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Search Results: 1 - 10 of 226959 matches for " Elizabeth C Engle "
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Divergence of the Yeast Transcription Factor FZF1 Affects Sulfite Resistance
Elizabeth K. Engle,Justin C. Fay
PLOS Genetics , 2012, DOI: 10.1371/journal.pgen.1002763
Abstract: Changes in gene expression are commonly observed during evolution. However, the phenotypic consequences of expression divergence are frequently unknown and difficult to measure. Transcriptional regulators provide a mechanism by which phenotypic divergence can occur through multiple, coordinated changes in gene expression during development or in response to environmental changes. Yet, some changes in transcriptional regulators may be constrained by their pleiotropic effects on gene expression. Here, we use a genome-wide screen for promoters that are likely to have diverged in function and identify a yeast transcription factor, FZF1, that has evolved substantial differences in its ability to confer resistance to sulfites. Chimeric alleles from four Saccharomyces species show that divergence in FZF1 activity is due to changes in both its coding and upstream noncoding sequence. Between the two closest species, noncoding changes affect the expression of FZF1, whereas coding changes affect the expression of SSU1, a sulfite efflux pump activated by FZF1. Both coding and noncoding changes also affect the expression of many other genes. Our results show how divergence in the coding and promoter region of a transcription factor alters the response to an environmental stress.
ZRT1 harbors an excess of nonsynonymous polymorphism and shows evidence of balancing selection in Saccharomyces cerevisiae
Elizabeth K. Engle,Justin C. Fay
Quantitative Biology , 2012,
Abstract: Estimates of the fraction of nucleotide substitutions driven by positive selection vary widely across different species. Accounting for different estimates of positive selection has been difficult, in part because selection on polymorphism within a species is known to obscure a signal of positive selection between species. While methods have been developed to control for the confounding effects of negative selection against deleterious polymorphism, the impact of balancing selection on estimates of positive selection has not been assessed. In Saccharomyces cerevisiae, there is no signal of positive selection within protein coding sequences as the ratio of nonsynonymous to synonymous polymorphism is higher than that of divergence. To investigate the impact of balancing selection on estimates of positive selection we examined five genes with high rates of nonsynonymous polymorphism in S. cerevisiae relative to divergence from S. paradoxus. One of the genes, a high affinity zinc transporter ZRT1, shows an elevated rate of synonymous polymorphism indicative of balancing selection. The high rate of synonymous polymorphism coincides with nonsynonymous divergence between three haplotype groups, which we find to be functionally indistinguishable. We conclude that balancing selection is not likely to be a common cause of genes harboring a large excess of nonsynonymous polymorphism in yeast.
Analysis of human sarcospan as a candidate gene for CFEOM1
Kristine F O'Brien, Elizabeth C Engle, Louis M Kunkel
BMC Genetics , 2001, DOI: 10.1186/1471-2156-2-3
Abstract: When tested by polymerase chain reaction, sarcospan sequence was not detected on yeast or bacterial artificial chromosomes from the CFEOM1 critical region. Sequencing of the sarcospan gene in CFEOM1 patients from 6 families revealed no mutations. Immunohistochemical studies of CFEOM1 extraocular muscles showed normal levels of sarcospan at the membrane. Finally, sarcospan was electronically mapped to bacterial artificial chromosomes that are considered to be outside of the CFEOM1 critical region.In this report we evaluate sarcospan as a candidate gene for CFEOM1. We have found that it is highly unlikely that sarcospan is involved in the pathogenesis of this disease. As of yet no sarcospan gene mutations have been found to cause muscular abnormalities.CFEOM1 is an autosomal dominant disorder that has been linked to the pericentromere of chromosome 12, flanked by marker D12S1584 on the p arm and D12S1668 on the q arm [1, 2]. The clinical phenotype consists of congenital, bilateral ptosis and external ophthalmoplegia, with the eyes partially or completely fixed in a hypotrophic or downward position. On autopsy, CFEOM1 patients appear to be lacking the superior division of cranial nerve III, which innervates the levator and superior rectus muscles [3]. Whether this disease is caused by a primary defect in the nerve or the muscle remains unclear. The disease was initially linked to an 8 centiMorgan region spanning the centromere of chromosome 12, and then further refined to a critical region of 3 cM [1, 2]. Yeast and bacterial artificial chromosome (YAC and BAC) contigs have been generated and a positional cloning approach to identify the CFEOM1 causative gene is ongoing.Sarcospan is a member of the dystrophin associated protein complex present in skeletal and extraocular muscle [4,5,6]. Sarcospan is most tightly associated with the transmembrane sarcoglycan subcomplex, mutation of which causes autosomal recessive limb girdle muscular dystrophy (LGMD2C-2F) [7,8,9,10,11].
