Neural crest stem cells arise within the central nervous system but then undergo an epithelial-to-mesenchymal transition to migrate away and contribute to the peripheral nervous system and craniofacial skeleton. Here we show that DNA methyltransferase 3B (DNMT3B) is responsible for the loss of competence of dorsal neural tube cells to generate emigrating neural crest cells. DNMT3B knockdown res...

Different construction materials with different roughness used to make circular weirs highly affect surface roughness and, in turn, flow hydraulics passing over these structures.  In the present research, numerous experiments under different hydraulic conditions were performed on a physical model to study the effects of roughness on flow hydraulics over a circular weir. The flow hydraulics incl...

1 Abstract A method is presented to extract space curves, deened by diierential invariants, at increasing scales. The curves are considered as the intersection of two iso-surfaces in 3D, so their moving paths or orbits can be explicitly obtained in scale space as the intersection of two iso-surfaces in 4D. This method is based on a novel algorithm to search for iso-surfaces and their intersecti...

enamel matrix derivative emdogain (emd) is widely used in periodontal treatment in spite of the fact that its effect on the developing embryo has not been elucidated. the aim of this study was to investigate the teratogenic effect of emd on the rat embryo neural crest cells. the neural crest is a unique population of cells that migrates from the dorsal neural tube along defined pathways and pro...

BACKGROUND In vertebrates, the skeletal elements of the jaw, together with the connective tissues and tendons, originate from neural crest cells, while the associated muscles derive mainly from cranial mesoderm. Previous studies have shown that neural crest cells migrate in close association with cranial mesoderm and then circumscribe but do not penetrate the core of muscle precursor cells of t...

The neural crest is a vertebrate-specific cell population that contributes to the facial skeleton and other derivatives. We have performed focal DiI injection into the cranial neural tube of the developing lamprey in order to follow the migratory pathways of discrete groups of cells from origin to destination and to compare neural crest migratory pathways in a basal vertebrate to those of gnath...

Hoxa2 is expressed in cranial neural crest cells that migrate into the second branchial arch and is essential for proper patterning of neural-crest-derived structures in this region. We have used transgenic analysis to begin to address the regulatory mechanisms which underlie neural-crest-specific expression of Hoxa2. By performing a deletion analysis on an enhancer from the Hoxa2 gene that is ...

Neural crest cells originating in the occipital region of the avian embryo are known to play a vital role in formation of the septum of the cardiac outflow tract and to contribute cells to the aortic arches, thymus, thyroid and parathyroids. This 'cardiac' neural crest sub-population is assumed to exist in mammals, but without direct evidence. In this paper we demonstrate, using RT-PCR and in s...

Neural crest cells arising from different rostrocaudal axial levels form different sets of derivatives as diverse as ganglia, cartilage and cornea. These variations may be due to intrinsic properties of the cell populations, different environmental factors encountered during migration or some combination thereof. We test the relative roles of intrinsic versus extrinsic factors by challenging th...

The neural crest is a transient embryonic structure whose cells migrate extensively before giving rise to a variety of differentiated cell types. Both intrinsic cell lineage information and environmental cues are thought to play a role in determining the fate of these cells. Early in development, these cells can be divided into distinct populations based on their axial level of origin. Cranial ...