Biology Commons^™

Gastrin Induces Nuclear Export And Proteasomal Degradation Of Menin In Enteric Glial Cells, Sinju Sundaresan, Cameron A. Meininger, Anthony J. Kang, Amanda L. Photenhauer, Michael M. Hayes, Nirakar Sahoo, Jolanda Lindenberg, Jolanta Grembecka, Tomasz Cierpicki, Lin Ding

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Background & aims: The multiple endocrine neoplasia, type 1 (MEN1) locus encodes the nuclear protein and tumor suppressor menin. MEN1 mutations frequently cause neuroendocrine tumors such as gastrinomas, characterized by their predominant duodenal location and local metastasis at time of diagnosis. Diffuse gastrin cell hyperplasia precedes the appearance of MEN1 gastrinomas, which develop within submucosal Brunner's glands. We investigated how menin regulates expression of the gastrin gene and induces generation of submucosal gastrin-expressing cell hyperplasia.

Methods: Primary enteric glial cultures were generated from the VillinCre:Men1FL/FL:Sst-/- mice or C57BL/6 mice (controls), with or without inhibition of gastric acid by omeprazole. Primary …

Morganella Morganii (Enterobacteriales: Enterobacteriaceae) Is A Lethal Pathogen Of Mexican Fruit Fly (Diptera: Tephritidae) Larvae, Bacilio Salas, Hugh E. Conway, Erin Schuenzel, Kristen Hopperstad, Christopher Vitek, Don C. Vacek

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Tephritid pests, such as the Mexican fruit fly, Anastrepha ludens (Loew), represent a major threat to fruit production worldwide. In order to control these pests, sterile insect technique is used to suppress and eradicate wild populations. For this control method to be successful, hundreds of millions of flies must be produced weekly in mass rearing facilities. The large quantity of artificial diet and close proximity of flies at various life stages allows bacteria from family Enterobacteriaceae, Bacillaceae, Pseudomonadaceae, and others to multiply and spread more easily. In this study, bacteria with a possible pathogenic effect were isolated from Mexican fruit …

The Algz/R Two-Component System Is Responsible For Attenuation Of Virulence In Pseudomonas Aeruginosa, Danielle A. Williams

Electronic Theses and Dissertations

Pseudomonas aeruginosa is an important opportunistic pathogen. Many P. aeruginosa virulence factors are regulated by the AlgZ/R two component system. AlgZ is the sensor histidine kinase which phosphorylates AlgR, the response regulator. AlgR activates transcription of different gene targets based upon its phosphorylation state. The genes that encode AlgZ and AlgR are transcribed in an operon. While regulation of algR expression has been well studied, regulation of algZ expression has not. Using a pilW mutant in concert with algZTF-lacZ transcriptional fusion, we conducted a transposon mutagenesis to identify algZ regulators. We identified an unknown autoregulatory loop. The type …

Bio Buzz Newsletter, Issue 14, November 2017, Department Of Biology

Biology Buzz Newsletter

Denison University, Department of Biology newsletter for Fall 2017.

Transcriptomic Regulation Of Alternative Phenotypic Trajectories In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Amie L. Romney

Dissertations and Theses

The Annual Killifish, Austrofundulus limnaeus, survives the seasonal drying of their pond habitat in the form of embryos entering diapause midway through development. The diapause trajectory is one of two developmental phenotypes. Alternatively, individuals can "escape" entry into diapause and develop continuously until hatching. The alternative phenotypes of A. limnaeus are a form of developmental plasticity that provides this species with a physiological adaption for surviving stressful environments. The developmental trajectory of an embryo is not distinguishable morphologically upon fertilization and phenotype is believed to be influenced by maternal provisioning within the egg based on observations of offspring phenotype …

