Specification of spatial identities of cerebellar neuron progenitors by ptf1a and atoh1 for proper production of GABAergic and glutamatergic neurons.
In the cerebellum, the bHLH transcription factors Ptf1a and Atoh1 are expressed in distinct neuroepithelial regions, the ventricular zone (VZ) and the rhombic lip (RL), and are required for producing GABAergic and glutamatergic neurons, respectively. However, it is unclear whether Ptf1a or Atoh1 is sufficient for specifying GABAergic or glutamatergic neuronal fates. To test this, we generated two novel knock-in mouse lines, Ptf1a(Atoh1) and Atoh1(Ptf1a), that are designed to express Atoh1 and Ptf1a ectopically in the VZ and RL, respectively. In Ptf1a(Atoh1) embryos, ectopically Atoh1-expressing VZ cells produced glutamatergic neurons, including granule cells and deep cerebellar nuclei neurons. Correspondingly, in Atoh1(Ptf1a) animals, ectopically Ptf1a-expressing RL cells produced GABAergic populations, such as Purkinje cells and GABAergic interneurons. Consistent results were also obtained from in utero electroporation of Ptf1a or Atoh1 into embryonic cerebella, suggesting that Ptf1a and Atoh1 are essential and sufficient for GABAergic versus glutamatergic specification in the neuroepithelium. Furthermore, birthdating analyses with BrdU in the knock-in mice or with electroporation studies showed that ectopically produced fate-changed neuronal types were generated at temporal schedules closely simulating those of the wild-type RL and VZ, suggesting that the VZ and RL share common temporal information. Observations of knock-in brains as well as electroporated brains revealed that Ptf1a and Atoh1 mutually negatively regulate their expression, probably contributing to formation of non-overlapping neuroepithelial domains. These findings suggest that Ptf1a and Atoh1 specify spatial identities of cerebellar neuron progenitors in the neuroepithelium, leading to appropriate production of GABAergic and glutamatergic neurons, respectively.
Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan, Integrative Bioscience and Biomedical Engineering, Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan, Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan, and Laboratory of Molecular Life Science, Foundation for Biomedical Research and Innovation, Kobe 650-0047, Japan.
Mayumi
M
Yamada
Yusuke
Y
Seto
Shinichiro
S
Taya
Tomoo
T
Owa
Yukiko U
YU
Inoue
Takayoshi
T
Inoue
Yoshiya
Y
Kawaguchi
Yo-Ichi
Y
Nabeshima
Mikio
M
Hoshino
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002531:Cerebellum / Q000166:cytology* / Q000196:embryology; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D018698:Glutamic Acid / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics; D058953:Neural Stem Cells / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D051792:Basic Helix-Loop-Helix Proteins; D018698:Glutamic Acid; D019394:Ki-67 Antigen; D014157:Transcription Factors; D005680:gamma-Aminobutyric Acid; C500943:Atoh1 protein, mouse; C062602:transcription factor PTF1
cerebellum; development; identity; neuron; spatial; transcription factor