Digital Commons Network^™

Assessment Of Ecological Risks In Weed Biocontrol: Input From Retrospective Ecological Analyses, Svata M. Louda, Tatyana A. Rand, F. Leland Russell, Amy E. Arnett

School of Biological Sciences: Faculty Publications

Prediction of the outcomes of natural enemy introductions remains the most fundamental challenge in biological control. Quantitative retrospective analyses of ongoing biocontrol projects provide a systematic strategy to evaluate and further develop ecological risk assessment. In this review, we highlight a crucial assumption underlying a continued reliance on the host specificity paradigm as a quantitative prediction of ecological risk, summarize the status of our retrospective analyses of nontarget effects of two weevils used against exotic thistles in North America, and discuss our prospective assessment of risk to a federally listed, threatened species (Cirsium pitcheri) based on those studies. …

The Tree-Thinking Challenge, David A. Baum, Stacey Dewitt Smith, Samuel S.S. Donovan

School of Biological Sciences: Faculty Publications

The preferred interpretation of a phylogenetic tree is as a depiction of lines of descent. That is, trees communicate the evolutionary relationships among elements, such as genes or species, that connect a sample of branch tips. Under this interpretation, the nodes (branching points) on a tree are taken to correspond to actual biological entities that existed in the past: ancestral populations or ancestral genes. However, tree diagrams are also used in many nonevolutionary contexts, which can cause confusion. For example, trees can depict the clustering of genes on the basis of their expression profiles from microarrays, or the clustering of …

Rapid Senescence In Pacific Salmon, Yolanda E. Morbey, Chad Brassil, Andrew P. Hendry

School of Biological Sciences: Faculty Publications

Any useful evolutionary theory of senescence must be able to explain variation within and among natural populations and species. This requires a careful characterization of age-specific mortality rates in nature as well as the intrinsic and extrinsic factors that influence these rates. We perform this task for two populations of semelparous Pacific salmon. During the breeding season, estimated daily mortality rates increased from 0 to 0.2–0.5 (depending on the year) over the course of several weeks. Early-arriving individuals had a later onset and/or a lower rate of senescence in each breeding season, consistent with adaptive expectations based on temporal variation …

A Multi-Forest Comparison Of Dietary Preferences And Seed Dispersal By Ateles Spp., Sabrina E. Russo, Christina J. Campbell, J. Lawrence Dew, Pablo R. Stevenson, Scott A. Suarez

School of Biological Sciences: Faculty Publications

Investigations of coevolutionary relationships between plants and the animals that disperse their seeds suggest that disperser-plant interactions are likely shaped by diffuse, rather than species-to-species, coevolution. We studied the role of dietary plasticity in shaping the potential for diffuse coevolution by comparing dietary fruit preferences and seed dispersal by 3 species of spider monkeys (Ateles spp.) in 4 moist forests in Colombia, Ecuador, Panama, and Surinam. In all forests, spider monkeys were highly frugivorous and preyed upon seeds of few species. We estimated dietary use of fruiting taxa based on absolute consumption and preference, which accounts for resource availability. …

Radiative Neutron Β-Decay In Effective Field Theory, Susan Gardner, Véronique Bernard, Chi Zhang

School of Biological Sciences: Faculty Publications

We consider radiative β-decay of the neutron in heavy baryon chiral perturbation theory. Nucleon-structure effects not encoded in the weak coupling constants g_A and g_V are determined at next-to-leading order in the chiral expansion, and enter at the O(0.5%)-level, making a sensitive test of the Dirac structure of the weak currents possible.

