Innovating carbon-capture biotechnologies through ecosystem-inspired solutions

Rising atmospheric carbon concentrations affect global health, the economy, and overall quality of life. We are fast approaching climate tipping points that must be addressed, not only by reducing emissions but also through new innovation and action toward carbon capture for sequestration and utilization (CCSU). In this perspective, we delineate next-generation biotechnologies for CCSU supported by engineering design principles derived from ecological processes inspired by three major biomes (plant-soil, deep biosphere, and marine). These are to interface with existing industrial infrastructure and, in some cases, tap into the carbon sink potential of nature. To develop ecosystem-inspired biotechnology, it is important to identify accessible control points of CO2 and CH4 within a given system as well as value-chain opportunities that drive innovation. In essence, we must supplement natural biogeochemical carbon sinks with new bioengineering solutions

SAM68 interaction with U1A modulates U1 snRNP recruitment and regulates mTor pre-mRNA splicing

Src associated in mitosis (SAM68) plays major roles in regulating RNA processing events, such as alternative splicing and mRNA translation, implicated in several developmental processes. It was previously shown that SAM68 regulates the alternative splicing of the mechanistic target of rapamycin (mTor), but the mechanism regulating this process remains elusive. Here, we report that SAM68 interacts with U1 small nuclear ribonucleoprotein (U1 snRNP) to promote splicing at the 5′ splice site in intron 5 of mTor. We also show that this direct interaction is mediated through U1A, a core-component of U1snRNP. SAM68 was found to bind the RRM1 domain of U1A through its C-terminal tyrosine rich region (YY domain). Deletion of the U1A-SAM68 interaction domain or mutation in SAM68-binding sites in intron 5 of mTor abrogates U1A recruitment and 5′ splice site recognition by the U1 snRNP, leading to premature intron 5 termination and polyadenylation. Taken together, our results provide the first mechanistic study by which SAM68 modulates alternative splicing decision, by affecting U1 snRNP recruitment at 5′ splice sites.ISSN:1362-4962ISSN:0301-561

Targeted volume correlative light and electron microscopy of an environmental marine microorganism

International audienceABSTRACT Photosynthetic microalgae are responsible for an important fraction of CO2 fixation and O2 production on Earth. Three-dimensional (3D) ultrastructural characterization of these organisms in their natural environment can contribute to a deeper understanding of their cell biology. However, the low throughput of volume electron microscopy (vEM) methods along with the complexity and heterogeneity of environmental samples pose great technical challenges. In the present study, we used a workflow based on a specific electron microscopy sample preparation method compatible with both light and vEM imaging in order to target one cell among a complex natural community. This method revealed the 3D subcellular landscape of a photosynthetic dinoflagellate, which we identified as Ensiculifera tyrrhenica, with quantitative characterization of multiple organelles. We show that this cell contains a single convoluted chloroplast and show the arrangement of the flagellar apparatus with its associated photosensitive elements. Moreover, we observed partial chromatin unfolding, potentially associated with transcription activity in these organisms, in which chromosomes are permanently condensed. Together with providing insights in dinoflagellate biology, this proof-of-principle study illustrates an efficient tool for the targeted ultrastructural analysis of environmental microorganisms in heterogeneous mixes

Innovating carbon-capture biotechnologies through ecosystem-inspired solutions

Rising atmospheric carbon concentrations affect global health, the economy, and overall quality of life. We are fast approaching climate tipping points that must be addressed, not only by reducing emissions but also through new innovation and action toward carbon capture for sequestration and utilization (CCSU). In this perspective, we delineate next-generation biotechnologies for CCSU supported by engineering design principles derived from ecological processes inspired by three major biomes (plant-soil, deep biosphere, and marine). These are to interface with existing industrial infrastructure and, in some cases, tap into the carbon sink potential of nature. To develop ecosystem-inspired biotechnology, it is important to identify accessible control points of CO2 and CH4 within a given system as well as value-chain opportunities that drive innovation. In essence, we must supplement natural biogeochemical carbon sinks with new bioengineering solutions

Hypometabolism to survive the long polar night and subsequent successful return to light in the diatom Fragilariopsis cylindrus

International audienceSummary Diatoms, the main eukaryotic phytoplankton of the polar marine regions, are essential for the maintenance of food chains specific to Arctic and Antarctic ecosystems, and are experiencing major disturbances under current climate change. As such, it is fundamental to understand the physiological mechanisms and associated molecular basis of their endurance during the long polar night. Here, using the polar diatom Fragilariopsis cylindrus , we report an integrative analysis combining transcriptomic, microscopic and biochemical approaches to shed light on the strategies used to survive the polar night. We reveal that in prolonged darkness, diatom cells enter a state of quiescence with reduced metabolic and transcriptional activity, during which no cell division occurs. We propose that minimal energy is provided by respiration and degradation of protein, carbohydrate and lipid stores and that homeostasis is maintained by autophagy in prolonged darkness. We also report internal structural changes that manifest the morphological acclimation of cells to darkness, including the appearance of a large vacuole. Our results further show that immediately following a return to light, diatom cells are able to use photoprotective mechanisms and rapidly resume photosynthesis, demonstrating the remarkable robustness of polar diatoms to prolonged darkness at low temperature