A Culture Of Health: Herbal Remedies Of The Peruvian Highlands, Jarred Rimby

Whittier Scholars Program

I have divided this paper into three related sections, and each subsequent section of this paper builds on the conclusions of the previous sections. Section I seeks to define a “model of health” for people living in the Peruvian Highlands. Section I draws heavily on one month of fieldwork that I conducted. Section II catalogues and describes the use of culturally significant herbs in the Peruvian Highlands. Section III explores the physiological function of the therapeutic agents in coca, muna, ayahuasca, and sangre de grado, drawing on a review of scientific literature to summarize what is known about each. By …

Phyllotactic Regularity Requires The Paf1 Complex In Arabidopsis, Kateryna Fal, Mengying Liu, Assem Duisembekova, Yassin Refahi, Elizabeth S. Haswell, Olivier Hamant

Biology Faculty Research

In plants, aerial organs are initiated at stereotyped intervals, both spatially (every 137° in a pattern called phyllotaxis) and temporally (at prescribed time intervals called plastochrons). To investigate the molecular basis of such regularity, mutants with altered architecture have been isolated. However, most of them only exhibit plastochron defects and/or produce a new, albeit equally reproducible, phyllotactic pattern. This leaves open the question of a molecular control of phyllotaxis regularity. Here, we show that phyllotaxis regularity depends on the function of VIP proteins, components of the RNA polymerase II-associated factor 1 complex (Paf1c). Divergence angles between successive organs along the …

Polyploidy And Hybridization Have A Role In Plant Distribution In The United States: A Bioinformatics Study, Andrea Ortiz

Biology Theses

Introduction: Polyploidy is the doubling of a genome. Autopolyploidy and allopolyploidy are two different modes of genome duplication. These events are common in angiosperms and usually involve diploids and tetraploids, a resulting polyploid species. Both cytotypes exhibit competitive exclusion and environmental adaptation according to their spatial distributions. My research focuses on how abiotic environmental factors affect the range and the amount of range overlap of the taxon within the Callisia graminea and Allium canadense systems over time. Niche modeling determines whether there is substantial niche overlap between the Callisia graminea diploid and tetraploid, whether range shifts occur between the Callisia …

Dynamics Of Prochlorococcus And Synechococcus At Station Aloha Revealed Through Flow Cytometry And High-Resolution Vertical Sampling, Ger J. Van Den Engh, Joseph K. Doggett, Anne W. Thompson, Martina A. Doblin, Carla N.G. Gimpel, David M. Karl

Biology Faculty Publications and Presentations

The fluorescence and scattering properties of Prochlorococcus and Synechococcus at Station ALOHA as measured by flow cytometry (termed the FCM phenotype) vary with depth and over a variety of time scales. The variation in FCM phenotypes may reflect population selection or physiological acclimation to local conditions. Observations before, during, and after a storm with deep water mixing show a short-term homogenization of the FCM phenotypes with depth, followed by a return to the stable pattern over the time span of a few days. These dynamics indicate that, within the upper mixed-layer, the FCM phenotype distribution represents acclimation to ambient light. …

Genomic Data Reveal A Loss Of Diversity In Two Species Of Tuco-Tucos (Genus Ctenomys) Following A Volcanic Eruption, Jeremy L. Hsu, Jeremy Chase Crawford, Mauro N. Tammone, Uma Ramakrishnan, Eileen A. Lacey, Elizabeth A. Hadly

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Marked reductions in population size can trigger corresponding declines in genetic variation. Understanding the precise genetic consequences of such reductions, however, is often challenging due to the absence of robust pre- and post-reduction datasets. Here, we use heterochronous genomic data from samples obtained before and immediately after the 2011 eruption of the Puyehue-Cordón Caulle volcanic complex in Patagonia to explore the genetic impacts of this event on two parapatric species of rodents, the colonial tuco-tuco (Ctenomys sociabilis) and the Patagonian tuco-tuco (C. haigi). Previous analyses using microsatellites revealed no post-eruption changes in genetic variation in C. …

