Limit cycles in models of circular gene networks regulated by negative feedback loops

摘要

Molecular-genetic systems or gene networks are molecular machines which decode genetic programs and bring them up to all the levels of living systems organization, from the molecular level (metabolic networks, signaling pathways, splicing, transport etc.) to subcellular, cellular, tissue, and organismic one. During the evolution, these systems have obtained ability to adequate reaction on the external signals and on changing of the environmental conditions. Their structure is based on regulatory circuits, i.e., on sub-networks composed by genes, which encode transcriptional factors and some types of enzymes (for example kinase), and their different combinations configure gene networks regulated by positive, negative, or variable feedback mechanisms.