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A defining focus of synthetic biology is the engineering of genetic circuits with predictive functionality in living cells. Here, a decade after the first synthesized genetic toggle switch and oscillator, an engineered gene network with global intercellular coupling is designed that is capable of generating synchronized oscillations in a growing population of cells.

Thousands of quorum-sensing Escherichia coli colonies are synchronized over centimetres using redox signalling to create ‘biopixels’ that can sense trace amounts of arsenic in water.

Protease competition is used to produce rapid and tunable coupling of genetic circuits, enabling a coupled clock network that can encode independent environmental cues into a single time series output, a form of frequency multiplexing in a genetic circuit context.

Jeff Hasty and colleagues use an endonuclease from S. cerevisiae along with quorum sensing from A. fischeri to produce sustained cycling of DNA plasmid concentration across a colony of E. coli cells. This copy number modulation system enables dynamic regulation of gene circuit elements without the need for specially engineered promoters.

Synthetic biologists aim to apply well-known principles of gene regulation to build living systems with desired properties. This study has combined microfluidics, single-cell microscopy and computational modelling to develop a bacterial gene oscillator that is fast, robust, persistent and whose frequency can be tuned externally. The combination of experimental and theoretical work reveals a simplified oscillator design without the need for positive feedback.

Microfluidic 'lab-on-a-chip' devices can be used to study the dynamics of gene networks in single cells. This Review discusses the various designs of these devices and the insights into modelling the complex dynamics of gene regulation that these new technologies have provided.

Bacteria can be engineered as biosensors for the detection and analysis of DNA in unpurified samples. This Review examines the engineering of bacterial DNA biosensors, highlighting performance metrics and applications in comparison with in vitro DNA biosensors.

Plasmid copy number heterogeneity can be used as a tool to build synthetic microbial populations that adapt to changing environments due to specific plasmid-encoded fitness effects.

Synthetic gene networks can be readily redesigned using new libraries of quantitatively characterized promoters coupled with predictive mathematical modeling.

Within a genome, genes are connected to each other through a complex network of interactions. One way to assess how robust and evolvable such genomic networks are is to introduce new links between unrelated genes.

Clinically relevant bacteria have been engineered to lyse synchronously at a threshold population density and release genetically encoded therapeutics; treatment of mice with these bacteria slowed the growth of tumours.

micov computes coverage breadth across genomes and samples. Its application in metagenomics highlights strain heterogeneity, uncovers associations linking genetic elements to phenotypic traits, and aids taxonomic filtering in low-biomass settings.

Understanding how cells dynamically adapt to their environment is important, but temporal information about cellular behaviour is often limited. Here, Miano et al. apply unsupervised machine learning to a dataset describing the activity of over 1,800 promoters in E. coli, measured every 10 minutes, defining three primary stages of promoter activation in response to heavy metal stress.

Biotechnology innovations require the precise control over microbial dynamics. Here the authors engineer an inducible quorum sensing system to fine tune population and community level behaviour.

The maintenance of ecological diversity depends on the strength and direction of competitive interactions, but these interactions are difficult to study in microbial communities. Here the authors use engineered E. coli strains to show that competitively weak strains can persist when pairwise interactions are asymmetrical.

Riffelmacher et al. show that immunization with a live vaccine strain leads to the expansion of two memory-like mucosal-associated invariant T cell lineages with distinct metabolic needs, effector programmes and protective capacities.

A study demonstrates that metabolic signalling and inflammatory cues associated with obesity selectively induce expression of PD-1 on tumour-associated macrophages to suppress anti-tumour immunity.

The hypothesis of ubiquitous fluctuations in gene expression has spurred the development of general methods for tracking temporal changes in protein concentrations in individual cells. The determination of protein levels with single-molecule sensitivity represents a significant advancement in the monitoring of cellular behavior that is driven by gene expression.

A large-scale study of the protein network in yeast cells demonstrates the merit of taking an integrated approach to cellular dynamics, and shows the value of databases.

A systematic exploration of noise in gene expression demonstrates the value of integrating novel experiments with computational modeling.

A new study examines the agn43 epigenetic switch of Escherichia coli, providing an alternative to feedback regulation as a model for gene expression regulation. Through a combination of synthetic network construction and computational modeling, the authors show that the generated bistable gene expression involves transitions between several rarely occupied states between 'on' and 'off'.

Live microorganisms can be manipulated and engineered for colorectal cancer detection and treatment through methods such as faecal microbiota transplantation, native bacteria engineering and synthetic circuit engineering. Although promising, substantial effort is required to translate these approaches for clinical use.

Gene circuits that exploit the mutual interaction between nutrient diffusion, bacterial growth and gene regulation enable the control of microbial colony structure in complex environments.

Synthetic orthogonal lysis circuits promote stable co-culture of metabolically competitive bacteria.