Life Sciences Commons^™

Rosette Iron Deficiency Transcript And Microrna Profiling Reveals Links Between Copper And Iron Homeostasis In Arabidopsis Thaliana, Brian M. Waters, Samuel A. Mcinturf, Ricardo J. Stein

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) is an essential plant micronutrient, and its deficiency limits plant growth and development on alkaline soils. Under Fe deficiency, plant responses include up-regulation of genes involved in Fe uptake from the soil. However, little is known about shoot responses to Fe deficiency. Using microarrays to probe gene expression in Kas-1 and Tsu-1 ecotypes of Arabidopsis thaliana, and comparison with existing Col-0 data, revealed conserved rosette gene expression responses to Fe deficiency. Fe-regulated genes included known metal homeostasis-related genes, and a number of genes of unknown function. Several genes responded to Fe deficiency in both roots and rosettes. …

The Effect Of Acp1-Ada1 Genetic Interaction On Human Life Span, Nazzareno Lucarini, Valerio Napolioni, Andrea Magrini, Fulvia Gloria

Human Biology Open Access Pre-Prints

Acid phosphatase (ACP1) is a polymorphic enzyme which catalyzes the conversion of flavinmononucleotide (FMN) to riboflavin and regulates the cellular concentration of flavin-adeninedinucleotide (FAD) and, consequently, energy metabolism. Its activity is modulated by adenosine deaminase (ADA1) genotype. Aim of our work is to verify whether individuals with a high proportion of ACP1 f isozyme and carrying ADA*2 allele, displaying the highest phosphatase activity, may have a higher life expectancy. Genomic DNA was extracted from peripheral blood of 569 females and 509 males (18-106 years) randomly recruited from Central Italy. These samples were subdivided into three sexspecific age groups …

Extensive Population Structure In San, Khoe And Mixed Ancestry Populations From Southern Africa Revealed By 44 Short 5-Snp Haplotypes, Carina M. Schlebusch, Himla Soodyall

Human Biology Open Access Pre-Prints

The San and Khoe people currently represent remnant groups of a much larger and widely distributed population of hunter gatherers and pastoralists who had exclusive occupation of southern Africa before the arrival of Bantu-speaking groups in the past 1,200 years and sea-borne immigrants within the last 350 years. Genetic studies (mitochondrial DNA and Y-chromosome) conducted on San and Khoe groups revealed that they harbour some the most divergent lineages found in living peoples throughout the world. Recently, high-density autosomal SNP-array studies confirmed the early divergence of Khoe-San population groups from all other human populations. The present study made use of …

Analysis Of A Genetic Isolate: The Case Of Carloforte (Italy), R. Robledo, L. Corrias, V. Bachis, N. Puddu, A. Mameli, G. Vona, C. M. Calò

Human Biology Open Access Pre-Prints

We reviewed data collected during several studies concerning the genetic isolate of Carloforte (Sardinia, Italy) and analyzed new data on Y-chromosome markers. Carloforte is also a language island, where people still speaks Tabarchino, an archaic form of Ligurian dialect. Demographic data indicate that, in the early years of its history, Carloforte population was characterized by a high degree of endogamy and consanguinity rates that started to decrease around 1850, when marriages with Sardinian people began to occur more frequently. Cultural factors, mainly language, account for the high endogamy. Genetic data from classical markers, mtDNA and Ychromosome markers confirmed the strong …

A Tale Of Two Haplotypes: The Eda2r/Ar Intergenic Region Is The Most Divergent Genomic Segment Between Africans And East Asians In The Human Genome, Amanda M. Casto, Brenna M. Henn, Jeffery M. Kidd, Carlos D. Bustamante, Marcus W. Feldman

Human Biology Open Access Pre-Prints

Single nucleotide polymorphisms (SNPs) with large allele frequency differences between human populations are relatively rare. The longest run of SNPs with an allele frequency difference of one between the Yoruba of Nigeria and the Han Chinese is found on the long arm of the X chromosome in the intergenic region separating the EDA2R and AR genes. It has been proposed that the unusual allele frequency distributions of these SNPs are the result of a selective sweep affecting African populations that occurred after the Out-of-Africa migration. To investigate the evolutionary history of the EDA2R/AR intergenic region, we characterized the haplotype structure …

Mutations In Dmrt3 Affect Locomotion In Horses And Spinal Circuit Function In Mice, Lisa S. Andersson, Martin Larhammar, Fatima Memic, Hanna Wootz, Doreen Schwochow, Carl-Johan Rubin, Kalicharan Patra, Thorvaldur Arnason, Lisbeth Wellbring, Göran Hjälm, Freyja Imsland, Jessica Lynn Petersen, Molly E. Mccue, James R. Mickelson, Gus Cothran, Nadav Ahituv, Lars Roepstorff, Sofia Mikko, Anna Vallstedt, Gabriella Lindgren, Leif Andersson, Klas Kullander

Department of Animal Science: Faculty Publications

Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left–right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favorable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes …

The Role Of Epigenetics In Evolution: The Extended Synthesis, Aaron W. Schrey, Christina L. Richards, Victoria Meller, Vincent Sollars, Douglas M. Ruden

Vincent E Sollars

Evolutionary biology is currently experiencing an emergence of several research topics that transcend the boundaries of the Modern Synthesis, which was the last major conceptual integration in evolutionary biology [1]. The Modern Synthesis used the concepts of population genetics to integrate Mendelian genetics with evolution by natural selection [2]. Pigliucci [3, and citations within] identified several major areas of innovation that transcend the Modern Synthesis: epigenetics, evolvability, phenotypic plasticity, evolution on adaptive landscapes, evolutionary developmental biology, and systems biology. Integrating these new ideas with the Modern Synthesis will form a new conceptual framework of evolution, which they termed the Extended …

Postzygotic Isolation In Drosophila Simulans And D. Mauritiana, Christopher T. D. Dickman

Electronic Thesis and Dissertation Repository

The study of speciation requires examination of barriers that produce and maintain species separation. Using Drosophila simulans and D. mauritiana, this thesis focuses on post-zygotic isolating mechanisms, which occur after the formation of interspecies hybrids. This study aims to examine the genetic causes of male hybrid sterility and decreased hybrid female lifespan. Quantitative trait locus (QTL) mapping using flies with an attached-X chromosome, identified seven autosomal QTLs that contribute to hybrid sterility. Separately, reduction in hybrid female lifespan was noted for females bearing an attached-X chromosome and was more severe in individuals who were mated. This reduction is caused …

Disparities In Allele Frequencies And Population Differentiation For 101 Disease-Associated Single Nucleotide Polymorphisms Between Puerto Ricans And Non-Hispanic Whites, Josiemer Mattei, Laurence D. Parnell, Chao-Qiang Lai, Bibiana Garcia-Bailo, Xian Adiconis, Jian Shen, Donna Arnett, Serkalem Demissie, Katherine L. Tucker, Jose M. Ordovas

Katherine L. Tucker

Background: Variations in gene allele frequencies can contribute to differences in the prevalence of some common complex diseases among populations. Natural selection modulates the balance in allele frequencies across populations. Population differentiation (FST) can evidence environmental selection pressures. Such genetic information is limited in Puerto Ricans, the second largest Hispanic ethnic group in the US, and a group with high prevalence of chronic disease. We determined allele frequencies and population differentiation for 101 single nucleotide polymorphisms (SNPs) in 30 genes involved in major metabolic and disease-relevant pathways in Puerto Ricans (n = 969, ages 45–75 years) and compared them to …

Farnesol And Cyclic Amp Signaling Effects On The Hypha-To-Yeast Transition In Candida Albicans, Allia K. Lindsay, Aurélie Deveau, Amy E. Piispanen, Deborah A. Hogan

