Biological Complexity and Systems Biology
The most fascinating challenge, rich of human values, that is open to science in this beginning of the 21st century is to uncover the laws of biological complexity.
Even the numbers of biological complexity are overwhelming: a human body is made up by about 50 thousand billion cells, and each cell is a world by itself, being made by almost a billion protein molecules of about 10’000 different types, that vary from a kind of cell to another.
Besides the activity of each protein may be changed by post-translational modifications, such as phosphorylation, acetylation, ubiquitination, etc.
High throughput technologies are able to yield accurate descriptions of molecular level of different cells in various physiological and pathological conditions.
The great scientific challenge is to extract from these “omics” data (transcriptome, proteome, metabolome, etc.) mechanistic insight so to become able to understand how a given cellular functions is performed and to become able to predict its behavior under perturbed conditions (i.e. pathology).
A new scientific paradigm is needed: Systems Biology.
The need for the Systems Biology approach is indicated by the present difficulties to investigate the relationships between genotype and phenotype.
While for Mendelian genes, to one gene correspond one character, complex cellular functions (metabolism, growth, cycle, differentiation, neoplastic transformation, etc.) derive from the dynamic interaction of a large number of gene products that produce, in a non-linear manner, the functional properties of living cells.
Thus a complex function derive as a system-level property of a network of interacting components, being not present in its individual components. An interactive integration of molecular analysis with mathematical modeling and simulation analysis is required in order to investigate this systems-level properties.