Graphical modelling of biological pathways

Biological pathways underlie the basic functions of a living cell. They are complex diagrams featuring genes, proteins and other small molecules, showing how they work together to achieve a particular biological effect. From a technical point of view, they are networks represented through a graph where genes and their connections are, respectively, nodes and edges of a graph. The main research objective of this thesis is to develop a framework for simulating effects of gene silencing. To this end, we propose a three step approach. First, we refine the structure of a pathway via our CK2 algorithm. Next, we assess the uncertainty in the refined structure. Finally, we simulate gene silencing through intervention analysis in causal graphical models. The proposed approach showed promising results when applied to the problem of predicting the effect of the knockdown of the nkd gene in Drosophila Melanogaster.