Nodal signaling induces the formation of the endoderm and mesoderm during gastrulation. Nodal expression persists until the definitive endoderm progenitor has completely formed, and disappears thereafter. A tightly regulated Nodal expression system is essential for the differentiation of embryonic stem (ES) cells into distinct tissue lineages. On this basis, we established an ES cell differenti...

BACKGROUND Several potentially important regulators of vertebrate endoderm development have been identified, including Activin-related growth factors and their receptors; transcriptional regulators encoded by the genes Mixer, Xsox17, and HNF3beta; zebrafish One-eyed pinhead (Oep), a member of the Cripto/FRL-1/Cryptic family of epidermal growth factor related proteins (EGF-CFC); and the product ...

Continuous cultures of bovine trophectoderm (CT-1 and CT-5) and bovine endoderm (CE-1 and CE-2) were initiated and maintained on STO feeder cells. CT-1 and CT-5 were derived from the culture of intact, 10- to 11-day in vitro-produced blastocysts. CE-1 and CE-2 were derived from the culture of immunodissected inner cell masses of 7- to 8-day in vitro-produced blastocysts. The cultures were routi...

move inwards on the surface of, yet solid, oral endoderm. On the basis of this movement, ectoderm cells become the basal layer, whereas endoderm cells become the apical layer of the definite oral epithelium. As a direct consequence, the endoderm cells are observed even at an outer lip surface outside of mouth, as well as significantly contribute to tooth anlagen. This alternative mode of axolot...

In combination with classical manipulation studies, recent molecular analyses have begun to elucidate the cellular and molecular mechanisms that pattern the sea urchin animalvegetal (A-V) axis during early development (reviewed by Davidson et al., 1998; Logan and McClay, 1998; Wessel and Wikramanayake, 1999; Angerer and Angerer, 2000; Ettensohn and Sweet, 2000). This patterning process establis...

POP-1, a Tcf/Lef-1-like target of the convergent Wnt and MAP kinase (MAPK) signaling pathways, functions throughout Caenorhabditis elegans development to generate unequal daughters during asymmetric cell divisions. A particularly prominent such asymmetric division occurs when the EMS blastomere divides to produce MS, a mesoderm precursor, and E, the sole endoderm progenitor. POP-1 allows mesode...

The generation of insulin producing cells from human embryonic stem cells (hESCs) has shown great promise as a cellular replacement therapy for the treatment of Type 1 Diabetes. Mature functional β-cell surrogates however, have yet to be successfully generated in vivo. One approach to potentially improve current differentiation protocols is the use of 3 dimensional (3D) scaffolds, which has bee...

In the mouse, the initial signals that establish left-right (LR) asymmetry are determined in the node by nodal flow. These signals are then transferred to the lateral plate mesoderm (LPM) through cellular and molecular mechanisms that are not well characterized. We hypothesized that endoderm might play a role in this process because it is tightly apposed to the node and covers the outer surface...

The genital ridges of Xenopus laevis tadpoles reared from eggs kept in an inverted position contain less than 40% of the number of primordial germ cells (PGCs) of controls (Cleine & Dixon, 1985). It has been suggested that this reduction is caused by the germ cells' ectopic position in the anterior endoderm of larvae from inverted eggs, from where they may be unable to migrate into the genital ...