Three-dimensional genome re-wiring in loci with Human Accelerated Regions
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ABSTRACT:
ORGANISM(S): Pan troglodytes Homo sapiens
PROVIDER: GSE183137 | GEO | 2022/12/21
REPOSITORIES: GEO
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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.
2024-06-25 | GSE270272 | GEO
Project description:Human accelerated regions (HARs) are conserved genomic loci that have experienced rapid nucleotide substitutions following the divergence from chimpanzees. HARs are enriched in candidate regulatory regions near neurodevelopmental genes, suggesting their roles in gene regulation. However, their target genes and functional contributions to human brain development remain largely uncharacterized. Here, we elucidate the cis-regulatory functions of HARs in human and chimpanzee induced pluripotent stem cell (iPSC)-induced excitatory neurons. Using genomic and chromatin looping information, we prioritized 20 HARs and their chimpanzee orthologs for functional characterization via single-cell CRISPRi, and demonstrated their species-specific gene regulatory functions. Our findings reveal diverse functional outcomes of HAR-mediated cis-regulation in human neurons, including attenuated NPAS3 expression by altering the binding affinities of multiple transcription factors in HAR202 and maintaining iPSC pluripotency and neuronal differentiation capacities through the upregulation of PUM2 by 2xHAR.319. Finally, we use prime editing to demonstrate differential enhancer activity caused by several HAR26;2xHAR.178 variants. In particular, we link one variant in HAR26;2xHAR.178 to elevated SOCS2 expression and increased neurite outgrowth in human neurons. Thus, our study sheds new light on the endogenous gene regulatory functions of HARs and their potential contribution to human brain evolution.
2024-11-12 | GSE269798 | GEO
Project description:Human accelerated regions (HARs) are conserved genomic loci that have experienced rapid nucleotide substitutions following the divergence from chimpanzees. HARs are enriched in candidate regulatory regions near neurodevelopmental genes, suggesting their roles in gene regulation. However, their target genes and functional contributions to human brain development remain largely uncharacterized. Here, we elucidate the cis-regulatory functions of HARs in human and chimpanzee induced pluripotent stem cell (iPSC)-induced excitatory neurons. Using genomic and chromatin looping information, we prioritized 20 HARs and their chimpanzee orthologs for functional characterization via single-cell CRISPRi, and demonstrated their species-specific gene regulatory functions. Our findings reveal diverse functional outcomes of HAR-mediated cis-regulation in human neurons, including attenuated NPAS3 expression by altering the binding affinities of multiple transcription factors in HAR202 and maintaining iPSC pluripotency and neuronal differentiation capacities through the upregulation of PUM2 by 2xHAR.319. Finally, we use prime editing to demonstrate differential enhancer activity caused by several HAR26;2xHAR.178 variants. In particular, we link one variant in HAR26;2xHAR.178 to elevated SOCS2 expression and increased neurite outgrowth in human neurons. Thus, our study sheds new light on the endogenous gene regulatory functions of HARs and their potential contribution to human brain evolution.
2024-11-12 | GSE222112 | GEO
Project description:Human accelerated regions (HARs) are conserved genomic loci that have experienced rapid nucleotide substitutions following the divergence from chimpanzees. HARs are enriched in candidate regulatory regions near neurodevelopmental genes, suggesting their roles in gene regulation. However, their target genes and functional contributions to human brain development remain largely uncharacterized. Here, we elucidate the cis-regulatory functions of HARs in human and chimpanzee induced pluripotent stem cell (iPSC)-induced excitatory neurons. Using genomic and chromatin looping information, we prioritized 20 HARs and their chimpanzee orthologs for functional characterization via single-cell CRISPRi, and demonstrated their species-specific gene regulatory functions. Our findings reveal diverse functional outcomes of HAR-mediated cis-regulation in human neurons, including attenuated NPAS3 expression by altering the binding affinities of multiple transcription factors in HAR202 and maintaining iPSC pluripotency and neuronal differentiation capacities through the upregulation of PUM2 by 2xHAR.319. Finally, we use prime editing to demonstrate differential enhancer activity caused by several HAR26;2xHAR.178 variants. In particular, we link one variant in HAR26;2xHAR.178 to elevated SOCS2 expression and increased neurite outgrowth in human neurons. Thus, our study sheds new light on the endogenous gene regulatory functions of HARs and their potential contribution to human brain evolution.
2024-11-12 | GSE221830 | GEO
Project description:Human accelerated regions (HARs) are conserved genomic loci that have experienced rapid nucleotide substitutions following the divergence from chimpanzees. HARs are enriched in candidate regulatory regions near neurodevelopmental genes, suggesting their roles in gene regulation. However, their target genes and functional contributions to human brain development remain largely uncharacterized. Here, we elucidate the cis-regulatory functions of HARs in human and chimpanzee induced pluripotent stem cell (iPSC)-induced excitatory neurons. Using genomic and chromatin looping information, we prioritized 20 HARs and their chimpanzee orthologs for functional characterization via single-cell CRISPRi, and demonstrated their species-specific gene regulatory functions. Our findings reveal diverse functional outcomes of HAR-mediated cis-regulation in human neurons, including attenuated NPAS3 expression by altering the binding affinities of multiple transcription factors in HAR202 and maintaining iPSC pluripotency and neuronal differentiation capacities through the upregulation of PUM2 by 2xHAR.319. Finally, we use prime editing to demonstrate differential enhancer activity caused by several HAR26;2xHAR.178 variants. In particular, we link one variant in HAR26;2xHAR.178 to elevated SOCS2 expression and increased neurite outgrowth in human neurons. Thus, our study sheds new light on the endogenous gene regulatory functions of HARs and their potential contribution to human brain evolution.
