Tracing developmental and adult hematopoiesis with an endogenous zebrafish runx1-2A-CreERT2 CRISPR knock-in
- 1Iowa State University
Abstract
Zebrafish combines the power of genetics and unparalleled in vivo imaging to investigate the dynamics of vertebrate hematopoietic development. The conserved transcription factor Runx1 is essential for definitive hematopoiesis. We generated an endogenous zebrafish runx1-2A-creERT2 CRISPR knock-in for tamoxifen-regulated Runx1 lineage tracing and characterized its activity using recombinase-dependent fluorescence reporters, live imaging and flow cytometry. Tamoxifen induction of Cre in the early embryo labeled all expected Runx1 lineages, including neuroectodermal olfactory placode and Rohan-Beard neurons, primitive hematopoietic blood cells, and emerging definitive hematopoietic stem and progenitor cells (HSPCs) in the dorsal aorta. Short windows of tamoxifen treatment allowed separation of Runx1 primitive from definitive hematopoiesis and visualization of HSPC colonization of the larval caudal hematopoietic tissue, thymus and kidney. Runx1 HSPCs labeled during development persisted into adulthood and contributed to hematopoietic precursors, myeloid, lymphoid, and peripheral blood lineages. Labeling of all blood lineages was also effective by tamoxifen treatment of 5-month-old adults. The runx1-2A-creERT2 knock-in line provides a novel genetic tool for inducible spatial and temporal analysis of Runx1 progenitor mechanisms in developmental and adult hematopoiesis.
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BibTeX
@misc{preston2026tracing,
title = {{Tracing developmental and adult hematopoiesis with an endogenous zebrafish runx1-2A-CreERT2 CRISPR knock-in}},
author = {J. A. Preston and M. K. Usha and S. C. Ekker and K. J. Clark and J. Essner and R. Espin Palazon and M. McGrail},
howpublished = {bioRxiv},
year = {2026},
month = jul,
doi = {10.64898/2026.07.03.736368},
url = {https://www.biorxiv.org/content/10.64898/2026.07.03.736368v2},
note = {CC BY-NC},
}
RIS
TY - UNPB
TI - Tracing developmental and adult hematopoiesis with an endogenous zebrafish runx1-2A-CreERT2 CRISPR knock-in
AU - J. A. Preston
AU - M. K. Usha
AU - S. C. Ekker
AU - K. J. Clark
AU - J. Essner
AU - R. Espin Palazon
AU - M. McGrail
PY - 2026
DA - 2026/07/03
PB - bioRxiv
DO - 10.64898/2026.07.03.736368
UR - https://www.biorxiv.org/content/10.64898/2026.07.03.736368v2
AB - Zebrafish combines the power of genetics and unparalleled in vivo imaging to investigate the dynamics of vertebrate hematopoietic development. The conserved transcription factor Runx1 is essential for definitive hematopoiesis. We generated an endogenous zebrafish runx1-2A-creERT2 CRISPR knock-in for tamoxifen-regulated Runx1 lineage tracing and characterized its activity using recombinase-dependent fluorescence reporters, live imaging and flow cytometry. Tamoxifen induction of Cre in the early embryo labeled all expected Runx1 lineages, including neuroectodermal olfactory placode and Rohan-Beard neurons, primitive hematopoietic blood cells, and emerging definitive hematopoietic stem and progenitor cells (HSPCs) in the dorsal aorta. Short windows of tamoxifen treatment allowed separation of Runx1 primitive from definitive hematopoiesis and visualization of HSPC colonization of the larval caudal hematopoietic tissue, thymus and kidney. Runx1 HSPCs labeled during development persisted into adulthood and contributed to hematopoietic precursors, myeloid, lymphoid, and peripheral blood lineages. Labeling of all blood lineages was also effective by tamoxifen treatment of 5-month-old adults. The runx1-2A-creERT2 knock-in line provides a novel genetic tool for inducible spatial and temporal analysis of Runx1 progenitor mechanisms in developmental and adult hematopoiesis.
ER -