The mechanisms underlying haematopoietic lineage decisions remain disputed. Lineage-affiliated transcription factors with the capacity for lineage reprogramming, positive auto-regulation and mutual inhibition have been described as being expressed in uncommitted cell populations. This led to the assumption that lineage choice is cell-intrinsically initiated and determined by stochastic switches of randomly fluctuating cross-antagonistic transcription factors. However, this hypothesis was developed on the basis of RNA expression data from snapshot and/or population-averaged analyses. Alternative models of lineage choice therefore cannot be excluded. Here we use novel reporter mouse lines and live imaging for continuous single-cell long-term quantification of the transcription factors GATA1 and PU.1 (also known as SPI1). We analyse individual haematopoietic stem cells throughout differentiation into megakaryocytic–erythroid and granulocytic–monocytic lineages. The observed expression dynamics are incompatible with the assumption that stochastic switching between PU.1 and GATA1 precedes and initiates megakaryocytic–erythroid versus granulocytic–monocytic lineage decision-making. Rather, our findings suggest that these transcription factors are only executing and reinforcing lineage choice once made. These results challenge the current prevailing model of early myeloid lineage choice.

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lineage reprogramming positive autoregulation reporter mouse snapshot andor populationaveraged expression dynamics live imaging stochastic switches of randomly fluctuating crossantagonistic transcription factors uncommitted cell rna expression data continuous singlecell longterm quantification haematopoietic lineage decisions spi1 megakaryocyticerythroid versus granulocyticmonocytic lineage decisionmaking mutual inhibition stochastic switching between pu1 early myeloid lineage choice

Philipp S. Hoppe,Dirk Loeffler,Antje Bürger,Heiko Lickert,Bernhard Schauberger,Michael Schwarzfischer,Ingo Burtscher,Carsten Marr,Adriana Gambardella,Fabian J. Theis,Konstantinos D. Kokkaliaris,Adam Filipczyk,Michael K. Strasser,Oliver Hilsenbeck,Martin Etzrodt,Nouraiz Ahmed,Max Endele,Michael A. Rieger,Daniel L. Coutu,Nadine Moritz,Olga Ermakova,Claus Nerlov,Timm Schroeder,.Early myeloid lineage choice is not initiated by random PU.1 to GATA1 protein ratios. 2016 (7),.

Philipp S. Hoppe, et al."Early myeloid lineage choice is not initiated by random PU.1 to GATA1 protein ratios" 2016

Philipp S. Hoppe,Dirk Loeffler,Antje Bürger,Heiko Lickert,Bernhard Schauberger,Michael Schwarzfischer,Ingo Burtscher,Carsten Marr,Adriana Gambardella,Fabian J. Theis,Konstantinos D. Kokkaliaris,Adam Filipczyk,Michael K. Strasser,Oliver Hilsenbeck,Martin Etzrodt,Nouraiz Ahmed,Max Endele,Michael A. Rieger,Daniel L. Coutu,Nadine Moritz,Olga Ermakova,Claus Nerlov,Timm Schroeder,"Early myeloid lineage choice is not initiated by random PU.1 to GATA1 protein ratios"