Gamma and alpha motor neurons distinguished by expression of transcription factor Err3.
Spinal motor neurons are specified to innervate different muscle targets through combinatorial programs of transcription factor expression. Whether transcriptional programs also establish finer aspects of motor neuron subtype identity, notably the prominent functional distinction between alpha and gamma motor neurons, remains unclear. In this study, we identify DNA binding proteins with complementary expression profiles in alpha and gamma motor neurons, providing evidence for molecular distinctions in these two motor neuron subtypes. The transcription factor Err3 is expressed at high levels in gamma but not alpha motor neurons, whereas the neuronal DNA binding protein NeuN marks alpha but not gamma motor neurons. Signals from muscle spindles are needed to support the differentiation of Err3(on)/NeuN(off) presumptive gamma motor neurons, whereas direct proprioceptive sensory input to a motor neuron pool is apparently dispensable. Together, these findings provide evidence that transcriptional programs define functionally distinct motor neuron subpopulations, even within anatomically defined motor pools.
Friese
Andreas
A
Biozentrum, Department of Cell Biology, University of Basel and Friedrich Miescher Institute for Biomedical Research, CH-4058 Basel, Switzerland.
Kaltschmidt
Julia A
JA
Ladle
David R
DR
Sigrist
Markus
M
Jessell
Thomas M
TM
Arber
Silvia
S
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D051379:Mice; D009046:Motor Neurons / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D009470:Muscle Spindles / Q000378:metabolism / Q000473:pathology; D009439:Neuraminidase / Q000378:metabolism; D009475:Neurons, Afferent / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D011434:Proprioception; D011960:Receptors, Estrogen / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D015415:Biomarkers; C490916:Esrrg protein, mouse; D011960:Receptors, Estrogen; D014157:Transcription Factors; D009439:Neuraminidase