Dataset Information

Human Accelerated Regions regulate gene networks implicated in apical-to-basal neural progenitor fate transitions

ABSTRACT: The evolution of the human cerebral cortex involved modifications in the composition and proliferative potential of the neural stem cell (NSC) niche during brain development. Genetic changes that altered the activity of transcriptional enhancers have been linked to phenotypic differences between humans and other primates. Human Accelerated Regions (HARs) consist of >1600 highly constrained noncoding regions of the genome that show significant evolutionary acceleration on the human lineage, suggesting they encode human-specific functions. Multiple studies support that HARs include neurodevelopmental enhancers with novel activities in humans, but the regulatory roles of HARs in NSC biology has not been empirically assessed at scale. Here we conducted a direct-capture Perturb-seq screen repressing 180 neurodevelopmentally active HARs in human iPSC-derived NSCs with single-cell transcriptional readout. After profiling over 188,000 NSCs, we identified a set of HAR perturbations with convergent transcriptional effects on gene networks related to the specification of basal radial glia (bRG), a progenitor population that is expanded in humans. Processes associated with these networks included the regulation of apicobasal polarity and migration. We found convergent dysregulation of specific apicobasal polarity and adherens junction regulators, including PARD3, ABI2, SETD2, and PCM1, which are critical to apical-basal RG fate decisions. Autism- and intellectual-disability-associated genes were also enriched among genes showing changes in expression due to HAR perturbations. Our findings reveal interconnected roles for HARs in NSC biology and cortical development and link specific HARs to processes implicated in human cortical expansion.

ORGANISM(S): Homo sapiens

PROVIDER: GSE270828 | GEO | 2024/07/05

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Human Accelerated Regions (HARs) are highly conserved across species but exhibit a significant excess of human-specific sequence changes, suggesting they may have gained novel functions in human evolution. HARs include gene regulatory elements with human-specific activity and have been implicated in the evolution of the human brain. However, our understanding of how HARs contributed to uniquely human features of the brain is hindered by a lack of insight into the genes and pathways that HARs regulate. It is unknown whether HARs acted by altering the expression of gene targets conserved between HARs and their chimpanzee orthologs or by gaining new gene targets in human, a mechanism termed enhancer hijacking. We generated a high-resolution map of chromatin interactions for 1,590 HARs and their orthologs in human and chimpanzee neural stem cells (NSCs) to comprehensively identify gene targets in both species. HARs and their chimpanzee orthologs targeted a conserved set of 2,963 genes enriched for neurodevelopmental processes including neurogenesis and synaptic transmission. Changes in HAR enhancer activity were correlated with changes in conserved gene target expression. Conserved targets were enriched among genes differentially expressed between human and chimpanzee NSCs or between human and non-human primate developing and adult brain. Species-specific HAR gene targets did not converge on known biological functions and were not significantly enriched among differentially expressed genes, suggesting that most HARs did not alter gene expression via enhancer hijacking. HAR gene targets, including differentially expressed targets, also showed cell type-specific expression patterns in the developing human brain, notably in outer radial glia, which are hypothesized to contribute to human cortical expansion. Our findings support that HARs influenced human brain evolution by altering the expression of a conserved set of gene targets and provide the means to functionally link HARs with novel human brain features.

Dataset Information

Human Accelerated Regions regulate gene networks implicated in apical-to-basal neural progenitor fate transitions

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets