Life Sciences Commons^™

Origin Of The Polycomb Repressive Complex 2 And Gene Silencing By An E(Z) Homolog In The Unicellular Alga Chlamydomonas, Scott Shaver, J. Armando Casas-Mollano, Ronald L. Cerny, Heriberto D. Cerutti

Faculty Publications from the Center for Plant Science Innovation

Polycomb group proteins play an essential role in the maintenance of cell identity and the regulation of development in both animals and plants. The Polycomb Repressive Complex 2 (PRC2) is involved in the establishment of transcriptionally silent chromatin states, in part through its ability to methylate lysine 27 of histone H3 by the Enhancer of zeste [E(z)] subunit. The absence of PRC2 in unicellular model fungi and its function in the repression of genes vital for the development of higher eukaryotes led to the proposal that this complex may have evolved together with the emergence of multicellularity. However, we report …

Microbial Stoichiometry And Homeostasis Of Nutrient Ratios In Fungi, Desiree Leach

Honors Theses

Stoichiometry is the ratio of elements in a substance or microbial biomass. This paper investigates microbial stoichiometry and the responses of microbes to dissolved nutrient concentrations and ratios. The current work assesses both autrotrophic and heterotrophic responses to nutrient enrichment: autotrophic and heterotrophic states are defined mainly by ecosystem primary production and respiration. In ecosystems dominated by autotrophic microbes, nutrient enrichment can lead to increased biomass and biomass-specific rates of primary production. Heterotrophic ecosystems rely on subsides of organic carbon from outside the system. Their enrichment with N and/or P can accelerate microbial respiration rates and result in carbon losses …

Growth Rate Of Mugil Cephalus From Two Isolated Ponds In Huntington Beach State Park, South Carolina, Matthew Vincent

Honors Theses

Measurement of growth of the euryhaline teleost Mugil cephalus is quite common in open ocean settings, but growth rates of M. cephalus in isolated areas is non-existent. Two isolated ponds in Huntington Beach State, Horry County, South Carolina were selected to study the growth rate of M. cephalus; Sandpiper Pond with virtual no hydrologic connection to the ocean and Jetty Pond with adequate hydrologic connection to the ocean were the sites of sample collection. Scales from M. cephalus in both ponds were collected then aged by two readers, where agreeing ages were kept in the dataset. A von Bertalanffy growth …

Cell Culture Models Of Genetic Variation, Joshua T. Witten

Arts & Sciences Electronic Theses and Dissertations

Studying genetic variation presents a dilemma. While the genetic variation of greatest interest is that causing variation in traits and disease risk in natural populations, natural populations have characteristics that make them challenging to study. In this work, I have assessed the use of cell culture methods as a solution to some of these challenges. In particular, I studied genetic variation in the budding yeast Saccharomyces cerevisiae that was generated by selection in the lab as a model for natural genetic variation. I have found that even simplistic selection programs in the laboratory, including the use of chemical mutagenesis to …

Individuals Differences In Exploratory Behavior Of Prairie Voles, Microtus Ochrogaster, Danielle N. Lee

Dissertations

Individual differences in behavior are significant because they serve as the substrate for natural selection. Within the Behavioral Syndromes framework, researchers study individual differences in behavior of animals. Behavioral Syndromes are defined as correlations between behaviors in different environmental contexts or testing situations. In this study, I examined the effects of litter size and sex ratio, familial relationships, and age and sex on exploratory behavior of prairie voles, Microtus ochrogaster. Exploratory behavior, defined as spontaneous behavioral responses to unfamiliar stimuli, was examined in three novel situations: an open-field with novel objects, a two-way novel choice apparatus, and a complex maze. …

The Effect Of Green Tea Extract On Endurance Performance In Young Adults, Eric D. Green

Nutrition Theses

Background: Green tea is rich in catechin, a polyphenolic antioxidant. Consumption of green tea or extract from green tea has been shown to result in weight loss, increased fat oxidation, and elevated energy expenditure in mice and humans. Green tea consumption has also been shown to result in increased exercise endurance in mice and improved maximal oxygen uptake (VO2max) in humans. It is not clearly known whether green tea consumption would increase exercise endurance in humans. Objective: The aim of this study was to determine if the daily consumption of decaffeinated green tea extract for 4-5 weeks, would improve exercise …

