Evolutionary Gain of Dbx1 Expression Drives Subplate Identity in the Cerebral Cortex
Résumé
Changes in transcriptional regulation throughcis-regulatory elements are thought to drive brainevolution. However, how this impacts the identityof primate cortical neurons is still unresolved.Here, we show that primate-specificcis-regulatorysequences upstream of theDbx1gene promote hu-man-like expression in the mouse embryonic cere-bral cortex, and this imparts cell identity. Indeed,while Dbx1 is expressed in highly restricted corticalprogenitors in the mouse ventral pallium, it is main-tained in neurons in primates. Phenocopy of theprimate-like Dbx1 expression in mouse cortical pro-genitors induces ectopic Cajal-Retzius and subplate(SP) neurons, which are transient populations play-ing crucial roles in cortical development. A condi-tional expression solely in neurons uncouples mitoticand postmitotic activities of Dbx1 and exclusivelypromotes a SP-like fate. Our results highlight howtranscriptional changes of a single fate determinantin postmitotic cells may contribute to the expansionof neuronal diversity during cortical evolution
Domaines
NeurobiologieOrigine | Fichiers éditeurs autorisés sur une archive ouverte |
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