Biology Commons^™

Exploring The Effects Of Hypoxia On Sulfate Reducing Anaerobes, Annaliese K. Jones

Senior Honors Projects

Exploring the Effects of Hypoxia on Sulfate Reducing Anaerobes

Annaliese K. Jones

Sponsor: Bethany Jenkins, Cell and Molecular Biology

As a student about to graduate with a degree in Biological Sciences, I find myself faced with the need to find my own independent research interests and scientific voice. As a result of my interests in the fields of both microbiology and ecology, I am drawn to questions surrounding the role and behavior of microorganisms in the environment. With climate change being an issue capturing the attention of a large portion of the scientific community, I have chosen to focus my …

Quantitative Comparison Of Cis-Regulatory Element (Cre) Activities In Transgenic Drosophila Melanogaster, William A. Rogers, Thomas M. Williams

Biology Faculty Publications

Gene expression patterns are specified by cis-regulatory element (CRE) sequences, which are also called enhancers or cis-regulatory modules. A typical CRE possesses an arrangement of binding sites for several transcription factor proteins that confer a regulatory logic specifying when, where, and at what level the regulated gene(s) is expressed. The full set of CREs within an animal genome encodes the organism′s program for development¹, and empirical as well as theoretical studies indicate that mutations in CREs played a prominent role in morphological evolution^2-4. Moreover, human genome wide association studies indicate that genetic variation in CREs …

Protein Trap Lines Of Drosophila To Demonstrate Spatio-Temporal Localization Of Proteins In An Undergraduate Lab, Oorvashi Roy Puli, Amit Singh

Biology Faculty Publications

The objective of this teaching note is to generate a laboratory exercise, which allows students to get a hands-on experience of a cell biology technique. The short duration of the laboratory classes is the biggest challenge with the development of a cell biology lab for an undergraduate curriculum. Therefore, it is necessary to design a laboratory exercise that enables the students to carry out cell biological assays in the desired time. This laboratory exercise focuses on tracking protein expression levels along a spatial (space) and temporal (time) axis in developing Drosophila melanogaster organ primordium. Here we use the protein trap …

Global Analysis Of Serine-Threonine Protein Kinase Genes In Neurospora Crassa, Gyungsoon Park, Jacqueline A. Servin, Gloria E. Turner, Lorena Altamirano

Dartmouth Scholarship

Serine/threonine (S/T) protein kinases are crucial components of diverse signaling pathways in eukaryotes, including the model filamentous fungus Neurospora crassa. In order to assess the importance of S/T kinases to Neurospora biology, we embarked on a global analysis of 86 S/T kinase genes in Neurospora. We were able to isolate viable mutants for 77 of the 86 kinase genes. Of these, 57% exhibited at least one growth or developmental phenotype, with a relatively large fraction (40%) possessing a defect in more than one trait. S/T kinase knockouts were subjected to chemical screening using a panel of eight chemical treatments, with …

Activation Of Jnk Signaling Mediates Amyloid-Ss- Dependent Cell Death, Meghana Tare, Rohan Modi, Jaison Nainaparampil, Oorvashi Roy Puli, Shimpi Bedi, Pedro Fernandez-Funez, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Background: Alzheimer's disease (AD) is an age related progressive neurodegenerative disorder. One of the reasons for Alzheimer's neuropathology is the generation of large aggregates of Aß42 that are toxic in nature and induce oxidative stress, aberrant signaling and many other cellular alterations that trigger neuronal cell death. However, the exact mechanisms leading to cell death are not clearly understood.

Methodology/Principal Findings: We employed a Drosophila eye model of AD to study how Aß42 causes cell death. Misexpression of higher levels of Aß42 in the differentiating photoreceptors of fly retina rapidly induced aberrant cellular phenotypes and cell death. We found that …

Evolving Hard Problems: Generating Human Genetics Datasets With A Complex Etiology, Daniel S Himmelstein, Casey S Greene, Jason H Moore

Dartmouth Scholarship

BackgroundA goal of human genetics is to discover genetic factors that influence individuals' susceptibility to common diseases. Most common diseases are thought to result from the joint failure of two or more interacting components instead of single component failures. This greatly complicates both the task of selecting informative genetic variants and the task of modeling interactions between them. We and others have previously developed algorithms to detect and model the relationships between these genetic factors and disease. Previously these methods have been evaluated with datasets simulated according to pre-defined genetic models.

Mechanical Test Methods For Assessing Porcine Carotid And Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal And Transection, Carissa M. Krane, Margaret Pinnell, Courtney Gardner, Mercedes Thompson, James Coleman, Robert Wilkens

Biology Faculty Publications

A test method was developed to identify those variables important for assessing the performance of ultrasonic surgical devices in ex vivo ligature sealing of porcine carotid and uterine arteries. Ruggedness testing using a small sample size in pilot experiments was conducted using a newly developed test method in an effort to assess the usefulness of this methodology and to identify test variables that might warrant further testing. The development of this test method included the use of a custom-designed prototypic tension device for load-controlled ex vivo vessel stretching during saline perfusion and subsequent seal and transection of porcine arteries with …

Emb-1 Encodes The Apc16 Subunit Of The Caenorhabditis Elegans Anaphase-Promoting Complex, Diane Shakes, Anna Allen, Kelsey Albert, Andy Golden

Department of Biology Faculty Publications

In the nematode Caenorhabditis elegans, temperature-sensitive mutants of emb-1 arrest as one-cell embryos in metaphase of meiosis I in a manner that is indistinguishable from embryos that have been depleted of known subunits of the anaphase-promoting complex or cyclosome (APC/C). Here we show that the emb-1 phenotype is enhanced in double mutant combinations with known APC/C subunits and suppressed in double mutant combinations with known APC/C suppressors. In addition to its meiotic function, emb-1 is required for mitotic proliferation of the germline. These studies reveal that emb-1 encodes K10D2.4, a homolog of the small, recently discovered APC/C subunit, APC16.

