Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. STKE, 13 March 2001
Vol. 2001, Issue 73, p. tw3
[DOI: 10.1126/stke.2001.73.tw3]


Molecular Genetics Building a Brain Map

Leighton et al. developed a sophisticated screen to specifically detect mouse proteins that function in axonal guidance. To identify cell-surface and secreted proteins, which would include receptors and ligands that contribute to proper patterning in the brain, they used a gene trapping strategy that selects for vector insertion into a gene that encodes a signal sequence. To identify axons expressing such targeted genes, they included an internal ribosome entry site (IRES) to drive the expression of placental alkaline phosphatase (PLAP), a convenient axonal marker. Such labeling of axons allowed visualization of the wiring pattern of altered cells in the brains of transgenic mice. Among the targeted genes, the authors identified those encoding semaphorin 6A, a transmembrane protein previously implicated as a receptor that signals axon repulsion, and the Eph4a receptor tyrosine kinase. The authors suggest that this method will contribute to the creation of a "molecular map of axonal projections" and will deposit the information about PLAP-expressing embryonic stem cells and transgenic mouse lines in an online database (

P. A. Leighton, K. J. Mitchell, L. V. Goodrich, X. Lu, K. Pinson, P. Scherz, W. C. Skarnes, M. Tessier-Lavigne. Defining brain wiring patterns and mechanisms through gene trapping in mice. Nature 410, 174-179 (2001). [Online Journal]

Citation: Building a Brain Map. Sci. STKE 2001, tw3 (2001).

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882