A Hox regulatory network establishes motor neuron pool identity and target-muscle connectivity.
Spinal motor neurons acquire specialized "pool" identities that determine their ability to form selective connections with target muscles in the limb, but the molecular basis of this striking example of neuronal specificity has remained unclear. We show here that a Hox transcriptional regulatory network specifies motor neuron pool identity and connectivity. Two interdependent sets of Hox regulatory interactions operate within motor neurons, one assigning rostrocaudal motor pool position and a second directing motor pool diversity at a single segmental level. This Hox regulatory network directs the downstream transcriptional identity of motor neuron pools and defines the pattern of target-muscle connectivity.
Dasen
Jeremy S
JS
Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, NY 10032, USA.
Tice
Bonnie C
BC
Brenner-Morton
Susan
S
Jessell
Thomas M
TM
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002454:Cell Differentiation; D002642:Chick Embryo; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000502:physiology*; D009046:Motor Neurons / Q000378:metabolism / Q000502:physiology*; D018482:Muscle, Skeletal / Q000196:embryology / Q000294:innervation*; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology
D018398:Homeodomain Proteins; D014157:Transcription Factors