Project description:Human higher cognition is attributed to the evolutionary expansion and elaboration of the human cerebral cortex. However, the genetic mechanisms contributing to these developmental changes are poorly understood. We used comparative epigenetic profiling of human, rhesus macaque, and mouse corticogenesis to identify promoters and enhancers that have gained activity in humans. These gains are significantly enriched in modules of coexpressed genes in the cortex that function in neuronal proliferation, migration, and cortical-map organization. Gain-enriched modules also showed correlated gene expression patterns and similar transcription factor binding site enrichments in promoters and enhancers, suggesting that they are connected by common regulatory mechanisms. Our results reveal coordinated patterns of potential regulatory changes associated with conserved developmental processes during corticogenesis, providing insight into human cortical evolution.
Project description:Evolutionary changes in gene regulation during cortical development likely contributed to the expansion and specialization of the cortex in humans. However, the lack of a regulatory map of the human embryonic cortex has hindered identification of these changes and the biological processes they influenced. We performed genome-wide epigenetic profiling to compare promoter and enhancer activity during corticogenesis in human, rhesus, and mouse. We identified 2,855 promoters and 8,996 enhancers that have gained activity in human based on increased epigenetic marking. To detect biological pathways enriched for these changes, we mapped promoters and enhancers exhibiting epigenetic gains onto modules of co-expressed genes constructed using spatio-temporally rich expression data from developing human cortex. We identified multiple modules enriched in human lineage epigenetic gains. Gains in enriched modules were associated with genes functioning in neuronal proliferation and migration, cortical patterning, and the extracellular matrix. Gain-enriched modules also showed correlated gene expression patterns and similar transcription factor binding site enrichments in promoters and enhancers, suggesting they are connected by common regulatory mechanisms. Our results reveal coordinated patterns of potential regulatory changes associated with conserved developmental processes in corticogenesis, providing insight into human cortical evolution.
Project description:Evolutionary changes in gene regulation during cortical development likely contributed to the expansion and specialization of the cortex. However, the lack of a regulatory map of the embryonic cortex has hindered identification of these changes and the biological processes they influenced. We performed genome-wide epigenetic profiling to compare promoter and enhancer activity during corticogenesis in rhesus and mouse. We identified 2,855 promoters and 8,996 enhancers that have gained activity in based on increased epigenetic marking. To detect biological pathways enriched for these changes, we mapped promoters and enhancers exhibiting epigenetic gains onto modules of co-expressed genes constructed using spatio-temporally rich expression data from developing cortex. We identified multiple modules enriched in lineage epigenetic gains. Gains in enriched modules were associated with genes functioning in neuronal proliferation and migration, cortical patterning, and the extracellular matrix. Gain-enriched modules also showed correlated gene expression patterns and similar transcription factor binding site enrichments in promoters and enhancers, suggesting they are connected by common regulatory mechanisms. Our results reveal coordinated patterns of potential regulatory changes associated with conserved developmental processes in corticogenesis, providing insight into cortical evolution.