The Effects Of Livestock On California Ground Squirrels (Spermophilus Beecheyii), Jeffrey S. Fehmi, Sabrina E. Russo, James W. Bartolome

School of Biological Sciences: Faculty Publications

Understanding the impacts of livestock grazing on wildlands is important for making appropriate ecosystem management decisions. Using livestock exclosures, we examined the effects of moderate cattle grazing on the abundance of California ground squirrels (Spermophilus beecheyii Richardson) and the spatial distribution of active burrows within their colonies in grassland and blue oak (Quercus douglasii Hook. & Arn.) savanna habitats in the coastal range of California over a 3-year period (1991– 1994). Overall, relative population densities of California ground squirrels declined significantly throughout the experiment, but did not differ between grazed and ungrazed colonies or between habitats. There was …

A Nontechnical Introduction To "Biocontrol As Usual": Review Of Ann Hajek, Natural Enemies, Svata M. Louda

School of Biological Sciences: Faculty Publications

Increasing recognition of the problems posed by invasive, exotic species has led to a recent upsurge of interest in the potential of biological control as a sustainable management strategy. The idea that ‘‘natural control’’ could be re-established on a species in its new environment is a seductive one, nurtured by a small set of impressive success stories and the belief in a simple solution (‘‘silver bullet’’). Yet, recent serendipitous discoveries also make it clear that attempts to engineer the outcome of species interactions in new systems can lead to undesired direct and indirect effects of unanticipated magnitude on non-targeted native …

Demographic And Evolutionary Impacts Of Native And Invasive Insect Herbivores On Cirsium Canescens, Karen E. Rose, Svata M. Louda, Mark Rees

School of Biological Sciences: Faculty Publications

Invasive species have the potential to alter trade-offs leading to selection in the populations they invade. Here we quantify the demographic and selective effects of herbivory by native insects and the introduced floral feeder Rhinocyllus conicus on Platte thistle (Cirsium canescens), a sparse monocarpic thistle endemic to North America. Rhinocyllus first invaded the Platte thistle population in 1993. Since then, its numbers have increased exponentially, while the Platte thistle population size has decreased. Data from 11 years were analyzed to determine how demographic rates varied with plant size and damage by native insects and Rhinocyllus. Individual growth, …

Microsatellite Dna Analysis Shows That Greater Sage Grouse Leks Are Not Kin Groups, Robert M. Gibson, Debra Pires, Kathleen S. Delaney, Robert K. Wayne

School of Biological Sciences: Faculty Publications

The spectacular social courtship displays of lekking birds are thought to evolve via sexual selection, but this view does not easily explain the participation of many males that apparently fail to mate. One of several proposed solutions to this ‘lek skew paradox’ is that kin selection favors low-ranking males joining leks to increase the fitness of closely related breeders. We investigated the potential for kin selection to operate in leks of the greater sage grouse, Centrocercus urophasianus, by estimating relatedness between lekking males using microsatellite DNA markers. We also calibrated these estimates using data from known families. Mean relatedness within …

Evaluation Of Ecological Risk To Populations Of A Threatened Plant From An Invasive Biocontrol Insect, Svata M. Louda, Tatyana A. Rand, Amy E. Arnett, A. S. Mcclay, K. Shea, A. Kathryn Mceachern

School of Biological Sciences: Faculty Publications

Controversy exists over estimation of ecological risk in biological control. At present, the risk to the rare, federally listed Pitcher’s thistle (Cirsium pitcheri) in North America from Rhinocyllus conicus, a biological control weevil now feeding on many native thistles, is unknown. We hypothesized that quantification of host specificity and potential phenological overlap between insect and plant would improve assessment of the magnitude of risk. In laboratory host specificity tests, we found no significant difference in R. conicus feeding or oviposition preference between the rare C. pitcheri and the targeted exotic weed (Carduus nutans) or between …

Homologous And Heterologous Reconstitution Of Golgi To Chloroplast Transport And Protein Import Into The Complex Chloroplasts Of Euglena, Silvia Sláviková, Rostislav Vacula, Zhiwei Fang, Tomoko Ehara, Tetsuaki Osafune, Steven D. Schwartzbach

School of Biological Sciences: Faculty Publications

Euglena complex chloroplasts evolved through secondary endosymbiosis between a phagotrophic trypanosome host and eukaryotic algal endosymbiont. Cytoplasmically synthesized chloroplast proteins are transported in vesicles as integral membrane proteins from the ER to the Golgi apparatus to the Euglena chloroplast. Euglena chloroplast preprotein pre-sequences contain a functional N-terminal ER-targeting signal peptide and a domain having characteristics of a higher plant chloroplast targeting transit peptide, which contains a hydrophobic stop-transfer membrane anchor sequence that anchors the precursor in the vesicle membrane. Pulse-chase subcellular fractionation studies showed that ³⁵S-labeled precursor to the light harvesting chlorophyll a/b binding protein accumulated in the Golgi …

