Current Opinion in Systems Biology最新文献

Anthropogenic carbon emissions are driving rapid changes to the earth's climate, disrupting whole ecosystems and endangering the stability of human society. Innovations in engineered microbial fermentation enable the fossil resource-free production of fuels, commodity chemicals, and materials, thereby reducing the carbon emissions associated with these products. Microorganisms have been engineered to catabolize sustainable sources of carbon and energy (i.e., plant biomass, plastic waste, and one-carbon feedstocks) and biosynthesize carbon-neutral or carbon-negative products. These engineering efforts exploit and optimize natural biological pathways or generate unnatural pathways which can biosynthesize chemicals that have not yet been accessed using synthetic chemistry. Recent advances in microbial fermentation seek not only to maximize the titer, rate, and yield of desired products, but also to tailor microbial catabolism to utilize inexpensive feedstocks. Ultimately, these advances aim to lower the cost of bioproduction so that microorganism-derived chemicals can be economically competitive with fossil-derived chemicals.

Microbial phototrophic communities dominated early Earth and thrive to this day, particularly in extreme environments. We focus on the impact of diel oscillations on phototrophic biofilms, especially in hot springs, where oxygenic phototrophs are keystone species that use light energy to fix carbon and often nitrogen. They exhibit photo-motility and stratification, and alter the physicochemical environment by driving O₂, CO_2, and pH oscillations. Omics analyses reveal extensive genomic and functional diversity in biofilms, but linking this to a predictive understanding of their structure and dynamics remains challenging. This can be addressed by better spatiotemporal resolution of microbial interactions, improved tools for building and manipulating synthetic communities, and integration of empirical and theoretical approaches.

Over the past two decades, genome sequencing has uncovered the diversity and distribution of insertion sequences within prokaryotic genomes. However, the complexity of insertion sequence ecology and evolution hinders us from understanding their nature. Recent studies have employed experimental and computational models to study insertion sequences, emphasizing their role in shaping prokaryotic genome structures. Nonetheless, related areas remain with limited understanding, such as the speciation of insertion sequences. We believe that future studies should continue to develop tractable experimental and computational models to advance our understanding of IS ecology and evolution and their influence on the evolution of prokaryotic genomes.

Microbial communities perform metabolic processes that sustain life on Earth and promote human health. Microbial consortia sustain these functions in the face of constant structural and environmental perturbations. How do complex communities robustly sustain their functional properties despite perturbations? Most studies of functional robustness in the microbiome have been limited to biodiversity and functional redundancy, the idea that there are multiple members of the community that can sustain a specific function. Here, we propose that ideas from other complex biological systems may be applied to deepen our understanding of microbiome robustness. By surveying the causes of functional robustness in a variety of biological systems, including proteins and cells, and discussing how they can be applied to the microbiome, we build conceptual and experimental frameworks for understanding the functional robustness of microbial communities. We hope that these insights might help better predict and engineer microbiome function.

Prophages, latent viral elements residing in bacterial genomes affect bacterial ecology and evolution in diverse ways. Do these prophage-mediated effects extend beyond the prophage-bacterial relationship? Here, I summarize the latest advances exploring how the impacts of prophages are transmitted through multiple levels of biological systems with potential impacts on ecosystem stability and functioning. The diverse effects of prophages on higher-order interactions are context-specific, ranging from contributions to global biogeochemical processes and mutualistic interactions to increased disease severity with negative impacts on ecosystem engineers and potential cascading effects for multiple species. While we have a solid understanding of the mechanisms by which prophages modulate their bacterial hosts at the cellular and population levels, future research may take an integrative approach to quantify their effects in complex ecosystems.

Bacteriophages are central to microbial ecosystems for balancing bacterial populations and promoting evolution by applying strong selection pressure. Here, we review some of the known aspects that modulate phage–bacteria interaction in a way that naturally promotes their coexistence. We focus on the modulations that arise from structural, physical, or physiological constraints. We argue they should play roles in many phage–bacteria systems providing sustainable diversity.

Despite its fundamental importance for development, the question of how organs achieve their correct size and shape is poorly understood. This complex process requires coordination between the generation of cell mass and the morphogenetic mechanisms that sculpt tissues. These processes are regulated by morphogen signalling pathways and mechanical forces. Yet, in many systems, it is unclear how biochemical and mechanical signalling are quantitatively interpreted to determine the behaviours of individual cells and how they contribute to growth and morphogenesis at the tissue scale. In this review, we discuss the development of the vertebrate neural tube and somites as an example of the state of knowledge, as well as the challenges in understanding the mechanisms of tissue size control in vertebrate organogenesis. We highlight how the recent advances in stem cell differentiation and organoid approaches can be harnessed to provide new insights into this question.

Most life forms harbor multiple, diverse mobile genetic elements (MGE) that widely differ in their rates and mechanisms of mobility. Recent findings on two classes of MGE in prokaryotes revealed a novel mechanism, RNA-guided transposition, where a transposon-encoded guide RNA directs the transposase to a unique site in the host genome. Tn7-like transposons, on multiple occasions, recruited CRISPR systems that lost the capacity to cleave target DNA and instead mediate RNA-guided transposition via CRISPR RNA. Conversely, the abundant transposon-associated, RNA-guided nucleases IscB and TnpB that appear to promote proliferation of IS200/IS605 and IS607 transposons were the likely evolutionary ancestors of type II and type V CRISPR systems, respectively. Thus, RNA-guided target recognition is a major biological phenomenon that connects MGE with host defense mechanisms. More RNA-guided defensive and MGE-associated functionalities are likely to be discovered.