Expression of the transcription factor Pax 6 in the adult rat dentate gyrus.
The transcription factor Pax 6 is expressed in precursor cells during embryonic CNS development, and it plays an important role in the regulation of cell proliferation and neuronal fate determination. Pax 6-expressing cells are also present in the adult hippocampal dentate gyrus and subventricular zone/rostral migratory stream, regions in which neuronal precursors exist during adult life. In the adult dentate gyrus, precursor cells are located in the innermost portion of the granule cell layer, and Pax 6-expressing nuclei are most abundant in this region. To examine the putative role of Pax 6 in adult hippocampal neurogenesis, we have studied the proliferative activity, distribution, and phenotype of Pax 6-expressing cells by using immunohistochemistry. Our results indicate that Pax 6 is intensely expressed in proliferating precursors of the adult dentate gyrus. Pax 6 is also expressed in nonproliferating cells, which may correspond to resting progenitor cells and to granule neurons in their very early developmental stages, because this transcription factor is strongly down-regulated during granule neuron differentiation. However, a small subpopulation of hilar mature neurons and certain astrocytes of the adult hippocampus also express Pax 6. Although the precise roles of this transcription factor in the adult brain remain to be determined, our findings support the idea that its function in the control of cell proliferation and neuronal fate determination during embryogenesis is also operative in the adult hippocampus. However, the expression of Pax 6 in astrocytes and certain mature neurons may indicate the existence of other roles for this transcription factor in this telencephalic region.
Nacher
Juan
J
Neurobiology, Cell Biology Department, Universitat de València, Burjassot, Spain. nacher@uv.es
Varea
Emilio
E
Blasco-Ibañez
Jose M
JM
Castillo-Gomez
Esther
E
Crespo
Carlos
C
Martinez-Guijarro
Francisco J
FJ
McEwen
Bruce S
BS
D000818:Animals; D000963:Antimetabolites; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D001973:Bromodeoxyuridine; D049109:Cell Proliferation; D018891:Dentate Gyrus / Q000166:cytology / Q000378:metabolism*; D000089622:Doublecortin Domain Proteins; D005136:Eye Proteins / Q000096:biosynthesis* / Q000235:genetics; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D037121:Plant Lectins; D051381:Rats; D017207:Rats, Sprague-Dawley; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D013234:Stem Cells / Q000378:metabolism
D000963:Antimetabolites; D051792:Basic Helix-Loop-Helix Proteins; D001973:Bromodeoxyuridine; D000089622:Doublecortin Domain Proteins; D005136:Eye Proteins; D005904:Glial Fibrillary Acidic Protein; D049452:Green Fluorescent Proteins; D018398:Homeodomain Proteins; D007381:Intermediate Filament Proteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D064231:Nestin; D009479:Neuropeptides; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D037121:Plant Lectins; D012097:Repressor Proteins; C577486:Nes protein, rat; C000605733:Pax6 protein, rat; C034981:tomato lectin; C093564:Neurogenic differentiation factor 1