BioProject

The cerebral cortex underwent a rapid expansion and complexification during recent primate evolution, but the underlying developmental mechanisms remain essentially unknown. More...

The cerebral cortex underwent a rapid expansion and complexification during recent primate evolution, but the underlying developmental mechanisms remain essentially unknown. In order to uncover genetic networks underlying the development of the human cerebral cortex, we profiled the transcriptome of human fetal cortical domains containing language areas of Broca and Wernicke, as well as associative areas. We thus identified hundreds of genes displaying differential expression between the two areas or between distinct temporal stages. A subset of these genes was further validated by qRTPCR and in situ hybridization, revealing novel patterns of area and layer-specific expression throughout the developing cortex at midgestation, a critical period of cortical patterning. Computational genomic analyses revealed that the proportion of genes located close to evolutionarily accelerated regions was far more abundant among the genes differentially expressed between the two cortical areas examined, but not among those differentially expressed between different stages of development. In silico screening enabled to identify accelerated regions displaying increased turnover of change in transcription factor binding sites, which were enriched among those closer to genes differentially expressed between cortical areas. Overall our work points to the identification of cortical genes that display a unique combination of patterns of evolution and expression, which may constitute an important part of the genetic framework underlying human-specific neural traits and diseases. Overall design: We determined gene expression patterns in cortical domains that contain areas thought to have undergone significant divergence during primate evolution, including language areas of Broca and Wernicke, as well as association areas of the frontal and parieto-temporal cortex in the right and left sides of human fetal brains at 17 and 19 gestional weeks. Less...