Dartmouth Scholarship

Candida albicans, a fungal pathogen of humans, regulates its morphology in response to many environmental cues and this morphological plasticity contributes to virulence. Farnesol, an autoregulatory molecule produced by C. albicans, inhibits the induction of hyphal growth by inhibiting adenylate cyclase (Cyr1). The role of farnesol and Cyr1 in controlling the maintenance of hyphal growth has been less clear. Here, we demonstrate that preformed hyphae transition to growth as yeast in response to farnesol and that strains with increased cyclic AMP (cAMP) signaling exhibit more resistance to farnesol. Exogenous farnesol did not induce the hypha-to-yeast transition in mutants …

Brain In A Jar: Writing About Alzheimer's Disease, Nancy Stearns Bercaw

UVM Libraries Conference Day

Living with, and writing about, Alzheimer's disease.

A Genetic Survey Of English Sole Populations In The Salish Sea, Elizabeth S. Gutierrez, Gary A. Winans, Jon Baker, Amanda Cope

STAR Program Research Presentations

This summer I interned at the Northwest Fisheries Science Center in Seattle, WA and participated in NOAA’s Salish Sea Project. The Salish Sea Project’s goal is to identify genetically distinctive groups of species in the Salish Sea that may have unique evolutionary and/or adaptive backgrounds. These findings will allow NOAA to promote and monitor the natural production of species in the Salish Sea, to select representative populations for experimental work regarding pollution, ocean acidification and climate change, to contribute to managing the ecosystem for intra- and inter-species diversity, and to help make informed decisions about adaptive management and marine protected …

Genetic Susceptibility To Type 2 Diabetes: A Global Meta-Analysis Studying The Genetic Differences In Tunisian Populations, Rym Berhouma, S. Kouidhi, M. Ammar, H. Abid, T. Baroudi, H. Ennafaa, A. Benammar-Elgaaied

Human Biology Open Access Pre-Prints

The present study is the first meta-analysis to evaluate type 2 diabetes (T2D) - associated polymorphisms in cohorts originated from several Tunisian regions. In fact, we evaluated the effect of seven polymorphisms in the following genes; PPARg ( Pro12Ala), TNFα (-308A/G), ENPP1(K121Q), TCF7L2(rs7903146 C/T), MTHFR( C677T), ACE(I/D), CAPN10(3R/2R) on T2D risk, through a meta-analysis combining data of previous studies performed on Tunisian populations originating from the north, centre or south of the country. R statistics version 2.12.1 software was used to estimate the heterogeneity between studies. Pooled ORs were computed by the fixed-effects method of Mantel-Haenszel if no heterogeneity between …

Condensin Ii Promotes The Formation Of Chromosome Territories By Inducing Axial Compaction Of Polyploid Interphase Chromosomes, Christopher R. R. Bauer, Tom A. Hartl, Giovanni Bosco

Dartmouth Scholarship

The eukaryotic nucleus is both spatially and functionally partitioned. This organization contributes to the maintenance, expression, and transmission of genetic information. Though our ability to probe the physical structure of the genome within the nucleus has improved substantially in recent years, relatively little is known about the factors that regulate its organization or the mechanisms through which specific organizational states are achieved. Here, we show that Drosophila melanogaster Condensin II induces axial compaction of interphase chromosomes, globally disrupts interchromosomal interactions, and promotes the dispersal of peri-centric heterochromatin. These Condensin II activities compartmentalize the nucleus into discrete chromosome territories and indicate …

Paternal Lineage Analysis Supports An Armenian Rather Than A Central Asian Genetic Origin Of The Hamshenis, Ashot Margaryan, Ashot Harutyunyan, Zaruhi Khachatryan, Armine Khudoyan, Levon Yepiskoposyan

