Genetic Phenomena Commons^™

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

Polysorbate 80 Inhibition Of Pseudomonas Aeruginosa Biofilm Formation And Its Cleavage By The Secreted Lipase Lipa, C M. Toutain-Kidd, S C. Kadivar, C T. Bramante, S A. Bobin, Michael E. Zegans

Dartmouth Scholarship

Surface-associated bacterial communities known as biofilms are an important source of nosocomial infections. Microorganisms such as Pseudomonas aeruginosa can colonize the abiotic surfaces of medical implants, leading to chronic infections that are difficult to eradicate. Our study demonstrates that polysorbate 80 (PS80), a surfactant commonly added to food and medicines, is able to inhibit biofilm formation by P. aeruginosa on a variety of surfaces, including contact lenses.

Aging And Environmental Exposures Alter Tissue-Specific Dna Methylation Dependent Upon Cpg Island Context, Brock C. Christensen, E Andres Houseman, Carmen J. Marsit, Shichun Zheng, Margaret R. Wrensch, Joseph L. Wiemels, Heather H. Nelson, Margaret R. Karagas

Dartmouth Scholarship

Epigenetic control of gene transcription is critical for normal human development and cellular differentiation. While alterations of epigenetic marks such as DNA methylation have been linked to cancers and many other human diseases, interindividual epigenetic variations in normal tissues due to aging, environmental factors, or innate susceptibility are poorly characterized. The plasticity, tissue-specific nature, and variability of gene expression are related to epigenomic states that vary across individuals. Thus, population-based investigations are needed to further our understanding of the fundamental dynamics of normal individual epigenomes. We analyzed 217 non-pathologic human tissues from 10 anatomic sites at 1,413 autosomal CpG loci …

Comparative Transcriptome Analyses Of Pseudomonas Aeruginosa, Deepak Balasubramanian, Kalai Mathee

HWCOM Faculty Publications

One of the hallmarks of bacterial survival is their ability to adapt rapidly to changing environmental conditions. Niche adaptation is a response to the signals received that are relayed, often to regulators that modulate gene expression. In the post-genomic era, DNA microarrays are used to study the dynamics of gene expression on a global scale. Numerous studies have used Pseudomonas aeruginosa--a Gram-negative environmental and opportunistic human pathogenic bacterium--as the model organism in whole-genome transcriptome analysis. This paper reviews the transcriptome studies that have led to immense advances in our understanding of the biology of this intractable human pathogen. Comparative …

A Truncation Mutation In Tbc1d4 In A Family With Acanthosis Nigricans And Postprandial Hyperinsulinemia, Satya Dash, Hiroyuki Sano, Justin J. Rochford, Robert K. Semple

Dartmouth Scholarship

Tre-2, BUB2, CDC16, 1 domain family member 4 (TBC1D4) (AS160) is a Rab-GTPase activating protein implicated in insulin-stimulated glucose transporter 4 (GLUT4) translocation in adipocytes and myotubes. To determine whether loss-of-function mutations in TBC1D4 might impair GLUT4 translocation and cause insulin resistance in humans, we screened the coding regions of this gene in 156 severely insulin-resistant patients. A female presenting at age 11 years with acanthosis nigricans and extreme postprandial hyperinsulinemia was heterozygous for a premature stop mutation (R363X) in TBC1D4. After demonstrating reduced expression of wild-type TBC1D4 protein and expression of the truncated protein in lymphocytes from the proband, …

When Old-Order Amish Meet New Order Science: Genetic Maladies And The Amish Dilemma, Kelley Downey

Undergraduate Research Conference

The Old World Amish, an Anabaptist Christian domination in the United States and Canada are know for their plain dress, avoidance of modern technology, and separation from the mainstream society.

A traditional agricultural religious group, the Old World Amish maintains isolation from the rest of the community. Financially well-off, they are homogeneous on education, occupation by gender, age at marriage, religion/ethnicity, and health care.

Although the Amish strongly discourage marriage between close cousins, the Lancaster Amish genealogy is described as mutational - inbreeding from multiple, remote connections rather than close consanguinity (first-cousin marriages).

