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Biology Faculty Publications and Presentations

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Articles 601 - 630 of 662

Full-Text Articles in Biology

Correlation Between Animal And Mathematical Models For Prostate Cancer Progression, Zdzislaw Jackiewiczy, Cheryl L. Jorcyk, Mikhail K. Kolev, Barbara Zubik-Kowal Feb 2009

Correlation Between Animal And Mathematical Models For Prostate Cancer Progression, Zdzislaw Jackiewiczy, Cheryl L. Jorcyk, Mikhail K. Kolev, Barbara Zubik-Kowal

Biology Faculty Publications and Presentations

This work demonstrates that prostate tumour progression in vivo can be analysed by using solutions of a mathematical model supplemented by initial conditions chosen according to growth rates of cell lines in vitro. The mathematical model is investigated and solved numerically. Its numerical solutions are compared with experimental data from animal models. The numerical results confirm the experimental results with the growth rates in vivo.


Caspase Cleavage Of The Amyloid Precursor Protein Is Prevented After Overexpression Of Bcl-2 In A Triple Transgenic Mouse Model Of Alzheimer’S Disease, Debra K. Kumasaka, Veronica Galvan, Elizabeth Head, Troy T. Rohn Jan 2009

Caspase Cleavage Of The Amyloid Precursor Protein Is Prevented After Overexpression Of Bcl-2 In A Triple Transgenic Mouse Model Of Alzheimer’S Disease, Debra K. Kumasaka, Veronica Galvan, Elizabeth Head, Troy T. Rohn

Biology Faculty Publications and Presentations

A recent study demonstrated the lack of beta-amyloid (Aβ) plaque formation and accumulation of the amyloid precursor protein (APP) in a triple transgenic mouse model of Alzheimer’s disease (3xTg-AD) following overexpression of the anti-apoptotic protein, Bcl-2 (Rohn et al., J. Neurosci. 28: 3051-9, 2008). The supposition from that study was the accumulation of APP resulted from a decrease in caspase-mediated processing of APP. To determine a direct role for the caspase-cleavage of APP in 3xTg-AD mice, we designed a site-directed caspasecleavage antibody to APP and demonstrated it is a specific marker for caspase-cleaved APP. Application of this antibody revealed neuronal …


Pathogenic Bacillus Anthracis In The Progressive Gene Losses And Gains In Adaptive Evolution, Gongxin Yu Jan 2009

Pathogenic Bacillus Anthracis In The Progressive Gene Losses And Gains In Adaptive Evolution, Gongxin Yu

Biology Faculty Publications and Presentations

Background: Sequence mutations represent a driving force of adaptive evolution in bacterial pathogens. It is especially evident in reductive genome evolution where bacteria underwent lifestyles shifting from a free-living to a strictly intracellular or host-depending life. It resulted in loss of function mutations and/or the acquisition of virulence gene clusters. Bacillus anthracis shares a common soil bacterial ancestor with its closely related bacillus species but is the only obligate, causative agent of inhalation anthrax within the genus Bacillus. The anthrax-causing Bacillus anthracis experienced the similar lifestyle changes. We thus hypothesized that the bacterial pathogen would follow a compatible evolution path. …


Caspase-Cleaved Tar Dna-Binding Protein-43 In Pick’S Disease, Troy T. Rohn, Polina Kokoulina Jan 2009

Caspase-Cleaved Tar Dna-Binding Protein-43 In Pick’S Disease, Troy T. Rohn, Polina Kokoulina

Biology Faculty Publications and Presentations

The hyperphosphorylation and proteolytic modification of the TAR DNA binding protein-43 (TDP-43) is a key finding in a number of neurodegenerative diseases including frontotemporal dementia with ubiquitin-positive inclusions (FTLD-U), amyotrophic lateral sclerosis (ALS), and most recently Alzheimer’s disease (AD). To examine whether proteolytic modifications of TDP-43 is a relevant finding in Pick’s disease, we utilized a novel site-directed caspase-cleavage antibody based upon a known caspase-3 cleavage consensus site within TDP-43 at position 219. Application of this antibody, termed TDP caspase-cleavage product (TDPccp) to postmortem Pick’s disease brain sections revealed the presence of caspase-cleaved TDP-43 in Pick and Hirano bodies predominantly …