Human Biology Open Access Pre-Prints

The Hamshenis are an isolated geographic group of Armenians with a strong ethnic identity who, until the early decades of the twentieth century, inhabited the Pontus area on the southern coast of the Black Sea. Scholars hold alternative views on their origin, proposing eastern Armenia, western Armenia and Central Asia, respectively, as their most likely homeland. To ascertain whether genetic data from the non-recombining portion of the Y chromosome is supportive any of these suggestions, we screened 82 Armenian males of the Hamsheni descent for 12 biallelic and 6 microsatellite Y-chromosomal markers. These data were compared with the corresponding datasets …

Gene Ontology Analysis Of Pairwise Genetic Associations In Two Genome-Wide Studies Of Sporadic Als, Nora Chung Kim, Peter C. Andrews, Folkert W. Asselbergs, H Robert Frost, Scott M. Williams, Brent T. Harris, Cynthia Read, Kathleen D. Askland, Jason H. Moore

Dartmouth Scholarship

It is increasingly clear that common human diseases have a complex genetic architecture characterized by both additive and nonadditive genetic effects. The goal of the present study was to determine whether patterns of both additive and nonadditive genetic associations aggregate in specific functional groups as defined by the Gene Ontology (GO).

Politicizing Patents - Patenting Biotechnology In The Wake Of Section 33, Prometheus, And Cls Bank, Jonathan R. K. Stroud

Articles in Law Reviews & Journals

Tucked into the America Invents Act is the first statutory exemption for any patentable subject matter. Section 33 renders unpatentable all claims “encompassing a human being.” By recognizing a vague subject matter – exception for human beings despite the fact that internal policies had long militated against such patent claims, Congress has politicized the patent law to an unheard-of degree. While textually consistent with internal USPTO policy, the passage of § 33 should not be seen as an invitation to litigators to expand § 101 unpatentable-subject-matter challenges to validity by including arguments that medical methods, genetic tests, biological chimeras, or …

Selfish Little Circles: Transmission Bias And Evolution Of Large Deletion-Bearing Mitochondrial Dna In Caenorhabditis Briggsae Nematodes, Katie A. Clark, Dana K. Howe, Kristin Gafner, Danika Kusuma, Sita Ping, Suzanne Estes

Biology Faculty Publications and Presentations

Selfish DNA poses a significant challenge to genome stability and organismal fitness in diverse eukaryotic lineages. Although selfish mitochondrial DNA (mtDNA) has known associations with cytoplasmic male sterility in numerous gynodioecious plant species and is manifested as petite mutants in experimental yeast lab populations, examples of selfish mtDNA in animals are less common. We analyzed the inheritance and evolution of mitochondrial DNA bearing large heteroplasmic deletions including nad5 gene sequences (nad5Δ mtDNA), in the nematode Caenorhabditis briggsae. The deletion is widespread in C. briggsae natural populations and is associated with deleterious organismal effects. We studied the inheritance patterns of nad5Δ …

The Effects Of Cytokinin On The Transcriptional Regulation Of Pin Expression In Arabidopsis Thaliana, Elizabeth Burgess

Honors Theses and Capstones

The processes of cell division and differentiation are critical to the development of any multicellular organism. During the formation of plant roots these processes take place at a region of the root tip called the meristem. Cytokinin and auxin are two plant growth hormones that influence this process. Although these two growth hormones are both necessary they also appear in many ways to have an antagonistic relationship. As meristematic root cells undergo differentiation they cease dividing. It has been proposed that the size of the root meristem and thus the overall rate of root growth are determined by the balance …

Uncovering Dual Roles For Perk Signaling During Experimentally Induced Pancreatitis, Elena Fazio

Electronic Thesis and Dissertation Repository

Pancreatitis is characterized by inappropriate activation of digestive enzyme

precursors, or zymogens, local and systemic inflammation, dysregulation of

cellular calcium (Ca2+), and induction of the unfolded protein response (UPR).

