The central nervous system is derived from the neural plate that undergoes a series of complex morphogenetic movements resulting in formation of the neural tube in a process known as neurulation. During neurulation, morphogenesis of the mesenchyme that underlies the neural plate is believed to drive neural fold elevation. The cranial mesenchyme is comprised of the paraxial mesoderm and neural c...

Hyaluronate (HA) distribution patterns were examined in the cranial mesenchyme underlying the mesencephalic neural folds of mouse embryos maintained in roller tube culture. Using standard image-processing techniques, the digitized images of Alcian blue-stained or 3H-glucosamine-labeled sections digested with an enzyme specific for HA, were subtracted from adjacent, undigested sections. The resu...

In the androgen response of the embryonic mammary rudiment of the mouse, both gland epithelium and surrounding mesenchyme are visibly involved. The question whether this is due to a direct action of testosterone on both tissues was investigated in experimental combination of mammary epithelium and mammary mesenchyme, derived either from normal or from androgen-insensitive (XTfm/Y) embryos. A ty...

Gli genes encode a family of zinc finger transcription factors that mediate signaling by Hedgehog proteins. We have cloned the chick Gli3 gene and studied its expression in developing chick limbs. Gli3 expression is highly similar to that of chick Gli2. Gli3 mRNA is evenly distributed in the early limb mesenchyme and subsequently downregulated in the posterior mesenchyme by the polarizing activ...

Tenascin, an extracellular matrix protein, is expressed in the mesenchyme around growing epithelia in the embryo. We therefore investigated whether epithelial cells can stimulate expression of tenascin in embryonic mesenchyme. Mesenchyme from the presumptive small intestine was used because it is known that reciprocal epithelial-mesenchymal interactions are important for gut morphogenesis. Rat ...

Mesenchymal-epithelial interactions are essential for the development of the male reproductive tract. Tissue recombination experiments have been used to define the characteristics of these interactions. When mesenchyme, embryonic connective tissue, is recombined with epithelium from another organ an instructive induction may occur in which the developmental fate of the epithelium is altered. In...

During metanephric development, non-polarized mesenchymal cells are induced to form the epithelial structures of the nephron following interaction with extracellular matrix proteins and factors produced by the inducing tissue, ureteric bud. This induction can occur in a transfilter organ culture system where it can also be produced by heterologous cells such as the embryonic spinal cord. We fou...

The signalling peptide encoded by the sonic hedgehog gene is restricted to localised thickenings of oral epithelium, which mark the first morphological evidence of tooth development, and is known to play a crucial role during the initiation of odontogenesis. We show that at these stages in the murine mandibular arch in the absence of epithelium, the Shh targets Ptc1 and Gli1 are upregulated in ...

objective: the development of vertebrae is a complex phenomenon that is correlated with distinct morphological and biochemical alterations in the paraxial mesenchyme and glycoconjugates. the purpose of this study is to investigate the glycosylation pattern in paraxial mesenchyme-forming vertebrae by using the lectin histochemical technique. materials and methods: in this descriptive-analytic st...