Relationships between neural crest cells and catecholamine in suckling mice.

In suckling mice injected i.p. with a 27 mg/kg dose of L-hydrochloric acid isoproterenol, multiple neural crest tumors developed and cell death of neural crest cells occurred. It is speculated that neural crest derivatives may be beta-receptor cells and contain regulatory units of neurotransmission mediated through cyclic AMP.     

Multiple oncogenesis of neural crest cells by steroids in suckling mice

Summary In suckling mice injected with steroids, multiple tumors occurred in the sites where neural crest cells normally are present. It is speculated that the phase of the cell cycle of the neural crest cells may have something to do with its cell surface and cellular phenotypic expression in the system mediated by cyclic AMP.     

Relationships between neural crest cells and catecholamine in suckling mice

Summary In suckling mice injected i.p. with a 27 mg/kg dose of L-hydrochloric acid isoproterenol, multiple neural crest tumors developed and cell death of neural crest cells occurred. It is speculated that neural crest derivatives may be -receptor cells and contain regulatory units of neurotransmission mediated through cyclic AMP.     

Wnt1 and BMP2: two factors recruiting multipotent neural crest progenitors isolated from adult bone marrow

Recent studies have shown that neural crest-derived progenitor cells can be found in diverse mammalian tissues including tissues that were not previously shown to contain neural crest derivatives, such as bone marrow. The identification of those "new" neural crest-derived progenitor cells opens new strategies for developing autologous cell replacement therapies in regenerative medicine. However, their potential use is still a challenge as only few neural crest-derived progenitor cells were found in those new accessible locations. In this study, we developed a protocol, based on wnt1 and BMP2 effects, to enrich neural crest-derived cells from adult bone marrow. Those two factors are known to maintain and stimulate the proliferation of embryonic neural crest stem cells, however, their effects have never been characterized on neural crest cells isolated from adult tissues. Using multiple strategies from microarray to 2D-DIGE proteomic analyses, we characterized those recruited neural crest-derived cells, defining their identity and their differentiating abilities.     

Glial versus melanocyte cell fate choice: Schwann cell precursors as a cellular origin of melanocytes

Melanocytes and Schwann cells are derived from the multipotent population of neural crest cells. Although both cell types were thought to be generated through completely distinct pathways and molecular processes, a recent study has revealed that these different cell types are intimately interconnected far beyond previously postulated limits in that they share a common post-neural crest progenitor, i.e. the Schwann cell precursor. This finding raises interesting questions about the lineage relationships of hitherto unrelated cell types such as melanocytes and Schwann cells, and may provide clinical insights into mechanisms of pigmentation disorders and for cancer involving Schwann cells and melanocytes.     

Multiple APUD system (neural crest) tumors caused by endotoxin in suckling mice

Summary In suckling mice injected i. p. with endotoxin on the 1st day after birth and surviving up to the 4th day, multiple tumors and heterotopic melanin pigmentation occurred in the sites where the neural crest cells may be present.     

The effects of ethanol on embryonic actin: A possible role in teratogenesis

Summary When the neural crest is cultured in the long or short term presence of ethanol, monoclonal anti-actin reveals the development of a disorganized actin cytoskeleton. In the long term, many cells fail to differentiate morphologically, whereas in the short term already differentiated cells rapidly alter their shape and their cell-to-cell contacts.     

The effects of ethanol on embryonic actin: a possible role in teratogenesis

When the neural crest is cultured in the long or short term presence of ethanol, monoclonal anti-actin reveals the development of a disorganized actin cytoskeleton. In the long term, many cells fail to differentiate morphologically, whereas in the short term already differentiated cells rapidly alter their shape and their cell-to-cell contacts.     

A possibility to achieve genetic transformation in the platyfish-swordtail system (Platypoecilus maculatus — Xiphophorus helleri)

Summary In order to determine how informative homologous donor DNA might be made available to propigment cells of the recipientXiphophorus helleri for transformation, labelled heterologous DNA fromE. coli was injected into the neural crest region or the yolk sac of embryos of the recipient. On the basis of the degradation rate of the donor DNA and the incorporation rate of radioactivity into the recipient DNA, it is concluded that injection into the neural crest region may be a suitable method to make available informative homologous donor DNA for transformation.Supported by DFG through SFB No. 103, and by Stiftung Volkswagenwerk.     

Role of extracardiac factors in heart development

Many factors extrinsic to the developing heart play important roles in determining its final form. The neural crest has been shown to provide ectomesenchyme to the pharyngeal apparatus and outflow tract, as well as the postganglionic innervation of the heart. Ablation of the neural crest providing ectomesenchyme to the outflow tract results in various cardiac malformations. These malformations have in common either outflow and/or inflow tract malalignment. Although the reason for this malalignment is not understood, it is thought that hemodynamic parameters during early cardiac morphogenesis may be disrupted causing cardiac dysmorphogenesis. The most likely area for this alteration to occur is in the pharyngeal apparatus which houses the aortic arch arteries. Various possibilities are discussed. The innervation of the heart by neural crest-derived autonomic neurons and nodose placode-derived sensory neurons is outlined, and the interactions between the two progenitive sites is discussed.     

An isoform of the vacuolar (H+)-ATPase accessory subunit Ac45

The vacuolar (H⁺)-ATPase (V-ATPase) is the main regulator of intraorganellar pH and in neuroendocrine cells is controlled by its accessory subunit, Ac45. Here, we report the discovery of the first isoform of a V-ATPase accessory subunit, namely an Ac45-like protein, denoted Ac45LP. Phylogenetic analysis revealed a lineage-dependent evolutionary history: Ac45 is absent in birds, and Ac45LP is absent in placental mammals, whereas all other tetrapod species contain both genes. In contrast to Ac45, Ac45LP is not proteolytically cleaved, a prerequisite for proper Ac45 routing. Intriguingly, Xenopus Ac45LP mRNA was expressed in developing neural tissue and in neural crest cells. In adult Xenopus, Ac45 mRNA is widely expressed mostly in neuroendocrine tissues, while Ac45LP mRNA expression was found to be restricted to the kidney and the lung. This novel Ac45LP may provide additional possibilities for V-ATPase regulation during neurodevelopment as well as in kidney and lung cells.     

Die frühe Differenzierung erster Melanocyten beim Entenembryo

Summary The first melanocytes in the duck (Khaki Campbell) appear after an incubation period of 88 h (about 40 somites) in the otic region. The melanoblasts of that region can be traced back to cells of the rhombencephalic neural crest of the 17-somites stage.

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Das Untersuchungsmaterial wurde während des Aufenthaltes am Hubrecht-Laboratorium in Utrecht anlässlich des Second International Teamwork gesammelt. Zur Durchführung der Untersuchungen standen Mittel der Deutschen Forschungsgemeinschaft zur Verfügung.     

Role of extracellular matrix molecules in the development of the sodium current in quail mesencephalic neural crest cells

The occurrence of the voltage-dependent sodium current has been studied in developing neurons from quail mesencephalic neural crest on different substrates, using the whole-cell patch clamp technique. Explants from 9–12 somite embryos were cultured on dishes coated with type I collagen, fibronectin, laminin or on plastic dishes in a chemically defined medium. After 18 h of culture the sodium current was observed in 70% of the neurons tested, and at 24 h some of these neurons were able to generate an action potential. After 18–25 h cells grown on fibronectinor collagen I-coated dishes showed a significantly higher occurrence of the sodium current (83% and 84% respectively) as compared to cells grown on uncoated plastic dishes (51%). Moreover, in the presence of fibronectin, the current density of the sodium current was more than doubled in comparison with cells grown on other substrates.