Biology Commons^™

Scaling Of Olfactory Antennae Of The Terrestrial Hermit Crabs Coenobita Rugosus And Coenobita Perlatus During Ontogeny, Lindsay D. Waldrop, Roxanne M. Bantay, Quang V. Nguyen

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Although many lineages of terrestrial crustaceans have poor olfactory capabilities, crabs in the family Coenobitidae, including the terrestrial hermit crabs in the genus Coenobita, are able to locate food and water using olfactory antennae (antennules) to capture odors from the surrounding air. Terrestrial hermit crabs begin their lives as small marine larvae and must find a suitable place to undergo metamorphosis into a juvenile form, which initiates their transition to land. Juveniles increase in size by more than an order of magnitude to reach adult size. Since odor capture is a process heavily dependent on the size and speed …

Sex And Basic Science. A Title Ix Position, Kathryn Sandberg, Joseph G. Verbalis, Gina L.C. Yosten, Willis K. Samson

Biological Sciences Faculty Research & Creative Works

No abstract provided.

Serotonergic Signaling Pathways That Suppress Amyloid Beta In Mouse Models Of Ad, Jonathan Robert Fisher

All Theses and Dissertations (ETDs)

A diagnosis of Alzheimer's disease is one of the most devastating things one can hear. This terrible disease robs people of their ability to remember cherished events as their brains become riddled with beta amyloid plaques. Alzheimer's is especially terrifying because there currently are no effective treatments for slowing or stopping the disease. However, recent research has shown that plaque formation is correlated to concentrations of amyloid beta. This discovery suggests that limiting amyloid beta production could potentially halt the disease. One promising avenue for slowing amyloid beta production is serotonergic signaling.

This dissertation presents evidence for a direct sequence …

Group 3 Late Embryogenesis Abundant Proteins From Embryos Of Artemia Franciscana: Structural Properties And Protective Abilities During Desiccation, Leaf C. Boswell, Michael A. Menze, Steven C. Hand

Faculty Research & Creative Activity

Group 3 late embryogenesis abundant (LEA) proteins are highly

hydrophilic, and their expression is associated with desiccation

tolerance in both plants and animals. Here we show that two

LEA proteins from embryos of Artemia franciscana, AfrLEA2

and AfrLEA3m, are intrinsically disordered in solution but

upon desiccation gain secondary structure, as measured by circular

dichroism. Trifluoroethanol and sodium dodecyl sulfate

are both shown to induce a-helical structure in AfrLEA2 and

AfrLEA3m. Bioinformatic predictions of secondary-structure

content for both proteins correspond most closely to conformations

measured in the dry state. Because some LEA proteins

afford protection to desiccation-sensitive proteins during drying

and …

Molecular Xenomonitoring Using Mosquitoes To Map Lymphatic Filariasis After Mass Drug Administration In American Samoa, Mark A. Schmaedick, Amanda L. Koppel, Nils Pilotte, Melissa Torres, Steven A. Williams, Stephen L. Dobson, Patrick J. Lammie, Kimberly Y. Won

Biological Sciences: Faculty Publications

Background: Mass drug administration (MDA) programs have dramatically reduced lymphatic filariasis (LF) incidence in many areas around the globe, including American Samoa. As infection rates decline and MDA programs end, efficient and sensitive methods for detecting infections are needed to monitor for recrudescence. Molecular methods, collectively termed ‘molecular xenomonitoring,’ can identify parasite DNA or RNA in human blood-feeding mosquitoes. We tested mosquitoes trapped throughout the inhabited islands of American Samoa to identify areas of possible continuing LF transmission after completion of MDA.

Methodology/Principle Findings: Mosquitoes were collected using BG Sentinel traps from most of the villages on American Samoa’s largest …

Phenotypic Robustness And The Assortativity Signature Of Human Transcription Factor Networks, Dov A. Pechenick, Joshua L. Payne, Jason H. Moore

Dartmouth Scholarship

Many developmental, physiological, and behavioral processes depend on the precise expression of genes in space and time. Such spatiotemporal gene expression phenotypes arise from the binding of sequence-specific transcription factors (TFs) to DNA, and from the regulation of nearby genes that such binding causes. These nearby genes may themselves encode TFs, giving rise to a transcription factor network (TFN), wherein nodes represent TFs and directed edges denote regulatory interactions between TFs. Computational studies have linked several topological properties of TFNs - such as their degree distribution - with the robustness of a TFN's gene expression phenotype to genetic and environmental …

