Runx3 is required for the specification of TrkC-expressing mechanoreceptive trigeminal ganglion neurons.
Sensory neurons project axons to specific peripheral and central targets according to their sensory modality. Runx3 is crucially involved in proprioceptive dorsal root ganglion neuron development. Runx3 is also expressed in trigeminal ganglion (TG) neurons. The role of Runx3 in the TG, however, is largely unknown because the TG does not contain proprioceptive neurons. In Runx3-deficient (Runx3(-/-)) mice, TrkB-expressing TG neurons were increased, whereas TrkC-expressing TG neurons were decreased during TG neuron development. In Runx3(-/-) neonatal mice, TrkC-expressing TG neurons did not project to the Merkel cells in the outer root sheath (ORS) of whisker vibrissae peripherally and the spinal trigeminal nucleus pars interpolaris (Sp5I) centrally. These findings suggest that Runx3 is required for the specification of TrkC-expressing TG neurons, conveying mechanoreceptive signals from the Merkel cells in the ORS of the whisker vibrissae to the Sp5I.
Senzaki
Kouji
K
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
Ozaki
Shigeru
S
Yoshikawa
Masaaki
M
Ito
Yoshiaki
Y
Shiga
Takashi
T
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D050677:Core Binding Factor Alpha 3 Subunit / Q000235:genetics / Q000378:metabolism*; D008465:Mechanoreceptors / Q000166:cytology / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009475:Neurons, Afferent / Q000166:cytology / Q000502:physiology*; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism; D020812:Receptor, trkC / Q000235:genetics / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000166:cytology*; D014738:Vibrissae / Q000166:cytology / Q000502:physiology
D015415:Biomarkers; D050677:Core Binding Factor Alpha 3 Subunit; C493730:Runx3 protein, mouse; D020813:Receptor, trkB; D020812:Receptor, trkC