Decision Time

Like a timed gate that allows early birds one way and steers latecomers elsewhere, a gene regulator helps guide choices developing cells must make. Researchers studied structures grown from human stem cells that resemble the core embryonic body region , observing how some of the earliest body-building decisions are made. They found that within the mesoderm – one of the embryo’s early cell layers – the duration of activity of a regulator called TBX6 helps steer cell fate: too little favours neural identity, intermediate activity allows diversification, and prolonged activity biases cells toward somitic fate, producing precursors of vertebrae, skeletal muscle and more. When TBX6 was experimentally silenced (right), neural tissue (yellow) expanded while somitic tissue (pink) and intermediate mesoderm (giving rise to kidneys and other urogenital structures; blue) fell back compared to normal (left). They further identified factors that help lock in somitic identity, helping paint a picture of spine and kidney development that could help explain how disorders arise.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

Website

• Image from work by John-Poul Ng-Blichfeldt and colleagues
• Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in bioRxiv, April 2026 (not peer reviewed)