Oct4 regulates the embryonic axis and coordinates exit from pluripotency and germ layer specification in the mouse embryo

Autor: Carla, Mulas, Gloryn, Chia, Kenneth Alan, Jones, Andrew Christopher, Hodgson, Giuliano Giuseppe, Stirparo, Jennifer, Nichols
Rok vydání: 2017
Předmět:
Zdroj: Development (Cambridge, England)
ISSN: 1477-9129
Popis: Lineage segregation in the mouse embryo is a finely controlled process dependent upon coordination of signalling pathways and transcriptional responses. Here we employ a conditional deletion system to investigate embryonic patterning and lineage specification in response to loss of Oct4. We first observe ectopic expression of Nanog in Oct4-negative postimplantation epiblast cells. The expression domains of lineage markers are subsequently disrupted. Definitive endoderm expands at the expense of mesoderm; the anterior-posterior axis is positioned more distally and an ectopic posterior-like domain appears anteriorly, suggesting a role for Oct4 in maintaining the embryonic axis. Although primitive streak forms in the presumptive proximal-posterior region, epithelial-to-mesenchymal transition is impeded by an increase of E-cadherin, leading to complete tissue disorganisation and failure to generate germ layers. In explant and in vitro differentiation assays, Oct4 mutants also show upregulation of E-cadherin and Foxa2, suggesting a cell-autonomous phenotype. We confirm requirement for Oct4 in self-renewal of postimplantation epiblast ex vivo. Our results indicate a role for Oct4 in orchestrating multiple fates and enabling expansion, correct patterning and lineage choice in the postimplantation epiblast.
Highlighted Article: Ectopic expression of Nanog, expansion of the presumptive endodermal domain and trapping of cells in the primitive streak ultimately result in consistent disrupted phenotype with loss of embryonic structures.
Databáze: OpenAIRE