Neocortex Patterning by the Secreted Signaling Molecule FGF8
Tomomi Fukuchi-Shimogori,
Elizabeth A. Grove*
A classic model proposes that the mammalian neocortex is divided
into areas early in neurogenesis, but the molecular mechanisms that
generate the area map have been elusive. Here we provide evidence that
FGF8 regulates development of the map from a source in the anterior
telencephalon. Using electroporation-mediated gene transfer in mouse
embryos, we show that augmenting the endogenous anterior FGF8 signal
shifts area boundaries posteriorly, reducing the signal shifts them
anteriorly, and introducing a posterior source of FGF8 elicits partial
area duplications, revealed by ectopic somatosensory barrel fields.
These findings support a role for FGF signaling in specifying
positional identity in the neocortex.
Department of Neurobiology, Pharmacology and Physiology,
University of Chicago, Chicago, IL 60637, USA.
*
To whom correspondence should be addressed. E-mail:
egrove{at}drugs.bsd.uchicago.edu