Identification of midbrain floor plate radial glia-like cells as dopaminergic progenitors.
The floor plate (FP), a signaling center and a structure rich in radial glia-like cells, has been traditionally thought to be devoid of neurons and neuronal progenitors. However, in the midbrain, the FP contains neurons of the dopaminergic (DA) lineage that require contact with radial glia-like cells for their induction. We, therefore, decided to explore the interaction relationship between radial glia and neurons during DA neurogenesis. Taking advantage of a novel FP radial glia-like cell culture system and retroviruses, DA neurons were lineage traced in vitro. In utero BrdU pulse-chases extensively labeled the midbrain FP and traced DA neurons both in vivo and in FP cultures. Moreover, from E9.5 to E13.5 the midbrain FP contained dividing cells only in the most apical part of the neuroepithelium, in cells identified as radial glia-like cells. We, therefore, hypothesized that midbrain FP radial glia-like cells could be DA progenitors and tested our hypothesis in vivo. Lineage tracing of DA progenitors with EGFP in Tis21-EGFP knock-in mice, and genetic fate mapping in GLAST::CreERT2/ZEG mice identified the neuroepithelium of the midbrain FP, and specifically, GLAST+ radial glia-like cells as DA progenitors. Combined, our experiments support the concept that the midbrain FP differs from other FP regions and demonstrate that FP radial glia-like cells in the midbrain are neurogenic and give rise to midbrain DA neurons.
Bonilla
Sonia
S
Laboratory of Molecular Neurobiology, MBB, Karolinska Institutet, Scheeles väg 1, A1:2, 171 77 Stockholm, Sweden.
Hall
Anita C
AC
Pinto
Luisa
L
Attardo
Alessio
A
Götz
Magdalena
M
Huttner
Wieland B
WB
Arenas
Ernest
E
D000367:Age Factors; D000818:Animals; D019521:Body Patterning / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D001973:Bromodeoxyuridine / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D004298:Dopamine / Q000378:metabolism*; D004622:Embryo, Mammalian; D053595:Embryonic Stem Cells / Q000166:cytology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D027341:Excitatory Amino Acid Transporter 1 / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D016147:Genes, Tumor Suppressor; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D017874:Immediate-Early Proteins / Q000235:genetics; D008636:Mesencephalon / Q000166:cytology* / Q000196:embryology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy; D013629:Tamoxifen / Q000494:pharmacology; D025521:Tumor Suppressor Proteins
C489435:Btg2 protein, mouse; D004965:Estrogen Antagonists; D027341:Excitatory Amino Acid Transporter 1; D017874:Immediate-Early Proteins; C493393:Slc1a3 protein, mouse; D025521:Tumor Suppressor Proteins; C485184:enhanced green fluorescent protein; D013629:Tamoxifen; D049452:Green Fluorescent Proteins; D001973:Bromodeoxyuridine; D004298:Dopamine