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.
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 w