A monoastral mitotic spindle determines lineage fate and position in the mouse embryo.
Nat Cell Biol
; 24(2): 155-167, 2022 02.
Article
em En
| MEDLINE
| ID: mdl-35102267
ABSTRACT
During mammalian development, the first asymmetric cell divisions segregate cells into inner and outer positions of the embryo to establish the pluripotent and trophectoderm lineages. Typically, polarity components differentially regulate the mitotic spindle via astral microtubule arrays to trigger asymmetric division patterns. However, early mouse embryos lack centrosomes, the microtubule-organizing centres (MTOCs) that usually generate microtubule asters. Thus, it remains unknown whether spindle organization regulates lineage segregation. Here we find that heterogeneities in cell polarity in the early 8-cell-stage mouse embryo trigger the assembly of a highly asymmetric spindle organization. This spindle arises in an unusual modular manner, forming a single microtubule aster from an apically localized, non-centrosomal MTOC, before joining it to the rest of the spindle apparatus. When fully assembled, this 'monoastral' spindle triggers spatially asymmetric division patterns to segregate cells into inner and outer positions. Moreover, the asymmetric inheritance of spindle components causes differential cell polarization to determine pluripotent versus trophectoderm lineage fate.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Diferenciação Celular
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Divisão Celular
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Polaridade Celular
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Linhagem da Célula
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Embrião de Mamíferos
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Fuso Acromático
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article