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, 16 May 2000
Vol. 2000, Issue 32, p. tw6
[DOI: 10.1126/stke.2000.32.tw6]


Developmental Neurobiology Axons With Brakes

Migration of neuronal growth cones in the Drosophila visual system is a model system useful for understanding how axons seek their targets during development. Axons from certain photoreceptor cells in the fly's compound eye project specifically to the lamina region of the brain's optic lobe. In a genetic screen for mutations that disrupt this precision, Senti et al. identified a gene called brakeless (bks) that is necessary for these axons to terminate in the lamina. Without bks, axons fail to stop in the lamina and project onto the medulla. One of the two alternatively spliced isoforms of the gene product for bks has a zinc-finger-like domain, and both isoforms localized to cellular nuclei. Hence, in addition to target-derived cues that regulate axon outgrowth, intrinsic factors in the migrating neurons play a key role as well. It is not clear whether bks provides growth cones with the molecular machinery needed to respond to targeting signals, or acts in the nucleus to stop axon extension in response to these signals.

Senti, K.-A., Keleman, K., Eisenhaber, F., and Dickson, B.J. (2000) brakeless is required for lamina targeting of R1-R6 axons in the Drosophila visual system. Development 127: 2291-2301. [Online Journal]

Citation: Axons With Brakes. Sci. STKE 2000, tw6 (2000).

To Advertise     Find Products

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