Group 3 Late Embryogenesis Abundant Proteins From Embryos Of Artemia Franciscana : Structural Properties And Protective Abilities During Desiccation., Leaf C. Boswell, Michael A. Menze, Steven C. Hand

Faculty and Staff Scholarship

Group 3 late embryogenesis abundant (LEA) proteins are highly hydrophilic, and their expression is associated with desiccation tolerance in both plants and animals. Here we show that two LEA proteins from embryos of Artemia franciscana, AfrLEA2 and AfrLEA3m, are intrinsically disordered in solution but upon desiccation gain secondary structure, as measured by circular dichroism. Trifluoroethanol and sodium dodecyl sulfate are both shown to induce a-helical structure in AfrLEA2 and AfrLEA3m. Bioinformatic predictions of secondary-structure content for both proteins correspond most closely to conformations measured in the dry state. Because some LEA proteins afford protection to desiccation-sensitive proteins during drying and …

Phylogenetics And Mating System Evolution In The Southern South American Valeriana (Valerianaceae), Lauren A. Gonzalez

LSU New Orleans Theses and Dissertations

Species of Valerianaceae in South America represent one of the best examples of rapid diversification on a continental scale. The phylogeny of Valerianaceae has received a lot of attention within the last 10 years, but relationships among the South American species are fairly unresolved. Results from previous studies have not been well resolved with traditional genetic markers, most likely due to its recent and rapid radiation. Species in this clade exhibit a variety mating systems and inflorescence types. For the first part of this research I used several traditional plastid markers, and 3 new low copy nuclear markers to better …

Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael A. Menze

Faculty Research & Creative Activity

A simple method to cryogenically preserve hepatocyte monolayers is currently not available but such a technique would facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. We investigated the effect of trehalose and dimethyl sulfoxide (Me2SO) in cryopreservation of human hepatocellular carcinoma (HepG2) cells in suspension and monolayer formats. HepG2 cell monolayers were incubated for 24 h at varying concentrations of trehalose (50–150 mM) prior to cryopreservation to identify the optimum concentration for such preincubation. When trehalose alone was used as the cryoprotective agent (CPA), cells in monolayer format did not survive freezing while …

Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael Menze

Faculty and Staff Scholarship

A simple method to cryogenically preserve hepatocyte monolayers is currently not available but such a technique would facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. We investigated the effect of trehalose and dimethyl sulfoxide (Me2SO) in cryopreservation of human hepatocellular carcinoma (HepG2) cells in suspension and monolayer formats. HepG2 cell monolayers were incubated for 24 h at varying concentrations of trehalose (50–150 mM) prior to cryopreservation to identify the optimum concentration for such preincubation. When trehalose alone was used as the cryoprotective agent (CPA), cells in monolayer format did not survive freezing while …

Genetic Background Influences Behavior And Responses To Epigenetic Changes Induced By A Methyl-Donor Diet, Kimberly R. Shorter

Theses and Dissertations

With recent strides in epigenetics, mainstream media informs the public that we can “beat our genes” by, for instance, changing our diet. Genetics, however, still plays a role in phenotype. Folate and other methyl-donor pathway components are widely supplemented due to their ability to prevent neural tube defects during prenatal development. In addition to vitamins, these compounds are also added to commercial flour, energy drinks, and other supplements. Several lines of evidence suggest that these supplements act through epigenetic mechanisms, including altering DNA methylation. Increasing evidence suggests potential deleterious effects of excessive folate. Given the benefits of these compounds, risk …

Utilizing Next Generation Sequencing To Generate Bacterial Genomic Sequences For Evolutionary Analysis, Derrick C. Scott

Theses and Dissertations

Many important questions in the field of prokaryotic biology cannot be answered due to the low availability of sequenced and finished genomes. Recent improvements in technology and decreases in price have made the ambition of de novo bacterial genomic sequencing a reality for a wide range of researchers. However, with the advancement of sequencing technology comes the need for an evaluation to determine the most reliable bioinformatics methods in generating a complete and accurate assembly. Biases inherent in the sequencing technology and GC-rich genomes complicate genome assemblies. Here, we sequenced bacterial strains from the GC-rich Caulobacter genus and the closely …

Muscarinic Modulation Of Basolateral Amygdala, Lei Liu

Theses and Dissertations

The basolateral amygdala (BL) receives a dense cholinergic innervation from the basal forebrain. Despite the importance of muscarinic acetylcholine receptors (mAChRs) in fear learning, consolidation, and extinction, there have been no studies that have systematically investigated the functional role of mAChRs in regulating emotional processing in the BL. To address this critical knowledge gap we combined brain slice whole-cell recording, optogenetics, and immunohistochemistry to determine how muscarine, acting on mAChRs, regulates neuronal oscillations, synaptic transmission and plasticity in the BL.