Opioid Addiction And Pregnancy: Potential Effects Of Substitution Therapies On Developmental Myelination, Andrew Eschenroeder

Theses and Dissertations

While most cells of the central nervous system (CNS) express opioid receptors, the role of the endogenous opioid system in CNS development remains poorly understood. Identification of opioid functions during brain maturation is particularly crucial in light of the increasing trend in opioid abuse and the use of opioid drugs during pregnancy. New substitution therapies in pregnant opioid addicts include buprenorphine, a mu opioid receptor partial agonist and kappa opioid receptor antagonist. However, while clinical studies demonstrated buprenorphine efficacy in reducing neonatal withdrawal symptoms, there is a lack of information on the potential effects of this drug on brain development. …

Regulation Of Dna Damage Processing By Covalent Modification Of Thymine Dna Glycosylase, Ryan D. Mohan

Electronic Thesis and Dissertation Repository

Thymine DNA glycosylase (TDG) is an essential DNA repair enzyme mediating excision of uracil and thymine mispaired with guanine within CpG contexts. Unrepaired, these lesions result in G:C to A:T transitions which are major contributors to genome instability. Interestingly, TDG interacts functionally with transcriptional regulators and participates in directed cytosine demethylation at promoters. TDG is subject to multiple post-translational modifications (PTM) and we undertook an analysis of how these regulate TDG function. Initially, we examined TDG regulation by small ubiquitin-like modifier (SUMO) and identified a novel SUMO binding motif (SBM1, residues 144-148). We hypothesized that SBM1, along with SBM2 (319-322), …

Interview With Jeff Luebbers, Us Forest Service, 2010 (Audio), Jeff Luebbers

All Sustainability History Project Oral Histories

Interview of Jeff Luebbers by Chelsea Saurman on May 13th, 2010.

The interview index is available for download.

Viola Blanda Willd., P. Harwood

Specimens by Name

No abstract provided.

Viola Cucullata Moc. & Sessé Ex Ging., P. Harwood

Specimens by Name

No abstract provided.

Hops Initiates Vacuole Docking By Tethering Membranes Before Trans-Snare Complex Assembly, Christopher M. Hickey, William Wickner

Dartmouth Scholarship

Vacuole homotypic fusion has been reconstituted with all purified components: vacuolar lipids, four soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, Sec17p, Sec18p, the Rab Ypt7p, and the hexameric homotypic fusion and vacuole protein sorting complex (HOPS). HOPS is a Rab-effector with direct affinity for SNAREs (presumably via its Sec1-Munc18 homologous subunit Vps33p) and for certain vacuolar lipids. Each of these pure vacuolar proteins was required for optimal proteoliposome clustering, raising the question of which was most directly involved. We now present model subreactions of clustering and fusion that reveal that HOPS is the direct agent of tethering. The …

Student Content Knowledge Increases After Participation In A Hands-On Biotechnology Intervention, Amber L. Bigler

Theses and Dissertations

Hands-on learning is at the heart of science learning. This study examined increased changes of student content knowledge in biology, particularly biotechnology, after a hands-on biotechnology intervention was implemented into a secondary school. A traditional learning school was selected for a control. Both teachers had participated in a biotechnology professional development program called Project Crawfish. Students from both schools took the same assessment before and after their respective units (biotechnology intervention and genetics unit), and the classroom was the unit of analysis (n=5, n=6, respectively). The assessment was compared as a whole and then divided into five components, eight questions …

Powerful Snp Set Analysis For Case-Control Genome Wide Association Studies, Michael C. Wu, Peter Kraft, Michael P. Epstein, Deanne M. Taylor, Stephen J. Chanock, David J. Hunter, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

Comparative Transcriptional Profiling Identifies Takeout As A Gene That Regulates Life Span, Johannes Bauer, Michael Antosh, Chengyi Chang, Christoph Schorl, Santharam Kolli, Nicola Neretti, Stephen L. Helfand

