Publications by authors named "Leonard Sean"

Article Synopsis
  • The study presents a one-step genome engineering method for making gene deletions and insertions in honey bee gut bacteria, which is simple and efficient.
  • This technique uses electroporation with plasmid DNA to integrate antibiotic resistance and fluorescent protein genes into bacterial chromosomes without needing additional recombination tools.
  • The approach shows promise for studying gene functions in various bee-associated microbes, aiding in the understanding of their role in bee health and interactions with their hosts.
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Engineered DNA will slow the growth of a host cell if it redirects limiting resources or otherwise interferes with homeostasis. Escape mutants that alleviate this burden can rapidly evolve and take over cell populations, making genetic engineering less reliable and predictable. Synthetic biologists often use genetic parts encoded on plasmids, but their burden is rarely characterized.

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Article Synopsis
  • The design of overlapping genes in microbes is a new method aimed at enhancing control and stability in genetically engineered organisms.
  • GENTANGLE is a computational pipeline that helps design and test these overlapping gene pairs, making the process more efficient.
  • The software and its related data are freely accessible on platforms like GitHub and Singularity, and comprehensive resources for users are provided in the repository wiki and manual.
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Engineered DNA will slow the growth of a host cell if it redirects limiting resources or otherwise interferes with homeostasis. Populations of engineered cells can rapidly become dominated by "escape mutants" that evolve to alleviate this burden by inactivating the intended function. Synthetic biologists working with bacteria rely on genetic parts and devices encoded on plasmids, but the burden of different engineered DNA sequences is rarely characterized.

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Background: Sepsis is a dysregulated systemic inflammatory response triggered by infection, resulting in organ dysfunction. A major challenge in clinical pediatrics is to identify sepsis early and then quickly intervene to reduce morbidity and mortality. As blood biomarkers hold promise as early sepsis diagnostic tools, we aimed to measure a large number of blood inflammatory biomarkers from pediatric sepsis patients to determine their predictive ability, as well as their correlations with clinical variables and illness severity scores.

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Honey bees are economically relevant pollinators experiencing population declines due to a number of threats. As in humans, the health of bees is influenced by their microbiome. The bacterium is a key member of the bee gut microbiome and has a role in excluding pathogens.

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Youth (aged 15 to 29 years) account for one quarter of new HIV cases in Canada. Of those, men-who-have-sex-with-men make up one third to one half of new cases in that age range. Moreover, Indigenous youth are over-represented in the proportion of new cases.

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Microbiology sample swabs may be unsuccessful or rejected for a variety of reasons. Typically, errors occur in the preanalytical phase of sample collection. Errors with collection, handling and transport can lead to the need to repeat specimen collection.

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The development of synthetic biological circuits that maintain functionality over application-relevant time scales remains a significant challenge. Here, we employed synthetic overlapping sequences in which one gene is encoded or 'entangled' entirely within an alternative reading frame of another gene. In this design, the toxin-encoding relE was entangled within ilvA, which encodes threonine deaminase, an enzyme essential for isoleucine biosynthesis.

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Toolkits of plasmids and genetic parts streamline the process of assembling DNA constructs and engineering microbes. Many of these kits were designed with specific industrial or laboratory microbes in mind. For researchers interested in non-model microbial systems, it is often unclear which tools and techniques will function in newly isolated strains.

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Unlabelled: Toolkits of plasmids and genetic parts streamline the process of assembling DNA constructs and engineering microbes. Many of these kits were designed with specific industrial or laboratory microbes in mind. For researchers interested in non-model microbial systems, it is often unclear which tools and techniques will function in newly isolated strains.

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Research on natural-fiber-reinforced polymer composite is continuously developing. Natural fibers from flora have received considerable attention from researchers because their use in biobased composites is safe and sustainable for the environment. Natural fibers that mixed with Carbon Fiber and or Glass Fiber are low-cost, lightweight, and biodegradable and have lower environmental influences than metal-based materials.