An Exon-Based Comparative Variant Analysis Pipeline To Study The Scale And Role Of Frameshift And Nonsense Mutation In The Human-Chimpanzee Divergence, Gongxin Yu Jan 2009

An Exon-Based Comparative Variant Analysis Pipeline To Study The Scale And Role Of Frameshift And Nonsense Mutation In The Human-Chimpanzee Divergence, Gongxin Yu

Biology Faculty Publications and Presentations

Chimpanzees and humans are closely related but differ in many deadly human diseases and other characteristics in physiology, anatomy, and pathology. In spite of decades of extensive research, crucial questions about the molecular mechanisms behind the differences are yet to be understood. Here I report ExonVar, a novel computational pipeline for Exon-based human-chimpanzee comparative Variant analysis. The objective is to comparatively analyze mutations specifically those that caused the frameshift and nonsense mutations and to assess their scale and potential impacts on human-chimpanzee divergence. Genomewide analysis of human and chimpanzee exons with ExonVar identified a number of species-specific, …


Trichomycetes From Lentic And Lotic Aquatic Habitats In Ontario, Canada, D. B. Strongman, Merlin M. White Dec 2008

Trichomycetes From Lentic And Lotic Aquatic Habitats In Ontario, Canada, D. B. Strongman, Merlin M. White

Biology Faculty Publications and Presentations

Fungi and protists make up an ecological group, trichomycetes, that inhabit the guts of invertebrates, mostly aquatic insects. Trichomycetes are reported herein from arthropods collected in lotic habitats (fast flowing streams) and lentic environments (ponds, ditches, seeps, and lakes) from 11 sites in Algonquin Park and 6 other sites in Ontario, Canada. Thirty-two trichomycete species were recovered, including 7 new species: Legeriomyces algonquinensis, Legeriosimilis leptocerci, Legeriosimilis whitneyi and Paramoebidium umbonatum are described from mayfly nymphs (Ephemeroptera); Pennella digitata and Glotzia incilis from black fly and midge larvae (Diptera), respectively; and Arundinula opeongoensis from a crayfish (Crustacea). Legeriomyces rarus Lichtw. & …


Pseudomonas Aeruginosa Elastase Induces Il-8 Production In The Lung Cells Via The Epidermal Growth Factor/Extracellular Signal-Regulated Proteins/Nfîºb Pathway, Ali Azghani Nov 2008

Pseudomonas Aeruginosa Elastase Induces Il-8 Production In The Lung Cells Via The Epidermal Growth Factor/Extracellular Signal-Regulated Proteins/Nfîºb Pathway, Ali Azghani

Biology Faculty Publications and Presentations

Background: The induction of chemokine secretion by fibroblasts is crucial for the migration of leukocytes into the parenchyma of the injured lung. Several bacterial products activate the lung’s structural as well as immune cells to produce pro inflammatory cytokines and chemokines. We report that elastase from Pseudomonas aeruginosa (PE) evokes IL-8 mRNA expression and protein secretion in nonmalignant culture of human lung fibroblasts by activating the receptor for epidermal growth factor (EGFR) and downstream mitogen-activated protein kinases (MAPK) pathway. Methods: We utilized western blot analysis to detect phosphorylation of EGFR and signal transduction intermediates. Northern blot and ELISA analyses were …


Ambient Temperature Influences Diet Selection And Physiology Of An Herbivorous Mammal, Neotoma Albigula, M. D. Dearing, Jennifer S. Forbey, J. D. Mclister, L. Santos Oct 2008

Ambient Temperature Influences Diet Selection And Physiology Of An Herbivorous Mammal, Neotoma Albigula, M. D. Dearing, Jennifer S. Forbey, J. D. Mclister, L. Santos

