One of the fundamental and eternal questions of life involves the mechanism by which life is born. Take human development: How do individual cells come together to form complex structures like skin, muscles, bones, or even brains, fingers, or spines? Although the answers to these questions remain unknown, one direction of scientific inquiry lies in understanding embryonic development - the stage during which embryonic cells develop from a single layer into a multi-dimensional structure with a main body axis. Implantation of a human embryo occurs approximately 14 days after conception.
Human embryos cannot be studied at this stage, so researchers at the University of California, San Diego, the University of Dundee in the United Kingdom, and Harvard University were able to study stomach formation in chick embryos, which have many similarities to human embryos at this stage.
The research was conducted through what Mattia Serra, assistant professor of physics at UC San Diego, calls the ideal cycle: an interdisciplinary back-and-forth between theoretical and experimental science. Mattia is a theorist interested in discovering emerging patterns in complex biophysical systems.
Develop predictive mathematical models
Here, he and his team built a mathematical model based on input from biologists at the University of Dundee. The model was able to accurately predict the developmental flow of chick embryos (the movement of thousands of cells throughout the chick embryo) observed under a microscope. This is the first time a mathematical model of self-organization has been able to reproduce these flows in the chick embryo.
The biologists then wanted to see whether the model could not only replicate what they knew from experiments but also predict what might happen under different conditions. Serra's team "perturbed" the model -- in other words, changed the initial conditions or current parameters.
The results were surprising: The model produced cell flows that were not observed naturally in chicks, but were observed in two other vertebrates: frogs and fish.
To ensure that these results were not mathematical illusions of the model, the biology collaborators mimicked the precise perturbations in the model in chick embryos in the laboratory. Surprisingly, these treated chick embryos also showed the gastric formation process naturally observed in fish and frogs.
Impact and future research
The findings, published in Science Advances, suggest that the same physical principles behind multicellular self-organization may have evolved across vertebrate species.
"Fish, frogs and nestlings all live in different environments, so evolutionary pressures may have changed the parameters and initial conditions of embryonic development over time," Serra said. "However, at least in the early stages of embryonic development, some of the core principles of self-organization may be the same among all three."
The research team is currently investigating other mechanisms that generate embryonic-level self-organizing patterns. They hope this research will advance the development of biomaterial design and regenerative medicine, helping humans live longer, healthier lives.
"The human body is the most complex dynamic system in existence," he said. "There are so many interesting biological, physical and mathematical questions about our bodies - it's amazing to think about. There is no end to what we can discover."
Compiled source: ScitechDaily