RT Journal Article
SR Electronic
T1 MicroRNA miR-9 Modifies Motor Neuron Columns by a Tuning Regulation of FoxP1 Levels in Developing Spinal Cords
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 809
OP 818
DO 10.1523/JNEUROSCI.4330-10.2011
VO 31
IS 3
A1 Gaizka Otaegi
A1 Andrew Pollock
A1 Janet Hong
A1 Tao Sun
YR 2011
UL http://www.jneurosci.org/content/31/3/809.abstract
AB The precise organization of motor neuron subtypes in a columnar pattern in developing spinal cords is controlled by cross-interactions of multiple transcription factors and segmental expressions of Hox genes and their accessory proteins. Accurate expression levels and domains of these regulators are essential for organizing spinal motor neuron columns and axonal projections to target muscles. Here, we show that microRNA miR-9 is transiently expressed in a motor neuron subtype and displays overlapping expression with its target gene FoxP1. Overexpression or knockdown of miR-9 alters motor neuron subtypes, switches columnar identities, and changes axonal innervations in developing chick spinal cords. miR-9 modifies spinal columnar organization by specifically regulating FoxP1 protein levels, which in turn determine distinct motor neuron subtypes. Our findings demonstrate that miR-9 is an essential regulator of motor neuron specification and columnar formation. Moreover, the overlapping expression of miR-9 and its target FoxP1 further illuminates the importance of fine-tuning regulation by microRNAs in motor neuron development.