Synchronization of Oscillatory Gene Networks

Abstract

Periodic gene expression in living cells could be subject to synchronization during processes such as cell-to-cell communication, quorum sensing, and entrainment of circadian rhythms. Synchronization occurs when two oscillatory gene networks coordinate the expression of their genes, and subsequently perform in-phase gene transcription. Coordination in gene expression of two oscillatory gene networks can occur when these networks are coupled by a cell signaling pathway. Cell signaling is common in all multicellular systems to perform cell-to-cell signaling and communication. For example, bacteria use a cell communication process known as quorum sensing to coordinate gene expression according to the density of their local population. Bacteria implement quorum sensing by secreting a signal molecule (autoinducer) into the environment. The autoinducer molecules can be taken up by bacteria, which activates gene expression, and also includes production of the autoinducer itself. Bacterial quorum sensing is used to engineer cell-to-cell communication systems that are composed of populations of “sender cells” and “receiver cells,” performing cell-to-cell communication that can be experimentally controlled. If sender and receiver cells exhibit oscillatory gene expression dynamics, then cell-to-cell communication may lead to synchronization of their oscillatory gene networks. By studying this synchronization, we can better understand how cells coordinate the decision-making process.