Biology Faculty Publications and Presentations

The whitethroat woodrat (Neotoma albigula) eats juniper (Juniperus monosperma), but the amount of juniper in its diet varies seasonally. We tested whether changes in juniper consumption are due to changes in ambient temperature and what the physiological consequences of consuming plant secondary compounds (PSCs) at different ambient temperatures might be. Woodrats were acclimated to either 20ºC or 28ºC. Later, they were given two diets to choose from (50% juniper and a nontoxic control) for 7 d. Food intake, resting metabolic rate (RMR), and body temperature (Tb) were measured over the last 2 d. Woodrats at 28ºC …


Caspase-Cleaved Tar Dna Binding Protein-43 Is A Major Pathological Finding In Alzheimer’S Disease, Troy T. Rohn Sep 2008

Caspase-Cleaved Tar Dna Binding Protein-43 Is A Major Pathological Finding In Alzheimer’S Disease, Troy T. Rohn

Biology Faculty Publications and Presentations

The TAR DNA binding protein-43 (TDP-43) has been identified as a major constituent of inclusions found in frontotemporal dementia with ubiquitin-positive inclusions (FTLD-U) and amyotrophic lateral sclerosis (ALS). To determine a possible role for TDP-43 in Alzheimer’s disease (AD), a site-directed caspase-cleavage antibody to TDP-43 based upon a known caspase-3 cleavage consensus site within TDP-43 at position D219 was designed. In vitro, this antibody labeled the predicted 25 kDa caspase-cleavage fragment of TDP-43 without labeling full-length TDP-43 following digestion of recombinant TDP-43 with caspase-3 or treatment of Hela cells with staurosporine. Application of this antibody in postmortem brain sections …


Intrafeather And Intraindividual Variation In The Stable-Hydrogen Isotope (Δd) Content Of Raptor Feathers, Adam D. Smith, Kara Donohue, Alfred M. Dufty Jr. Aug 2008

Intrafeather And Intraindividual Variation In The Stable-Hydrogen Isotope (Δd) Content Of Raptor Feathers, Adam D. Smith, Kara Donohue, Alfred M. Dufty Jr.

Biology Faculty Publications and Presentations

Stable-hydrogen isotope ratios (deuterium:protium; δD) in feathers enable researchers to evaluate patterns of avian movement and to estimate the source areas of migratory birds. However, variation in feather δD remains inadequately described, thus confounding inferences of avian movement and origin. We assessed variation within a feather and among feathers within and between tracts in three species of immature raptors. Within contour feathers, measurements of δD increased from a distal section to an adjacent, proximal section; the magnitude of δD increase varied with raptor species. Furthermore, contour and flight feathers differed systematically in their δD content. Two explanations for intrafeather and …


Lack Of Pathology In A Triple Transgenic Mouse Model Of Alzheimer’S Disease After Overexpression Of The Anti-Apoptotic Protein Bcl-2, Troy T. Rohn, Veera Vyas, Tatiana Hernandez-Estrada, Kathryn E. Nichol, Lori-Ann Christie, Elizabeth Head Mar 2008

Lack Of Pathology In A Triple Transgenic Mouse Model Of Alzheimer’S Disease After Overexpression Of The Anti-Apoptotic Protein Bcl-2, Troy T. Rohn, Veera Vyas, Tatiana Hernandez-Estrada, Kathryn E. Nichol, Lori-Ann Christie, Elizabeth Head

Biology Faculty Publications and Presentations

Alzheimer’s disease (AD) is characterized by the accumulation of plaques containing ß-amyloid (Aß) and neurofibrillary tangles (NFTs) consisting of modified tau. Although Aß deposition is thought to precede the formation of NFTs in AD, the molecular steps connecting these two pathologies is not known. Previous studies have suggested that caspase activation plays an important role in promoting the pathology associated with AD. To further understand the contribution of caspases in disease progression, a triple transgenic Alzheimer’s mouse model overexpressing the anti-apoptotic protein Bcl-2 was generated. Here we show that overexpression of Bcl-2 limited caspase-9 activation and reduced the caspase cleavage …