Endo-Porter–Mediated Delivery Of Phosphorodiamidate Morpholino Oligos (Pmos) In Erythrocyte Suspension Cultures From Cope's Gray Treefrog Hyla Chrysoscelis, Venkateshwar Mutyam, Matthew V. Puccetti, James Frisbie, David L. Goldstein, Carissa M. Krane

Biology Faculty Publications

Cope's gray treefrog, Hyla chrysoscelis, is a freeze-tolerant anuran that accumulates cryoprotective glycerol during cold acclimation. H. chrysoscelis erythrocytes express the aquaglyceroporin HC-3, which facilitates transmembrane glycerol and water movement. Aquaglyceroporins have no pharmacological inhibitors, and no genetic knockout tools currently exist for H. chrysoscelis. A phosphorodiamidate morpholino oligo (PMO)–mediated expression knockdown approach was therefore pursued to provide a model for testing the role of HC-3. We describe a novel procedure optimized for specific, efficient knockdown of HC-3 expression in amphibian erythrocyte suspensions cultured at nonmammalian physiological temperatures using Endo-Porter. Our protocol includes three critical components: pre-incubation at 37°C, …

Design Of A Factorial Experiment With Randomization Restrictions To Assess Medical Device Performance On Vascular Tissue, Wiebke Diestelkamp, Carissa M. Krane, Margaret Pinnell

Biology Faculty Publications

Background: Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.

Methods: The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the …

Drosophila Model For Fetal Alcohol Syndrome Disorders: Role For The Insulin Pathway, Rachael L. French, K D. Mcclure, U Heberlein

Faculty Publications, Biological Sciences

Prenatal exposure to ethanol in humans results in a wide range of developmental abnormalities, including growth deficiency, developmental delay, reduced brain size, permanent neurobehavioral abnormalities and fetal death. Here we describe the use of Drosophila melanogaster as a model for exploring the effects of ethanol exposure on development and behavior. We show that developmental ethanol exposure causes reduced viability, developmental delay and reduced adult body size. We find that flies reared on ethanol-containing food have smaller brains and imaginal discs, which is due to reduced cell division rather than increased apoptosis. Additionally, we show that, as in mammals, flies reared …

Reduced Mhc And Neutral Variation In The Galápagos Hawk, An Island Endemic, Jennifer Bollmer, Joshua Hull, Holly Ernest, José Sarasola, Patricia Parker

Biology Department Faculty Works

BackgroundGenes at the major histocompatibility complex (MHC) are known for high levels of polymorphism maintained by balancing selection. In small or bottlenecked populations, however, genetic drift may be strong enough to overwhelm the effect of balancing selection, resulting in reduced MHC variability. In this study we investigated MHC evolution in two recently diverged bird species: the endemic Galápagos hawk (Buteo galapagoensis), which occurs in small, isolated island populations, and its widespread mainland relative, the Swainson's hawk (B. swainsoni).ResultsWe amplified at least two MHC class II B gene copies in each species. We recovered only three different sequences from 32 Galápagos …

The Arabidopsis Trithorax-Like Factor Atx1 Functions In Dehydration Stress Responses Via Aba-Dependent And Aba-Independent Pathways, Yong Ding, Zoya Avramova, Michael Fromm

School of Biological Sciences: Faculty Publications

Emerging evidence suggests that the molecular mechanisms driving the responses of plants to environmental stresses are associated with specific chromatin modifications. Here, we demonstrate that the Arabidopsis trithorax-like factor ATX1, which trimethylates histone H3 at lysine 4 (H3K4me3), is involved in dehydration stress signaling in both abscisic acid (ABA)-dependent and ABA-independent pathways. The loss of function of ATX1 results in decreased germination rates, larger stomatal apertures, more rapid transpiration and decreased tolerance to dehydration stress in atx1 plants. This deficiency is caused in part by reduced ABA biosynthesis in atx1 plants resulting from decreased transcript levels from NCED3, which …

Copper Tolerance Of Saccharomyces Cerevisiae Nonsense-Mediated Mrna Decay Mutants, Rafael Deliz-Aguirre, Audrey L. Atkin, Bessie W. Kebaara

School of Biological Sciences: Faculty Publications

The eukaryotic nonsense-mediated mRNA (NMD) is a specialized pathway that leads to the recognition and rapid degradation of mRNAs with premature termination codons, and importantly some natural mRNAs as well. Natural mRNAs with atypically long 3′-untranslated regions (UTRs) are degraded by NMD in Saccharomyces cerevisiae. A number of S. cerevisiae mRNAs undergo alternative 3′-end processing producing mRNA isoforms that differ in their 3′-UTR lengths. Some of these alternatively 3′-end processed mRNA isoforms have atypically long 3′-UTRs and would be likely targets for NMD-mediated degradation. Here, we investigated the role NMD plays in the regulation of expression of CTR2, …