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1.
Nat Commun ; 12(1): 4897, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385432

RESUMO

Precise control of mammalian gene expression is facilitated through epigenetic mechanisms and nuclear organization. In particular, insulated chromosome structures are important for regulatory control, but the phenotypic consequences of their boundary disruption on developmental processes are complex and remain insufficiently understood. Here, we generated deeply sequenced Hi-C data for human pluripotent stem cells (hPSCs) that allowed us to identify CTCF loop domains that have highly conserved boundary CTCF sites and show a notable enrichment of individual developmental regulators. Importantly, perturbation of such a boundary in hPSCs interfered with proper differentiation through deregulated distal enhancer-promoter activity. Finally, we found that germline variations affecting such boundaries are subject to purifying selection and are underrepresented in the human population. Taken together, our findings highlight the importance of developmental gene isolation through chromosomal folding structures as a mechanism to ensure their proper expression.


Assuntos
Diferenciação Celular/genética , Perfilação da Expressão Gênica/métodos , Genoma Humano/genética , Células-Tronco Embrionárias Humanas/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Elementos Reguladores de Transcrição/genética , Sítios de Ligação/genética , Western Blotting , Fator de Ligação a CCCTC/genética , Fator de Ligação a CCCTC/metabolismo , Linhagem Celular , Elementos Facilitadores Genéticos/genética , Células-Tronco Embrionárias Humanas/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA/métodos
2.
Bio Protoc ; 11(11): e4042, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34250208

RESUMO

Post-implantation mammalian embryogenesis involves profound molecular, cellular, and morphogenetic changes. The study of these highly dynamic processes is complicated by the limited accessibility of in utero development. In recent years, several complementary in vitro systems comprising self-organized assemblies of mouse embryonic stem cells, such as gastruloids, have been reported. We recently demonstrated that the morphogenetic potential of gastruloids can be further unlocked by the addition of a low percentage of Matrigel as an extracellular matrix surrogate. This resulted in the formation of highly organized trunk-like structures (TLSs) with a neural tube that is frequently flanked by bilateral somites. Notably, development at the molecular and morphogenetic levels is highly reminiscent of the natural embryo. To facilitate access to this powerful model, here we provide a detailed step-by-step protocol that should allow any lab with access to standard cell culture techniques to implement the culture system. This will provide the user with a means to investigate early mid-gestational mouse embryogenesis at an unprecedented spatiotemporal resolution.

3.
Science ; 370(6522)2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33303587

RESUMO

Post-implantation embryogenesis is a highly dynamic process comprising multiple lineage decisions and morphogenetic changes that are inaccessible to deep analysis in vivo. We found that pluripotent mouse embryonic stem cells (mESCs) form aggregates that upon embedding in an extracellular matrix compound induce the formation of highly organized "trunk-like structures" (TLSs) comprising the neural tube and somites. Comparative single-cell RNA sequencing analysis confirmed that this process is highly analogous to mouse development and follows the same stepwise gene-regulatory program. Tbx6 knockout TLSs developed additional neural tubes mirroring the embryonic mutant phenotype, and chemical modulation could induce excess somite formation. TLSs thus reveal an advanced level of self-organization and provide a powerful platform for investigating post-implantation embryogenesis in a dish.


Assuntos
Desenvolvimento Embrionário/fisiologia , Células-Tronco Embrionárias Murinas/fisiologia , Tubo Neural/embriologia , Somitos/embriologia , Animais , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Knockout , Piridinas/farmacologia , Pirimidinas/farmacologia , Proteínas com Domínio T/genética , Proteínas Wnt/antagonistas & inibidores
4.
Cell Stem Cell ; 22(4): 575-588.e7, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29625070

RESUMO

While gene expression dynamics have been extensively cataloged during hematopoietic differentiation in the adult, less is known about transcriptome diversity of human hematopoietic stem cells (HSCs) during development. To characterize transcriptional and post-transcriptional changes in HSCs during development, we leveraged high-throughput genomic approaches to profile miRNAs, lincRNAs, and mRNAs. Our findings indicate that HSCs manifest distinct alternative splicing patterns in key hematopoietic regulators. Detailed analysis of the splicing dynamics and function of one such regulator, HMGA2, identified an alternative isoform that escapes miRNA-mediated targeting. We further identified the splicing kinase CLK3 that, by regulating HMGA2 splicing, preserves HMGA2 function in the setting of an increase in let-7 miRNA levels, delineating how CLK3 and HMGA2 form a functional axis that influences HSC properties during development. Collectively, our study highlights molecular mechanisms by which alternative splicing and miRNA-mediated post-transcriptional regulation impact the molecular identity and stage-specific developmental features of human HSCs.


Assuntos
Processamento Alternativo/genética , Proteína HMGA2/genética , Células-Tronco Hematopoéticas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Proteína HMGA2/metabolismo , Células-Tronco Hematopoéticas/citologia , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
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