Tuesday, May 11, 2004
Much of the major work in development has been done in Xenopus (frog) embryos, thanks to the pioneering work of Hans Spemann, who discovered that embryos develop based on organized areas of cells, that there were certain (seemingly identical) cells that were predetermined to produce head, body, arms, etc. All this was based largely on concentration gradients of various trophic and inhibitory factors.
The nervous system has long been thought to rise from ectoderm due to chemical signals from the Spemann Organizer in the mesoderm.
New research, however, suggests that neural induction begins much earlier: at the blastula phase. A center in the blastular pre-ectoderm called BCNE seems predisposed to become neural tissue, due to its high production of induction factors Noggin and Chordin. It turns out, however, that these cells do require factors from the Spemann Organizer to develop properly. The Organizerproduces Cerberus, which is required, or else no head develops...and partial inhibition along with Chordin prevents brain development.
This kind of research leads to all kinds of cool stuff...like regrowth, enhancement, and other therapies...plus all the fun names!