ABSTRACT
The central riddle of an integrative biology is the genome-to-phenome mapping problem, that is, the functional relationship between the genes and the organism. A paradigm for the structural aspect of the relationship between the parts and the whole is the reaction-diffusion mechanism, proposed by Alan Turing to explain the formation of biological patterns, such as segmentation or spiral waves. The intricate tissue architecture in higher organisms consists of patterns jointly generated by the cells and the extracellular matrix that they produce. For the functional aspect of the part-whole relationship, the analogue to the geometric structure as a higher level pattern is the coordinated 'genetic program' that governs physiological processes, such as cell differentiation, regeneration or an immune response. For the regulation of cellular functions by specific molecules, the intracellular biochemical machinery involved in the switch from quiescence to proliferation and in cell cycle progression are pretty well understood.
