Tbx3 controls Dppa3 levels to regulate exit from pluripotency towards mesodermal lineage

Tbx3, a member of the T-box family, plays important roles in development, stem cells, nuclear reprogramming and cancer. Loss of Tbx3 induces differentiation in mouse embryonic stem cells (mESCs). However, we show that mESCs exist in an alternate stable pluripotent state in the absence of Tbx3. In-depth transcriptome analysis of this mESC state reveals Dppa3 as a direct downstream target of Tbx3. Also Tbx3 facilitates the cell fate transition from pluripotent cells to mesoderm progenitors by directly repressing Wnt pathway members required for differentiation. Wnt signaling regulates differentiation of mESCs into mesoderm progenitors and helps maintain a naïve pluripotent state. We show that Tbx3, a downstream target of Wnt signaling, fine-tunes these divergent roles of Wnt signaling in mESCs. In conclusion, we identify a signaling-TF axis that controls the exit of mESCs from a self-renewing pluripotent state towards mesoderm differentiation. ChIPSeq and RNASeq (population and single cell) was performed on the indicated cell lines. Replicates are indicated as needed. The mm9 genome assembly was used. For single cell mRNA-Seq preparation, SSEA1+DAPI- mESCs were sorted and collected.