The contribution of extrinsic and genetic mechanisms in determining areas of the mammalian neocortex has been a contested issue. This study analyzes the roles of the regulatory genesEmx2 and Pax6, which are expressed in opposing gradients in the neocortical ventricular zone, in specifying areas. Changes in the patterning of molecular markers and area-specific connections between the cortex and thalamus suggest that arealization of the neocortex is disproportionately altered in Emx2 andPax6 mutant mice in opposing manners predicted from their countergradients of expression: rostral areas expand and caudal areas contract in Emx2 mutants, whereas the opposite effect is seen in Pax6 mutants. These findings suggest thatEmx2 and Pax6 cooperate to regulate arealization of the neocortex and to confer area identity to cortical cells.

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We are grateful to P. Gruss for the gift of Emx2 mice, M. Goulding for Sey mice and Pax6 plasmid, and Y. Nakagawa for Cad6, Cad8, and Gbx2 plasmids and helpful discussions. This work was supported by NIH grant NS31558 (D.D.M.O'L.), the Natural Sciences and Engineering Research Council of Canada (K.M.B.), and the Max-Planck Society and European Commission grant BI04-CT96-0378 (G.G.).

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Published In

Volume 288 | Issue 5464
14 April 2000

Submission history

Received: 4 October 1999
Accepted: 22 February 2000
Published in print: 14 April 2000


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Kathie M. Bishop
Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Guy Goudreau
Max-Planck-Institute for Biophysical Chemistry, Department of Molecular Cell Biology, Am Fassberg 11, 37077 Göttingen, Germany.
Dennis D. M. O'Leary*
Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.


To whom correspondence should be addressed. E-mail: [email protected]

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