Excited to share how we use neighbour labelling to investigate cell fate decisions in neuromesodermal progenitors. Find me at Poster 165 @biologists.bsky.social #biologists100.

Transcriptional analysis of A8301-treated human blastocysts indicated that NANOG transcription did not decrease under NODAL signalling inhibition, in contrast to naïve human embryonic stem cells in t2iLifGo conditions pubmed.ncbi.nlm.nih.gov/34463252/ 7/10

A8301 treatment throughout human blastocyst development from 5 to 7 days post fertilisation did not impact the number of cells expressing epiblast markers NANOG, SOX2, KLF17 or primitive endoderm marker GATA4. 6/10

We next characterised three NODAL signalling inhibitors, yet only A8301 reliably inhibited SMAD2/3 phosphorylation and nuclear accumulation. The required high concentration of A8301 also inhibited BMP signalling, found in the primitive endoderm of human blastocysts. 5/10

We found that NANOG expression emerges in the inner cell mass of human blastocysts at 5 days post fertilisation, in the absence of NODAL signalling activity. NODAL signalling then becomes active throughout the pluripotent epiblast and extra-embryonic primitive endoderm. 4/10

To characterise NODAL signalling activity, we optimised an immunofluorescence protocol to detect the intracellular effectors SMAD2/3, which become phosphorylated and accumulate in the nucleus upon ligand binding. See also Kruger et al doi.org/10.1242/dev.... 3/10