Biology Commons^™

Neo-Allopatry And Rapid Reproductive Isolation, Daniel Montesinos, Gilberto Santiago, Ragan M. Callaway

Biological Sciences Faculty Publications

Over the past 3 centuries, many species have been dispersed beyond their natural geographic limits by humans, but to our knowledge, reproductive isolation has not been demonstrated for such neo-allopatric species. We grew seeds from three species of Centaurea (Centaurea solstitialis, Centaurea calcitrapa, and Centaurea sulphurea) that are native to Spain and have been introduced into California, and we tested to what extent seed production was affected by pollen source. Compared with within-population crosses, seed production decreased by 52% and 44%, respectively, when C. solstitialis and C. sulphurea from California were pollinated with conspecific pollen from native populations in Spain. …

Spatial And Oceanographic Factors Affecting Black-Legged Kittiwake And Thick-Billed Murre Distributions In The Southeastern Bering Sea, Brian Hoover

Capstone Projects and Master's Theses

The distribution patterns of Thick-billed Murres (Uria lomvia) and Black-legged Kittiwakes (Rissa tridactyla) in the southeastern Bering Sea were documented at sea during vessel-based surveys in July-August of 2008 and 2009. The relationships of murre and kittiwake densities with environmental variables were investigated using binomial generalized additive models (GAMs) to model the presence or absence of birds, and Gamma-error distribution GAMs to model the positive densities of birds. Environmental variables included oceanographic factors (Chlorophyll, Chlorophyll anomalies, Daily SST, Monthly SST), spatial factors (Distance to nearest colony, Distance to 300m shelf break, Depth), and a temporal factor (Year). Nocturnal surveys were …

Role Of Provisions And Season On Foraging And Female Dominance Behavior In Ring-Tailed Lemurs (Lemur Catta) On St. Catherine's Island, Timothy Moore

College of Graduate Studies: Theses & Dissertations

Madagascar is undergoing habitat destruction and degradation that is threatening its unique species, including ring-tailed lemurs. Ring-tailed lemurs (Lemur catta) live in matriarchal groups composed of a dominant female, adult males, subadult males and females, and young. Due to their dominance, it has been suggested that female ringtailed lemurs have access to the highest quality resources and can monopolize food patches. Lemurs on St. Catherine's are free ranging and have unlimited access to natural food sources, but they are also provisioned with supplementary food to ensure a balanced diet. My study aimed to determine the impact of provisions on female …

West Nile Virus Seroreversion And The Influence Of Herd Immunity On Disease Risk In A Long-Term Study Of Free-Ranging Birds, Eileen M. Mckee

All Student Theses and Dissertations

The transmission and amplification of West Nile virus (WNV) is driven by the number of susceptible avian hosts. The quantity of susceptible hosts is determined by 1) recruitment of juvenile birds during the breeding season, 2) adult birds previously unexposed to WNV, and 3) adult birds with waning antibody titers. Although rarely tested, avian herd immunity and seroreversion could have a direct impact on Culex infection rate, a proxy for the reproductive number of WNV. In this study, we utilized data from a seven year study investigating WNV transmission ecology in suburban Chicago, Illinois. We tested the hypothesis that herd …

Dpy-30 Domain And Its Flanking Sequence Mediate The Assembly Modulation Of Flagellar Radial Spoke Complexes, Radhika Gopal, Kenneth W. Foster, Pinfen Yang

Biological Sciences Faculty Research and Publications

RIIa is known as the dimerization and docking (D/D) domain of the cyclic AMP (cAMP)-dependent protein kinase. However, numerous molecules, including radial spoke protein 2 (RSP2) in Chlamydomonas flagella, also contain an RIIa or a similar DPY-30 domain. To elucidate new roles of D/D domain-containing proteins, we investigated a panel of RSP2 mutants. An RSP2 mutant had paralyzed flagella defective in RSP2 and multiple subunits near the spokehead. New transgenic strains lacking only the DPY-30 domain in RSP2 were also paralyzed. In contrast, motility was restored in strains that lacked only RSP2’s calmodulin- binding C-terminal region. These cells swam normally …

Deep Diversification And Long-Term Persistence In The South American ‘Dry Diagona’: Integrating Continent-Wide Phylogeography And Distribution Modeling Of Geckos, Fernanda P. Werneck, Tony Gamble, Guarino R. Colli, Miguel T. Rodrigues, Jack W. Sites Jr.

Biological Sciences Faculty Research and Publications

The relative influence of Neogene geomorphological events and Quaternary climatic changes as causal mechanisms on Neotropical diversification remains largely speculative, as most divergence timing inferences are based on a single locus and have limited taxonomic or geographic sampling. To investigate these influences, we use a multilocus (two mitochondrial and 11 nuclear genes) range‐wide sampling of Phyllopezus pollicaris, a gecko complex widely distributed across the poorly studied South American ‘dry diagonal’ biomes. Our approach couples traditional and model‐based phylogeography with geospatial methods, and demonstrates Miocene diversification and limited influence of Pleistocene climatic fluctuations on P. pollicaris. Phylogeographic structure and …

Characterization Of The Stem Cell Niche In Drosophila Testes, Vittorio Mena Jr.

Seton Hall University Dissertations and Theses (ETDs)

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The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self

College of Graduate Studies: Theses & Dissertations

The ability to efficiently move over uneven terrain is critical for most terrestrial animals. Bipedal running is common in lizard species, however the biological advantage of a bipedal running posture remains uncertain. I examined the hypothesis that a bipedal posture is advantageous when crossing obstacles. Particularly, I determined whether kinematic adjustments differ among four focal species with contrasting body forms and ecology. I also examined how sprint speed changed when crossing obstacles with a quadrupedal versus a bipedal posture. I quantified kinematics from high-speed video (300 frames/second) of lizards running down a 3m runway both with and without the presence …

Bird Use Of Cumberland Island's Freshwater Wetlands, Lisa Dlugolecki

College of Graduate Studies: Theses & Dissertations

Cumberland Island is the southernmost barrier island off the coast of Georgia. Its freshwater wetlands are an important, rare habitat to have on a barrier island surrounded by saltmarsh and ocean. Many species of birds require freshwater wetlands as feeding, roosting and nesting grounds. However, the freshwater wetlands on Cumberland Island have been impacted by humans for centuries causing birds to abandon their historic nesting ground. Known land use histories of Cumberland Island's freshwater wetlands were gathered to try and determine how the wetlands changed over time Wetlands were analyzed for presence of wetland-dependent birds and recorded. Thirty-six species of …

Patterns Of Chemosensory Behavior In A Closed Population Of Wild African Elephants (Loxodonta Africana), Russell W. Blogg

College of Graduate Studies: Theses & Dissertations

Chemosensory behaviors are used by many mammalian species to assess chemical signals in the environment. These chemical signals may contain important information about reproductive state, identity, status, or location of conspecifics. Elephants are a long-lived species and males reproduce at a much later age than females, which provides a protracted developmental period for males. This study examined chemosensory behaviors in a population of African elephants living in Addo Elephant National Park, South Africa and demonstrated that patterns emerge as elephants develop and approach sexual maturity. Older pubescent males (15-19 year olds) performed more chemosensory behaviors than younger pubescent males (10-14 …

Spatial And Temporal Immune Response In House Flies In Response To Ingestion Of Bacillus Cereus And Eschericha Coli 0157-H7, Adam Fleming

College of Graduate Studies: Theses & Dissertations

House flies (Musca domestica L.) feed and breed on septic substrates, putting them in direct contact with a multitude of disease causing agents and can act as a bridge for those agents to humans. The house fly has previously been shown to carry many different species of bacteria that are pathogenic. Escherichia coli O157:H7 is a pathogenic enterohemorrhagic serotype of E. coli that can be vectored by the house fly. Bacillus cereus is a foodborne pathogen that has also been isolated from the house fly in previous studies. To examine vector potential for these pathogens, house flies were fed green …

Predation Risk And Colony Structure In The Pea Aphid, Acyrthosiphon Pisum, Carl Nicolas Keiser

College of Graduate Studies: Theses & Dissertations

Many organisms live in transient or permanent aggregations to reduce individual predation risk. Hamilton's "Selfish Herd" theory states that an individual should assume a central position within a group to decrease individual predation risk relative to that of its neighbors (i.e., individuals should be selfish). This theory, however, cannot predict the spatial distribution of individuals within clonal aggregations, that is, when individuals are genetically identical (the "evolutionary self"). As aphids (small, herbivorous insects) are parthenogenetic, emit alarm signals, and have high levels of phenotypic plasticity to cope with environmental stressors like predation risk, they are a model organism for investigating …

Functions Of The Arabidopsis Kinesin Superfamily Of Microtubule-Based Motor Proteins, Chuanmei Zhu, Ram Dixit

Biology Faculty Research

Plants possess a large number of microtubule-based kinesin motor proteins. While the kinesin-2, 3, 9, and 11 families are absent from land plants, the kinesin-7 and 14 families are greatly expanded. In addition, some kinesins are specifically present only in land plants. The distinctive inventory of plant kinesins suggests that kinesins have evolved to perform specialized functions in plants. Plants assemble unique microtubule arrays during their cell cycle, including the interphase cortical microtubule array, preprophase band, anastral spindle and phragmoplast. In this review, we explore the functions of plant kinesins from a microtubule array viewpoint, focusing mainly on Arabidopsis kinesins. …

Small Molecule Inhibitors Of Bacillus Anthracis Protective Antigen Proteolytic Activation And Oligomerization, Alexander N. Wein, Brian N. Williams, Shihui Liu, Boris Ermolinsky, Daniele Provenzano, Ruben Abagyan, Andrew Orry, Stephen H. Leppla, Michael Peredelchuk

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

Protective antigen (PA), lethal factor, and edema factor, the protein toxins of Bacillus anthracis, are among its most important virulence factors and play a key role in infection. We performed a virtual ligand screen of a library of 10000 members to identify compounds predicted to bind to PA and prevent its oligomerization. Four of these compounds slowed PA association in a FRET-based oligomerization assay, and two of those protected cells from intoxication at concentrations of 1-10 μM. Exploration of the protective mechanism by Western blot showed decreased SDS-resistant PA oligomer on cells and, surprisingly, decreased amounts of activated PA. In …

Identification Of An Amino-Terminal Fragment Of Apolipoprotein E4 That Localizes To Neurofibrillary Tangles Of The Alzheimer’S Disease Brain, Troy T. Rohn, Lindsey W. Catlin, Kendra G. Coonse, Jeffrey W. Habig

Biology Faculty Publications and Presentations

Although the risk factor for harboring the apolipoprotein E4 (apoE4) allele in late-onset Alzheimer’s disease (AD) is well known, the mechanism by which apoE4 contributes to AD pathogenesis has yet to be clarified. Preferential cleavage of the ApoE4 isoform relative to other polymorphic forms appears to be significant, as the resulting fragments are associated with hallmarks of AD. To examine the possible role of apoE4 proteolysis in AD, we designed a site-directed antibody directed at position D172, which would yield a predicted amino-terminal fragment previously identified in AD brain extracts. Western blot analysis utilizing this novel antibody, termed the amino-terminal …

Seed Dimorphism, Nutrients And Salinity Differentially Affect Seed Traits Of The Desert Halophyte Suaeda Aralocaspica Via Multiple Maternal Effects, Lei Wang, Jerry M. Baskin, Carol C. Baskin, J. Hans C. Cornelissen, Ming Dong, Zhenying Huang

Biology Faculty Publications

BACKGROUND: Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects.

RESULTS: Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient …

An Experimental Evaluation Of The Use Of C3 Δ13C Plant Tissue As A Proxy For The Paleoatmospheric Δ13Co2 Signature Of Air, B. H. Lomax, C. A. Knight, J. A. Lake

Biological Sciences

Previous work suggests that the relationship between the carbon isotope composition of air (d13Ca) and plant leaf tissue (d13Cp) can be used to track changes in the carbon isotope composition of paleo-atmospheric CO2. Here we test this assertion in a series of experiments using the model plant Arabidopsis thaliana grown under a range of atmospheric CO2 concentrations relevant to geologic time (380, 760, 1000, 1500, 2000 and 3000 ppm). Nested within these CO2 experiments water availability was controlled (giving two sets of experimental plants; low and high water treatment at each CO2 concentration) to manipulate stomatal opening, a key process …

Current Strategies For Promoting Regeneration After Spinal Cord Injury, Seth Schirmer

Student Theses and Dissertations

Each year 12,000 people suffer spinal cord injury (SCI) in the USA. Thus, it is critical we find a means by which to stimulate regeneration in the injured spinal cord towards recovery of function in these patients. Therefore, significant amount of federal and private funding is directed to SCI research, with research focusing on anything measures from using embryonic stem cells to replace damaged cells, to stimulating regeneration through daily physical therapy. This paper is a review of some of the current strategies evolved from such research for promoting spinal cord regeneration after spinal cord injury, and has focused on …

Influence Of Microsite Disturbance On The Establishment Of Two Congeneric Invasive Thistles, Emily S.J. Rauschert, Katriona Shea

