Details

Autor(en) / Beteiligte

• Simon, Claire S.
• Rahman, Shahadat
• Raina, Dhruv
• Schröter, Christian
• Hadjantonakis, Anna-Katerina

Titel

Live Visualization of ERK Activity in the Mouse Blastocyst Reveals Lineage-Specific Signaling Dynamics

Ist Teil von

• Developmental cell, 2020-11, Vol.55 (3), p.341-353.e5

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2020

Quelle

MEDLINE

Beschreibungen/Notizen

• FGF/ERK signaling is crucial for the patterning and proliferation of cell lineages that comprise the mouse blastocyst. However, ERK signaling dynamics have never been directly visualized in live embryos. To address whether differential signaling is associated with particular cell fates and states, we generated a targeted mouse line expressing an ERK-kinase translocation reporter (KTR) that enables live quantification of ERK activity at single-cell resolution. 3D time-lapse imaging of this biosensor in embryos revealed spatially graded ERK activity in the trophectoderm prior to overt polar versus mural differentiation. Within the inner cell mass (ICM), all cells relayed FGF/ERK signals with varying durations and magnitude. Primitive endoderm cells displayed higher overall levels of ERK activity, while pluripotent epiblast cells exhibited lower basal activity with sporadic pulses. These results constitute a direct visualization of signaling events during mammalian pre-implantation development and reveal the existence of spatial and temporal lineage-specific dynamics. [Display omitted] •Generation of a targeted ERK-KTR mouse line that reports ERK signaling in blastocysts•FGF4 signals from the ICM spatially pattern the trophectoderm•Signaling heterogeneity in ICM cells corresponds to distinct lineage identities•PrE exhibit elevated ERK activity, while EPI show sporadic pulses of activity FGF/ERK signaling is crucial for the patterning and proliferation of cell lineages that comprise the mouse blastocyst. Using an ERK-kinase translocation biosensor, Simon et al. show that the trophectoderm is patterned by spatially graded ERK activity and that primitive endoderm and epiblast cells have distinct ERK dynamics.