Publications by authors named "Peter A Carr"

Introduction: Organisms engineered with synthetic genes and genomes have the potential to play critical roles to address important issues in the environment, human health, and manufacturing. Engineered genetic biocontainment technologies are needed to manage the risks of unintended consequences when deploying these biological systems in consultation with the biosafety and biosecurity communities. Metrics measuring genetic biocontainment and a methodology to apply them are required to determine which genetic biocontainment technologies warrant further development for real-world applications.

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Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont.

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Previous studies have documented natural infections of SARS-CoV-2 in various domestic and wild animals. More recently, studies have been published noting the susceptibility of members of the Cervidae family, and infections in both wild and captive cervid populations. In this study, we investigated the presence of SARS-CoV-2 in mammalian wildlife within the state of Vermont.

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We developed the PERSIA technique with an interest in quantifying proteins as they are being produced during a cell-free synthesis reaction. A short 6-amino acid sequence added to a protein of interest reacts with a fluorogenic reagent (ReAsH), yielding a measure of protein concentration in close to real time. We combine this measurement with simultaneous fluorescent detection of mRNA production, quantifying both transcription and translation.

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Human space exploration and settlement will require leaps forward in life support for environmental management and healthcare. Life support systems must efficiently use nonrenewable resources packed from Earth while increasingly relying on resources available locally in space. On-demand production of components and materials (e.

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Quantification of biology's central dogma (transcription and translation) is pursued by a variety of methods. Direct, immediate, and ongoing quantification of these events is difficult to achieve. Common practice is to use fluorescent or luminescent proteins to report indirectly on prior cellular events, such as turning on a gene in a genetic circuit.

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The advancement of synthetic biology requires the ability to create new DNA sequences to produce unique behaviors in biological systems. Automation is increasingly employed to carry out well-established assembly methods of DNA fragments in a multiplexed, high-throughput fashion, allowing many different configurations to be tested simultaneously. However, metrics are required to determine when automation is warranted based on factors such as assembly methodology, protocol details, and number of samples.

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Microfluidic devices have the potential to automate and miniaturize biological experiments, but open-source sharing of device designs has lagged behind sharing of other resources such as software. Synthetic biologists have used microfluidics for DNA assembly, cell-free expression, and cell culture, but a combination of expense, device complexity, and reliance on custom set-ups hampers their widespread adoption. We present Metafluidics, an open-source, community-driven repository that hosts digital design files, assembly specifications, and open-source software to enable users to build, configure, and operate a microfluidic device.

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The traditional requirement for clean rooms and specialized skills has inhibited many biologists from pursuing new microfluidic innovations. Makerspaces provide a growing alternative to clean rooms: they provide low-cost access to fabrication equipment such as laser cutters, plotter cutters, and 3D printers; use commercially available materials; and attract a diverse community of product designers. This Opinion discusses the materials, tools, and building methodologies particularly suited for developing novel microfluidic devices in these spaces, with insight into biological applications and leveraging the maker community.

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Synthetic DNA has great propensity for efficiently and stably storing non-biological information. With DNA writing and reading technologies rapidly advancing, new applications for synthetic DNA are emerging in data storage and communication. Traditionally, DNA communication has focused on the encoding and transfer of complete sets of information.

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The process of connecting genetic parts-DNA assembly-is a foundational technology for synthetic biology. Microfluidics present an attractive solution for minimizing use of costly reagents, enabling multiplexed reactions, and automating protocols by integrating multiple protocol steps. However, microfluidics fabrication and operation can be expensive and requires expertise, limiting access to the technology.

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Synthetic nucleic acids offer rich potential to understand and engineer new cellular functions, yet an unresolved limitation in their production and usage is deleterious products, which restrict design complexity and add cost. Herein, we employ a solid-state nanopore to differentiate molecules of a gene synthesis reaction into categories of correct and incorrect assemblies. This new method offers a solution that provides information on gene synthesis reactions in near-real time with higher complexity and lower costs.

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In this paper, we report on a method to probe the breakdown of the organophosphate (OP) simulants o,s-diethyl methyl phosphonothioate (OSDMP) and demeton S by the enzyme organophosphorous hydrolase (OPH) in a microfluidic device by surface enhanced Raman spectroscopy (SERS). SERS hotspots were formed on-demand inside the microfluidic device by laser-induced aggregation of injected Ag NPs suspensions. The Ag NP clusters, covering micron-sized areas, were formed within minutes using a conventional confocal Raman laser microscope.

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We describe the construction and characterization of a genomically recoded organism (GRO). We replaced all known UAG stop codons in Escherichia coli MG1655 with synonymous UAA codons, which permitted the deletion of release factor 1 and reassignment of UAG translation function. This GRO exhibited improved properties for incorporation of nonstandard amino acids that expand the chemical diversity of proteins in vivo.

