The molecular machinery that directs formation of definitive endoderm from pluripotent stem cells is not well understood. Wnt/β-catenin and Nodal signalling have been implicated, but the requirements for lineage specification remain incompletely defined. Here, we demonstrate a potent effect of inhibiting glycogen synthase kinase 3 (GSK3) on definitive endoderm production. We find that downstrea...

In pregastrula stage mouse embryos, visceral endoderm (VE) migrates from a distal to anterior position to initiate anterior identity in the adjacent epiblast. This anterior visceral endoderm (AVE) is then displaced away from the epiblast by the definitive endoderm to become associated with the extra-embryonic ectoderm and subsequently contributes to the yolk sac. Little is known about the molec...

BACKGROUND & AIMS The Lgr family of transmembrane proteins (Lgr4, 5, 6) act as functional receptors for R-spondin proteins (Rspo 1, 2, 3, 4), and potentiate Wnt signaling in different contexts. Lgr5 is arguably the best characterized of the Lgr family members in a number of adult and embryonic contexts in mice. However, the function of LGR family members in early embryonic development is unclea...

Human embryonic stem cells have the ability to generate all cell types in the body and can potentially provide an unlimited source of cells for cell replacement therapy to treat degenerative diseases such as diabetes. Current differentiation protocols of human embryonic stem cells towards insulin producing beta cells focus on soluble molecules whereas the impact of cell-matrix interactions has ...

The molecular machinery that directs formation of definitive endoderm from pluripotent stem cells is not well understood. Wnt/ b-catenin and Nodal signalling have been implicated, but the requirements for lineage specification remain incompletely defined. Here, we demonstrate a potent effect of inhibiting glycogen synthase kinase 3 (GSK3) on definitive endoderm production. We find that downstre...

We have produced a comprehensive fate map showing where the organs of the gut and respiratory system are derived from in the early Xenopus laevis endoderm. We also show the origin of the associated smooth muscle layer on a separate fate map. Comparison of the two maps shows that for most organs of the gut the prospective epithelium and smooth muscle do not overlie each other in the early embryo...

In this chapter I focus on the emergence of endoderm, the origin of these cells and their organization in space. I also discuss the molecular events that lead to endoderm formation and how endoderm can be molecularly defined. Although the molecular control of endoderm formation has initially been deciphered using Xenopus, Zebrafish, sea urchin and several other species many molecular switches h...