Neurons in the BL oscillate rhythmically during emotional processing, which are thought to be important to integrate sensory inputs, allow …

Differential Expression Of Snmps And Their Underlying Transcriptional Regulation In Chemosensory Pathways Of Drosophila, Richard A. Fandino

Theses and Dissertations

Insects possess complex and diverse chemosensory pathways which have specific phenotypes determined by the regulated expression of specific combinations of genes. While many of these genes (e.g. ORs and GRs) have very narrow expression patterns, associating with only a limited number of chemosensory sensilla, SNMPs show a very broad expression pattern. In Drosophila, SNMP1 and SNMP2 associate with the majority of olfactory and gustatory sensilla, but express in different cell types. In olfactory sensilla, SNMP1 and SNMP2 associate with trichoid or coeloconic neurons respectively, and both additionally express in a variety of sensilla support cells; in gustatory sensilla, SNMP2 expresses …

Mechanical Properties Of Diet And Its Effect On Oral Health, Varsha Kapoor

Theses and Dissertations

The predominant diet fed to captive carnivores consists of ground meat formulated to provide full nutritional requirements. However, this ground meat diet completely lacks the mechanical properties such as toughness, hardness and stiffness of the foods the animals would eat in the wild. The goal of this research was to evaluate the effect of mechanical properties of diet on oral health by comparing prevalence of periodontal disease and calculus accumulation in wild and captive felids. One-way ANOVA analysis of variance indicated that these differences are statistically significant (P

Functional Characterization Of Fro4 And Fro5: Two Members Of The Ferric Chelate Reductase Family Of Arabidopsis, Grandon Thomas Wilson

Theses and Dissertations

Iron (Fe) is the fourth most abundant element within the earth’s crust and is an essential micronutrient for plants and animals. Fe plays key roles in photosynthesis, respiration and chlorophyll biosynthesis in plants and in hemoglobin in animals. Like Fe, copper (Cu) is also an important micronutrient in plants and is needed for photosynthesis and respiration, especially in the important copper-containing protein plastocyanin. Copper also is important in scavenging reactive oxygen species and ethylene perception. The reduction of Fe3+ to Fe2+ at the root surface of Arabidopsis thaliana during times of Fe deficiency has been a well-characterized process; however, reduction …

An Investigation Of Mitochondrial Bioenergetics And The Turnover Of Succinated Proteins In The Adipocyte During Diabetes, Ross Tanis

Theses and Dissertations

We previously identified the chemical modification S-(2-succino)cysteine (2SC), which is formed when the Krebs cycle metabolite fumarate reacts with protein cysteine residues, also termed protein succination. Protein succination is increased in the adipose tissue of ob/ob and db/db mice in vivo and in 3T3-L1 adipocytes grown in high glucose in vitro. The increase in 2SC in the 3T3-L1 adipocyte occurs as a direct result of glucotoxicity and increased mitochondrial stress. We have shown that uncoupling agents, which lower mitochondrial stress, prevent the increase in succinated proteins.

In this study we examined the relationship between increased succination and mitochondrial bioenergetics in …

Role Of Apelin And Endothelin Systems In The Pain Associated With Sickle Cell Disease, Terika Smith

Theses and Dissertations

Sickle cell disease (SCD) is a common genetic blood disorders that is characterized by painful vaso-occlusive episodes (VOEs), which are the major cause of hospitalizations for these patients. One of the mechanisms that may contribute to the development of painful VOEs is the imbalance between vasoconstrictors and vasodilators. This thesis focuses on the vasoconstrictors endothelin-1 (ET-1), which is elevated during VOEs and is pro-nociceptive, and angiotensin II (Ang II) and the vasodilator apelin, which has anti-nociceptive properties. This thesis tested two hypotheses: 1) an imbalance between the vasoconstrictive and pro-nociceptive systems and vasodilatory and anti-nociceptive systems contributes to pain in …

Phenotypic Signatures Arising From Unbalanced Bacterial Growth, Cheemang Tan, Robert P. Smith, Ming-Chi Tsai, Russell Schwartz, Lingchong You

