Description
This study aimed to understand the transcriptional networks regulating endoderm specification from HESC and therefore explored the phenotype of CA1 and CA2 HESC constitutively over-expressing SOX7 or SOX17. Cell lines were created using an inducible construct whereby clonal populations containing transgene integration are selected by Neomycin resistance without expressing of the gene of interest (NoCre controls). Transgene expression is induced via Cre-mediated recombination and selected for puromycin resistance (SOX O/E). The phenotype of the resulting cells suggests that SOX7 expressing HESC represent stable extraembryonic endoderm progenitors, while SOX17 expressing HESC represent early definitive endoderm progenitors. Both in vitro and in vivo SOX7 expressing HESC are restricted to the extraembryonic endoderm lineage, while SOX17 expressing HESC demonstrate mesendodermal specificity. In vitro, SOX17 expressing HESC efficiently produce mature definitive endoderm derivatives.