First published online November 28, 2005
Development 132, 2405e (2005)
© The Company of Biologists Limited
Axon guidance made SIMple
During brain development, attractive and repulsive signals establish
functional connections within the brain by guiding the growth of axons. The
genetic and transcriptional regulation of axonal guidance is poorly understood
but, on p. 5527,
Marion et al. report that, in the developing mouse brain, the transcription
factors SIM1 and SIM2 are required for the correct targeting of mammillary
body axons, part of the neuronal circuitry involved in spatial learning. The
authors show, for example, that, in mouse embryos that lack both copies of
Sim1 and one or two copies of Sim2, mammillary body neurons
form but fail to lay down normal axonal projections. Overall, the researchers
conclude that Sim1 and Sim2 play similar roles in vivo, and
suggest that they should be added to the growing list of transcription factors
that regulate the expression of molecules that control axonal morphology and
connectivity.
Related articles in Development:
- Sim1 and Sim2 are required for the correct targeting of mammillary body axons
- Jean-François Marion, Chun Yang, Aurore Caqueret, Francine Boucher, and Jacques L. Michaud
Development 2005 132: 5527-5537.
[Abstract]
[Full Text]