Hydrogen Cyanide Produced By Pseudomonas Chlororaphis O6 Exhibits Nematicidal Activity Against Meloidogyne Hapla, Beom Ryong Kang, Anne J. Anderson, Young Cheol Kim

Biology Faculty Publications

Root-knot nematodes (Meloidogyne spp.) are parasites that attack many field crops and orchard trees, and affect both the quantity and quality of the products. A root-colonizing bacterium, Pseudomonas chlororaphis O6, possesses beneficial traits including strong nematicidal activity. To determine the molecular mechanisms involved in the nematicidal activity of P. chlororaphis O6, we constructed two mutants; one lacking hydrogen cyanide production, and a second lacking an insecticidal toxin, FitD. Root drenching with wild-type P. chlororaphis O6 cells caused juvenile mortality in vitro and in planta. Efficacy was not altered in the fitD mutant compared to the wild-type but was reduced in …

Msaabcr Operon Is Involved In Persister Cell Formation In Staphylococcus Aureus, Gyan S. Sahukhal, Shanti Pandey, Mohamed O. Elasri

Faculty Publications

Background

Persister cells comprise a phenotypic variant that shows extreme antibiotic tolerance resulting in treatment failures of bacterial infections. While this phenomenon has posed a great threat in public health, mechanisms underlying their formation in Staphylococcus aureus remain largely unknown. Increasing evidences of the presence of persister cells in recalcitrant infections underscores the great urgency to unravel the mechanism by which these cells develop. Previously, we characterized msaABCR operon that plays roles in regulation of virulence, biofilm development and antibiotic resistance. We also characterized the function of MsaB protein and showed that MsaB is a putative transcription factor that binds …

A Comparison Of Water Potential, Photosynthetic Rate, Electron Transport Rate, And Stomatal Conductance Between Native Malosma Laurina And Exotic Schinus Molle, Karagan L. Smith, Agatha C. Heng, Viridiana Hernandez-Lopez, Stephen D. Davis

Biology

Schinus molle is a relatively new invasive chaparral shrub in the Santa Monica Mountains and has only recently been observed to displace native shrubs like Malosma laurina. To investigate the probable cause of S. molle’s competitive displacement of M. laurina, we compared their water status, photosynthetic rates, electron transport rates, and stomatal conductance to water vapor diffusion during the fall months of 2016. We hypothesized that S. molle would physiologically outperform M. laurina indicated by higher photosynthetic rates, electron transport rates, stomatal conductance rates, and less negative water potential. We found that there was no significant difference between dry …

Greenhouse Gas Methane And Nitrous Oxide Production And Mircobial Functioning Gene Characterization In Grasslands And The Influences By Grazing Land Management, Maura M. Purcell

Biology Theses

Methane and nitrous oxide gases are significantly more potent in their ability to create a greenhouse effect than CO₂. Grazing lands can either be a sink or source of GHG depending on management scenarios and climatic conditions. Management of grasslands can have a broad impact on the levels of GHG emissions, as grazing pressure, crop rotations, and levels and types of fertilization inputs can alter microbial communities and influence on GHG production. Methanogens and denitrifying microbial communities are two major groups associated with the production of GHGs. This study attempted to unravel the microbial and geochemical characteristics associated …

Stability Of Equilibria In Quantitative Genetic Models Based On Modified-Gradient Systems, Benjamin J. Ridenhour, Jerry R. Ridenhour

Mathematics and Statistics Faculty Publications

Motivated by questions in biology, we investigate the stability of equilibria of the dynamical system x′ = P(t)∇f(x) which arise as critical points of f, under the assumption that P(t) is positive semi-definite. It is shown that the condition ∫^∞λ₁(P(t)) dt = ∞, where λ₁(P(t)) is the smallest eigenvalue of P(t), plays a key role in guaranteeing uniform asymptotic stability and in providing information on the basis of attraction of those equilibria.

