Solving Differential Equations in Developmental Models of Multicellular Structures Expressed Using L-systems

Mathematical modeling of growing multicellular structures creates the problem of solving systems of equations in which not only the values of variables, but the equations themselves, may change over time. We consider this problem in the framework of Lindenmayer systems, a standard formalism for modeling plants, and show how parametric context-sensitive L-systems can be used to numerically solve growing systems of coupled differential equations. We illustrate our technique with a developmental model of the multicellular bacterium Anabaena.