Amish settlements have been identified with certain …

Genetic Mapping Of Secretion And Functional Determinants Of The Vibrio Cholerae Tcpf Colonization Factor, Shelly J. Krebs, Thomas J. Kirn, Ronald K. Taylor

Dartmouth Scholarship

Colonization of the human small intestine by Vibrio cholerae requires the type IV toxin-coregulated pilus (TCP). TcpF, which is encoded within the tcp operon, is secreted from the bacterial cell by the TCP apparatus and is also essential for colonization. Bacteria lacking tcpF are deficient in colonization, and anti-TcpF antibodies are protective in the infant mouse cholera model. In order to elucidate the regions of the protein that are required for secretion through the TCP apparatus and for its function in colonization, random mutagenesis of tcpF was performed. Analysis of these mutants suggests that multiple regions throughout the protein influence …

Human Ribosomal Rna Gene Clusters Are Recombinational Hotspots In Cancer, Dawn Michelle Stults

University of Kentucky Master's Theses

The gene that produces the precursor RNA transcript to the three largest ribosomal RNA molecules (rDNA) is present in multiple copies and organized into gene clusters. They represent 0.5% of the diploid human genome but are critical for cellular viability. The individual genes possess very high levels of sequence identity and are present in high local concentration, making them ideal substrates for genomic rearrangement driven by dysregulated homologous recombination. Our laboratory has developed a sensitive physical assay capable of detecting recombination-mediated genomic restructuring in the rDNA by monitoring changes in lengths of the individual clusters. In order to determine whether …

Dermatoglyphics: Comparison Between Negritos Orang Asli And The Malays, Chinese And Indian, Farahnaz Amini

Farahnaz Amini

No abstract provided.

Evaluation Of Polymorphism At Codon 192 Of Paraoxonase 1 On Its Kinetic Behavior, Rozaida @ Poh Yuen Ying

Rozaida @ Poh Yuen Ying

Human paraoxonase 1 (PON1), a High-Density Lipoprotein (HDL)-associated esterase has been implicated in slowing down the development of atherosclerosis. In the present study, kinetic and inhibition studies on PON1 were conducted to assess three parameters: the Michaelis constant (KM) and maximal rate of metabolisme (Vmax) of paraoxonase and inhibition constant (Ki) of phenylacetate. Human paraoxonase 1 (PON1) activity was measured spectrophotometrically at 405 nm, using plasma samples in basal (without added NaCl) and salt-stimulated assays with 1 M NaCl. Inhibition studies were performed using phenylacetate as an inhibitor of PON1 in basal assays, pH 8.0. Estimates of KM and Vmax …

Identification And Characterization Of Novel Sir3/Mecp2-Chromatin Interactions, Nicholas L. Adkins

Theses, Dissertations and Capstones

The eukaryotic genome is packaged into chromosomes that are made up of a highly organized and heavily regulated structure called chromatin. The proteins involved in the compaction of DNA into this condensed state are mostly understood at the level of the structure of the nucleosome. The higher order arrangement of chromatin and how it effects gene regulation is only partially understood and characterized. The compaction of nucleosomal arrays into 30-nm and higher structures are partially the responsibility of architectural, or structural, chromatin associated proteins. The following dissertation analyzes the individual chromatin contributions of two well studied architectural proteins, the yeast …

Autistic Disorder Associated With A Paternally Derived Unbalanced Translocation Leading To Duplication Of Chromosome 15pter-Q13.2: A Case Report., David J Wu, Nicholas J Wang, Jennette Driscoll, Naghmeh Dorrani, Dahai Liu, Marian Sigman, N Carolyn Schanen

Department of Pediatrics Faculty Papers

Autism spectrum disorders have been associated with maternally derived duplications that involve the imprinted region on the proximal long arm of chromosome 15. Here we describe a boy with a chromosome 15 duplication arising from a 3:1 segregation error of a paternally derived translocation between chromosome 15q13.2 and chromosome 9q34.12, which led to trisomy of chromosome 15pter-q13.2 and 9q34.12-qter. Using array comparative genome hybridization, we localized the breakpoints on both chromosomes and sequence homology suggests that the translocation arose from non-allelic homologous recombination involving the low copy repeats on chromosome 15. The child manifests many characteristics of the maternally-derived duplication …

Metabolomic Investigation Of A New Rat Model Of Autosomal Recessive Polycystic Kidney Disease, Hayley White

Theses : Honours

Metabolomics is complementary to genomics, transcriptomics and proteomics; however, it has the capacity to reflect the activities of the organism at a functional level. Metabolomics can therefore be used as a diagnostic tool by identifying the up- or down-regulation of metabolites in the cell, tissue, plasma, serum or urine. Specifically, these are, but are not limited to, identifying biomarkers of disease, monitoring drug treatments, and monitoring surgical procedures such as organ transplant. Autosomal recessive polycystic kidney disease (ARPKD) makes up 5-8% of patients requiring kidney dialysis and/or transplantation and of these, an estimated 50% of patients progress to end-stage renal …