Identification and morphogenesis of the eminentia thalami in the zebrafish.
This study documents early zebrafish brain expression patterns (2-5 days postfertilization) of proliferating neural (PCNA) as well as early-determined (Pax6, Zash-1a, Zash-1b, neurogenin1, neuroD) and differentiating (Hu-proteins) neuronal cells. These patterns are used to outline the spatiotemporal local dynamics of secondary neurogenesis as well as neuronal migration and differentiation in the region of the eminentia thalami. The analysis presented not only allows identification for the first time of the eminentia thalami in the zebrafish model system (because it forms a neurogenin1/neuroD-guided locus of neurogenesis in contrast to adjacent preoptic region and ventral thalamus) but furthermore shows that the entopeduncular complex is a derivative of the embryonic zebrafish eminentia thalami, which has never been reported for a teleost before. An analysis of the relevant literature shows that the mammalian entopeduncular nucleus/avian paleostriatum primitivum/reptilian globus pallidus clearly are part of the basal ganglia (i.e., the pallidum). In amniote embryos, an anterior entopeduncular area is recognized at the base of the medial ganglionic eminence (i.e., the future pallidum; part of alar plate of prosomere 5), separate from the more posterior eminentia thalami (alar prosomere 4). There is a comparable periventricular eminentia thalami in (young and adult) amphibians and teleosts. However, the migrated anterior entopeduncular nucleus of anuran amphibians likely is homologous to part of the pallidum of other vertebrates and has no developmental relationship to the eminentia thalami. In contrast, the migrated teleostean entopeduncular complex does not correspond to a pallidal division but is indeed the adult derivative of the early-recognized eminentia thalami as shown in this study.
Centre National de la Recherche Scientifique Institute of Neurobiology A. Fessard, Development, Evolution, Plasticity of the Nervous System--Research Unit 2197, F-91198 Gif-sur-Yvette Cedex, France. mario.wullimann@iaf.cnrs-gif.fr
Mario F
MF
Wullimann
Thomas
T
Mueller
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D019521:Body Patterning / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D051959:ELAV Proteins; D020392:Entopeduncular Nucleus / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism; D005136:Eye Proteins; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D009024:Morphogenesis; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D012097:Repressor Proteins; D013788:Thalamus / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000378:metabolism*
D051792:Basic Helix-Loop-Helix Proteins; D051959:ELAV Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D018809:Proliferating Cell Nuclear Antigen; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C468127:Ascl1a protein, zebrafish; C471336:Ascl1b protein, zebrafish; C486337:neurog1 protein, zebrafish; C093564:Neurogenic differentiation factor 1