Biology Faculty Articles

Fluctuations in the growth rate of a bacterial culture during unbalanced growth are generally considered undesirable in quantitative studies of bacterial physiology. Under well-controlled experimental conditions, however, these fluctuations are not random but instead reflect the interplay between intra-cellular networks underlying bacterial growth and the growth environment. Therefore, these fluctuations could be considered quantitative phenotypes of the bacteria under a specific growth condition. Here, we present a method to identify “phenotypic signatures” by time-frequency analysis of unbalanced growth curves measured with high temporal resolution. The signatures are then applied to differentiate amongst different bacterial strains or the same strain under …

Electrophoresis Staining: A New Method Of Whole Mount Staining, Mitchell G. Ayers, Sarah Calve, Zhiyu Li

The Summer Undergraduate Research Fellowship (SURF) Symposium

Advances in tissue clearing techniques have allowed almost a ten-fold increase in the viewing depth of confocal microscopy. This allows for intact cellular structures to be rendered in 3D. However, viewing tissues to this depth is often limited to endogenous fluorescence as passive diffusion of antibodies via whole mount staining can take weeks. Our lab is developing a new method involving electrophoresis as a driving force that will promote active antibody binding deep into tissue, reducing the amount of time needed to stain for cellular structures. Due to the inherent charge within antibodies, they are able to be directionally forced …

Interaction Between Insecticide Exposure And Trematode Infection Across Four Wood Frog Populations, Michael J. Hiatt, Jessica Hua Dr., Vanessa Wuerthner, Jason Hoverman Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Amphibian populations are declining worldwide due to a number of stressors including pesticides and parasites. Conservation of these animals can be complicated because populations can differ dramatically in response to the same stressor. When consistently exposed to pesticides, some populations evolve tolerance through the process of natural selection acting across multiple generations. Alternatively, populations that are intermittently exposed to pesticides induce tolerance within a single generation. To date, however, there have been few studies examining the costs associated with these different stress tolerance mechanisms. In this study, we examined how difference in stress tolerance influence susceptibility to parasitic infections. We …

Determining The Binding Between Saga Subunits And Spliceosomal Components, Peyton J. Spreacker, Rachel L. Stegeman, Vikki M. Weake

The Summer Undergraduate Research Fellowship (SURF) Symposium

Proper gene regulation is vital to the health and development of an organism. Determining the relationship between splicing, transcription, and chromatin structure is vital for understanding gene regulation as a whole. There have been previous studies linking these elements pairwise; however, no evidence exists for a direct link between all three. Recent data shows that splicing components of the U2 small nuclear ribonucleic protein (snRNP) co-purify with Spt-Ada-Gcn5-acetyltransferase (SAGA), a highly conserved transcriptional co-activator and chromatin modifier. We hypothesize that SAGA binds with splicing components through a multi-protein binding surface with certain core components based on preliminary yeast two-hybrid data. …

The Geomagnetic Environment In Which Sea Turtle Eggs Incubate Affects Subsequent Magnetic Navigation Behaviour Of Hatchlings, Matthew J. Fuxjager, Kyla R. Davidoff, Lisa A. Mangiamele, Kenneth J. Lohmann

Biological Sciences: Faculty Publications

Loggerhead sea turtle hatchlings (Caretta caretta) use regional magnetic fields as open-ocean navigational markers during trans-oceanic migrations. Little is known, however, about the ontogeny of this behaviour. As a first step towards investigating whether the magnetic environment in which hatchlings develop affects subsequent magnetic orientation behaviour, eggs deposited by nesting female loggerheads were permitted to develop in situ either in the natural ambient magnetic field or in a magnetic field distorted by magnets placed around the nest. In orientation experiments, hatchlings that developed in the normal ambient field oriented approximately south when exposed to a field that exists near the …

Recent Shifts In The Occurrence, Cause, And Magnitude Of Animal Mass Mortality Events, Samuel B. Fey, Adam M. Siepielski, Sébastien Nusslé, Kristina Cervantes-Yoshida, Jason L. Hwan, Eric R. Huber, Maxfield J. Fey, Alessandro Catenazzi, Stephanie M. Carlson

Dartmouth Scholarship

Mass mortality events (MMEs) are rapidly occurring catastrophic demographic events that punctuate background mortality levels. Individual MMEs are staggering in their observed magnitude: re- moving more than 90% of a population, resulting in the death of more than a billion individuals, or producing 700 million tons of dead biomass in a single event. Despite extensive documentation of individual MMEs, we have no understanding of the major features characterizing the occurrence and magnitude of MMEs, their causes, or trends through time. Thus, no framework exists for contextualizing MMEs in the wake of ongoing global and regional perturbations to natural systems. Here …

