Despite the importance of the gut and its accessory organs, our understanding of early endoderm development is still incomplete. Traditionally, endoderm has been difficult to study because of its small size and relative fragility. However, recent advances in live cell imaging technologies have dramatically expanded our understanding of this tissue, adding a new appreciation for the complex mole...

The inhibitory mechanisms that prevent gene expression programs from one tissue to be expressed in another are poorly understood. Foxp1/2/4 are forkhead transcription factors that repress gene expression and are individually important for endoderm development. We show that combined loss of all three Foxp1/2/4 family members in the developing anterior foregut endoderm leads to a loss of lung end...

During embryonic development signalling pathways act repeatedly in different contexts to pattern the emerging germ layers. Understanding how these different responses are regulated is a central question for developmental biology. In this study, we used mouse embryonic stem cell (mESC) differentiation to uncover a new mechanism for PI3K signalling that is required for endoderm specification. We ...

Retinoic acid (RA) is an important signaling molecule in the development of the endoderm and an important molecule in protocols used to generate endodermal cell types from stem cells. In this review, we describe the RA signaling pathway and its role in the patterning and specification of the extra embryonic endoderm and different endodermal organs. The formation of endoderm is an ancient evolut...

It is well known that cardiac neural crest participates in development of the cardiac outflow septation and patterning of the great arteries. Less well known is that ablation of the cardiac neural crest leads to a primary myocardial dysfunction. Recent data suggests that the myocardial dysfunction occurs because of the absence of an interaction of neural crest and pharyngeal endoderm to alter s...

Teratomas are tumors originated from mature or immature tissues. Teratomas are made up of one embryonic layer or all three embryonic layers (endoderm, mesoderm, or ectoderm). Herein we report a 41-year-old man who presented with vertigo, vomiting, and tinnitus. After physical examination, laboratory evaluation and performing computed tomography, cholesteatoma was diagnosed, however, during radi...

The mechanisms involved in the induction of yolk sac mesoderm into blood islands and the role of visceral endoderm and mesoderm cells in regulating the restricted differentiation and proliferation of hematopoietic cells in the yolk sac remain largely unexplored. To better define the role of murine yolk sac microenvironment cells in supporting hematopoiesis, we established cell lines from day-9....

The liver and pancreas are specified from the foregut endoderm through an interaction with the adjacent mesoderm. However, the earlier molecular mechanisms that establish the foregut precursors are largely unknown. In this study, we have identified a molecular pathway linking gastrula-stage endoderm patterning to organ specification. We show that in gastrula and early-somite stage Xenopus embry...

In vertebrates, epibranchial placodes are transient ectodermal thickenings that contribute sensory neurons to the epibranchial ganglia. These ganglia innervate internal organs and transmit information on heart rate, blood pressure and visceral distension from the periphery to the central nervous system. Despite their importance, the molecular mechanisms that govern the induction and neurogenesi...

When retinoic acid-primed F9 cells are allowed to aggregate, they form embryoid bodies with an outer layer of (&agr;)-fetoprotein-producing visceral endoderm cells and an internal cavity. I show that maturation of the visceral endoderm is dependent on the size of F9 aggregates. Size fractionation of aggregates of retinoic acid-primed F9 cells on Percoll density gradients revealed that only aggr...