2024-11-12 | GSE221828 | GEO
Project description:Human accelerated regions (HARs) are evolutionarily conserved sequences that acquired human-specific nucleotide changes and reside in genomic regions associated with unique human traits and disease. The majority of HARs (96%) are noncoding, a few of which have been shown to be functional enhancers. Here, we comprehensively tested human and chimpanzee sequences of HARs (N=714) for enhancer activity using a lentivirus-based massively parallel reporter assay (lentiMPRA) in human and chimpanzee iPSC derived neural progenitors at two differentiation time points. We found that 43% (306/714) function as enhancers and over two-thirds (204/306) showed consistent differences in activity between human and chimpanzee sequences across conditions. We also tested all possible permutations of substitutions in seven HARs and found significant positive and negative interactions. Our study provides a comprehensive resource of functional neurodevelopmental HAR enhancers and shows that multiple interacting sites drive evolutionary activity differences.
2018-02-17 | GSE110758 | GEO
Project description:Human accelerated regions (HARs) are evolutionarily conserved sequences that acquired human-specific nucleotide changes and reside in genomic regions associated with unique human traits and disease. The majority of HARs (96%) are noncoding, a few of which have been shown to be functional enhancers. Here, we comprehensively tested human and chimpanzee sequences of HARs (N=714) for enhancer activity using a lentivirus-based massively parallel reporter assay (lentiMPRA) in human and chimpanzee iPSC derived neural progenitors at two differentiation time points. We found that 43% (306/714) function as enhancers and over two-thirds (204/306) showed consistent differences in activity between human and chimpanzee sequences across conditions. We also tested all possible permutations of substitutions in seven HARs and found significant positive and negative interactions. Our study provides a comprehensive resource of functional neurodevelopmental HAR enhancers and shows that multiple interacting sites drive evolutionary activity differences.
2018-02-17 | GSE110759 | GEO
Project description:Human accelerated regions (HARs) are conserved genomic loci that have experienced rapid nucleotide substitutions following the divergence from chimpanzees1,2. HARs are enriched in candidate regulatory regions near neurodevelopmental genes, suggesting their roles in gene regulation3. However, their target genes and functional contributions to human brain development remain largely uncharacterized. Here, we elucidate the cis-regulatory functions of HARs in human and chimpanzee induced pluripotent stem cell (iPSC)-induced excitatory neurons. Using genomic4 and chromatin looping information, we prioritized 20 HARs and their chimpanzee orthologs for functional characterization via single-cell CRISPRi, and demonstrated their species-specific gene regulatory functions. Our findings reveal diverse functional outcomes of HAR-mediated cis-regulation in human neurons, including attenuated NPAS3 expression by altering the binding affinities of multiple transcription factors in HAR202 and maintaining iPSC pluripotency and neuronal differentiation capacities through the upregulation of PUM2 by 2xHAR.319. Finally, we use prime editing to demonstrate differential enhancer activity caused by several HAR26;2xHAR.178 variants. In particular, we link one variant in HAR26;2xHAR.178 to elevated SOCS2 expression and increased neurite outgrowth in human neurons. Thus, our study sheds new light on the endogenous gene regulatory functions of HARs and their potential contribution to human brain evolution.
2024-11-12 | GSE221832 | GEO
Project description:We performed a Massively Parallel Reporter Assay (MPRA) to screen >30,000 human-specific substitutions in ChIP-seq-identified Human Gain Enhancers (HGEs) and Human Accelerated Regions (HARs), highly conserved non-coding regions that show accelerated sequence evolution in humans. After comparing human and chimpanzee reference alleles, we used a second MPRA to deconvolute individual substitutions within differentially active enhancers from substitutions in the same fragment and from other variants (human segregating variants or chimpanzee-specific variants) to isolate their specific effects on enhancer activity.
2019-11-26 | GSE140983 | GEO
Project description:A long-standing goal of evolutionary biology is to decode how changes in gene regulatory networks contribute to human-specific traits. Human Accelerated Regions (HARs) are prime candidates for driving gene regulatory modifications in human development. The RBFOX1 locus is densely populated with HARs, providing a set of potential regulatory elements that could have changed its expression in the human lineage. Here we examined the role of RBFOX1-HARs using transgenic zebrafish reporter assays and identified fifteen transcriptional enhancers that are active in the developing nervous system, ten of which displayed differential expression between the human and chimpanzee sequences. The engineered loss of two selected RBFOX1-HARs in knockout mouse models increased Rbfox1 expression at specific developmental stages and tissues in the brain, influencing the expression and splicing of a high number of Rbfox1 target genes. Our results provided insight into the spatial and temporal changes in gene expression driven by RBFOX1-HARs.
2024-05-21 | GSE242503 | GEO