Rapidly Self-Renewing Human Multipotent Marrow Stromal Cells (Hmsc) Express Sialyl Lewis X And Actively Adhere To Arterial Endothelium In A Chick Embryo Model System, Harris E. Mcferrin, Scott D. Olson, Miriam V. Gutschow, Julie A. Semon, Deborah E. Sullivan, Darwin J. Prockop

Biological Sciences Faculty Research & Creative Works

Background: There have been conflicting observations regarding the receptors utilized by human multipotent mesenchymal bone marrow stromal cells (hMSC) to adhere to endothelial cells (EC). To address the discrepancies, we performed experiments with cells prepared with a standardized, low-density protocol preserving a sub-population of small cells that are rapidly self-renewing.

Methods: Sialyl Lewis X (SLeX) and α4 integrin expression were determined by flow cytometry. Fucosyltransferase expression was determined by quantitative realtime RT-PCR. Cell adhesion assays were carried out with a panel of endothelial cells from arteries, veins and the microvasculature in vitro. In Vivo experiments were performed to determine …

Increasing Energetic Cost Of Biosynthesis During Growth Makes Refeeding Deleterious, Chen Hou

Biological Sciences Faculty Research & Creative Works

Diet restriction (DR) enhances animals' health maintenance, but refeeding reverses its beneficial effects. However, to what degree refeeding reverses the beneficial effects of DR remains controversial. Here, I develop a theoretical model for reconciling the results of refeeding studies and understanding the dynamic and reversible mechanism underlying the effects of diet on health from the energetic viewpoint. By illustrating the negative correlation between health maintenance and the energetic cost of growth in animals under different diet regimes, the model explains why, in some cases, refed animals have better health and live longer than freely fed controls. More importantly, the model …

Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer

STAR Program Research Presentations

Jellyfish are generally characterized by their jelly-like bodies and internal lining (two tissue layers). They found both in the phylum Ctenophora and the phylum Cnidaria. Ctenophores differ from cnidarians primarily due to the rows of “combs”, or cilia, which are used for transportation. Additionally, ctenophores possess sticky cells while cindarians possess stinging cells. Jellyfish depend on zooplankton (small floating aquatic animals) as a food source; as a result, they are potential competitors and predators to plankton-eating fish and may negatively impact fish populations.

As recently as 1950, jellyfish have entered the San Francisco Bay from the Mediterranean Sea (probably …

Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea

STAR Program Research Presentations

With the growing demands of water in California and the increasing cost of fossil fuels to operate water-cleaning equipment, Algae was cultivated in different concentrations of Nitrogen, Phosphorus, and Potassium (NPK) during different trails to identify the best growing conditions for the removal water contaminates. Before testing algae in waste water, the Algae: Dunaliella Primolecta, Chlorella Vulgaris, and Scenedesmus Dimorphus were cultivated in four different media containing distilled water and plant vitamins. The different mediums used include: Orchid Grow More (20-20-20), Miracle Grow (30-10-10), Murashige & Skoog, and Orchid Bloom Boster (11-35-15). As a result of the investigation, the algae, …

Xrf Analyses Of Prehanford Orchards, Komal Rana

STAR Program Research Presentations

Subsequent to 1943, the use of Lead Arsenic was banned from the Orchards standing on the Hanford site. This use of Lead Arsenate pesticide was popular among the orchard owners and was dispersed over the site in a myriad of ways. The presence of the traces of lead and arsenic are found today, more than half a century later. Using a portable X-ray florescence analyzer (XRF), the values of lead and arsenic are evaluated while determining the efficiency of the equipment itself. Samples from different decision sites were collected, with lead arsenic values in the low, high and medium range …

Habitat Preference Of The Introduced Green Crab Carcinus Maenas, Brittany Susan Daum, Andy Chang

STAR Program Research Presentations

The aim of this experiment was to determine if Carcinus Maenas (European Green Crab) hhas a habitat preference in Seadrift Lagoon located in Stinson Beach, California. This experiment was accomplished by placing crab traps on the two types of substrate in Seadrift (sand and algae). The traps were pulled up every 24 hours and the size and sex of crabs was recorded. The data was analyzed to see if there was a difference in habitat preference based upon size, sex, and number of crabs. Using a Poisson Regression model, the size and sex of crabs were not significantly different between …