Estelle Hirsinger

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In vertebrates, muscles of the limbs and body wall derive from the lateral compartment of the embryonic somites, and axial muscles derive from the medial compartment. Whereas the mechanisms that direct patterning of somites along the dorsoventral axis are beginning to be understood, little is known about the tissue interactions and signaling molecules that(More)
BACKGROUND Neurons of the vertebrate central nervous system (CNS) are generated sequentially over a prolonged period from dividing neuroepithelial progenitor cells. Some cells in the progenitor cell population continue to proliferate while others stop dividing and differentiate as neurons. The mechanism that maintains the balance between these two(More)
The myogenic basic helix-loop-helix (bHLH) transcription factors, Myf5, MyoD, myogenin and MRF4, are unique in their ability to direct a program of specific gene transcription leading to skeletal muscle phenotype. The observation that Myf5 and MyoD can force myogenic conversion in non-muscle cells in vitro does not imply that they are equivalent. In this(More)
During Drosophila myogenesis, Notch signalling acts at multiple steps of the muscle differentiation process. In vertebrates, Notch activation has been shown to block MyoD activation and muscle differentiation in vitro, suggesting that this pathway may act to maintain the cells in an undifferentiated proliferative state. In this paper, we address the role of(More)
The Notch receptor is involved in many cell fate determination events in vertebrates and invertebrates. It has been shown in Drosophila melanogaster that Delta-dependent Notch signaling activates the transcription factor Suppressor of Hairless, leading to an increased expression of the Enhancer of Split genes. Genetic evidence has also implicated the(More)
In the vertebrate embryo, the lateral compartment of the somite gives rise to muscles of the limb and body wall and is patterned in response to lateral-plate-derived BMP4. Activation of the myogenic program distinctive to the medial somite, i.e. relatively immediate development of the epaxial muscle lineage, requires neutralization of this lateral signal.(More)
Recent data suggest that dental cells utilize the evolutonarily conserved Notch-mediated intercellular signaling pathway to regulate their fates. Here we report on the expression and regulation of Delta1, a transmembrane ligand of the Notch receptors, during mouse odontogenesis. Delta1 is weakly expressed in dental epithelium during tooth initiation and(More)
Recent evidence indicates that oligodendrocytes originate initially from the ventral neural tube. We have documented in chick embryos the effect of early ventralization of the dorsal neural tube on oligodendrocyte differentiation. Notochord or floor plate grafted at stage 10 in dorsal position induced the development of oligodendrocyte precursors in the(More)
The chick dermis is known to control the formation of feathers and interfeathery skin in a hexagonal pattern. The evidence that the segregation of two types of fibroblasts involves Delta/Notch signalling is based on three facts. Rings of C-Delta-1-expressing fibroblasts precede and delimit the forming feather primordia. C-Delta-1 is uniformly expressed in(More)
The cephalochordate amphioxus (Branchiostoma sp.) is an important animal model for studying the evolution of chordate developmental mechanisms. Obtaining amphioxus embryos is a key step for these studies. It has been shown that an increase of 3-4 degrees C in water temperature triggers spawning of the European amphioxus (Branchiostoma lanceolatum) in(More)