Indirect Interaction Between Two Native Thistles Mediated By An Invasive Exotic Floral Herbivore, F. Leland Russell, Svata M. Louda

School of Biological Sciences: Faculty Publications

Spatial and temporal variation in insect floral herbivory is common and often important. Yet, the determinants of such variation remain incompletely understood. Using 12 years of flowering data and 4 years of biweekly insect counts, we evaluated four hypotheses to explain variation in damage by the Eurasian flower head weevil, Rhinocyllus conicus, to the native North American wavyleaf thistle, Cirsium undulatum. The four factors hypothesized to influence weevil impact were variations in climate, weevil abundance, phenological synchrony, and number of flower heads available, either on wavyleaf thistle or on the other co-occurring, acquired native host plant (Platte thistle, Cirsium …

First Record Of Drosophila Parthenogenetica And D. Neomorpha, Cardini Group, Heed, 1962 (Drosophila, Drosophilidae), In Brazil, Daniela Cristina De Toni, Jennifer A. Brisson, Paulo R. P. Hofmann, Marlucia Martins, Hope Hollocher

School of Biological Sciences: Faculty Publications

The cardini group of the Quinaria section of the genus Drosophila is composed of 16 Neotropical species. The two focal species of this report, Drosophila parthenogenetica and D. neomorpha, are included in this group, and are placed in the cardini subgroup with seven other species: D. polymorpha, D. cardinoides, D. cardini, D. neocardini, D. acutilabella, D. bedicheki and D. procardinoides (Heed and Krishnamurthy, 1959; Heed, 1962; Heed and Russell, 1971; Wilder et al., 2003). The group is characterized by medium-sized flies with a shiny thorax (Vilela et al., 2002). Different species of the group display different abdominal pigmentation patterns …

Abdominal Pigmentation Variation In Drosophila Polymorpha: Geographic Variation In The Trait, And Underlying Phylogeography, Jennifer A. Brisson, Daniela Cristina De Toni, Ian Duncan, Alan R. Templeton

School of Biological Sciences: Faculty Publications

Drosophila polymorpha is a widespread species that exhibits abdominal pigmentation variation throughout its range. To gain insight into this variation we combined phenotypic and genotypic data to test a series of nested hypotheses. First, we tested the null hypothesis that geographic variation in pigmentation is due to neutral factors. We used nested clade analysis to examine the distribution of haplotypes from a nuclear and a mitochrondrial locus. Restricted gene flow via isolation by distance, the primary inference of this phylogeographic analysis, was then used to generate and test the hypothesis of increasing average abdominal pigmentation difference with increasing geographic distance. …

Effects Of Endogenous Steroid Hormone Levels On Annual Survival In Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Samrrah A. Raouf, Linda C. Smith, John C. Wingfield

School of Biological Sciences: Faculty Publications

The hormone corticosterone is an important part of animals’ response to environmental stress, modulating short-term adaptive changes in behavior and physiology. The hormone testosterone is also critical, especially for males, in regulating the expression of sexual behavior and parental care. These hormones can have costly consequences, however, and within populations individuals show variation in endogenous levels of both corticosterone and testosterone. We studied how annual survival varied as a function of natural levels of these hormones in colonially breeding Cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, USA, in 2000–2003. We sampled hormone levels of birds caught at colonies …

Web-Based Toolkits For Topology Prediction Of Transmembrane Helical Proteins, Fold Recognition, Structure And Binding Scoring, Folding-Kinetics Analysis And Comparative Analysis Of Domain Combinations, Hongyi Zhou, Chi Zhang, Song Liu, Yaoqi Zhou

