate embryos contributes to robustness of the blood system

Natl Sci Rev. 2026 Jan 19;13(6):nwag035. doi: 10.1093/nsr/nwag035. eCollection 2026 Mar.

Authors

Zheng Jiang^{1

2

3}, Tianqi Li³, Yixiao Song^{2

3}, Luxi Chen^{2

3}, Juhui Qiu⁴, Fan Zhou³, Xiaotong Wu^{2

3}, Jianbin Wang^{3

5}, Anming Meng^{1

2

3}

Affiliations

¹ Laboratory of Stem Cell Regulation, Guangzhou National Laboratory, Guangzhou 510320, China.
² Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua University, Beijing 100084, China.
³ Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China.
⁴ Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing 400030, China.
⁵ State Key Laboratory of Green Biomanufacturing, and Center for Synthetic & Systems Biology, Tsinghua University, Beijing 100084, China.

Abstract

During vertebrate embryogenesis, hematopoietic stem cells (HSCs) are believed to almost exclusively arise from hemogenic endothelial cells (ECs) of the dorsal aorta through endothelial-to-hematopoietic transition (EHT). It remains elusive whether HSCs can be generated by other tissues. Sclerotomal cells (SCs) in embryonic somites predominantly form vertebrae and ribs, and some SCs may also insert into aortic endothelia. Here we show that a subset of SCs directly enter the vascular lumen to become hematopoietic stem and progenitor cells (HSPCs) in an EHT-independent way in both zebrafish and mouse embryos. The sclerotome-derived HSPCs (scHSPCs) contribute to various blood cells throughout the lifetime. The proportion of scHSPCs increases dramatically when endothelium hematopoiesis is defective. Thus, the sclerotomal hematopoiesis is evolutionarily conserved and would ensure the robustness of hematopoiesis.

Keywords: hematopoiesis; hematopoietic stem and progenitor cells (HSPCs); sclerotome; somite.