The UPR consists of three distinct pathways all of which are activated during

pancreatitis. However, the molecular roles of each remain unclear. The

protein kinase RNA (PKR)-like ER kinase (PERK) pathway reduces general

protein translation by phosphorylating eIF2!, and is activated within minutes

of initiating pancreatic damage. Microarray analysis carried out by our lab

revealed robust upregulation of the PERK pathways members Activating

Transcription Factor (ATF) 3 and stanniocalcin (STC) 2. …

Two Boundaries Separate Borrelia Burgdorferi Populations In North America, Gabriele Margos, Jean I. Tsao, Santiago Castillo-Ramirez, Yvette A. Girard, Anne G. Hoen

Dartmouth Scholarship

Understanding the spread of infectious diseases is crucial for implementing effective control measures. For this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. Here, we investigate on a continental scale the population structure of Borrelia burgdorferi, the causative agent of Lyme borreliosis (LB), a tick-borne disease, in North America. We test the hypothesis that the observed d population structure is congruent with recent population expansions and that these were preceded by bottlenecks mostly likely caused by the near extirpation in the 1900s …

Genetic Comparison Of Water Molds From Embryos Of Amphibians Rana Cascadae, Bufo Boreas And Pseudacris Regilla, Kori K. Ault, James E. Johnson, Holly C. Pinkart, R. Steven Wagner

All Faculty Scholarship for the College of the Sciences

Water molds that cause the disease saprolegniasis have been implicated in widespread mortality of amphibian embryos. However, because of the limitations of traditional identification methods, water mold species involved in die-offs or utilized in ecological studies often remain unidentified or identified only as Saprolegnia ferax. Furthermore, water mold taxonomy requires revision, so very distinct organisms may all be called S. ferax. Recent DNA-based studies indicate that the diversity of water molds infecting amphibian embryos is significantly higher than what was previously known, but these studies rely on culture methods, which may be biased towards taxa that grow best …

Computational Design And Characterization Of A Temperature-Sensitive Plasmid Replicon For Gram Positive Thermophiles, Daniel G. Olson, Lee R. Lynd

Dartmouth Scholarship

Temperature-sensitive (Ts) plasmids are useful tools for genetic engineering, but there are currently none compatible with the gram positive, thermophilic, obligate anaerobe, Clostridium thermocellum. Traditional mutagenesis techniques yield Ts mutants at a low frequency, and therefore requires the development of high-throughput screening protocols, which are also not available for this organism. Recently there has been progress in the development of computer algorithms which can predict Ts mutations. Most plasmids currently used for genetic modification of C. thermocellum are based on the replicon of plasmid pNW33N, which replicates using the RepB replication protein. To address this problem, we set out …

Dna Methylation Arrays As Surrogate Measures Of Cell Mixture Distribution, Eugene Houseman, William P. Accomando, Devin C. Koestler, Brock C. Christensen, Carmen J. Marsit

Dartmouth Scholarship

There has been a long-standing need in biomedical research for a method that quantifies the normally mixed composition of leukocytes beyond what is possible by simple histological or flow cytometric assessments. The latter is restricted by the labile nature of protein epitopes, requirements for cell processing, and timely cell analysis. In a diverse array of diseases and following numerous immune-toxic exposures, leukocyte composition will critically inform the underlying immuno-biology to most chronic medical conditions. Emerging research demonstrates that DNA methylation is responsible for cellular differentiation, and when measured in whole peripheral blood, serves to distinguish cancer cases from controls.

