The collaborators at Yale and Caltech demonstrate with three different technologies -- immunostaining of proteins, in situ hybridization and multiplex RT-PCR of mRNAs -- that formation of neural crest cells in chick embryos is independent of both mesoderm and neural tissues. They also identify, Pax7, as an early marker of neural crest formation and prove that its function is required in the earliest stages of development.
Early chick embryo with Pax-7 (red) designating neural crest progenitor cells. Credit: Martín García-Castro
The neural crest is a population of stem cells that migrate extensively during development and give rise to many derivatives, including most of the bone and cartilage of the head skeleton, pigment cells of the skin, and cells of the peripheral nervous system.
In humans, cleft palate, heart valve malformations and various tumors are among the common malformations associated with disruption of neural crest development.
Chick embryos have well-characterized stages and are a valuable model for examining vertebrate development. While it was known that the ability to form neural crest cells declines after "stage 10," the researchers were seeking the earliest conditions surrounding formation of these important stem cells.
"Understanding the origin of neural crest cells -- where, when and how they arise -- is a critical step if we are to manipulate them for therapeutic purposes," said Martín García-Castro, assistant professor of molecular, cellular and developmental biology at Yale and principal investigator on the study. "Implications of these basic questions of biology and development reach far beyond these chicken and eggs."
Based on work from the 1940's before molecular tools were available, the neural crest was thought to form by interactions between neural and non-neural cell layers. "We show in this work that neural crest stem cell precursors are designated very early in development -- as early as the gastrula stages -- and in an independent fashion from those other tissues," said Martín García-Castro.
The researchers grew grafts of cells from "stage 3" chick embryos, before the neural plate formed, in non-inducing cultures. Surprisingly, restricted regions of the embryo generated both migrating neural crest cells and their derivative cell types, without any interaction with neural or mesodermal tissues.
"Our results are contrary to current text-book models and suggest that different modes of neural crest induction operate during development," said Martín García-Castro. "Interestingly, the one we have uncovered is related to the early, cranial neural crest cells, the only ones in higher vertebrates that retain bone and cartilage forming potential."
Janet Rettig Emanuel | EurekAlert!
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
Pollen taxi for bacteria
18.07.2018 | Technische Universität München
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
18.07.2018 | Materials Sciences
18.07.2018 | Life Sciences
18.07.2018 | Health and Medicine