The transcription factor, Lmx1b, is necessary for the development of the principal trigeminal nucleus-based lemniscal pathway.
Little is known of transcriptional mechanisms underlying the development of the trigeminal (V) principal sensory nucleus (PrV), the brainstem nucleus responsible for the development of the whisker-to-barrel cortex pathway. Lmx1b, a LIM homeodomain transcription factor, is expressed in embryonic PrV. In Lmx1b knockout ((-)(/)(-)) mice, V primary afferent projections to PrV are normal, albeit reduced in number, whereas the PrV-thalamic lemniscal pathway is sparse and develops late. Excess cell death occurs in the embryonic Lmx1b(-)(/)(-) PrV, but not in Lmx1b/Bax double null mutants. Expression of Drg11, a downstream transcription factor essential for PrV development and pattern formation, is abolished in PrV, but not in the V ganglion. Consequently, whisker patterns fail to develop in PrV by birth. Rescued PrV cells in Lmx1b/Bax double (-)(/)(-)s failed to rescue whisker-related PrV pattern formation. Thus, Lmx1b and Drg11 may act in the same genetic signaling pathway that is essential for PrV pattern formation.
Xiang
Chuanxi
C
Departments of Anesthesiology, Psychiatry, and Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Zhang
Kai-Hua
KH
Yin
Jun
J
Arends
Joop J A
JJ
Erzurumlu
Reha S
RS
Jacquin
Mark F
MF
Chen
Zhou-Feng
ZF
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D019521:Body Patterning / Q000235:genetics*; D016923:Cell Death / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D060850:LIM-Homeodomain Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics; D013788:Thalamus / Q000166:cytology / Q000196:embryology; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000196:embryology; D014278:Trigeminal Nuclei / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D014738:Vibrissae / Q000294:innervation*; D051028:bcl-2-Associated X Protein / Q000172:deficiency
D018398:Homeodomain Proteins; C112149:LIM homeobox transcription factor 1 beta; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; C433766:Prrxl1 protein, mouse; D014157:Transcription Factors; D051028:bcl-2-Associated X Protein