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Honey bees are indispensable pollinators and model organisms for studying social behavior, development and cognition. However, their eusociality makes it difficult to use standard forward genetic approaches to study gene function. Most functional genomics studies in bees currently utilize double-stranded RNA (dsRNA) injection or feeding to induce RNAi-mediated knockdown of a gene of interest.

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Article Synopsis
  • Social corbiculate bees, like honeybees and bumblebees, rely on unique bacterial microbiomes in their guts that help with immunity, digestion, and protection against pathogens.
  • Stressors such as toxins and poor nutrition can disrupt these microbiomes, making bees more vulnerable to diseases, and there’s potential to improve bee health with probiotics.
  • Recent research indicates that native bee gut bacteria are more effective at colonizing bee guts than commercial probiotics, suggesting that developing natural probiotics could enhance the health of managed bee colonies.
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Article Synopsis
  • The diversity in gut microbiomes, particularly among social bees, is shaped by reproductive isolation from barriers that prevent gene flow between microbial lineages.
  • Two gut-associated bacterial groups, Gilliamella and Snodgrassella, have evolved alongside honey bees and bumble bees for 80 million years, leading to distinct populations with limited gene exchange.
  • Genetic adaptations allow these bacteria to thrive in specific hosts and ecological niches, with Gilliamella demonstrating varying abilities to process dietary components based on their localized habitats within the bee gut.
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Antibiotics have been applied to honey bee (Apis mellifera) hives for decades to treat Paenibacillus larvae, which causes American foulbrood disease and kills honey bee larvae. One of the few antibiotics approved in apiculture is tylosin tartrate. This study examined how a realistic hive treatment regimen of tylosin affected the gut microbiota of bees and susceptibility to a bacterial pathogen.

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Insects are an incredibly diverse group of animals with species that benefit and harm natural ecosystems, agriculture, and human health. Many insects have consequential associations with microbes: bacterial symbionts may be embedded in different insect tissues and cell types, inherited across insect generations, and required for insect survival and reproduction. Genetically engineering insect symbionts is key to understanding and harnessing these associations.

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The gut microbiome plays a critical role in the health of many animals. Honeybees are no exception, as they host a core microbiome that affects their nutrition and immune function. However, the relationship between the honeybee immune system and its gut symbionts is poorly understood.

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One goal of synthetic biology is to improve the efficiency and predictability of living cells by removing extraneous genes from their genomes. We demonstrate improved methods for engineering the genome of the metabolically versatile and naturally transformable bacterium Acinetobacter baylyi ADP1 and apply them to a genome streamlining project. In Golden Transformation, linear DNA fragments constructed by Golden Gate Assembly are directly added to cells to create targeted deletions, edits, or additions to the chromosome.

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Honey bees are essential pollinators threatened by colony losses linked to the spread of parasites and pathogens. Here, we report a new approach for manipulating bee gene expression and protecting bee health. We engineered a symbiotic bee gut bacterium, , to induce eukaryotic RNA interference (RNAi) immune responses.

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Hemodialysis is a life-sustaining treatment for persons with kidney failure. However, those on hemodialysis still face a poor quality of life and a short life expectancy. High-quality research evidence from large randomized controlled trials is needed to identify interventions that improve the experiences, outcomes, and health care of persons receiving hemodialysis.

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The thermal tolerance of an organism limits its ecological and geographic ranges and is potentially affected by dependence on temperature-sensitive symbiotic partners. Aphid species vary widely in heat sensitivity, but almost all aphids are dependent on the nutrient-provisioning intracellular bacterium , which has evolved with aphids for 100 million years and which has a reduced genome potentially limiting heat tolerance. We addressed whether heat sensitivity of underlies variation in thermal tolerance among 5 aphid species.

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Mobile genetic elements drive evolution by disrupting genes and rearranging genomes. Eukaryotes have evolved epigenetic mechanisms, including DNA methylation and RNA interference, that silence mobile elements and thereby preserve the integrity of their genomes. We created an artificial reprogrammable epigenetic system based on CRISPR interference to give engineered bacteria a similar line of defense against transposons and other selfish elements in their genomes.

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