School of Biological Sciences: Faculty Publications

We have developed the following web servers for protein structural modeling and analysis at http:// theory.med.buffalo.edu: THUMBUP, UMDHMM^TMHP and TUPS, predictors of trans-membrane helical protein topology based on a mean-burial-propensity scale of amino acid residues (THUMBUP), hidden Markov model (UMDHMM^TMHP) and their combinations (TUPS); SPARKS 2.0 and SP3, two profile– profile alignment methods, that match input query sequence(s) to structural templates by integrating sequence profile with knowledge-based structural score (SPARKS 2.0) and structure-derived profile (SP³); DFIRE, a knowledge-based potential for scoring free energy of monomers (DMONOMER), loop conformations (DLOOP), mutant stability (DMUTANT) and binding affinity …

Linking Seed Fate To Natural Dispersal Patterns: Factors Affecting Predation And Scatter-Hoarding Of Virola Calophylla Seeds In Peru, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

Natural seed deposition patterns and their effects on post-dispersal seed fate are critical in tropical tree recruitment. Previous research showed that the key dispersal agent of the neotropical tree, Virola calophylla, is the spider monkey (Ateles paniscus). Spider monkeys generate a heterogeneous seed deposition pattern because they scatter-disperse seeds diurnally, whereas they clump-disperse seeds at their sleeping sites. The recruitment consequences of this pattern were investigated using manipulative experiments and observations. Scatter-hoarding by spiny rats (Proechimys spp.) caused little rearrangement of the initial seed deposition pattern because they moved seeds only short distances. Seed survival to …

Terrestrial Behavior Of Ateles Spp., Christina J. Campbell, Filippo Aureli, Colin A. Chapman, Gabriel Ramos-Fernández, Kim Matthews, Sabrina E. Russo, Scott Suarez, Laura Vick

School of Biological Sciences: Faculty Publications

Spider monkeys (Ateles spp.) are well known for their highly arboreal lifestyle, spending much of their time in the highest levels of the canopy and rarely venturing to the ground. To investigate terrestriality by Ateles and to illuminate the conditions under which spider monkeys venture to the ground, we analyzed ad libitum data from 5 study sites, covering 2 species and 5 subspecies. Three of the sites are in Central/North America: Barro Colorado Island (BCI), Panama (Ateles geoffroyi panamensis), Santa Rosa National Park, Costa Rica (A. g. frontatus), and Punta Laguna, Mexico (A. g. yucatanensis). The 2 remaining sites are …

Soil-Related Performance Variation And Distributions Of Tree Species In A Bornean Rain Forest, Sabrina E. Russo, Stuart J. Davies, David A. King, Sylvester Tan

School of Biological Sciences: Faculty Publications

1. Spatial distributions of tropical trees often correlate with environmental variation, suggesting that ecological sorting caused by niche differentiation may be important for maintaining species diversity.

2. Four soil types have been identified in a 52-ha forest dynamics plot in Bornean mixed dipterocarp forest (ranked by increasing fertility and moisture: sandy loam, loam, fine loam, and clay). The distributions of 73% of tree species in the plot are significantly aggregated on one of these soil types. We tested the hypothesis that variation in performance (growth and mortality) underlies these edaphically biased species distributions.

3. Annual growth and mortality rates over …

Methylation Patterns Of Histone H3 Lys 4, Lys 9 And Lys 27 In Transcriptionally Active And Inactive Arabidopsis Genes And In Atx1 Mutants, Raul Alvarez-Venegas, Zoya Avramova

School of Biological Sciences: Faculty Publications

Covalent modifications of histone-tail amino acid residues communicate information via a specific ‘histone code’. Here, we report histone H3-tail lysine methylation profiles of several Arabidopsis genes in correlation with their transcriptional activity and the input of the epigenetic factor ARABIDOPSIS HOMOLOGOF TRITHORAX (ATX1) at ATX1-regulated loci. By chromatin immunoprecipitation (ChIP) assays, we compared modification patterns of a constitutively expressed housekeeping gene, of a tissue-specific gene, and among genes that differed in degrees of transcriptional activity. Our results suggest that the di-methylated isoform of histone H3-lysine4 (m²K4/H3) provide a general mark for gene-related sequences distinguishing them from non-transcribed …

