Lineage Establishment and Progression within the Inner Cell Mass of the Mouse Blastocyst Requires FGFR1 and FGFR2

Publication date: Available online 25 May 2017
Source:Developmental Cell
Author(s): Minjung Kang, Vidur Garg, Anna-Katerina Hadjantonakis
Fibroblast growth factor 4 (FGF4) is the key signal driving specification of primitive endoderm (PrE) versus pluripotent epiblast (EPI) within the inner cell mass (ICM) of the mouse blastocyst. To gain insight into the receptor(s) responding to FGF4 within ICM cells, we combined single-cell-resolution quantitative imaging with single-cell transcriptomics of wild-type and Fgf receptor (Fgfr) mutant embryos. Despite the PrE-specific expression of FGFR2, it is FGFR1, expressed by all ICM cells, that is critical for establishment of a PrE identity. Signaling through FGFR1 is also required to constrain levels of the pluripotency-associated factor NANOG in EPI cells. However, the activity of both receptors is required for lineage establishment within the ICM. Gene expression profiling of 534 single ICM cells identified distinct downstream targets associated with each receptor. These data lead us to propose a model whereby unique and additive activities of FGFR1 and FGFR2 within the ICM coordinate establishment of two distinct lineages.

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Teaser

FGF4 is the key signal driving lineage specification within the mouse blastocyst inner cell mass. Kang et al. combine single-cell-resolution quantitative imaging with single-cell transcriptomics to elucidate relative requirements of FGF receptors FGFR1 and FGFR2 to transduce the FGF4 signal and establish FGFR1 as critical in primitive endoderm specification.


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