Life Sciences Commons^™

Facilitation By Pinus Flexilis During Succession: A Hierarchy Of Mechanisms Benefits Other Plant Species, Dayna Baumeister, Ragan M. Callaway

Biological Sciences Faculty Publications

Studies of facilitation have primarily been limited to single mechanisms, species, or environments. We examined interacting mechanisms governing the facilitative effects of Pinus flexilis on two later successional understory species, Pseudotsuga menziesii and Ribes cereum, in different microhabitats and seasons at the ecotone between the Rocky Mountain forests and Great Plains grasslands in Montana, USA. In field surveys, 69% of Pseudotsuga and 91% of Ribes were located beneath P. flexilis even though P. flexilis subcrowns accounted for a small proportion of available habitat. For three years, we monitored the survival of Pseudotsuga and Ribes seedlings experimentally planted beneath …

Estimating Detection Probablities Of River Birds Using Double Surveys, Robert J. Fletcher Jr., Richard L. Hutto

Biological Sciences Faculty Publications

We describe a method for surveying birds in river habitats that allows for rapid assessment across broad spatial scales and estimation of detection probabilities. Our river survey approach incorporates a double-survey technique, whereby observers in two canoes simultaneously survey birds along a river reach. Data are in the form of a two-sample mark-recapture history, and covariates suspected of influencing detection probabilities can be included in the modeling process and evaluated using information-theoretic approaches. We provide an example using the method along the Madison and upper Missouri rivers in Montana. Overall, detection probabilities for each observer ranged from 57% to 89%, …

Environmental Signals Generate A Differential And Coordinated Expression Of The Heme Receptor Gene Family Of Bartonella Quintana, James M. Battisti, Kate N. Sappington, Laura S, Smitherman, Nermi L. Parrow, Michael F. Minnick

Biological Sciences Faculty Publications

Of all bacteria, Bartonella quintana has the highest reported in vitro hemin requirement, yet an explanation for this remains elusive. To produce diseases such as trench fever, endocarditis, and bacillary angiomatosis, B. quintana must survive and replicate in the disparate environments of the Pediculus humanus corporis (body louse) gut and the human vasculature. We previously identified a five-member family of hemin binding proteins (Hbps) synthesized by B. quintana that bind hemin on the outer surface but share no similarity to known bacterial heme receptors. In the present study, we examine the transcription, regulation, and synthesis of this virulence factor family …

Role Of The Stable Signal Peptide And Cytoplasmic Domain Of G2 In Regulating Intracellular Transport Of The Junín Virus Envelope Glycoprotein Complex, Sudhakar S. Agnihothram, Joanne York, Jack H. Nunberg

Biological Sciences Faculty Publications

Enveloped viruses utilize the membranous compartments of the host cell for the assembly and budding of new virion particles. In this report, we have investigated the biogenesis and trafficking of the envelope glycoprotein (GP-Q of the Junin arenavirus. The mature GP-C complex is unusual in that it retains a stable signal peptide (SSP) as an essential component in association with the typical receptor-binding (G1) and transmembrane fusion (G2) subunits. We demonstrate that, in the absence of SSP, the G1-G2 precursor is restricted to the endoplasmic reticulum (ER). This constraint is relieved by coexpression of SSP in trans, allowing transit of …

Unexpected Diversity And Complexity Of The Guerrero Negro Hypersaline Microbial Mat, Ruth E. Ley, J. Kirk Harris, Joshua Wilcox, John R. Spear, Scott R. Miller, Brad M. Bebout, Julia A. Maresca, Donald A. Bryant, Mithcell L. Sogin, Norman R. Pace

Biological Sciences Faculty Publications

We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements of chemical gradients, to map microbial diversity vertically on a millimeter scale in a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents of the mat, small-subunit rRNA genes were amplified by PCR from community genomic DNA extracted from layers, cloned, and sequenced. Bacteria dominated the mat and displayed unexpected and unprecedented diversity. The majority (1,336) of the 1,586 bacterial 16S rRNA sequences generated were unique, representing 752 species (>= 97% rRNA sequence identity) in 42 of the …

What Use Is Half A Wing In The Ecology And Evolution Of Birds?, Kenneth P. Dial, Ross J. Randall, Terry R. Dial

Biological Sciences Faculty Publications

The use of incipient wings during ontogeny in living birds reveals not only the function of these developing forelimbs in growing birds’ survival but also the possible employment of protowings during transitional stages in the evolution of flight. When startled, juvenile galliform birds attempt aerial flight even though their wings are not fully developed. They also flap their incipient wings when they run up precipitous inclines, a behavior we have described as wing-assisted incline running (WAIR), and when they launch from elevated structures. The functional benefit of beating these protowings has only recently been evaluated. We report the first ontogenetic …

A Framework For Understanding Ecological Traps And An Evaluation Of Existing Evidence, Bruce A. Robertson, Richard L. Hutto

Biological Sciences Faculty Publications

When an animal settles preferentially in a habitat within which it does poorly relative to other available habitats, it is said to have been caught in an “ecological trap.” Although the theoretical possibility that animals may be so trapped is widely recognized, the absence of a clear mechanistic understanding of what constitutes a trap means that much of the literature cited as support for the idea may be weak, at best. Here, we develop a conceptual model to explain how an ecological trap might work, outline the specific criteria that are necessary for demonstrating the existence of an ecological trap, …

Invasive Plant Suppresses The Growth Of Native Tree Seedlings By Disrupting Belowground Mutualisms, Kristina A. Stinson, Stuart A. Campbell, Jeff R. Powell, Benjamin E. Wolfe, Ragan M. Callaway, Giles C. Thelen, Steven G. Hallett, Daniel Prati, John N. Klironomos

Biological Sciences Faculty Publications

The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat.

Time For International Policies On Biological Invasions, Inderjit, Ragan M. Callaway, Shalini Kaushik

Biological Sciences Faculty Publications

No abstract provided.

Mutations Conferring Aminoglycoside And Spectinomycin Resistance In Borrelia Burgdorferi, Daniel Criswell, Virginia L. Tobiason, J. Stephen Lodmell, D. Scott Samuels

Biological Sciences Faculty Publications

We have isolated and characterized in vitro mutants of the Lyme disease agent Borrelia burgdorferi that are resistant to spectinomycin, kanamycin, gentamicin, or streptomycin, antibiotics that target the small subunit of the ribosome. 16S rRNA mutations A1185G and C1186U, homologous to Escherichia coli nucleotides A1191 and C1192, conferred > 2,200-fold and 1,300-fold resistance to spectinomycin, respectively. A 16S rRNA A1402G mutation, homologous to E. coli A1408, conferred > 90-fold resistance to kanamycin and > 240-fold resistance to gentamicin. Two mutations were identified in the gene for ribosomal protein S12, at a site homologous to E. coli residue Lys-87, in mutants selected in streptomycin. …

Linking Direct And Indirect Data On Dispersal: Isolation By Slope In A Headwater Stream Salamander, Winsor H. Lowe, Gene E. Likens, Mark A. Mcpeek, Don C. Buso

Biological Sciences Faculty Publications

There is growing recognition of the need to incorporate information on movement behavior in landscape-scale studies of dispersal. One way to do this is by using indirect indices of dispersal (e.g., genetic differentiation) to test predictions derived from direct data on movement behavior. Mark–recapture studies documented upstream-biased movement in the salamander Gyrinophilus porphyriticus (Plethodontidae). Based on this information, we hypothesized that gene flow in G. porphyriticus is affected by the slope of the stream. Specifically, because the energy required for upstream dispersal is positively related to slope, we predicted gene flow to be negatively related to change in elevation between …

An Introduced Predator Alters Aleutian Island Plant Communities By Thwarting Nutrient Subsidies, John L. Maron, James A. Estes, Donald A. Croll, Eric M. Danner, Sarah C. Elmendorf, Stacey L. Buckelew

Biological Sciences Faculty Publications

The ramifying effects of top predators on food webs traditionally have been studied within the framework of trophic cascades. Trophic cascades are compelling because they embody powerful indirect effects of predators on primary production. Although less studied, indirect effects of predators may occur via routes that are not exclusively trophic. We quantified how the introduction of foxes onto the Aleutian Islands transformed plant communities by reducing abundant seabird populations, thereby disrupting nutrient subsidies vectored by seabirds from sea to land. We compared soil and plant fertility, plant biomass and community composition, and stable isotopes of nitrogen in soil, plants, and …

Photo Processes On Self-Associated Cationic Porphyrins And Plastocyanin Complexes 1. Ligation Of Plastocyanin Tyrosine 83 Onto Metalloporphyrins And Electron-Transfer Fluorescence Quenching, Hewa Anula, Eugene Myshkin, Anton Guliaev, Charles Luman, Evgeny Danilov, Felix Castellano, George S. Bullerjahn, Michael Rogers

Biological Sciences Faculty Publications

The spectroscopic properties of the self-associated complexes formed between the anionic surface docking site of spinach plastocyanin and the cationic metalloporphyrins, in which the tyrosine 83 (Y83) moiety is placed just below the docking site, tetrakis(N-methyl-4-pyridyl)porphyrin (Pd(II)TMPyP4+ and Zn(II)TMPyP4+), have been studied and reported herein. The fluorescence quenching phenomenon of the self-assembled complex of Zn(II)TMPyP4+/plastocyanin has also been discovered. The observed red-shifting of the Soret and Q-bands of the UV-visible spectra, ca. 9 nm for Pd(II)TMPyP4+/plastocyanin and ca. 6 nm for the Zn(II)TMPyP4+/ plastocyanin complexes, was explained in terms of exciton theory coupled with the Gouterman model. Thus, the hydroxyphenyl …

Mechanisms Of Genotoxin-Induced Transcription And Hypermutation In P53, Barbara E. Wright, Jacqueline Reimers, Karen Schmidt, Evan Burkala, Ping Wei, Ping Wei

Biological Sciences Faculty Publications

It is widely assumed that genotoxin-induced damage (e.g., G-to-T transversions) to the tumor suppressor gene, p53, is a direct cause of cancer. However, genotoxins also induce the stress response, which upregulates p53 transcription and the formation of secondary structures from ssDNA. Since unpaired bases are thermodynamically unstable and intrinsically mutable, increased transcription could be the cause of hypermutation, and thus cancer. Support for this hypothesis has been obtained by analyzing 6662 mutations in all types of cancer compared to lung and colon cancers, using the p53 mutation database. The data suggest that genotoxins have two independent effects: first, they induce …

Occurrence, Persistence, And Expansion Of Saltcedar (Tamarix Spp.) Populations In The Great Plains Of Montana, Jason P. Sexton, Anna Sala, Kevin Murray

Biological Sciences Faculty Publications

Saltcedar (Tamarix spp.), a shrub native to Eurasia, is associated with major alterations to wetland and riparian systems in the southwestern United States. Since the 1960s saltcedar has been naturalized in northern states of the U.S. where its growth potential and impacts are not well known. Here, we describe the occurrence, age, size, and relative cover of saltcedar populations in several river basins in central eastern Montana, USA, to identify potential patterns of spread across the region and changes in individual populations as they age. Stands were aged according to the oldest saltcedar individuals and were sampled for dominant plant …

Northern Region Landbird Monitoring Program: A Usfs-University Of Montana Partnership Designed To Provide Both Short-Term And Long-Term Feedback For Land Managers, Richard L. Hutto, Skip Kowalski

Biological Sciences Faculty Publications

The Northern Region Landbird Monitoring Program (NRLMP) began in 1990 as a cooperative effort between the United States Forest Service (USFS) and the University of Montana. The combination of a research-oriented perspective from the University and a management-needs perspective from the National Forests within the Northern Region led to the realization that landbirds as a group might serve as a powerful tool to address more widespread monitoring needs in the USFS Northern Region. The program quickly evolved from one that was put into place specifically to use federally earmarked dollars to address neotropical migratory bird conservation, into a more general …

Tick Pheromones And Their Use In Tick Control, Daniel E. Sonenshine

Biological Sciences Faculty Publications

Tick pheromones that regulate assembly, attraction/aggregation/attachment, and mating behavior have been described. Most of the compounds regulating these behaviors are purines, substituted phenols, or cholesteryl esters. Other pheromonal compounds include organic acids, hematin, or ecdysteroids. Novel devices have been developed that combine the specific compounds comprising these pheromones with an acaricide. When applied to tick-infested vegetation or directly to the body surfaces of livestock or companion animals, these devices are effective for tick control. This review summarizes the current state of knowledge of tick pheromones. In addition, this review also presents examples illustrating how devices using tick pheromones can offer …

The Adaptive Value Of Aggregation Among Juvenile Caribbean Spiny Lobster: An Evaluation Using Individual-Based Modeling, Thomas W. Dolan Iii, Mark J. Butler Iv

Biological Sciences Faculty Publications

Ontogenetic changes in gregariousness by pre-reproductive animals, like that observed in juvenile Caribbean spiny lobsters (Panulirus argus), may be adaptive and reflect size-specific changes in the effectiveness of aggregation in promoting survival. Alternatively, aggregation may simply result from changes in the distribution or availability of suitable habitat structure, or from other behaviors that enhance survival. There are currently two hypotheses explaining the potential benefits of gregarious behavior in juvenile spiny lobsters, both of which focus on increasing survivorship by reducing predation pressure: the group benefit hypothesis and the guide hypothesis. The group benefit hypothesis argues that aggregations of …

Habitat-Specific Impacts Of Multiple Consumers On Plant Population Dynamics, John L. Maron, Matthew J. Kauffman

Biological Sciences Faculty Publications

Multiple consumers often attack seeds, seedlings, and adult plants, but their population-level consequences remain uncertain. We examined how insect and small mammal consumers influenced the demography and abundance of the perennial shrub, bush lupine (Lupinus arboreus). In grassland and dune habitats we established replicate experimental lupine populations in 81-m² plots that were either protected from, or exposed to, herbivorous voles and granivorous mice (via fencing) and/or root feeding insects (via insecticide treatment). Populations were initiated with transplanted seedlings in 1999 and 2000. We followed the demography of these cohorts, subsequent generations, and the seed bank for 5.5 …

Bogidiella Indica, A New Species Of Subterranean Amphipod Crustacean (Bogidiellidae) From Wells In Southeastern India, With Remarks On The Biogeographic Importance Of Recently Discovered Bogidiellids On The Indian Subcontinent, John R. Holsinger, Y. Ranga Reddy, Mohammed Messouli

Biological Sciences Faculty Publications

Bogidiella indica, new species, is described from three water wells in southeastern India, including a bore-well on the campus of Acharya Nagarjuna University in Nagarjunanagar, a water well in Guntur town, and an agricultural well in the Godavari and Krishna Basin, all in the state of Andhra Pradesh, India. The new species is assigned to the genus Bogidiella Hertzog and to a newly designated species group within the genus. Despite the near circum-global distribution of the family Bogidiellidae, only a single, partially intact specimen of a bogidiellid had been collected from the Indian subcontinent prior to the discovery of specimens …

Mutation And Cloning Efficiency, Ronny C. Woodruff, Priti Azad

Biological Sciences Faculty Publications

No abstract provided.

Structure And Sequence Conservation Of A Putative Hypoxia Responsive Element In The Lactate Dehydrogenase-B Gene Of Fundulus, Bernard B. Rees, John A.L. Bowman, P M. Schulte

Biological Sciences Faculty Publications

No abstract provided.

Effects Of Long-Term Hypoxia On Enzymes Of Carbohydrate Metabolism In The Gulf Killifish, Fundulus Grandis, M L. Manning, C A. Landry, R D. Boehm, S Manning, A O. Cheek, Bernard B. Rees

Biological Sciences Faculty Publications

The goal of the current study was to generate a comprehensive, multi-tissue perspective of the effects of chronic hypoxic exposure on carbohydrate metabolism in the Gulf killifish Fundulus grandis. Fish were held at approximately 1.3·mg·l–1 dissolved oxygen (~3.6·kPa) for 4·weeks, after which maximal activities were measured for all glycolytic enzymes in four tissues (white skeletal muscle, liver, heart and brain), as well as for enzymes of glycogen metabolism (in muscle and liver) and gluconeogenesis (in liver). The specific activities of enzymes of glycolysis and glycogen metabolism were strongly suppressed by hypoxia in white skeletal muscle, which may reflect decreased energy …

Profiling Helper T Cell Subset Gene Expression In Deer Mice, Lauren Oko, Bethany Aduddell-Swope, Derall Willis, Robyn Hamor, Teresa A. Coons, Brian Hjelle

Biological Sciences Faculty Publications

BACKGROUND: Deer mice (Peromyscus maniculatus) are the most common mammals in North America and are reservoirs for several zoonotic agents, including Sin Nombre virus (SNV), the principal etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in North America. Unlike human HCPS patients, SNV-infected deer mice show no overt pathological symptoms, despite the presence of virus in the lungs. A neutralizing IgG antibody response occurs, but the virus establishes a persistent infection. Limitations of detailed analysis of deer mouse immune responses to SNV are the lack of reagents and methods for evaluating such responses.

RESULTS: We developed real-time PCR-based detection assays for …

Tracking Changes In Bioavailable Fe Within High-Nitrate Low-Chlorophyll Oceanic Waters: A First Estimate Using A Heterotrophic Bacterial Bioreporter, Robert Michael Mckay, C. E. Mioni, S. M. Handy, M. J. Ellwood, M. R. Twiss, P. W. Boyd, S. W. Wilhelm

Biological Sciences Faculty Publications

It is conventional knowledge that heterotrophic bacteria play a key role in the biogeochemical cycling of oceanic carbon. However, only recently has their role in marine iron ( Fe) biogeochemical cycles been examined. Research during this past decade has demonstrated an inextricable link between Fe chemistry and the biota, as >99% of Fe in marine systems is complexed to organic chelates of unknown but obviously biotic origin. Here we present a novel approach to assess and compare Fe bioavailability in low Fe HNLC waters using a bioluminescent bacterial reporter that quantitatively responds to the concentration of bioavailable Fe by producing …

Impact Of Phytoplankton On The Biogeochemical Cycling Of Iron In Subantarctic Waters Southeast Of New Zealand During Fecycle, Robert Michael Mckay, S. W. Wilhelm, J. Hall, D. A. Hutchins, M. M. D. Al-R Shaidat, C. E. Mioni, S. Pickmere, D. Porta, P. W. Boyd

Biological Sciences Faculty Publications

During austral summer 2003, we tracked a patch of surface water infused with the tracer sulfur hexafluoride, but without addition of Fe, through subantarctic waters over 10 days in order to characterize and quantify algal Fe pools and fluxes to construct a detailed biogeochemical budget. Nutrient profiles characterized this patch as a high-nitrate, low-silicic acid, low-chlorophyll (HNLSiLC) water mass deficient in dissolved Fe. The low Fe condition was confirmed by several approaches: shipboard iron enrichment experiments and physiological indices of Fe deficiency (F(v)/F(m) < 0.25, Ferredoxin Index < 0.2). During FeCycle, picophytoplankton (0.2-2 mu m) and nanophytoplankton (2-20 mu m) each contributed >40% of total chlorophyll. Whereas the picophytoplankton accounted for similar to 50% of total primary production, they …

Bartonella Bacilliformis Groel: Effect On Growth Of Human Vascular Endothelial Cells In Infected Cocultures, Laura S. Smitherman, Michael F. Minnick

Biological Sciences Faculty Publications

Bartonella are the only bacteria known to induce angioproliferative lesions of the human vasculature and liver during infection. Previous work from our lab suggests that GroEL participates in the mitogenic response observed in HUVEC cultures supplemented with the soluble fraction of Bartonella bacilliformis. Work in this study shows that exposure to high concentrations of the fraction is actually cytotoxic for HUVECs. To analyze this phenomenon, live B. bacilliformis-HUVEC cocultures were employed to study the effect of excess bacterial GroEL on the host cell during active infection. Four B. bacilliformis strains were generated to produce varying levels of GroEL. HUVEC cocultures …

Evolution Of Sexual Dimorphism And Male Dimorphism In The Expression Of Beetle Horns: Phylogenetic Evidence For Modularity, Evolutionary Lability, And Constraint, Douglas J. Emlen, John Hunt, Leigh W. Simmons

Biological Sciences Faculty Publications

Beetle horns are enlarged outgrowths of the head or thorax that are used as weapons in contests over access to mates. Horn development is typically confined to males (sexual dimorphism) and often only to the largest males (male dimorphism). Both types of dimorphism result from endocrine threshold mechanisms that coordinate cell proliferation near the end of the larval period. Here, we map the presence/absence of each type of dimorphism onto a recent phylogeny for the genus Onthophagits (Coleoptera: Scarabaeidae) to explore how horn development has changed over time. Our results provide empirical support for several recent predictions regarding the evolutionary …

Parc Mutations In Fluoroquinolone-Resistant Borrelia Burgdorfeti, Kendal M. Galbraith, Amanda C. Ng, Betsy J. Eggers, Craig R. Kuchel, Christian H. Eggers, D. Scott Samuels

Biological Sciences Faculty Publications

We have isolated in vitro fluoroquinolone-resistant mutants of the Lyme disease agent, Borrelia burgdorferi. Mutations in parC, which encodes a subunit of topoisomerase IV, were associated with loss of susceptibility to sparfloxacin, moxifloxacin, and Bay-Y3118, but not ciprofloxacin. This is the first description of fluoroquinolone resistance in the spirochete phylum.

Characterization And Expression Analysis Of The Groesl Operon Of Bartonella Bacilliformis, Julie A. Callison, James M. Battisti, Kate N. Sappington, Laura S. Smitherman, Michael F. Minnick

Biological Sciences Faculty Publications

The groESL operon of Bartonella bacilliformis, a facultative intracellular, Gram-negative bacterium and etiologic agent of Oroya Fever, was characterized. Sequence analysis revealed an operon containing two genes of 294 (groES) and 1632 nucleotides (groEL) separated by a 55-nt intergenic spacer. The operon is preceded by a 72-nt ORF (ORF1) that encodes a hypothetical protein with homology to a portion of the HrcA repressor for groESL. A divergent fumarate hydratase C (fumC) gene lies further upstream. Deduced amino acid sequences for B. bacilliformis GroEL and GroES revealed a high degree of identity with homologues from other Bartonella and alpha-Protebacteria. A single …