“The 84th of Stem Cell Biology and Regenerative Medicine Forum”
Date：Sep 15th (Tue) 2015
Time : 13:00 〜 14:30
Place：Auditorium in 1st Building at Institute of Medical Science in Univ. of Tokyo------------------------------------------------------------------------------------------------------------------------------------（Internal Speaker）
13:00-13:30
Yosuke Tanaka (Division of Cellular Therapy, IMSUT)
Identification of Runx1-direct targets important for definitive hematopoiesis（External Speaker）
13:30-14:30
Bertie Gottgens (Professor of Molecular Haematology,University of Cambridge)
Transcriptional Network Control of Blood Cell Development-------------------------------------------------------------------------------------------------------------------------------------

Hosted by Center for Stem Cell Biology and Regenerative Medicine---Information--＊ Please register attendance at the reception desk.

＊ Next forum（the85th）will be held on

Sep. 16th（Wed）18:00〜 at Auditorium＊ Please contact tatsu-m@ims.u-tokyo.ac.jp, for Forum speaker recommendations

Identification of Runx1-direct targets important for definitive hematopoiesis
Yosuke Tanaka (Division of Cellular Therapy, IMSUT)
Runx1 is an indispensable transcription factor for definitive hematopoiesis, not primitive
hematopoiesis. We previously showed that Runx1+Gata1+ cells are primitive erythrocyte
progenitor cells and Runx1+Gata1- cells contain definitive hematopoietic progenitor cells atembryonic day 7.5-8.0 (E7.5-8.0) in Runx1-GFP/Gata1-mCherry double reporter mouseembryos. The data suggest that lineage choice/commitment toward definitive hematopoiesis has
already occurred and could be monitored using these two reporters. In order to look for
Runx1-direct targets important for definitive hematopoiesis, we decided to compare gene
expression and Runx1-binding between two Runx1+ populations in ES cell differentiation. To
this end, we established Runx1-GFP/Gata1-mCherry double reporter ES cell lines and performed
RNA-Seq and Runx1-Chip-Seq analysis using two Runx1+ populations collected fromEmbryonic Bodies(EBs). Integration analysis gave us several candidate factors that are
preferentially expressed in Runx1+Gata1- populations and have nice Runx1 peaks withwell-conserved Runx1-binding motif between several species. We are characterizing function ofthese candidate factors for definitive hematopoiesis in ES cell differentiation system. Here wewill present our new findings in this attempt.

Transcriptional Network Control of Blood Cell Development
Bertie Gottgens (Professor of Molecular Haematology, University ofCambridge)
The first rigorous assays capable of identifying stem cell activity at the level of individual cells
were established for blood stem cells in the previous century. More recent technologicalinnovations now make it possible to also perform comprehensive genome-scale molecularanalysis at the single cell level. Such analysis holds great promise in our efforts to understandthe molecular mechanisms that underlie key stem cell properties such as self-renewal anddifferentiation, and likely will play a major role in unravelling the molecular causes of stem cell
heterogeneity.
Work in the Gottgens lab has recently utilised single cell expression profiling technology tostudy the emergence of the first wave of haematopoiesis in the developing embryo, and used theexpression data from nearly 4,000 single cells to construct a transcriptional regulatory networkmodel that captures key aspects of early blood development. In parallel work, the group has
used single cell expression profiling to study the cellular heterogeneity of the adult blood
stem/progenitor compartment, gaining new insights into the likely nature of long-term
repopulating haematopoietic stem cells (HSCs).
Taken together, this work highlights (i) that single cell genomics is a promising technology toadvance our knowledge of blood cell development, and (ii) that advanced computational analysis
is essential to optimise extraction of new biological knowledge from such data.