2/3 Special thank you to my supervisor Silvia, her continued mentorship and support throughout the PhD and onto my next step. 🙏

1/3 After 6+ years at @crick.ac.uk I split my last cells and hung up my lab coat! Thank you to the brilliant community from fellow PhDs/Postdocs, LOAs, STPs, academic training team and to all past/present @santoslab.bsky.social members. My Crick journey would not have been the same without you all!

6/7 Overall, this work demonstrates that distinct cell identities can arise through different developmental trajectories coordinated by combinatorial signalling.

5/7 When varying signalling conditions and measuring the proportion of endoderm cells from different paths, we found that the choice between routes to endoderm depends on the specific combination of BMP4 and Activin signals that cells are exposed to ⚖️.

4/7 Despite divergent origins we found that endoderm cells derived from different routes have the same developmental potential to form downstream cell types 🧫.

3/7 🔬Using single-cell transcriptomics as well as live-cell imaging of engineered hESCs, we measured individual gene expression histories and found that human endoderm arises from two distinct developmental trajectories: a direct path and an indirect one through a FOXC1+ progenitor state.

2/7 🔢 Pairing quantitative measurements of cell fate proportions in response to signalling combinations and mathematical modelling we found that hESC differentiation was best captured by cell state transitions including multiple paths to terminal fates.