Abstract
Embryonic stem cells (ESCs) serve as a model for development and as a potential source of cells for the treatment of a variety of human conditions. ESCs can undergo differentiation to each of the 3 germ layers and, upon successive elaboration, can generate all of the cell types of the developing embryo and adult. Multiple interconnected layers of regulatory networks/circuits control ESC self renewal, pluripotency, and differentiation. This complex biological system can only be partially understood and manipulated to advantage using reductive experimental approaches. Instead, complex systems analysis tools, which inherently take into consideration the nonlinear, non-intuitive, and highly interconnected nature of the system must be applied. In recent years, a combination of the development of high-throughput screening methods for measuring gross system properties, array technologies for measuring global system changes at various molecular levels, and mathematical algorithms and computer software for data handling and modelling has brought complex systems analysis to the fore. This Chapter highlights recent examples of complex systems applications to ESCs undergoing the earliest stages of differentiation to the germ layers via intermediate pluripotent populations.
Keywords: Complex systems, systems biology, regulatory networks, molecular circuits, emergent properties, bioinformatics, lineage commitment.