Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Development ; 149(22)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36326003

RESUMO

Stem cell-derived three-dimensional (3D) gastruloids show a remarkable capacity of self-organisation and recapitulate many aspects of gastrulation stage mammalian development. Gastruloids can be rapidly generated and offer several experimental advantages, such as scalability, observability and accessibility for manipulation. Here, we present approaches to further expand the experimental potency of murine 3D gastruloids by using functional genetics in mouse embryonic stem cells (mESCs) to generate chimeric gastruloids. In chimeric gastruloids, fluorescently labelled cells of different genotypes harbouring inducible gene expression or loss-of-function alleles are combined with wild-type cells. We showcase this experimental approach in chimeric gastruloids of mESCs carrying homozygous deletions of the Tbx transcription factor brachyury or inducible expression of Eomes. Resulting chimeric gastruloids recapitulate reported Eomes and brachyury functions, such as instructing cardiac fate and promoting posterior axial extension, respectively. Additionally, chimeric gastruloids revealed previously unrecognised phenotypes, such as the tissue sorting preference of brachyury deficient cells to endoderm and the cell non-autonomous effects of brachyury deficiency on Wnt3a patterning along the embryonic axis, demonstrating some of the advantages of chimeric gastruloids as an efficient tool for studies of mammalian gastrulation.


Assuntos
Gastrulação , Mamíferos , Animais , Camundongos , Endoderma , Células-Tronco Embrionárias Murinas , Alelos
2.
Dev Cell ; 58(18): 1627-1642.e7, 2023 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-37633271

RESUMO

Mammalian specification of mesoderm and definitive endoderm (DE) is instructed by the two related Tbx transcription factors (TFs) Eomesodermin (Eomes) and Brachyury sharing partially redundant functions. Gross differences in mutant embryonic phenotypes suggest specific functions of each TF. To date, the molecular details of separated lineage-specific gene regulation by Eomes and Brachyury remain poorly understood. Here, we combine mouse embryonic and stem-cell-based analyses to delineate the non-overlapping, lineage-specific transcriptional activities. On a genome-wide scale, binding of both TFs overlaps at promoters of target genes but shows specificity for distal enhancer regions that is conferred by differences in Tbx DNA-binding motifs. The unique binding to enhancer sites instructs the specification of anterior mesoderm (AM) and DE by Eomes and caudal mesoderm by Brachyury. Remarkably, EOMES antagonizes BRACHYURY gene regulatory functions in coexpressing cells during early gastrulation to ensure the proper sequence of early AM and DE lineage specification followed by posterior mesoderm derivatives.


Assuntos
Gastrulação , Proteínas com Domínio T , Camundongos , Animais , Gastrulação/genética , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Mesoderma/metabolismo , Proteínas Fetais/genética , Proteínas Fetais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Mamíferos/metabolismo
4.
Nat Cell Biol ; 21(12): 1518-1531, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31792383

RESUMO

The first lineage specification of pluripotent mouse epiblast segregates neuroectoderm (NE) from mesoderm and definitive endoderm (ME) by mechanisms that are not well understood. Here we demonstrate that the induction of ME gene programs critically relies on the T-box transcription factors Eomesodermin (also known as Eomes) and Brachyury, which concomitantly repress pluripotency and NE gene programs. Cells deficient in these T-box transcription factors retain pluripotency and differentiate to NE lineages despite the presence of ME-inducing signals transforming growth factor ß (TGF-ß)/Nodal and Wnt. Pluripotency and NE gene networks are additionally repressed by ME factors downstream of T-box factor induction, demonstrating a redundancy in program regulation to safeguard mutually exclusive lineage specification. Analyses of chromatin revealed that accessibility of ME enhancers depends on T-box factor binding, whereas NE enhancers are accessible and already activation primed at pluripotency. This asymmetry of the chromatin landscape thus explains the default differentiation of pluripotent cells to NE in the absence of ME induction that depends on activating and repressive functions of Eomes and Brachyury.


Assuntos
Cromatina/genética , Proteínas Fetais/genética , Camadas Germinativas/fisiologia , Células-Tronco Pluripotentes/fisiologia , Proteínas com Domínio T/genética , Animais , Diferenciação Celular/genética , Linhagem Celular , Separação Celular/métodos , Endoderma/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Masculino , Camundongos , Placa Neural/fisiologia , Fator de Crescimento Transformador beta/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA