Biology Commons^™

Investigation Of The Life History And Lipid Content Consequences Of Reduced Abundance Of Delta-9 Desaturases In Drosophila Melanogaster, Li Ko

School of Biological Sciences: Dissertations, Theses, and Student Research

Monounsaturated fatty acids (MUFAs) are essential components in all organisms, and the key enzymes that catalyze the production of MUFA are delta-9 desaturases. These enzymes are ER bound and introduce the first double bonds in saturated fatty acids. To investigate the role that delta-9 desaturases play in Drosophila life history and development we performed a series of studies using the RNAi method. Longevity results showed die-off peaks of the knocked-down (KD) flies at day 45. Fecundity study showed decreases in both egg productions and viability of these eggs. Development difficulties were observed in both regular diet and low fat diet. …

The Roles Of Phenotypic Plasticity And Genotypic Specialization In High Altitude Adaptation, Danielle M. Tufts

School of Biological Sciences: Dissertations, Theses, and Student Research

In vertebrates living at high altitude, arterial hypoxemia may be ameliorated by reversible changes in the oxygen-carrying capacity of the blood (regulated by erythropoiesis) and/or changes in blood–oxygen affinity (regulated by allosteric effectors of hemoglobin function). These hematological traits often differ between taxa that are native to different elevational zones, but it is often unknown whether the observed physiological differences reflect fixed, genetically based differences or environmentally induced acclimatization responses (phenotypic plasticity). Here, we report measurements of hematological traits related to blood–O₂ transport in populations of deer mice (Peromyscus maniculatus) that are native to high- and low-altitude …

High-Throughput Amplicon Sequencing Of Rrna Genes Requires A Copy Number Correction To Accurately Reflect The Effects Of Management Practices On Soil Nematode Community Structure, B. J. Darby, T. C. Todd, M. A. Herman

School of Biological Sciences: Faculty Publications

Nematodes are abundant consumers in grassland soils, but more sensitive and specific methods of enumeration are needed to improve our understanding of how different nematode species affect, and are affected by, ecosystem processes. High-throughput amplicon sequencing is used to enumerate microbial and invertebrate communities at a high level of taxonomic resolution, but the method requires validation against traditional specimen-based morphological identifications. To investigate the consistency between these approaches, we enumerated nematodes from a 25-year field experiment using both morphological and molecular identification techniques in order to determine the long-term effects of annual burning and nitrogen enrichment on soil nematode communities. …

Do Bacterial And Fungal Communities In Soils Of The Bolivian Altiplano Change Under Shorter Fallow Periods?, L. Gomez-Montano, A. Jumpponen, M. A. Gonzales, J. Cusicanqui, C. Valdivia, P. P. Motavalli, M. Herman, K. A. Garrett

School of Biological Sciences: Faculty Publications

Traditional fallow periods in the Bolivian highlands are being shortened in an effort to increase short-term crop yields, with potential long-term impacts on soil microbial communities and their functions. In addition, native vegetation, such as Parasthrephia sp. or Baccharis sp. (both locally known as “thola”) are often removed as a fuel for cooking. We evaluated the effects of fallow period and thola on soils in 29 farmers’ fields in two municipalities in the Bolivian Altiplano (Umala and Ancoraimes). Soil fungal and bacterial community responses were characterized using 454-pyrosequencing. Soils in Ancoraimes had significantly higher levels of organic matter, nitrogen, and …

Barrier To Autointegration Factor (Baf) Inhibits Vaccinia Virus Intermediate Transcription In The Absence Of The Viral B1 Kinase, Nouhou Ibrahim, April Wicklund, Augusta Jamin, Matthew S. Wiebe

Nebraska Center for Virology: Faculty Publications

Barrier to autointegration factor (BAF/BANF1) is a cellular DNA-binding protein found in the nucleus and cytoplasm. Cytoplasmic BAF binds to foreign DNA and can act as a defense against vaccinia DNA replication. To evade BAF, vaccinia expresses the B1 kinase, which phosphorylates BAF and blocks its ability to bind DNA. Interestingly, B1 is also needed for viral intermediate gene expression via an unknown mechanism. Therefore, we evaluated the impact of B1-BAF signaling on vaccinia transcription. Strikingly, the decrease in vaccinia transcription caused by loss of B1 can be rescued by depletion of BAF. The repressive action of BAF is greatest …

Low Seroprevalent Species D Adenovirus Vectors As Influenza Vaccines, Eric A. Weaver, Michael A. Barry

School of Biological Sciences: Faculty Publications

Seasonal and pandemic influenza remains a constant threat. While standard influenza vaccines have great utility, the need for improved vaccine technologies have been brought to light by the 2009 swine flu pandemic, highly pathogenic avian influenza infections, and the most recent early and widespread influenza activity. Species C adenoviruses based on serotype 5 (AD5) are potent vehicles for gene-based vaccination. While potent, most humans are already immune to this virus. In this study, low seroprevalent species D adenoviruses Ad26, 28, and 48 were cloned and modified to express the influenza virus A/PR/8/34 hemagglutinin gene for vaccine studies. When studied in …

Characteristics Of White-Tailed Deer Visits To Cattle Farms: Implications For Disease Transmission At The Wildlife-Livestock Interface, Are R. Berentsen, Ryan S. Miller, Regina Misiewicz, Jennifer L. Malmberg, Mike R. Dunbar

Zoonotics and Wildlife Disease: Publications

Bovine tuberculosis (bTB) is endemic in free-ranging white-tailed deer (Odocoileus virginianus) in MI, USA. Currently, the rates of farm visitation by deer and co-use of forage resources by cattle and deer are poorly understood. To evaluate the extent deer and livestock may share forage resources, we investigated farm, yard, and cattle-use area visitation by white-tailed deer and compared visitation with common livestock management practices. We fitted 25 female white-tailed deer near the bTB-infected zone in Michigan’s Lower Peninsula with global positioning system collars. Livestock management practices associated with farm visitation included presence of confined feeding pastures, number of …

Disturbance Frequency And Vertical Distribution Of Seeds Affect Long-Term Population Dynamics: A Mechanistic Seed Bank Model, Eric A. Eager, Chirakkal V. Haridas, Diana Pilson, Richard Rebarber, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

Seed banks are critically important for disturbance specialist plants because seeds of these species germinate only in disturbed soil. Disturbance and seed depth affect the survival and germination probability of seeds in the seed bank, which in turn affect population dynamics. We develop a density-dependent stochastic integral projection model to evaluate the effect of stochastic soil disturbances on plant population dynamics with an emphasis on mimicking how disturbances vertically redistribute seeds within the seed bank. We perform a simulation analysis of the effect of the frequency and mean depth of disturbances on the population’s quasi-extinction probability, as well as the …

Exploitation Of Channel Catfish In Nebraska Flood-Control Reservoirs, Christopher Lee Wiley

School of Natural Resources: Dissertations, Theses, and Student Research

Channel catfish Ictalurus punctatus, is a popular sportfish in North America, and is the third most-sought fish species in Nebraska. Exploitation rates of channel catfish populations have been estimated to be substantial in states neighboring Nebraska. Despite the popularity of channel catfish, little is known about the exploitation of channel catfish populations in Nebraska. The objectives of this study were to estimate the exploitation rates of channel catfish populations, identify the length bias of angling for channel catfish, and identify the self-imposed length limits for channel catfish at flood-control reservoirs of Nebraska. The software package Program Mark was used to …

Comparison Of Systemic And Mucosal Immunization Withhelper-Dependent Adenoviruses For Vaccination Against Mucosal Challenge With Shiv, Eric A. Weaver, Pramod N. Nehete, Bharti P. Nehete, Guojun Yang, Stephanie J. Buchl, Patrick W. Hanley, Donna Palmer, David C. Montefiori, Guido Ferrari, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

School of Biological Sciences: Faculty Publications

Most HIV-1 infections are thought to occur at mucosal surfaces during sexual contact. It has been hypothesized that vaccines delivered at mucosal surfaces may mediate better protection against HIV-1 than vaccines that are delivered systemically. To test this, rhesus macaques were vaccinated by intramuscular (i.m.) or intravaginal (ivag.) routes with helperdependent adenoviral (HD-Ad) vectors expressing HIV-1 envelope. Macaques were first immunized intranasally with species C Ad serotype 5 (Ad5) prior to serotype-switching with species C HD-Ad6, Ad1, Ad5, and Ad2 vectors expressing env followed by rectal challenge with CCR5-tropic SHIV-SF162P3. Vaccination by the systemic route generated stronger systemic CD8 T …

Estudios Científicos En El Estado De Hidalgo Y Zonas Aledañas, Volumen Ii, Griselda Pulido-Flores, Scott Monks

Zea E-Books Collection

Los 16 capítulos que conforman este libro son una contribución al conocimiento de la biodiversidad y conservación de los recursos naturales en el estado de Hidalgo, México.

Se aborda el derecho de propiedad intelectual en la biodiversidad, citando algunos ejemplos de México. Así mismo, se presenta un estudio de la biodiversidad y distribución de la herpetofauna en cuatro tipos de vegetación. Desde el punto de vista de la helmintología se presentan dos estudios de los helmintos parásitos de vertebrados silvestres; con nuevos registros de hospederos y localidades de algunas especies de helmintos para Hidalgo. También, se aborda el uso de …

Mycobacterium Bovis (Bovine Tuberculosis) Infection In North American Wildlife: Current Status And Opportunities For Mitigation Of Risks Of Further Infection In Wildlife Populations, Ryan S. Miller, Steven J. Sweeney

Zoonotics and Wildlife Disease: Publications

Mycobacterium bovis (M. bovis), the causative agent of bovine tuberculosis, has been identified in nine geographically distinct wildlife populations in North America and Hawaii and is endemic in at least three populations, including members of the Bovidae, Cervidae, and Suidae families. The emergence of M. bovis in North American wildlife poses a serious and growing risk for livestock and human health and for the recreational hunting industry. Experience in many countries, including the USA and Canada, has shown that while M. bovis can be controlled when restricted to livestock species, it is almost impossible to eradicate …

Diseases At The Livestock–Wildlife Interface: Status, Challenges, And Opportunities In The United States, Ryan S. Miller, Mathew L. Farnsworth, Jennifer L. Malmberg

Zoonotics and Wildlife Disease: Publications

In the last half century, significant attention has been given to animal diseases; however, our understanding of disease processes and how to manage them at the livestock–wildlife interface remains limited. In this study, we conduct a systematic review of the scientific literature to evaluate the status of diseases at the livestock–wildlife interface in the United States. Specifically, the goals of the literature review were three fold: first to evaluate domestic animal diseases currently found in the United States where wildlife may play a role; second to identify critical issues faced in managing these diseases at the livestock–wildlife interface; and third …

Reexamination Of Herpetofauna On Mormon Island, Hall County, Nebraska, With Notes On Natural History, Keith Geluso, Mary J. Harner

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The Platte River in central Nebraska, USA, was historically surrounded by mixed grass and tallgrass prairies and wet meadows, but many of those habitats were lost or altered during the last century with unknown effects on animals that reside in them. Researchers first surveyed herpetofauna on part of a large island preserve in the Platte River, Mormon Island, Hall County, Nebraska, in 1980 when the land was protected for conservation. They documented 10 species, including three species of amphibians and seven species of reptiles. We inventoried herpetofauna after 30 years of conservation management on Mormon Island and adjacent Shoemaker Island. …

Spontaneous Male Death And Monogyny In The Dark Fishing Spider Dolomedes Tenebrosus Hentz, 1843 (Araneae, Pisauridae), Steven K. Schwartz

School of Biological Sciences: Dissertations, Theses, and Student Research

Male animals typically attempt to mate with multiple females in order to increase their reproductive success. In some species, however, males instead invest in fertilizing the eggs of a single female. Monogyny (male monogamy) is found in a diverse assemblage of taxa, and recent theoretical work reveals that a male-biased sex ratio can favor the evolution of this relatively rare mating system. We integrate this theoretical framework with field observations and laboratory experiments involving the sexually size dimorphic fishing spider, Dolomedes tenebrosus. Results from mating trials revealed a novel form of self-sacrifice behavior where males spontaneously die when they …

Melanin Concentration Gradients In Modern And Fossil Feathers, Daniel J. Field, Liliana D’Alba, Jakob Vinther, Samuel M. Webb, William Gearty, Matthew D. Shawkey

School of Biological Sciences: Faculty Publications

In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ,55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly …

Inge Revsbech Wins The Journal Of Experimental Biology’S Outstanding Paper Prize 2013, Nicola Stead, Inge G. Revsbech, Hideaki Moriyama, Jay F. Storz, Angela Fago

School of Biological Sciences: Faculty Publications

The Editors of The Journal of Experimental Biology are pleased to announce that Inge Revsbech from Aarhus University, Denmark, is the winner of this year’s JEB Outstanding paper prize. The prize is awarded in memory of Bob Boutillier (JEB Editor-in-Chief 1994–2003) to a junior author who has made the most significant contribution to an outstanding paper. ‘The prize aims to promote and reward the hard work that individual young scientists have put into solving different riddles of any particular species using ingenuity, perseverance and sound technology and methodology’, explains Hans Hoppeler, Editor-In-Chief.

Revsbech was the first author on the paper …

Effects Of Nitrogen Availability On The Fate Of Litter-Carbon And Soil Organic Matter Decomposition, Amy Kochsiek, Johannes Knops

School of Biological Sciences: Faculty Publications

Aims: To determine whether addition of inorganic nitrogen (N) directly to maize litter (stalk and leaf) with differing tissue quality impacts litter and soil organic matter (SOM) decomposition. We tested whether N addition leads to 1) faster litter decomposition, 2) less SOM-C decomposition and 3) increased incorporation of organic-C into soil-C fractions thereby increasing C sequestration potential in maize-based systems.

Methodology: We investigated decomposition of two types of maize litter (stalk and leaf) with differing tissue quality both in the field and in a laboratory incubation experiment. In the field, litter was placed on the soil surface and at …

Tlr-Trif Pathway Enhances The Expression Of Kshv Replication And Transcription Activator, Florencia Meyer, Erica Ehlers, Andrew Steadman, Thomas Waterbury, Mingxia Cao, Luwen Zhang

School of Biological Sciences: Faculty Publications

Background: Host innate immunity is against virus infection and replication.

Results: Toll-like receptor 3 activation leads to enhanced expression of a key Kaposi’s sarcoma-associated herpesvirus (KSHV) protein.

Conclusion: KSHV uses host Toll-like receptor pathway to augment its critical gene expression. Significance: A virus may usurp host innate immunity for its own benefits.

Deer Mouse Hemoglobin Exhibits A Lowered Oxygen Affinity Owing To Mobility Of The E Helix, Noriko Inoguchi, Jake R. Oshlo, Chandrasekhar Natarajan, Roy E. Weber, Angela Fago, Jay F. Storz, Hideaki Moriyama

School of Biological Sciences: Faculty Publications

The deer mouse, Peromyscus maniculatus, exhibits altitude-associated variation in hemoglobin oxygen affinity. To examine the structural basis of this functional variation, the structure of the hemoglobin was solved. Recombinant hemoglobin was expressed in Escherichia coli and was purified by ion-exchange chromatography. Recombinant hemoglobin was crystallized by the hangingdrop vapor-diffusion method using polyethylene glycol as a precipitant. The obtained orthorhombic crystal contained two subunits in the asymmetric unit. The refined structure was interpreted as the aquo-met form. Structural comparisons were performed among hemoglobins from deer mouse, house mouse and human. In contrast to human hemoglobin, deer mouse hemoglobin lacks the …

Role Of Merh In Mercury Resistance In The Archaeon Sulfolobus Solfataricus, James Schelert, Deepak Rudrappa, Tyler Johnson, Paul H. Blum

School of Biological Sciences: Faculty Publications

Crenarchaeota include extremely thermoacidophilic organisms that thrive in geothermal

environments dominated by sulfidic ores and heavy metals such as mercury. Mercuric ion, Hg(II),

inactivates transcription in the crenarchaeote Sulfolobus solfataricus and simultaneously

derepresses transcription of a resistance operon, merHAI, through interaction with the MerR

transcription factor. While mercuric reductase (MerA) is required for metal resistance, the role of

MerH, an adjacent small and predicted product of an ORF, has not been explored. Inactivation of

MerH either by nonsense mutation or by in-frame deletion diminished Hg(II) resistance of mutant

cells. Promoter mapping studies indicated that Hg(II) sensitivity of the merH …

Antelope Mating Strategies Facilitate Invasion Of Grasslands By A Woody Weed, Shivani Jadeja, Soumya Prasad, Suhel Quader, Kavita Isvaran

School of Biological Sciences: Faculty Publications

Intra and interspecific variation in frugivore behaviour can have important consequences for seed dispersal outcomes. However, most information comes from among-species comparisons, and within-species variation is relatively poorly understood. We examined how large intraspecific differences in the behaviour of a native disperser, blackbuck antelope Antilope cervicapra, influence dispersal of a woody invasive, Prosopis juliflora, in a grassland ecosystem. Blackbuck disperse P. juliflora seeds through their dung. In lekking blackbuck populations, males defend clustered or dispersed mating territories. Territorial male movement is restricted, and within their territories males defecate on dung-piles. In contrast, mixed-sex herds range over large areas …

Diversification Under Sexual Selection: The Relative Roles Of Mate Preference Strength And The Degree Of Divergence In Mate Preferences, Rafael L. Rodríguez, Janette W. Boughman, David A. Gray, Eileen A. Hebets, Gerlinde Höbel, Laurel B. Symes

Eileen Hebets Publications

The contribution of sexual selection to diversification remains poorly understood after decades of research. This may be in part because studies have focused predominantly on the strength of sexual selection, which offers an incomplete view of selection regimes. By contrast, students of natural selection focus on environmental differences that help compare selection regimes across populations. To ask how this disparity in focus may affect the conclusions of evolutionary research, we relate the amount of diversification in mating displays to quantitative descriptions of the strength and the amount of divergence in mate preferences across a diverse set of case studies of …

An Incompatibility Between A Mitochondrial Trna And Its Nuclear-Encoded Trna Synthetase Compromises Development And Fitness In Drosophila, Colin D. Meiklejohn, Marissa A. Holmbeck, Mohammed A. Siddiq, Dawn N. Abt, David M. Rand, Kristi L. Montooth

School of Biological Sciences: Faculty Publications

Mitochondrial transcription, translation, and respiration require interactions between genes encoded in two distinct genomes, generating the potential for mutations in nuclear and mitochondrial genomes to interact epistatically and cause incompatibilities that decrease fitness. Mitochondrial-nuclear epistasis for fitness has been documented within and between populations and species of diverse taxa, but rarely has the genetic or mechanistic basis of these mitochondrial–nuclear interactions been elucidated, limiting our understanding of which genes harbor variants causing mitochondrial–nuclear disruption and of the pathways and processes that are impacted by mitochondrial–nuclear coevolution. Here we identify an amino acid polymorphism in the Drosophila melanogaster nuclear-encoded mitochondrial tyrosyl–tRNA …

Little Evidence For Demasculinization Of The Drosophila X Chromosome Among Genes Expressed In The Male Germline, Colin D. Meiklejohn, Daven C. Presgraves

School of Biological Sciences: Faculty Publications

Male-biased genes—those expressed at higher levels in males than in females—are underrepresented on the X chromosome of Drosophila melanogaster. Several evolutionary models have been posited to explain this so-called demasculinization of the X. Here, we show that the apparent paucity of male-biased genes on the X chromosome is attributable to global X-autosome differences in expression in Drosophila testes, owing to a lack of sex chromosome dosage compensation in the male germline, but not to any difference in the density of testis-specific or testis-biased genes on the X chromosome. First,using genome-wide gene expression data from 20 tissues,we find no evidence …

Long-Term Nitrogen Amendment Alters The Diversity And Assemblage Of Soil Bacterial Communities In Tallgrass Prairie, Joseph D. Coolon, Kenneth L. Jones, Timothy C. Todd, John M. Blair, Michael A. Herman

School of Biological Sciences: Faculty Publications

Anthropogenic changes are altering the environmental conditions and the biota of ecosystems worldwide. In many temperate grasslands, such as North American tallgrass prairie, these changes include alteration in historically important disturbance regimes (e.g., frequency of fires) and enhanced availability of potentially limiting nutrients, particularly nitrogen. Such anthropogenically-driven changes in the environment are known to elicit substantial changes in plant and consumer communities aboveground, but much less is known about their effects on soil microbial communities. Due to the high diversity of soil microbes and methodological challenges associated with assessing microbial community composition, relatively few studies have addressed specific taxonomic changes …

The Mid-Domain Effect: It’S Not Just About Space, Andrew D. Letten, S. Kathleen Lyons, Angela T. Moles

School of Biological Sciences: Faculty Publications

Ecologists and biogeographers have long sought to understand how and why diversity varies across space. Up until the late 20th century, the dominant role of environmental gradients and historical processes in driving geographical species richness patterns went largely undisputed. However, almost 20 years ago, Colwell & Hurtt (1994) proposed a radical reappraisal of ecological gradient theory that called into question decades of empirical and theoretical research. That controversial idea was later termed the ‘the mid-domain effect’: the simple proposition that in the absence of environmental gradients, the random placement of species ranges within a bounded domain will give rise to …

Nitrogen Uptake Strategies Of Edaphically Specialized Bornean Tree Species, Sabrina E. Russo, Amy Kochsiek, Jocelyn Olney, Lauren Thompson, Amy E. Miller, Sylvester Tan

School of Biological Sciences: Faculty Publications

The association of tree species with particular soil types contributes to high b diversity in forests, but the mechanisms producing such distributions are still debated. Soil nitrogen (N) often limits growth and occurs in differentially available chemical forms. In a Bornean forest where tree species composition changes dramatically along a soil gradient varying in supplies of different N-forms, we investigated whether tree species’ N-uptake and soil specialization strategies covaried. We analyzed foliar ¹⁵N natural abundance for a total of 216 tree species on clay or sandy loam (the soils at the gradient’s extremes) and conducted a ¹⁵N-tracer experiment …

Different Modes Of Evolution In Males And Females Generate Dichromatism In Fairy-Wrens (Maluridae), Allison E. Johnson, J. Jordan Price, Stephen Pruett-Jones

School of Biological Sciences: Faculty Publications

Sexual dichromatism in birds is often attributed to selection for elaboration in males. However, evolutionary changes in either sex can result in plumage differences between them, and such changes can result in either gains or losses of dimorphism. We reconstructed the evolution of plumage colors in both males and females of species in Maluridae, a family comprising the fairy-wrens (Malurus, Clytomias, Sipodotus), emu-wrens (Stipiturus), and grasswrens (Amytornis). Our results show that, across species, males and females differ in their patterns of color evolution. Male plumage has diverged at relatively steady rates, whereas …

Reductive Evolution And The Loss Of Pdc/Pas Domains From The Genus Staphylococcus, Neethu Shah, Rosmarie Gaupp, Hideaki Moriyama, Kent M. Eskridge, Etsuko N. Moriyama, Greg A. Somerville

School of Biological Sciences: Faculty Publications

Background: The Per-Arnt-Sim (PAS) domain represents a ubiquitous structural fold that is involved in bacterial sensing and adaptation systems, including several virulence related functions. Although PAS domains and the subclass of PhoQ-DcuS-CitA (PDC) domains have a common structure, there is limited amino acid sequence similarity. To gain greater insight into the evolution of PDC/PAS domains present in the bacterial kingdom and staphylococci in specific, the PDC/PAS domains from the genomic sequences of 48 bacteria, representing 5 phyla, were identified using the sensitive search method based on HMM-to-HMM comparisons (HHblits).

Results: A total of 1,007 PAS domains and 686 …