When can neural crest cells first be detected during embryonic development?
In the mouse and chick, we’ve gone all the way back to the induction process, which is the earliest relevant time point [embryonic Day 8 in the mouse, 1.5 in the chick]. If we went back any further, we’d see things that might influence neural crest formation secondarily, such as the development of the neural plate. But they may not be particularly relevant to the actual induction process. So, in these species, you can track neural crest cells from just about point A to Z of the developmental process? Yes, exactly. What we can’t do is tackle that in humans for technical and ethical reasons. What we do know, if you think about the different phases of neural crest development – whether it be the formation, migration, differentiation phase – if an anomaly arises in any one of those phases, you can end up with a very different craniofacial malformation. For example? Well, there a number of recognized neural crest-derived malformation syndromes. I’m talking about potentially devastating cond