Mapping Of Forest Alliances And Associations Using Fuzzy Systems And Nearest Neighbor Classifiers, F. Jack Triepke, C. Kenneth Brewer, Daniel M. Leavell, Stephen J. Novak Mar 2008

Mapping Of Forest Alliances And Associations Using Fuzzy Systems And Nearest Neighbor Classifiers, F. Jack Triepke, C. Kenneth Brewer, Daniel M. Leavell, Stephen J. Novak

Biology Faculty Publications and Presentations

The study and management of biological communities depends on systems of classification and mapping for the organization and communication of resource information. Recent advances in remote sensing technology may enable the mapping forest plant associations using image classification techniques. But few areas outside Europe have alliances and associations described in detail sufficient to support remote sensing-based modeling. Northwestern Montana has one of the few plant association treatments in the United States compliant with the recently established National Vegetation Classification system. This project examined the feasibility of mapping forest plant associations using Landsat Enhanced Thematic Mapper data and advanced remote sensing …


Stress Responsiveness In Nestlings: A Comparison Of Two Sampling Techniques, Alfred M. Dufty Jan 2008

Stress Responsiveness In Nestlings: A Comparison Of Two Sampling Techniques, Alfred M. Dufty

Biology Faculty Publications and Presentations

I compared the effects on plasma corticosterone levels of two methods of collecting blood samples during standardized capture and handling stress protocols. In one method, individual nestling American Kestrels (Falco sparverius) were bled at three time periods: when initially removed from the nest, and 15 and 30 min later. In the other method, siblings removed from a nest were bled once each, either at the time of removal, or 15 or 30 min later. I found that there was no difference between the two groups in plasma corticosterone levels at the first sampling period, but 15 and 30 min after …


Sporophytic Inbreeding Depression In Mosses Occurs In A Species With Separate Sexes But Not In A Species With Combined Sexes, Philip J. Taylor, Sarah M. Eppley, Linley K. Jesson Nov 2007

Sporophytic Inbreeding Depression In Mosses Occurs In A Species With Separate Sexes But Not In A Species With Combined Sexes, Philip J. Taylor, Sarah M. Eppley, Linley K. Jesson

Biology Faculty Publications and Presentations

Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reported on inbreeding depression in moss species. Here, we present data on the magnitude of inbreeding depression in sporophytic traits of moss species with contrasting breeding systems. In eratodon purpureus (Ditrichaceae), a moss species with separate sexes, self-fertilizations between sibling gametophytes (intergametophytic selfing) significantly reduced fitness in two of four traits quantified, with seta length and capsule length …


Present Effects Of Past Wildfires On The Diets Of Stream Fish, Peter Koetsier, Quenton Tuckett, Joshua White Jul 2007

Present Effects Of Past Wildfires On The Diets Of Stream Fish, Peter Koetsier, Quenton Tuckett, Joshua White

Biology Faculty Publications and Presentations

We investigated present indirect effects from a decade-old burn on the diets of stream fish. Based on soil instability and burn patterns from a 12–14-year-old wildfire complex, we separated 9 streams into 3 conditions: unburned, burned, and burned/scoured (i.e., experiencing a massive scour event 1 year post-burn). In the streams, we measured light levels and water temperatures, and we estimated fish density and biomass. We removed the digestive tracts from 9–15 rainbow trout (Oncorhynchus mykiss) from each stream and used a gravimetric procedure to analyze gut contents. Canopy cover development may dictate the composition of dietary items. Greater …


Lifetime Reproductive Success Of Female Eastern Kingbirds (Tyrannus Tyrannus): Influence Of Lifespan, Nest Predation And Body Size, Michael T. Murphy Jul 2007

Lifetime Reproductive Success Of Female Eastern Kingbirds (Tyrannus Tyrannus): Influence Of Lifespan, Nest Predation And Body Size, Michael T. Murphy

Biology Faculty Publications and Presentations

I report on the lifetime reproductive success (LRS) of female Eastern Kingbirds (Tyrannus tyrannus) in central New York. I investigated the major correlates of LRS and specifi cally tested the hypothesis that small body size yields reproductive benefi ts. Lifetime reproductive success varied widely: 15–20% of females failed to fledge young over their life, whereas 50% of young were fledged by 20% of females. Female lifespan varied between one and eight years, and females that died after one breeding season tended to be smaller-bodied than long-lived females (≥2 seasons). I therefore conducted analyses of LRS for the entire sample and …


A Versatile Computational Pipeline For Bacterial Genome Annotation Improvement And Comparative Analysis, With Brucella As A Use Case, Gongxin Yu, Eric E. Snyder, Stephen M. Boyle, Oswald R. Crasta, Michael Czar, Shrinivasrao P. Mane, Anjan Purkayastha, Bruno Sobral, João C. Setubal Jun 2007

A Versatile Computational Pipeline For Bacterial Genome Annotation Improvement And Comparative Analysis, With Brucella As A Use Case, Gongxin Yu, Eric E. Snyder, Stephen M. Boyle, Oswald R. Crasta, Michael Czar, Shrinivasrao P. Mane, Anjan Purkayastha, Bruno Sobral, João C. Setubal

Biology Faculty Publications and Presentations

We present a bacterial genome computational analysis pipeline, called GenVar. The pipeline, based on the program GeneWise, is designed to analyze an annotated genome and automatically identify missed gene calls and sequence variants such as genes with disrupted reading frames (split genes) and those with insertions and deletions (indels). For a given genome to be analyzed, GenVar relies on a database containing closely related genomes (such as other species or strains) as well as a few additional reference genomes. GenVar also helps identify gene disruptions probably caused by sequencing errors. We exemplify GenVar’s capabilities by presenting results from the analysis …


Spiders Fluoresce Variably Across Many Taxa, Kindra Andrews, Scott M. Reed, Susan E. Masta Apr 2007

Spiders Fluoresce Variably Across Many Taxa, Kindra Andrews, Scott M. Reed, Susan E. Masta

Biology Faculty Publications and Presentations

The evolution of fluorescence is largely unexplored, despite the newfound occurrence of this phenomenon in a variety of organisms. We document that spiders fluoresce under ultraviolet illumination, and find that the expression of this trait varies greatly among taxa in this species-rich group. All spiders we examined possess fluorophores in their haemolymph, but bright fluorescence appears to result when a spider sequesters fluorophores in its setae or cuticle. By sampling widely across spider taxa, we determine that fluorescent expression is labile and has evolved multiple times. Moreover, examination of the excitation and emission properties of extracted fluorophores reveals that spiders …


A Cautionary Tale: Cryptic Sexual Size Dimorphism In A Socially Monogamous Passerine, Michael T. Murphy Apr 2007

A Cautionary Tale: Cryptic Sexual Size Dimorphism In A Socially Monogamous Passerine, Michael T. Murphy

Biology Faculty Publications and Presentations

Among socially monogamous birds, standard metrics suggest that males are only ∼5% larger than females. An untested assumption is that, with the exception of reproductive systems, males and females are scaled mirror images of one another. I used external morphological and skeletal data, and information on muscle mass and organ size, to test this assumption in a population of breeding Eastern Kingbirds (Tyrannus tyrannus). Male and female Eastern Kingbirds exhibited no differences in body mass or standard measures of size, except in a longer (∼6%) wing chord and tail in males. However, keel length, a character rarely measured …


Nest Reuse By Eastern Kingbirds: Adaptive Behavior Or Ecological Constraint?, Lucas J. Redmond, Michael T. Murphy, Amy C. Dolan Jan 2007

Nest Reuse By Eastern Kingbirds: Adaptive Behavior Or Ecological Constraint?, Lucas J. Redmond, Michael T. Murphy, Amy C. Dolan

Biology Faculty Publications and Presentations

The reuse of old nests by open-cup nesting passerines is a seemingly rare but potentially adaptive behavior if, as a consequence, females begin to breed earlier, lay larger clutches, or fledge more young. We report an unusually high rate of nest reuse (~10% of 341 nests) for Eastern Kingbirds (Tyrannus tyrannus) breeding at Malheur National Wildlife Refuge, Oregon. We found no difference in availability of nesting habitat or food abundance in territories in which nests were and were not reused. We also found no support for the hypotheses that kingbirds benefited from nest reuse by breeding earlier, laying …