Achilles Is A Circadian Clock-Controlled Gene That Regulates The Immune System And Its Rhythmicity In Drosophila, Jiajia Li

Dissertations

Circadian clock is a transcriptional/translational feedback loop that drives the rhythmic expression of downstream mRNAs. Termed “clock-controlled genes,” these molecular outputs of the circadian clock orchestrate cellular, metabolic, and behavioral rhythms. As part of our on-going work to characterize key upstream regulators of circadian mRNA expression, we have identified a novel clock-controlled gene in Drosophila melanogaster, Achilles (Achl), which is rhythmic at the mRNA level in the brain and represses expression of immune response genes, especially anti-microbial peptides in the immune system. Achl knock-down in the brain dramatically elevates expression of crucial immune response genes, including IM1 …

Hardbottom Mapping And Community Characterization Of The West-Central Florida Gulf Coast, December 2011 - June 2016, Brian K. Walker, Rene Baumstark, Sean Keenan, Cory Ames

Marine & Environmental Sciences Faculty Datasets

The continental shelf off Florida’s west coast is a mosaic of fish habitats including seagrass beds and carbonate reef outcroppings (hard bottom) classified by the National Marine Fisheries Service (NMFS) as Essential Fish Habitat. Habitat maps and community baseline data, however, are nonexistent for a majority of the region. This collaborative effort between Nova Southeastern University, Florida Fish and Wildlife Conservation Commission, NMFS and other scientists will characterize and map continental shelf seagrass and hard bottom habitats in nearshore areas fished by many recreational fishermen. Objectives include: 1) map hard bottom and seagrass beds using various data types including sonar …

Ryan Kerney, Assistant Professor Of Biology, Musselman Library, Ryan R. Kerney

Next Page

In this last Next Page column of 2017, Ryan Kerney, Assistant Professor of Biology, shares some of his favorite science writers in the field of “evo devo;” his go-to science news sources and podcasts (note: “This Week in Parasitism” is a must-listen!); what he would ask Charles Darwin if given the chance; which books he likes to give as gifts; his favorite author of all time; and where he finds great recommendations for what to read next.

A Metabolic Hypothesis For The Evolution Of Temperature Effects On The Arterial Pco2 And Ph Of Vertebrate Ectotherms, Stanley S. Hillman, Michael Scott Hedrick

Biology Faculty Publications and Presentations

Body temperature increases in ectothermic vertebrates characteristically lead to both increases in arterial PCO2 (PaCO2) and declines in resting arterial pH (pHa) of about 0.017 pH units/°C increase in temperature. This ‘alphastat’ pH pattern has previously been interpreted as being evolutionarily-driven by the maintenance of a constant protonation state on the imidazole moiety of histidine protein residues, hence stabilizing protein structure-function. Analysis of the existing data for interclass responses of ectothermic vertebrates show different degrees of PaCO2 increases and pH declines with temperature between the classes with reptiles>amphibians>fish. The PaCO2 at the temperature where maximal aerobic metabolism (VO2max) …

Ecological Epigenetics Of Avian Range Expansions, Holly J. Kilvitis

USF Tampa Graduate Theses and Dissertations

In light of human-mediated environmental change, a fundamental goal for biologists is to determine which phenotypic characteristics enable some individuals, populations or species to be more adept at coping with such change, while rendering others more vulnerable. Studying ongoing range expansions provide a unique opportunity to address this question by allowing documentation of how novel environments shape phenotypic variation on ecological timescales. At range-edges, individuals are exposed to strong selective pressures and population genetic challenges (e.g. bottlenecks and/or founder effects), which make genetic adaptation difficult. Nevertheless, certain species, such as the house sparrow (Passer domesticus), seem to thrive in their …

Patterns In Abundance Of Louisiana’S Avifauna Revealed By The Louisiana Bird Atlas Project, Matthew L. Brady