Biological, Geological, and Environmental Faculty Publications

The successful establishment of invasive species has been shown to depend on aspects of the invaded community, such as gap characteristics. Biotic resistance may be particularly critical for stopping invaders at early life history stages, but new species can often invade following disturbances, which may create microsites with very different characteristics than are usually present. We examine the response of two invasive thistle species, Carduus nutans L. and C. acanthoides L., to three different microsite characteristics: disturbance type, size, and water availability. The two species initially responded differently to the type of disturbance: C. acanthoides had higher emergence and survival …

Behavioral And Physiological Female Responses To Male Sex Ratio Bias In A Pond-Breeding Amphibian, Kristine L. Grayson, Stephen P. De Lisle, Jerrah E. Jackson, Samuel J. Black, Erica J. Crespi

Biology Faculty Publications

Introduction: The phenomenon of sexual conflict has been well documented, and in populations with biased operational sex ratios the consequences for the rarer sex can be severe. Females are typically a limited resource and males often evolve aggressive mating behaviors, which can improve individual fitness for the male while negatively impacting female condition and fitness. In response, females can adjust their behavior to minimize exposure to aggressive mating tactics or minimize the costs of mating harassment. While male-male competition is common in amphibian mating systems, little is known about the consequences or responses of females. The red-spotted newt (Notophthalmus …

Serotonin And Synaptic Transmission At Invertebrate Neuromuscular Junctions, Wen-Hui Wu, Robin L. Cooper

Biology Faculty Publications

The serotonergic system in vertebrates and invertebrates has been a focus for over 50 years and will likely continue in the future. Recently, genomic analysis and discovery of alternative splicing and differential expression in tissues have increased the knowledge of serotonin (5-HT) receptor types. Comparative studies can provide useful insights to the wide variety of mechanistic actions of 5-HT responsible for behaviors regulated or modified by 5-HT. To determine cellular responses and influences on neural systems as well as the efferent control of behaviors by the motor units, preparations amenable to detailed studies of synapses are beneficial as working models. …

Transcriptional Cross Talk Within The Mar-Sox-Rob Regulon In Escherichia Coli Is Limited To The Rob And Marrab Operons, Lon Chubiz, George Glekas, Christopher Rao

Biology Department Faculty Works

Bacteria possess multiple mechanisms to survive exposure to various chemical stresses and antimicrobial compounds. In the enteric bacterium Escherichia coli, three homologous transcription factors—MarA, SoxS, and Rob—play a central role in coordinating this response. Three separate systems are known to regulate the expression and activities of MarA, SoxS, and Rob. However, a number of studies have shown that the three do not function in isolation but rather are coregulated through transcriptional cross talk. In this work, we systematically investigated the extent of transcriptional cross talk in the mar-sox-rob regulon. While the three transcription factors were found to have the potential …

Community Impacts Of Prosopis Juliflora Invasion: Biogeographic And Congeneric Comparisons, Rajwant Kaur, Wilfredo L. Gonzáles, Luis Daniel Llambi, Pascual J. Soriano, Ragan M. Callaway, Marnie E. Rout, Timothy J. Gallaher, Inderjit

Biological Sciences Faculty Publications

We coordinated biogeographical comparisons of the impacts of an exotic invasive tree in its native and non-native ranges with a congeneric comparison in the non-native range. Prosopis juliflora is taxonomically complicated and with P. pallida forms the P. juliflora complex. Thus we sampled P. juliflora in its native Venezuela, and also located two field sites in Peru, the native range of Prosopis pallida. Canopies of Prosopis juliflora, a native of the New World but an invader in many other regions, had facilitative effects on the diversity of other species in its native Venezuela, and P. pallida had both negative and …

Phylotranscriptomics To Bring The Understudied Into The Fold: Monophyletic Ostracoda, Fossil Placement, And Pancrustacean Phylogeny, Todd H. Oakley, Joanna M. Wolfe, Annie R. Lindgren, Alexander K. Zaharoff

Biology Faculty Publications and Presentations

An ambitious, yet fundamental goal for comparative biology is to understand the evolutionary relationships for all of life. However, many important taxonomic groups have remained recalcitrant to inclusion into broader scale studies. Here, we focus on collection of 9 new 454 transcriptome data sets from Ostracoda, an ancient and diverse group with a dense fossil record, which is often undersampled in broader studies. We combine the new transcriptomes with a new morphological matrix (including fossils) and existing expressed sequence tag, mitochondrial genome, nuclear genome, and ribosomal DNA data. Our analyses lead to new insights into ostracod and pancrustacean phylogeny. We …

Arabidopsis Bhlh100 And Bhlh101 Control Iron Homeostasis Via A Fit-Independent Pathway, Alicia B. Sivitz, Victor Hermand, Catherine Curie, Grégory Vert

Dartmouth Scholarship

Iron deficiency induces a complex set of responses in plants, including developmental and physiological changes, to increase iron uptake from soil. In Arabidopsis, many transporters involved in the absorption and distribution of iron have been identified over the past decade. However, little is known about the signaling pathways and networks driving the various responses to low iron. Only the basic helix–loop–helix (bHLH) transcription factor FIT has been shown to control the expression of the root iron uptake machinery genes FRO2 and IRT1. Here, we characterize the biological role of two other iron-regulated transcription factors, bHLH100 and bHLH101, in iron homeostasis. …

Heavy Metal Chemistry Of Sediments In Caves Of The Springfield Plateau, Missouri-Arkansas-Oklahoma: A Link To Subterranean Biodiversity, Travis M. Doughty, Aaron W. Johnson

The Compass: Earth Science Journal of Sigma Gamma Epsilon

We used X-ray fluorescence (XRF) to compare the heavy metal chemistry of sediments in caves in rural and urban areas to the chemistry of sediments from a control cave in a relatively undisturbed watershed in the Springfield (MO) Plateau. Sediment from Smallin Cave near Ozark, MO, the control cave, has the smallest peak sizes for Zn and Mn and a moderately-sized Pb peak. Sediment from the rural cave exhibited larger peaks of Zn and Mn and a smaller Pb peak. Sediment from the urban cave had the largest Zn, Mn and Pb peaks. Interestingly, smaller peak sizes appear to correlate …

Landscape Of Transcription In Human Cells, Jainab Khatun

Biology Faculty Publications and Presentations

Eukaryotic cells make many types of primary and processed RNAs that are found either in specific subcellular compartments or throughout the cells. A complete catalogue of these RNAs is not yet available and their characteristic subcellular localizations are also poorly understood. Because RNA represents the direct output of the genetic information encoded by genomes and a significant proportion of a cell’s regulatory capabilities are focused on its synthesis, processing, transport, modification and translation, the generation of such a catalogue is crucial for understanding genome function. Here we report evidence that three-quarters of the human genome is capable of being transcribed, …

An Integrated Encyclopedia Of Dna Elements In The Human Genome, Jainab Khatun

Biology Faculty Publications and Presentations

The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence …

Oncostatin M Promotes Mammary Tumor Metastasis To Bone And Osteolytic Bone Degradation, Celeste Bolin, Ken Tawara, Caleb Sutherland, Jeff Redshaw, Patrick S. Aranda, Jim Moselhy, Robin Anderson, Cheryl Jorcyk

Biology Faculty Publications and Presentations

Oncostatin M (OSM) is an interleukin-6 (IL-6) family cytokine that has been implicated in a number of biological processes including inflammation, hematopoiesis, immune responses, development, and bone homeostasis. Recent evidence suggests that OSM may promote breast tumor invasion and metastasis. We investigated the role of OSM in the formation of bone metastases in vivo using the 4T1.2 mouse mammary tumor model in which OSM expression was knocked down using shRNA (4T1.2-OSM). 4T1.2-OSM cells were injected orthotopically into Balb/c mice, resulting in a greater than 97% decrease in spontaneous metastasis to bone compared to control cells. Intratibial injection of these same …

Indirect Consequences Of Hypolimnetic Hypoxia On Zooplankton Growth In A Large Eutrophic Lake, Daisuke Goto, Kara Lindelof, David L. Fanslow, Stuart A. Ludsin, Steven A. Pothoven, James J. Roberts, Henry A. Vanderploeg, Alan E. Wilson, Tomas O. Höök

School of Biological Sciences: Faculty Publications

Diel vertical migration (DVM) of some zooplankters in eutrophic lakes is often compressed during peak hypoxia. To better understand the indirect consequences of seasonal hypolimnetic hypoxia, we integrated laboratory-based experimental and field-based observational approaches to quantify how compressed DVM can affect growth of a cladoceran, Daphnia mendotae, in central Lake Erie, North America. To evaluate hypoxia tolerance of D. mendotae, we conducted a survivorship experiment with varying dissolved oxygen concentrations, which demonstrated high sensitivity of D. mendotae to hypoxia (≤2 mg O2 l−1), supporting the field observations of their behavioral avoidance of the hypoxic hypolimnion. To investigate the …