Abstract
Hematopoietic stem cell (HSC) specification occurs in the embryonic aorta and requires Notch activation; however, most of the Notch-regulated elements controlling de novo HSC generation are still unknown. Here, we identify putative direct Notch targets in the aorta-gonad-mesonephros (AGM) embryonic tissue by chromatin precipitation using antibodies against the Notch partner RBPj. By ChIP-on-chip analysis of the precipitated DNA, we identified 701 promoter regions that were candidates to be regulated by Notch in the AGM. One of the most enriched regions corresponded to the Cdca7 gene, which was subsequently confirmed to recruit the RBPj factor but also Notch1 in AGM cells. We found that during embryonic hematopoietic development, expression of Cdca7 is restricted to the hematopoietic clusters of the aorta, and it is strongly up-regulated in the hemogenic population during human embryonic stem cell hematopoietic differentiation in a Notch-dependent manner. Down-regulation of Cdca7 mRNA in cultured AGM cells significantly induces hematopoietic differentiation and loss of the progenitor population. Finally, using loss-of-function experiments in zebrafish, we demonstrate that CDCA7 contributes to HSC emergence in vivo during embryonic development. Thus, our study identifies Cdca7 as an evolutionary conserved Notch target involved in HSC emergence.
© 2014 Guiu et al.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Aorta / embryology
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Aorta / metabolism
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Calcium-Binding Proteins / genetics
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Calcium-Binding Proteins / metabolism
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Cell Differentiation / genetics
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Cell Line
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Cells, Cultured
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Embryo, Mammalian / cytology
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Embryo, Mammalian / embryology
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Embryo, Mammalian / metabolism
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Embryo, Nonmammalian / embryology
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Embryo, Nonmammalian / metabolism
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Gene Expression Regulation, Developmental
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HEK293 Cells
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Hematopoietic Stem Cells / cytology
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Hematopoietic Stem Cells / metabolism*
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Humans
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Immunoglobulin J Recombination Signal Sequence-Binding Protein / genetics
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Immunoglobulin J Recombination Signal Sequence-Binding Protein / metabolism
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In Situ Hybridization
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Intercellular Signaling Peptides and Proteins / genetics
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Intercellular Signaling Peptides and Proteins / metabolism
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Mice, Inbred C57BL
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Mice, Knockout
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Nuclear Proteins / genetics*
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Nuclear Proteins / metabolism
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Protein Binding
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Receptor, Notch1 / genetics*
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Reverse Transcriptase Polymerase Chain Reaction
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Serrate-Jagged Proteins
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Transcription, Genetic*
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Zebrafish / embryology
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Zebrafish / genetics
Substances
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CDCA7 protein, human
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Calcium-Binding Proteins
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Immunoglobulin J Recombination Signal Sequence-Binding Protein
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Intercellular Signaling Peptides and Proteins
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Membrane Proteins
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Nuclear Proteins
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Rbpj protein, mouse
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Receptor, Notch1
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Serrate-Jagged Proteins