How does life develop? More specifically, how do human cells organize themselves to form skin, muscles, bones, a brain, a finger, or a spinal column? While the answers remain partially unknown, a promising research path lies in the study of gastrulation, the second phase of embryonic development following segmentation. During this crucial stage, embryonic cells evolve from a one-dimensional structure to a multi-dimensional structure with a main body axis. In humans, this process occurs approximately 14 days after conception.
Illustrative image Pixabay
Studying human embryos at this stage being impossible, researchers from the University of California, San Diego, the University of Dundee in the UK, and Harvard University have turned their attention to chicken embryos, which share many similarities with human embryos at this stage. Mattia Serra, an assistant professor of physics at UC San Diego and a theorist interested in emerging patterns in complex biophysical systems, led this research.
Serra's team developed a mathematical model based on data provided by biologists from the University of Dundee. For the first time, this model managed to replicate the gastrulation flows – the movement of tens of thousands of cells across the entire chicken embryo – observed under a microscope. Next, the model was "perturbed," meaning the initial conditions or existing parameters were altered.
The results were surprising: the model generated cellular streams that were not naturally observed in chickens but were present in two other vertebrate species: frogs and fish. To ensure that these results were not a mere mathematical fancy, the collaborators in biology reproduced the exact perturbations of the model in the laboratory on the chicken embryo. Strikingly, these manipulated chicken embryos also showed gastrulation flows naturally observed in fish and frogs.
Published in
Science Advances, these findings suggest that certain physical principles of multicellular self-organization could have evolved similarly across vertebrate species. According to Serra, although fish, frogs, and chickens live in different environments, the principles of self-organization at the beginning of gastrulation could be common to these three species.
This research could have significant implications in the design of biomaterials and regenerative medicine, with the hope of improving human health and longevity. Serra and his collaborators are now investigating other mechanisms that lead to self-organization patterns at the embryonic scale.