Testosterone And Group Size In Cliff Swallows: Testing The “Challenge Hypothesis” In A Colonial Bird, Linda C. Smith, Samrrah A. Raouf, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown

School of Biological Sciences: Faculty Publications

The “challenge hypothesis” states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, …

Between-Group Transmission Dynamics Of The Swallow Bug, Oeciacus Vicarius, Charles R. Brown, Mary Bomberger Brown

School of Biological Sciences: Faculty Publications

The parasitic cimicid swallow bug, Oeciacus vicarius, is the principal invertebrate vector for Buggy Creek virus (BCRV) and has also been associated with Venezuelan equine encephalitis virus. To help understand the spread of this vector, we experimentally measured the transmission of O. vicarius between groups (colonies) of its main host, the cliff swallow (Petrochelidon pyrrhonota), in the field. Transmission of bugs between colonies varied significantly with year, size of the colony, and week within the season. Bug immigration into sites tended to peak in mid-summer. Swallow nests in larger colonies had more consistent rates of bug introduction than …

Gene Set Coregulated By The Saccharomyces Cerevisiae Nonsense-Mediated Mrna Decay Pathway, Rachel Taylor, Bessie Wanja Kebaara, Tara Nazarenus, Ashley Jones, Rena Yamanaka, Rachel Uhrenholdt, Jason P. Wendler, Audrey L. Atkin

School of Biological Sciences: Faculty Publications

The nonsense-mediated mRNA decay (NMD) pathway has historically been thought of as an RNA surveillance system that degrades mRNAs with premature translation termination codons, but the NMD pathway of Saccharomyces cerevisiae has a second role regulating the decay of some wild-type mRNAs. In S. cerevisiae, a significant number of wild-type mRNAs are affected when NMD is inactivated. These mRNAs are either wild-type NMD substrates or mRNAs whose abundance increases as an indirect consequence of NMD. A current challenge is to sort the mRNAs that accumulate when NMD is inactivated into direct and indirect targets. We have developed a …

Characterization Of Different Crystal Forms Of The Α-Glucosidase Mala From Sulfolobus Solfataricus, Heidi Asschenfeldt Ernst, Martin Willemoës, Leila Lo Leggio, Gordon Leonard, Paul H. Blum, Sine Larsen

School of Biological Sciences: Faculty Publications

MalA is an _-glucosidase from the hyperthermophilic archaeon Sulfolobus

solfataricus. It belongs to glycoside hydrolase family 31, which includes several

medically interesting α-glucosidases. MalA and its selenomethionine derivative

have been overproduced in Escherichia coli and crystallized in four different

crystal forms. Microseeding was essential for the formation of good-quality

crystals of forms 2 and 4. For three of the crystal forms (2, 3 and 4) full data sets

could be collected. The most suitable crystals for structure determination are the

monoclinic form 4 crystals, belonging to space group P21, from which data sets

extending to 2.5 Å resolution …

Upf1p, A Highly Conserved Protein Required For Nonsense-Mediated Mrna Decay, Interacts With The Nuclear Pore Proteins Nup100p And Nup116p, Tara Nazarenus, Rebecca Cedarberg, Ryan Bell, Joseph Cheatle, Amanda Forch, Alexis Haifley, Ann Hou, Bessie Wanja Kebaara, Christina Shields, Kate Stoysich, Rachel Taylor, Audrey L. Atkin

School of Biological Sciences: Faculty Publications

Saccharomyces cerevisiae Upf1p is a 971-amino-acid protein that is required for the nonsense-mediated mRNA decay (NMD) pathway, a pathway that degrades mRNAs with premature translational termination codons. We have identified a two-hybrid interaction between Upf1p and the nuclear pore (Nup) proteins, Nup100p and Nup116p. Both nucleoporins predominantly localize to the cytoplasmic side of the nuclear pore and participate in mRNA transport. The two-hybrid interaction between Upf1p and the nuclear pore proteins, Nup100p and Nup116p, is dependent on the presence of the C-terminal 158 amino acids of Upf1p. Nup100p and Nup116p can be coimmunoprecipitated from whole-cell extracts with Upf1p, confirming in …