CFEOM1, the classic familial form of congenital fibrosis of the extraocular muscles, is genetically heterogeneous but does not result from mutations in ARIX
Elizabeth C Engle, Nathalie McIntosh, Koki Yamada, Bjorn A Lee, Roger Johnson, Michael O'Keefe, Robert Letson, Arnold London, Evan Ballard, Mark Ruttum, Naomichi Matsumoto, Nakamichi Saito, Mary Collins, Lisa Morris, Monte Monte, Adriano Magli, Teresa de Berardinis
BMC Genetics , 2002, DOI: 10.1186/1471-2156-3-3
Abstract: Eleven new CFEOM1 pedigrees were identified. All demonstrated autosomal dominant inheritance, and nine were consistent with linkage to FEOM1. Two small CFEOM1 families were not linked to FEOM1, and both were consistent with linkage to FEOM3. We screened two CFEOM1 families consistent with linkage to FEOM2 and 5 sporadic individuals with classic CFEOM and did not detect ARIX mutations.The phenotype of two small CFEOM1 families does not map to FEOM1, establishing genetic heterogeneity for this disorder. These two families may harbor mutations in the FEOM3 gene, as their phenotype is consistent with linkage to this locus. Thus far, we have not identified ARIX mutations in any affected members of CFEOM1 pedigrees or in any sporadic cases of classic CFEOM.Congenital fibrosis of the extraocular muscles (CFEOM) and Duane syndrome (DS) are complex strabismus disorders that present with congenital restrictive ophthalmoplegia with or without ptosis. These disorders were traditionally believed to reflect primary structural extraocular muscle (EOM) anomalies and have been referred to as 'congenital fibrosis syndromes' [1]. Neuropathology studies of DS [2,3] and one form of CFEOM (CFEOM1) [4], and the identification of ARIX as the gene mutated in a second form of CFEOM (CFEOM2) [5], however, support our hypothesis that CFEOM results from maldevelopment of the oculomotor (nIII) and/or trochlear (nIV) nuclei and DS results from maldevelopment of the abducens (nVI) nucleus. The continued definition of these phenotypes and identification of the underlying disease genes will assist clinical diagnostics and lead to a better understanding of the unique developmental features of the oculomotor lower motor neuron unit.Although several distinct CFEOM phenotypes have been defined [6-8], each likely resulting from maldevelopment of a unique combination of alpha motor neurons in nIII and/or nIV, most reports of CFEOM families describe a stereotypical clinical phenotype. The affected members
Three novel mutations in KIF21A highlight the importance of the third coiled-coil stalk domain in the etiology of CFEOM1
Wai-Man Chan, Caroline Andrews, Laryssa Dragan, Douglas Fredrick, Linlea Armstrong, Christopher Lyons, Michael T Geraghty, David G Hunter, Ahmad Yazdani, Elias I Traboulsi, Jan WR Pott, Nicholas J Gutowski, Sian Ellard, Elizabeth Young, Frank Hanisch, Feray Koc, Bruce Schnall, Elizabeth C Engle
BMC Genetics , 2007, DOI: 10.1186/1471-2156-8-26
Abstract: Sixteen CFEOM1 and 29 CFEOM3 probands were studied. Three previously unreported de novo KIF21A mutations were identified in three CFEOM1 probands, all located in the same coiled-coil region of the stalk that contains all but one of the previously reported mutations. Eight additional CFEOM1 probands harbored three of the mutations previously reported in KIF21A; seven had one of the two most common mutations, while one harbored the mutation in the distal motor domain. No mutation was detected in 5 CFEOM1 or any CFEOM3 probands.Analysis of sixteen CFEOM1 probands revealed three novel KIF21A mutations and confirmed three reported mutations, bringing the total number of reported KIF21A mutations in CFEOM1 to 11 mutations among 70 mutation positive probands. All three new mutations alter amino acids in heptad repeats within the third coiled-coil region of the KIF21A stalk, further highlighting the importance of alterations in this domain in the etiology of CFEOM1.Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; MIM#135700) is a congenital eye movement disorder inherited as an autosomal dominant trait and characterized by bilateral ptosis and bilateral ophthalmoplegia with the globes fixed downward and unable to be raised above the horizontal midline. Affected individuals have dysplasia of the levator palpebrae superioris and superior rectus muscles that elevate the eyelid and globe, respectively, absence of the superior division of the oculomotor nerve that innervates these muscles, and loss of corresponding motoneurons in the midbrain oculomotor nucleus [1,2]. CFEOM3 (MIM#600638 & MIM#607034) is a similar disorder with a somewhat broader phenotype; in pedigrees with autosomal dominant CFEOM3, some individuals may have the characteristic clinical features of CFEOM1, but at least one affected family member does not meet CFEOM1 criteria. S/he may be unilaterally affected, have one or both globes fixed at or above the midline, or have residual upgaze [3-5].Most
Use of Natural Abundance and N Species Concentrations to Assess N-Cycling in Constructed and Natural Coastal Wetlands
C. Marjorie Aelion,Melissa R. Engle,Hongbo Ma
Applied and Environmental Soil Science , 2010, DOI: 10.1155/2010/371259
Abstract: Natural abundance of N stable isotopes used in combination with concentrations may be useful indicators of N-cycling in wetlands. Concentrations and 15N signatures of NO?3, NH
Pulsation Period Change & Classical Cepheids: Probing the Details of Stellar Evolution
Hilding R. Neilson,Alexandra C. Bisol,Ed Guinan,Scott Engle
Physics , 2014, DOI: 10.1017/S1743921314006802
Abstract: Measurements of secular period change probe real-time stellar evolution of classical Cepheids making these measurements powerful constraints for stellar evolution models, especially when coupled with interferometric measurements. In this work, we present stellar evolution models and measured rates of period change for two Galactic Cepheids: Polaris and l Carinae, both important Cepheids for anchoring the Cepheid Leavitt law (period-luminosity relation). The combination of previously-measured parallaxes, interferometric angular diameters and rates of period change allows for predictions of Cepheid mass loss and stellar mass. Using the stellar evolution models, We find that l Car has a mass of about 9 $M_\odot$ consistent with stellar pulsation models, but is not undergoing enhanced stellar mass loss. Conversely, the rate of period change for Polaris requires including enhanced mass-loss rates. We discuss what these different results imply for Cepheid evolution and the mass-loss mechanism on the Cepheid instability strip.
Early Emergence and Selection of a SIV-LTR C/EBP Site Variant in SIV-Infected Macaques That Increases Virus Infectivity
Shruthi Ravimohan, Lucio Gama, Elizabeth L. Engle, M. Christine Zink, Janice E. Clements
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042801
Abstract: CCAAT/enhancer binding protein (C/EBP)β, and C/EBP binding sites in the HIV/SIV- long terminal repeat (LTR) are crucial for regulating transcription and for IFNβ-mediated suppression of virus replication in macrophages, the predominant source of productive virus replication in the brain. We investigated sequence variation within the SIV-LTR C/EBP sites that may be under selective pressure in vivo and therefore associated with disease progression. Using the SIV-macaque model, we examined viral LTR sequences derived from the spleen, a site of macrophage and lymphocyte infection, and the brain from macaques euthanized at 10, 21, 42, 48 and 84 days postinoculation (p.i.). A dominant variant, DS1C/A, containing an adenine-to-guanine substitution and a linked cytosine-to-adenine substitution in the downstream (DS1) C/EBP site, was detected in the spleen at 10 days p.i. The DS1C/A genotype was not detected in the brain until 42 days p.i., after which it was the predominant replicating genotype in both brain and spleen. Functional characterization of the DS1C/A containing SIV showed increased infectivity with or without IFNβ treatment over the wild-type virus, SIV/17E-Fr. The DS1C/A C/EBP site had higher affinity for both protein isoforms of C/EBPβ compared to the wild-type DS1 C/EBP site. Cytokine expression in spleen compared to brain implicated IFNβ and IL-6 responses as part of the selective pressures contributing to emergence of the DS1C/A genotype in vivo. These studies demonstrate selective replication of virus containing the DS1C/A genotype that either emerges very early in spleen and spreads to the brain, or evolves independently in the brain when IFNβ and IL-6 levels are similar to that found in spleen earlier in infection.
A Hard Day’s Knights: Movie Time Travel, the Middle Ages, and a New Millenium
John Engle
Babel : Littératures Plurielles , 2012,
Abstract: This article addresses the cinematic treatment of the Middle Ages through an analysis of two recent mass-audience American films, Black Knight and Timeline, both of which feature time travel as a leading plot element. Providing context for this discussion is a brief analysis of other similar films, as well as remarks regarding Twain's Connecticut Yankee, Ruskin's The Stones of Venice, and The Idylls of the King by Tennyson. As in these other works, the films in question use certain popular stereotypes of the Middle Ages—endemic violence, rigid class distinctions, religious fanaticism, spiritual cohesion, etc.—as lens through which to view the contemporary world. In addition to their roles as comic or action entertainment vehicles, Black Knight indirectly addresses American individualism and a cutthroat modern corporate culture, whereas Timeline touches upon millennial anxiety, '90's ethnic cleansing, and the American misadventure in Iraq.
A Bold New Timeless Classic: Fukunaga’s Partial Reading of Jane Eyre
John Engle
Babel : Littératures Plurielles , 2012,
Abstract: With its first person narrator, radical tonal changes, and wild blend of genres (autobiography, romance, Gothic melodrama, Christian exemplum, etc.), Bront ’s Jane Eyre is a case study in the difficulties of cinematic adaptation, as the filmmaker attempts to balance "fidelity" with contemporary relevance and entertainment value. This article examines Cary Fukunaga’s 2011 version, and in particular certain orientations animating his necessarily "partial" reading of the novel. Chief among these is the decision to begin the film when Jane leaves Thornfield; recounting much of the story in discontinuous flashback, the film manages simultaneously to admit Jane’s narrative voice while eliminating its potentially distracting nature. Fukunaga’s other choices include the toning down of the novel’s lurid Gothic quality, its overt romanticism, and—today an overly familiar romantic comedy stereotype—the teasing interplay between the two protagonists. Communicating in a compact language of visual symbol, he also uses the original’s "religious plot" as a tool for modern character analysis.
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