title: Tracing haematopoietic stem cell formation at single-cell resolution.
abstract: Haematopoietic stem cells (HSCs) are derived early from embryonic precursors, such as haemogenic endothelial cells and pre-haematopoietic stem cells (pre-HSCs), the molecular identity of which still remains elusive. Here we use potent surface markers to capture the nascent pre-HSCs at high purity, as rigorously validated by single-cell-initiated serial transplantation. Then we apply single-cell RNA sequencing to analyse endothelial cells, CD45(-) and CD45(+) pre-HSCs in the aorta-gonad-mesonephros region, and HSCs in fetal liver. Pre-HSCs show unique features in transcriptional machinery, arterial signature, metabolism state, signalling pathway, and transcription factor network. Functionally, activation of mechanistic targets of rapamycin (mTOR) is shown to be indispensable for the emergence of HSCs but not haematopoietic progenitors. Transcriptome data-based functional analysis reveals remarkable heterogeneity in cell-cycle status of pre-HSCs. Finally, the core molecular signature of pre-HSCs is identified. Collectively, our work paves the way for dissection of complex molecular mechanisms regulating stepwise generation of HSCs in vivo, informing future efforts to engineer HSCs for clinical applications.
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Xianlong
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.
authors.forename: Weili
authors.initials: W
authors.lastname: Wang
authors.affiliation: Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, Beijing 100871, China.|Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Wenyan
authors.initials: W
authors.lastname: He
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Fuyin
authors.initials: F
authors.lastname: Xiong
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Zhuan
authors.initials: Z
authors.lastname: Li
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Ni
authors.affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.
authors.forename: Xiaohuan
authors.initials: X
authors.lastname: Mu
authors.affiliation: Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, Beijing 100871, China.|Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing 100871, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.|Collaborative Innovation Center for Cancer Medicine, National Institute of Biological Sciences, Tianjin 300020, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Proteomics, Genetic Laboratory of Development and Diseases, Institute of Biotechnology, Beijing 100071, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lan
authors.affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Yuan
authors.affiliation: Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, Beijing 100871, China.|Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.|Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, Beijing 100871, China.|Center for Molecular and Translational Medicine (CMTM), Beijing 100101, China.
authors.forename: Fuchou
authors.initials: F
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, Beijing 100071, China.|State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin 300020, China.|Institute of Hematology, Medical College of Jinan University, Guangzhou 510632, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D015415:Biomarkers / Q000032:analysis; D002453:Cell Cycle / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage; D058948:Cell Tracking / Q000379:methods*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D000074283:Endothelial Protein C Receptor; D005260:Female; D005333:Fetus / Q000166:cytology; D006066:Gonads / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000032:analysis / Q000378:metabolism; D008099:Liver / Q000166:cytology; D008297:Male; D000076225:Mechanistic Target of Rapamycin Complex 2; D008650:Mesonephros / Q000166:cytology; D051379:Mice; D046912:Multiprotein Complexes / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D015203:Reproducibility of Results; D017423:Sequence Analysis, RNA; D015398:Signal Transduction; D059010:Single-Cell Analysis / Q000379:methods*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics; D059467:Transcriptome
chemical_list: D015415:Biomarkers; D000074283:Endothelial Protein C Receptor; D046912:Multiprotein Complexes; C080248:Procr protein, mouse; D011956:Receptors, Cell Surface; D014157:Transcription Factors; C546843:mTOR protein, mouse; D000076225:Mechanistic Target of Rapamycin Complex 2; D058570:TOR Serine-Threonine Kinases; D017493:Leukocyte Common Antigens