39 research outputs found

    Evolution of the Bovine TLR Gene Family and Member Associations with Mycobacterium avium Subspecies paratuberculosis Infection

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    Members of the Toll-like receptor (TLR) gene family occupy key roles in the mammalian innate immune system by functioning as sentries for the detection of invading pathogens, thereafter provoking host innate immune responses. We utilized a custom next-generation sequencing approach and allele-specific genotyping assays to detect and validate 280 biallelic variants across all 10 bovine TLR genes, including 71 nonsynonymous single nucleotide polymorphisms (SNPs) and one putative nonsense SNP. Bayesian haplotype reconstructions and median joining networks revealed haplotype sharing between Bos taurus taurus and Bos taurus indicus breeds at every locus, and specialized beef and dairy breeds could not be differentiated despite an average polymorphism density of 1 marker/158 bp. Collectively, 160 tagSNPs and two tag insertion-deletion mutations (indels) were sufficient to predict 100% of the variation at 280 variable sites for both Bos subspecies and their hybrids, whereas 118 tagSNPs and 1 tagIndel predictively captured 100% of the variation at 235 variable sites for B. t. taurus. Polyphen and SIFT analyses of amino acid (AA) replacements encoded by bovine TLR SNPs indicated that up to 32% of the AA substitutions were expected to impact protein function. Classical and newly developed tests of diversity provide strong support for balancing selection operating on TLR3 and TLR8, and purifying selection acting on TLR10. An investigation of the persistence and continuity of linkage disequilibrium (r2≥0.50) between adjacent variable sites also supported the presence of selection acting on TLR3 and TLR8. A case-control study employing validated variants from bovine TLR genes recognizing bacterial ligands revealed six SNPs potentially eliciting small effects on susceptibility to Mycobacterium avium spp paratuberculosis infection in dairy cattle. The results of this study will broadly impact domestic cattle research by providing the necessary foundation to explore several avenues of bovine translational genomics, and the potential for marker-assisted vaccination

    Making sense of confusion : Relating performance, confidence, and self-efficacy to expressions of confusion in an introductory physics class

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    Although confusion is generally perceived to be negative, educators dating as far back as Socrates, who asked students to question assumptions and wrestle with ideas, have challenged this notion. Can confusion be productive? How should instructors interpret student expressions of confusion? During two semesters of introductory physics that involved Just-in-Time Teaching (JiTT) and research-based reading materials, we evaluated performance on reading assignments while simultaneously measuring students’ self-assessment of their confusion over the preclass reading material (N = 137; Nfall = 106, Nspring = 88). We examined the relationship between confusion and correctness, confidence in reasoning, and (in the spring) precourse self-efficacy.We find that student expressions of confusion before coming to class are negatively related to correctness on preclass content-related questions, confidence in reasoning on those questions, and selfefficacy, but weakly positively related to final grade when controlling for these factors (β = 0.23, p = 0.03)

    Making sense of confusion : Relating performance, confidence, and self-efficacy to expressions of confusion in an introductory physics class

    Get PDF
    Although confusion is generally perceived to be negative, educators dating as far back as Socrates, who asked students to question assumptions and wrestle with ideas, have challenged this notion. Can confusion be productive? How should instructors interpret student expressions of confusion? During two semesters of introductory physics that involved Just-in-Time Teaching (JiTT) and research-based reading materials, we evaluated performance on reading assignments while simultaneously measuring students’ self-assessment of their confusion over the preclass reading material (N = 137; Nfall = 106, Nspring = 88). We examined the relationship between confusion and correctness, confidence in reasoning, and (in the spring) precourse self-efficacy.We find that student expressions of confusion before coming to class are negatively related to correctness on preclass content-related questions, confidence in reasoning on those questions, and selfefficacy, but weakly positively related to final grade when controlling for these factors (β = 0.23, p = 0.03)

    Small Non-coding RNA Expression and Vertebrate Anoxia Tolerance

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    Background: Extreme anoxia tolerance requires a metabolic depression whose modulation could involve small non-coding RNAs (small ncRNAs), which are specific, rapid, and reversible regulators of gene expression. A previous study of small ncRNA expression in embryos of the annual killifish Austrofundulus limnaeus, the most anoxiatolerant vertebrate known, revealed a specific expression pattern of small ncRNAs that could play important roles in anoxia tolerance. Here, we conduct a comparative study on the presence and expression of small ncRNAs in the most anoxia-tolerant representatives of several major vertebrate lineages, to investigate the evolution of and mechanisms supporting extreme anoxia tolerance. The epaulette shark (Hemiscyllium ocellatum), crucian carp (Carassius carassius), western painted turtle (Chrysemys picta bellii), and leopard frog (Rana pipiens) were exposed to anoxia and recovery, and small ncRNAs were sequenced from the brain (one of the most anoxia-sensitive tissues) prior to, during, and following exposure to anoxia. Results: Small ncRNA profiles were broadly conserved among species under normoxic conditions, and these expression patterns were largely conserved during exposure to anoxia. In contrast, differentially expressed genes are mostly unique to each species, suggesting that each species may have evolved distinct small ncRNA expression patterns in response to anoxia. Mitochondria-derived small ncRNAs (mitosRNAs) which have a robust response to anoxia in A. limnaeus embryos, were identified in the other anoxia tolerant vertebrates here but did not display a similarly robust response to anoxia. Conclusion: These findings support an overall stabilization of the small ncRNA transcriptome during exposure to anoxic insults, but also suggest that multiple small ncRNA expression pathways may support anoxia tolerance, as no conserved small ncRNA response was identified among the anoxia-tolerant vertebrates studied. This may reflect divergent strategies to achieve the same endpoint: anoxia tolerance. However, it may also indicate that there are multiple cellular pathways that can trigger the same cellular and physiological survival processes, including hypometabolism