Biosciences Research

A major challenge in translating the positive effects of dietary restriction (DR) for the improvement of human health is the development of therapeutic mimics. One approach to finding DR mimics is based upon identification of the proximal effectors of DR life span extension. Whole genome profiling of DR in Drosophila shows a large number of changes in gene expression, making it difficult to establish which changes are involved in life span determination as opposed to other unrelated physiological changes. We used comparative whole genome expression profiling to discover genes whose change in expression is shared between DR and two molecular …

Acid-Sensing Ion Channels And Pain, Qihai Gu, Lu-Yuan Lee

Physiology Faculty Publications

Pathophysiological conditions such as inflammation, ischemia, infection and tissue injury can all evoke pain, and each is accompanied by local acidosis. Acid sensing ion channels (ASICs) are proton-gated cation channels expressed in both central and peripheral nervous systems. Increasing evidence suggests that ASICs represent essential sensors for tissue acidosis-related pain. This review provides an update on the role of ASICs in pain sensation and discusses their therapeutic potential for pain management.

A Brain-Specific Cytochrome P450 Responsible For The Majority Of Deltamethrin Resistance In The Qtc279 Strain Of Tribolium Castaneum, Fang Zhu, R. Parthasarathy, Hua Bai, Katharina Woithe, Martin Kaussmann, Ralf Nauen, Douglas A. Harrison, Subba R. Palli

Entomology Faculty Publications

Cytochrome P450-mediated detoxification is one of the most important mechanisms involved in insecticide resistance. However, the molecular basis of this mechanism and the physiological functions of P450s associated with insecticide resistance remain largely unknown. Here, we exploited the functional genomics and reverse genetic approaches to identify and characterize a P450 gene responsible for the majority of deltamethrin resistance observed in the QTC279 strain of Tribolium castaneum. We used recently completed whole-genome sequence of T. castaneum to prepare custom microarrays and identified a P450 gene, CYP6BQ9, which showed more than a 200-fold higher expression in the deltamethrin-resistant QTC279 strain when compared …

Artificial Selection For Determinate Growth Habit In Soybean, Zhixi Tian, Xiaobo Wang, Rian Lee, Yinghui Li, James E. Specht, Randall L. Nelson, Phillip E. Mcclean, Lijuan Qiu, Jianxin Ma

Agronomy & Horticulture -- Faculty Publications

Determinacy is an agronomically important trait associated with the domestication in soybean (Glycine max). Most soybean cultivars are classifiable into indeterminate and determinate growth habit, whereas Glycine soja, the wild progenitor of soybean, is indeterminate. Indeterminate (Dt1/Dt1) and determinate (dt1/dt1) genotypes, when mated, produce progeny that segregate in a monogenic pattern. Here, we show evidence that Dt1 is a homolog (designated as GmTfl1) of Arabidopsis terminal flower 1 (TFL1), a regulatory gene encoding a signaling protein of shoot meristems. The transition from indeterminate to determinate phenotypes in soybean is associated …

Intrinsic Contact Geometry Of Protein Dynamics, Yosi Shibberu, Allen Holder, David Cooper

Mathematical Sciences Technical Reports (MSTR)

We introduce a new measure for comparing protein structures that is especially applicable to analysis of molecular dynamics simulation results. The new measure generalizes the widely used root-mean-squared-deviation (RMSD) measure from three dimensional to n-dimensional Euclidean space, where n equals the number of atoms in the protein molecule. The new measure shows that despite significant fluctuations in the three dimensional geometry of the estrogen receptor protein, the protein's intrinsic contact geometry is remarkably stable over nanosecond time scales. The new measure also identifies significant structural changes missed by RMSD for a residue that plays a key biological role in …

Effect Of Hyaluronidase Treatment On The Structural Integrity Of The Endothelial Glycocalyx Layer, Kristin Simmons

Theses and Dissertations

The endothelial glycocalyx plays an important role as part of the permeability barrier between the blood and the interstitium. In this study, we used different sized fluorescently labeled dextran molecules to determine the size of the macromolecular exclusion zone in capillaries. The width of the exclusion zone was calculated as one half the difference between the anatomic luminal diameter, as determined by transillumination, and the width of a fluorescent dextran column. During the first hour after systemic injection of labeled dextrans, neither 70 kDa dextran (Dextran 70) nor 500 kDa dextran (Dextran 500) labeled with the anionic fluorescein isothiocyanate (FITC) …