LSU Master's Theses

The Louisiana Bird Atlas Project is a multi-year citizen science effort designed to quantify bird distribution and abundance for all species regularly occurring in the state of Louisiana during two time periods: summer and winter. Data were collected by volunteers in a citizen science framework across eight years, from 2007 to 2014. A total of 351 species was recorded (254 during the Summer Bird Atlas and 315 during the Winter Bird Atlas). Maps showing distribution and relative abundance for each species were generated within a Geographical Information System, and were accompanied by short descriptions of status, distribution, abundance, and other …

Multiple Species Of Cuckoos Are Superior Predictors Of Bird Species Richness In Asia, Anders Pape Møller, Federico Morelli, Yanina Benedetti, Timothy Mousseau, Tongping Su, Bo Zhou, Piotr Tryjanowski, Wei Liang

Faculty Publications

The abundance and the presence of common cuckoos Cuculus canorus have been shown to predict species richness of birds across Europe, while there are no such analyses available for other continents where species richness of parasitic cuckoos is larger. Here, we tested whether species richness of birds increased with the number of cuckoo species in two study areas in China and one in Japan. We also tested whether species richness of birds can be predicted by the number of cuckoo individuals. Furthermore, we compared the strength of association between overall bird species richness and species richness of cuckoos, Paridae, Corvidae, …

Multimodal In Situ Datalogging Quantifies Inter-Individual Variation In Thermal Experience And Persistent Origin Effects On Gaping Behavior Among Intertidal Mussels (Mytilus Californianus), Luke P. Miller, Wesley Dowd

Faculty Publications, Biological Sciences

In complex habitats, environmental variation over small spatial scales can equal or exceed larger-scale gradients. This small-scale variation may allow motile organisms to mitigate stressful conditions by choosing benign microhabitats, whereas sessile organisms may rely on other behaviors to cope with environmental stresses in these variable environments. We developed a monitoring system to track body temperature, valve gaping behavior and posture of individual mussels (Mytilus californianus) in field conditions in the rocky intertidal zone. Neighboring mussels' body temperatures varied by up to 14°C during low tides. Valve gaping during low tide and postural adjustments, which could theoretically lower …

The Effect Of Drought On The Comparative Fitness Of Purple Needle Grass (Stipa Pulchra) In The Presence Of An Invasive Weed, Grace M. Palmer, Taylor M. Purdy, Stephen D. Davis

Biology

Studies on the relative health of Stipa pulchra, a California native perennial bunchgrass, were conducted at the transplant garden on the Drescher campus of Pepperdine University in the Spring semesters of 2016 and 2017. Following the trend of other perennial native grasses, Stipa pulchra is dwindling due to competition with Avena fatua and other invasive species introduced by human activities. In 2016, in the midst of historic five-year drought in California, stomatal conductance, dark adapted fluorescence, water potential, and height of S. pulchra and A. fatua were recorded and compared. As hypothesized, the wild S. pulchra exhibited greater overall fitness-- …

Thermal History And Gape Of Individual Mytilus Californianus Correlate With Oxidative Damage And Thermoprotective Osmolytes, Lani Gleason, Luke Miller, Jacob Winnikoff

Faculty Publications, Biological Sciences

The ability of animals to cope with environmental stress depends – in part – on past experience, yet knowledge of the factors influencing an individual's physiology in nature remains underdeveloped. We used an individual monitoring system to record body temperature and valve gaping behavior of rocky intertidal zone mussels (Mytilus californianus). Thirty individuals were selected from two mussel beds (wave-exposed and wave-protected) that differ in thermal regime. Instrumented mussels were deployed at two intertidal heights (near the lower and upper edges of the mussel zone) and in a continuously submerged tidepool. Following a 23-day monitoring period, measures of …

Mrpl35, A Mitospecific Component Of Mitoribosomes, Plays A Key Role In Cytochrome C Oxidase Assembly, Jodie M. Box, Jasvinder Kaur, Rosemary A. Stuart