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Genome-scale engineering of living organisms requires precise and economical methods to efficiently modify many loci within chromosomes. One such example is the directed integration of chemically synthesized single-stranded deoxyribonucleic acid (oligonucleotides) into the chromosome of Escherichia coli during replication. Herein, we present a general co-selection strategy in multiplex genome engineering that yields highly modified cells.

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We present genome engineering technologies that are capable of fundamentally reengineering genomes from the nucleotide to the megabase scale. We used multiplex automated genome engineering (MAGE) to site-specifically replace all 314 TAG stop codons with synonymous TAA codons in parallel across 32 Escherichia coli strains. This approach allowed us to measure individual recombination frequencies, confirm viability for each modification, and identify associated phenotypes.

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Automation and optimization of DNA construction results in the efficient production of large target sequences.

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Genome engineering.

Nat Biotechnol

December 2009

For more than 50 years, those engineering genetic material have pursued increasingly challenging targets. During that time, the tools and resources available to the genetic engineer have grown to encompass new extremes of both scale and precision, opening up new opportunities in genome engineering. Today, our capacity to generate larger de novo assemblies of DNA is increasing at a rapid pace (with concomitant decreases in manufacturing cost).

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The breadth of genomic diversity found among organisms in nature allows populations to adapt to diverse environments. However, genomic diversity is difficult to generate in the laboratory and new phenotypes do not easily arise on practical timescales. Although in vitro and directed evolution methods have created genetic variants with usefully altered phenotypes, these methods are limited to laborious and serial manipulation of single genes and are not used for parallel and continuous directed evolution of gene networks or genomes.

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The structure of the cardiac foramen ovale from 17 species representing six cetacean families, the Monodontidae, Phocoenidae, Delphinidae, Ziphiidae, Balaenidae and the Balaenopteridae, was studied using the scanning electron microscope. Eight white whale fetuses (Delphinapterus leucas) and a narwhal fetus (Monodon monoceros) represented the Monodontidae; one fetal and nine neonatal harbour porpoises (Phocoena phocoena) and a finless porpoise fetus (Neophocoena phocoenoides) represented the Phocoenidae; two white-beaked dolphin fetuses (Lagenorhynchus albirostris), four fetal and one neonatal Atlantic white-sided dolphins (Lagenorhynchus acutus), a Risso's dolphin fetus (Grampus griseus), two common bottle-nosed dolphin neonates (Tursiops truncatus), a female short-beaked common dolphin fetus (Delphinus delphis), four killer whale fetuses (Orcinus orca) and two long-finned pilot whale fetuses (Globicephala melas) represented the Delphinidae; two northern bottlenose whale fetuses (Hyperoodon ampullatus) represented the Ziphiidae; one bowhead whale fetus (Balaena mysticetus) represented the Balaenidae and five Common minke whale fetuses (Balaenoptera acutorostrata), one blue whale fetus (Balaenoptera musculus), nine fin whale fetuses (Balaenoptera physalus) and four humpback whale fetuses (Megaptera novaeangliae) represented the Balaenopteridae. The hearts of an additional two incompletely identified toothed and four baleen whale fetuses were also studied.

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The ability to synthesize custom de novo DNA constructs rapidly, accurately and inexpensively is highly desired by researchers, as synthetic genes and longer DNA constructs are enabling to numerous powerful applications in both traditional molecular biology and the emerging field of synthetic biology. However, the current cost of de novo synthesis-driven largely by reagent and handling costs-is a significant barrier to the widespread availability of such technology. In this work, we demonstrate, to our knowledge, the first gene synthesis in a microfluidic environment.

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The availability of inexpensive, on demand synthetic DNA has enabled numerous powerful applications in biotechnology, in turn driving considerable present interest in the de novo synthesis of increasingly longer DNA constructs. The synthesis of DNA from oligonucleotides into products even as large as small viral genomes has been accomplished. Despite such achievements, the costs and time required to generate such long constructs has, to date, precluded gene-length (and longer) DNA synthesis from being an everyday research tool in the same manner as PCR and DNA sequencing.

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Peptides corresponding to the C-terminal heptad repeat of HIV-1 gp41 (C-peptides) are potent inhibitors of HIV-1 entry into cells. Their mechanism of inhibition involves binding in a helical conformation to the central coiled coil of HIV-1 gp41 in a dominant-negative manner. Short C-peptides, however, have low binding affinity for gp41 and poor inhibitory activity, which creates an obstacle to the development of small drug-like C-peptides.

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