Why Odds Ratio Estimates Of Gwas Are Almost Always Close To 1.0, Yutaka Yasui

COBRA Preprint Series

“Missing heritability” in genome-wide association studies (GWAS) refers to the seeming inability for GWAS data to capture the great majority of genetic causes of a disease in comparison to the known degree of heritability for the disease, in spite of GWAS’ genome-wide measures of genetic variations. This paper presents a simple mathematical explanation for this phenomenon, assuming that the heritability information exists in GWAS data. Specifically, it focuses on the fact that the great majority of association measures (in the form of odds ratios) from GWAS are consistently close to the value that indicates no association, explains why this occurs, …

The Tlo Proteins Are Stoichiometric Components Of Candida Albicans Mediator Anchored Via The Med3 Subunit, Anda Zhang, Kostadin O. Petrov, Emily R. Hyun, Zhongle Liu, Scott A. Gerber, Lawrence C. Myers

Dartmouth Scholarship

The amplification of the TLO (for telomere-associated) genes in Candida albicans, compared to its less pathogenic, close relative Candida dubliniensis, suggests a role in virulence. Little, however, is known about the function of the Tlo proteins. We have purified the Mediator coactivator complex from C. albicans (caMediator) and found that Tlo proteins are a stoichiometric component of caMediator. Many members of the Tlo family are expressed, and each is a unique member of caMediator. Protein expression analysis of individual Tlo proteins, as well as the purification of tagged Tlo proteins, demonstrate that there is a large free population of Tlo …

An Integrative Functional Genomics Approach Towards Quantitative Trait Gene Nomination In Existing And Emerging Mouse Genetic Reference Populations, Vivek Philip

Doctoral Dissertations

An approach that has been widely applied for the genetic dissection of complex traits is Quantitative Trait Locus (QTL) mapping. QTL mapping identifies genomic regions that harbor polymorphisms, responsible for the observed variation in a complex trait. If these polymorphisms are located within a gene, then these genes are called Quantitative Trait Genes (QTG). Prior to advancements in QTL mapping populations, QTL mapping resolution was often poor, resulting in large QTL intervals. Therefore, after mapping a QTL, fine mapping was initiated to further reduce the QTL interval and to identify the QTG. While successful, fine mapping using genetic approaches have …

Genetic Variation In Field And Laboratory Populations Of The Spined Soldier Bug, Podisus Maculiventris, Kathleen Kneeland, Thomas A. Coudron, Erica Lindroth, David Stanley, John E. Foster

Department of Entomology: Faculty Publications

The predatory spined soldier bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae), is an economically important and highly valued biological control agent. There is substantial information on the biology, ecology, behavior, and rearing of this stink bug. However, virtually nothing is known of its genetic variation, in natural or domesticated populations. To address this lacuna, we used amplified fragment length polymorphism (AFLP) to assess the genetic variability of field and laboratory populations. Four AFLP universal primer combinations yielded a total of 209 usable loci. The AFLP results showed greater genetic variability between populations from Missouri and Mississippi (both USA), and relatively low …

Mutation And Complementation Of A Cellulose Synthase (Cesa) Gene, Ahmed Y. El-Araby

Senior Honors Projects

Cellulose is a carbohydrate polymer that is composed of repeating glucose subunits. Being the most abundant organic compound in the biosphere and comprising a large percentage of all plant biomass, cellulose is extremely plentiful and has a significant role in nature. Cellulose is present in plant cell walls, in commercial products such as those made from wood or cotton, and is of interest to the biofuel industry as a potential alternative fuel source. Although indigestible by humans, cellulose is nutritionally valuable, serving as a dietary fiber. Because of its ubiquity and importance in many areas, studying cellulose will prove to …

Signaling Pathways And Genetic Interactions That Lead To Metastatic Cancer In Drosophila Melanogaster, Amanda Cole

Honors Capstone Projects - All

Cancer is a complex and multigenic disease, which is typically initiated by genetic mutations in tumor suppressor genes that regulate homeostatic mechanisms within cells. Oncogenic promoter mutations, like those involved in signal transduction pathways, also have the potential to induce cancer in an otherwise healthy organism. Transformation is highly dependent upon mutations to both tumor suppressor and oncogenes, as neither mutation is exclusive in its ability to generate malignant tumors. In the model organism, Drosophila melanogaster, I have generated metastatic cancer through the genetic effect of overactive Raf signaling, in conjugation with silencing selected tumor suppressor genes using RNA …