Patric: The Vbi Pathosystems Resource Integration Center, Gongxin Yu Dec 2006

Patric: The Vbi Pathosystems Resource Integration Center, Gongxin Yu

Biology Faculty Publications and Presentations

The PathoSystems Resource Integration Center (PATRIC) is one of eight Bioinformatics Resource Centers (BRCs) funded by the National Institute of Allergy and Infection Diseases (NIAID) to create a data and analysis resource for selected NIAID priority pathogens, specifically proteobacteria of the genera Brucella, Rickettsia and Coxiella, and corona-, caliciand lyssaviruses and viruses associated with hepatitis A and E. The goal of the project is to provide a comprehensive bioinformatics resource for these pathogens, including consistently annotated genome, proteome and metabolic pathway data to facilitate research into counter-measures, including drugs, vaccines and diagnostics. The project’s curation strategy has three …


Mechanism Of Enhanced Activity Of Liposome-Entrapped Aminoglycosides Against Resistant Strains Of Pseudomonas Aeruginosa, Clement Mugabe, Majed Halwani, Ali Azghani, Robert M. Lafrenie, Abdelwahab Omri Apr 2006

Mechanism Of Enhanced Activity Of Liposome-Entrapped Aminoglycosides Against Resistant Strains Of Pseudomonas Aeruginosa, Clement Mugabe, Majed Halwani, Ali Azghani, Robert M. Lafrenie, Abdelwahab Omri

Biology Faculty Publications and Presentations

Pseudomonas aeruginosa is inherently resistant to most conventional antibiotics. The mechanism of resistance of this bacterium is mainly associated with the low permeability of its outer membrane to these agents. We sought to assess the bactericidal efficacy of liposome-entrapped aminoglycosides against resistant clinical strains of P. aeruginosa and to define the mechanism of liposome-bacterium interactions. Aminoglycosides were incorporated into liposomes, and the bactericidal efficacies of both free and liposomal drugs were evaluated. To define the mechanism of liposome-bacterium interactions, transmission electron microscopy (TEM), flow cytometry, lipid mixing assay, and immunocytochemistry were employed. Encapsulation of aminoglycosides into liposomes significantly increased their …


Sex Determination Of Red-Tailed Hawks (Buteo Jamaicensis Calurus) Using Dna Analysis And Morphometrics, Kara C. Donohue, Alfred M. Dufty Jr. Feb 2006

Sex Determination Of Red-Tailed Hawks (Buteo Jamaicensis Calurus) Using Dna Analysis And Morphometrics, Kara C. Donohue, Alfred M. Dufty Jr.

Biology Faculty Publications and Presentations

Currently the sex of Red-tailed hawks (Buteo jamaicensis) cannot be determined by in-hand methods. Males and females do not differ in plumage and overlap in size. During migration, we collected feather samples and morphological measurements from birds at four sites in the Western United States. Sex was determined for individual birds using sex-specific DNA markers and Polymerase Chain Reaction was used to identify these DNA markers. Through Discriminant Function Analysis, we created equations for determining the sex of Red-tailed hawks using in-hand measurements based on the DNA-determined sexes. We formed two equations, one for adults, which was 98% …


Cultivation Of Methanogens From Shallow Marine Sediments At Hydrate Ridge, Orego, Melissa Kendall, David R. Boone Jan 2006

Cultivation Of Methanogens From Shallow Marine Sediments At Hydrate Ridge, Orego, Melissa Kendall, David R. Boone

Biology Faculty Publications and Presentations

Little is known about the methanogenic degradation of acetate, the fate of molecular hydrogen and formate or the ability of methanogens to grow and produce methane in cold, anoxic marine sediments. The microbes that produce methane were examined in permanently cold, anoxic marine sediments at Hydrate Ridge (44°35' N, 125°10' W, depth 800 m). