18 research outputs found
Oasis Deluxe
This creative dissertation, submitted for partial fulfillment of requirements for the Master of Fine Arts (MFA) in Creative Writing degree, is a novella-length work of fiction set in Las Vegas, Nevada. My aesthetic intent was to construct a contemporary story around an unobtrusive but directive narrative voice that privileges multiple perspectives while uniting them into a coherent whole, and I hope the spirit of that goal is recognizable in the final product; While this work is not cumulative in terns of content, it does represent a narrative and structural sensibility I have developed during my years of study at this institution. In the end, the manuscript\u27s best qualities reflect the influence of numerous friends, mentors and colleagues who have been generous with insights and guidance; its failures are mine alone
The role of the Cucumber mosaic virus 2b protein in viral movement and symptom induction
The Cucumber mosaic virus (CMV) 2b protein is a counter-defense factor and symptom determinant. Conserved domains in the 2b protein sequence were mutated in the 2b gene of strain Fny-CMV. The effects of these mutations were assessed by infection of Nicotiana tabacum, N. benthamiana, and Arabidopsis thaliana (ecotype Col-0) with mutant viruses and by expression of mutant 2b transgenes in A. thaliana. We confirmed that two nuclear localization signals were required for symptom induction and found that the N-terminal domain was essential for symptom induction. The C-terminal domain and two serine residues within a putative phosphorylation domain modulated symptom severity. Further infection studies were conducted using Fny-CMVΔ2b, a mutant that cannot express the 2b protein and that induces no symptoms in N. tabacum, N. benthamiana, or A. thaliana ecotype Col-0. Surprisingly, in plants of A. thaliana ecotype C24, Fny-CMVΔ2b induced severe symptoms similar to those induced by the wild-type virus. However, C24 plants infected with the mutant virus recovered from disease while those infected with the wild-type virus did not. Expression of 2b transgenes from either Fny-CMV or from LS-CMV (a mild strain) in Col-0 plants enhanced systemic movement of Fny-CMVΔ2b and permitted symptom induction by Fny-CMVΔ2b. Taken together, the results indicate that the 2b protein itself is an important symptom determinant in certain hosts. However, they also suggest that the protein may somehow synergize symptom induction by other CMV-encoded factors
Genome sequence of adherent-invasive Escherichia coli and comparative genomic analysis with other E. coli pathotypes
<p>Abstract</p> <p>Background</p> <p>Adherent and invasive <it>Escherichia coli </it>(AIEC) are commonly found in ileal lesions of Crohn's Disease (CD) patients, where they adhere to intestinal epithelial cells and invade into and survive in epithelial cells and macrophages, thereby gaining access to a typically restricted host niche. Colonization leads to strong inflammatory responses in the gut suggesting that AIEC could play a role in CD immunopathology. Despite extensive investigation, the genetic determinants accounting for the AIEC phenotype remain poorly defined. To address this, we present the complete genome sequence of an AIEC, revealing the genetic blueprint for this disease-associated <it>E. coli </it>pathotype.</p> <p>Results</p> <p>We sequenced the complete genome of <it>E. coli </it>NRG857c (O83:H1), a clinical isolate of AIEC from the ileum of a Crohn's Disease patient. Our sequence data confirmed a phylogenetic linkage between AIEC and extraintestinal pathogenic <it>E. coli </it>causing urinary tract infections and neonatal meningitis. The comparison of the NRG857c AIEC genome with other pathogenic and commensal <it>E. coli </it>allowed for the identification of unique genetic features of the AIEC pathotype, including 41 genomic islands, and unique genes that are found only in strains exhibiting the adherent and invasive phenotype.</p> <p>Conclusions</p> <p>Up to now, the virulence-like features associated with AIEC are detectable only phenotypically. AIEC genome sequence data will facilitate the identification of genetic determinants implicated in invasion and intracellular growth, as well as enable functional genomic studies of AIEC gene expression during health and disease.</p
Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population
The effects of cucumber mosaic virus 2b protein on methyl jasmonate induced transcriptional responses and plant-aphid interactions in Arabidopsis
ICTV Virus Taxonomy Profile: Nanoviridae
International audienceNanoviridae is a family of plant viruses (nanovirids) whose members have small isometric virions and multipartite, circular, single-stranded (css) DNA genomes. Each of the six (genus Babuvirus ) or eight (genus Nanovirus ) genomic DNAs is 0.9–1.1 kb and is separately encapsidated. Many isolates are associated with satellite-like cssDNAs (alphasatellites) of 1.0–1.1 kb. Hosts are eudicots, predominantly legumes (genus Nanovirus ), and monocotyledons, predominantly in the order Zingiberales (genus Babuvirus ). Nanovirids require a virus-encoded helper factor for transmission by aphids in a circulative, non-propagative manner. This is a summary of the ICTV Report on the family Nanoviridae , which is available at ictv.global/report/nanoviridae
Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population
Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 Ă— Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass
Structural characterization of nonactive site, TrkA-selective kinase inhibitors
Current therapies for chronic pain can have insufficient efficacy and lead to side effects, necessitating research of novel targets against pain. Although originally identified as an oncogene, Tropomyosin-related kinase A (TrkA) is linked to pain and elevated levels of NGF (the ligand for TrkA) are associated with chronic pain. Antibodies that block TrkA interaction with its ligand, NGF, are in clinical trials for pain relief. Here, we describe the identification of TrkA-specific inhibitors and the structural basis for their selectivity over other Trk family kinases. The X-ray structures reveal a binding site outside the kinase active site that uses residues from the kinase domain and the juxtamembrane region. Three modes of binding with the juxtamembrane region are characterized through a series of ligand-bound complexes. The structures indicate a critical pharmacophore on the compounds that leads to the distinct binding modes. The mode of interaction can allow TrkA selectivity over TrkB and TrkC or promiscuous, pan-Trk inhibition. This finding highlights the difficulty in characterizing the structure-activity relationship of a chemical series in the absence of structural information because of substantial differences in the interacting residues. These structures illustrate the flexibility of binding to sequences outside of-but adjacent to-the kinase domain of TrkA. This knowledge allows development of compounds with specificity for TrkA or the family of Trk proteins