Biological Sciences Faculty Research and Publications

Mitoribosomes perform the synthesis of the core components of the oxidative phosphorylation (OXPHOS) system encoded by the mitochondrial genome. We provide evidence that MrpL35 (mL38), a mitospecific component of the yeast mitoribosomal central protuberance, assembles into a subcomplex with MrpL7 (uL5), Mrp7 (bL27), and MrpL36 (bL31) and mitospecific proteins MrpL17 (mL46) and MrpL28 (mL40). We isolated respiratory defective mrpL35 mutant yeast strains, which do not display an overall inhibition in mitochondrial protein synthesis but rather have a problem in cytochrome coxidase complex (COX) assembly. Our findings indicate that MrpL35, with its partner Mrp7, play a key role in coordinating …

Investigating X Chromosome Non-Disjunction In Drosophila Melanogaster Su(Var)3-9 Mutants, Camerun C. Washington, Kathryn Kohl

The Winthrop McNair Research Bulletin

Meiotic recombination is a highly regulated process necessary for promoting proper chromosome disjunction during the first meiotic division. Notably, reduced levels of meiotic recombination are observed in heterochromatic regions of the chromosome. This study seeks to investigate the molecular mechanisms underlying this observation by examining the effects of reduced heterochromatin on non-disjunction rates in Drosophila melanogaster. To accomplish this, we measured non-disjunction in wild-type and reduced heterochromatin mutant su(var)3-9 flies. To begin, we confirmed the presence of a mutation within su(var)3-9 via Sanger sequencing. Next, we created allele-specific primers and designed a PCR protocol to more accurately identify mutant …

Targeted Mutagenesis Of Fox0 Transcripts Using The Model Organism Ciona Intestinalis Utilizing The Crispr/Cas9 System, Nicole Mcmullen, Heather J. Evans-Anderson

The Winthrop McNair Research Bulletin

The chordate, Ciona intestinalis, has become an excellent model organism for the study of cardiac development. C. intestinalis is a member of the phylum Tunicata, which is the sister phylum to vertebrates. Since both phyla share a common ancestor, an orthologous gene has been identified in C. intestinalis and vertebrates, the FOX0 transcript. Multiple reasons makes Ciona intestinalis an interesting model organism. For instance, ease of access to the animal, close relation to vertebrates, and mapping of the genetic code of Ciona intestinalis makes this an excellent model organism. The FOX0 family of transcripts plays an important role in …

Controlling Oct4 Expression Levels Using Invitrogen’S Geneswitch™ System, Autumn S. Leggins, Nick Grossoehme, Matthew M. Stern

The Winthrop McNair Research Bulletin

Oct4 is a protein that is involved in the retention of pluripotency in adipose derived stem cells (ADSCs). Despite this knowledge, Oct4’s exact role in the complex system used in maintaining pluripotency is not known. One approach to explore Oct4’s role would be through the use of cellular assays to control the expression of Oct4. This can possibly be accomplished by introducing a biological switch and the gene of interest into ADSCs. In this project, the GeneSwitch™ System is used to ultimately induce Oct4 expression. Before the GeneSwitch™ System can be used, the Oct4 gene is extracted from murine embryonic …

Mperiod2Brdm1 And Other Single Period Mutant Mice Have Normal Food Anticipatory Activity, Julie S. Pendergast, Robert H. Wendroth, Rio C. Stenner, Charles D. Keil, Shin Yamazaki

Biology Faculty Publications

Animals anticipate the timing of food availability via the food-entrainable oscillator (FEO). The anatomical location and timekeeping mechanism of the FEO are unknown. Several studies showed the circadian gene, Period 2, is critical for FEO timekeeping. However, other studies concluded that canonical circadian genes are not essential for FEO timekeeping. In this study, we re-examined the effects of the Per2^Brdm1 mutation on food entrainment using methods that have revealed robust food anticipatory activity in other mutant lines. We examined food anticipatory activity, which is the output of the FEO, in single Period mutant mice. Single Per1, Per2 …