    Legislative Documents

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    Also, variously referred to as: House bills; House documents; House legislative documents; legislative documents; General Court documents

    Small Non-coding RNA Expression and Vertebrate Anoxia Tolerance

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    Background: Extreme anoxia tolerance requires a metabolic depression whose modulation could involve small non-coding RNAs (small ncRNAs), which are specific, rapid, and reversible regulators of gene expression. A previous study of small ncRNA expression in embryos of the annual killifish Austrofundulus limnaeus, the most anoxia-tolerant vertebrate known, revealed a specific expression pattern of small ncRNAs that could play important roles in anoxia tolerance. Here, we conduct a comparative study on the presence and expression of small ncRNAs in the most anoxia-tolerant representatives of several major vertebrate lineages, to investigate the evolution of and mechanisms supporting extreme anoxia tolerance. The epaulette shark (Hemiscyllium ocellatum), crucian carp (Carassius carassius), western painted turtle (Chrysemys picta bellii), and leopard frog (Rana pipiens) were exposed to anoxia and recovery, and small ncRNAs were sequenced from the brain (one of the most anoxia-sensitive tissues) prior to, during, and following exposure to anoxia.Results: Small ncRNA profiles were broadly conserved among species under normoxic conditions, and these expression patterns were largely conserved during exposure to anoxia. In contrast, differentially expressed genes are mostly unique to each species, suggesting that each species may have evolved distinct small ncRNA expression patterns in response to anoxia. Mitochondria-derived small ncRNAs (mitosRNAs) which have a robust response to anoxia in A. limnaeus embryos, were identified in the other anoxia tolerant vertebrates here but did not display a similarly robust response to anoxia.Conclusion: These findings support an overall stabilization of the small ncRNA transcriptome during exposure to anoxic insults, but also suggest that multiple small ncRNA expression pathways may support anoxia tolerance, as no conserved small ncRNA response was identified among the anoxia-tolerant vertebrates studied. This may reflect divergent strategies to achieve the same endpoint: anoxia tolerance. However, it may also indicate that there are multiple cellular pathways that can trigger the same cellular and physiological survival processes, including hypometabolism

    Table_5_Small Non-coding RNA Expression and Vertebrate Anoxia Tolerance.DOCX

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    <p>Background: Extreme anoxia tolerance requires a metabolic depression whose modulation could involve small non-coding RNAs (small ncRNAs), which are specific, rapid, and reversible regulators of gene expression. A previous study of small ncRNA expression in embryos of the annual killifish Austrofundulus limnaeus, the most anoxia-tolerant vertebrate known, revealed a specific expression pattern of small ncRNAs that could play important roles in anoxia tolerance. Here, we conduct a comparative study on the presence and expression of small ncRNAs in the most anoxia-tolerant representatives of several major vertebrate lineages, to investigate the evolution of and mechanisms supporting extreme anoxia tolerance. The epaulette shark (Hemiscyllium ocellatum), crucian carp (Carassius carassius), western painted turtle (Chrysemys picta bellii), and leopard frog (Rana pipiens) were exposed to anoxia and recovery, and small ncRNAs were sequenced from the brain (one of the most anoxia-sensitive tissues) prior to, during, and following exposure to anoxia.</p><p>Results: Small ncRNA profiles were broadly conserved among species under normoxic conditions, and these expression patterns were largely conserved during exposure to anoxia. In contrast, differentially expressed genes are mostly unique to each species, suggesting that each species may have evolved distinct small ncRNA expression patterns in response to anoxia. Mitochondria-derived small ncRNAs (mitosRNAs) which have a robust response to anoxia in A. limnaeus embryos, were identified in the other anoxia tolerant vertebrates here but did not display a similarly robust response to anoxia.</p><p>Conclusion: These findings support an overall stabilization of the small ncRNA transcriptome during exposure to anoxic insults, but also suggest that multiple small ncRNA expression pathways may support anoxia tolerance, as no conserved small ncRNA response was identified among the anoxia-tolerant vertebrates studied. This may reflect divergent strategies to achieve the same endpoint: anoxia tolerance. However, it may also indicate that there are multiple cellular pathways that can trigger the same cellular and physiological survival processes, including hypometabolism.</p
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