We demonstrate enhanced differentiation of oligodendrocytes during neurogenesis of human embryonic stem cells (hESCs) using an extracellular matrix protein, vitronectin (VN). We show that VN is expressed in the ventral part of the developing human spinal cord. Combined treatment of retinoic acid, sonic hedgehog, and noggin in the presence of VN allows hESCs to differentiate into O4-positive oli...

Fibrosis is a scarring process that is a common feature of chronic organ injury. It is characterized by elevated activity of transforming growth factor-beta resulting in increased and altered deposition of extracellular matrix and other fibrosis-associated proteins. Recent work has demonstrated that bone morphogenetic protein-7 blocks transforming growth factor-beta signaling. Moreover, member ...

Members of the transforming growth factor-beta superfamily, including bone morphogenetic protein 4 (BMP-4), have been implicated as regulators of neuronal and glial differentiation. To test for a possible role of BMP-4 in early mammalian neural specification, we examined its effect on neurogenesis in aggregate cultures of mouse embryonic stem (ES) cells. Compared to control aggregates, in which...

In the chick, most feathers are restricted to specific areas of the skin, the feather tracts or pterylae, while other areas, such as the apteria, remain bare. In the embryo, the expansion and closure of the somatopleure leads to the juxtaposition of the ventral pteryla, midventral apterium and amnion. The embryonic proximal somatopleural mesoderm is determined to form a feather-forming dermis a...

The development of remyelinating strategies designed to enhance recruitment and differentiation of endogenous precursor cells available to a site of demyelination in the adult spinal cord will require a fundamental understanding of the potential for adult spinal cord precursor cells to remyelinate as well as an insight into epigenetic cues that regulate their mobilization and differentiation. T...

We have studied the origin of muscle satellite cells in embryos of Xenopus laevis. Fate mapping at the open neural plate stage was carried out using orthotopic grafts from transgenic embryos expressing GFP. This shows that most satellite cells originate from the dorsolateral plate rather than from the paraxial mesoderm. Specification studies were made by isolation of explants from the paraxial ...

In order to study the mechanism of neural patterning in Xenopus, we used subtractive cloning to isolate genes activated early during this process. One gene isolated was opl, (odd-paired-like) that resembles the Drosophila pair-rule gene odd-paired and encodes a zinc finger protein that is a member of the Zic gene family. At the onset of gastrulation, opl is expressed throughout the presumptive ...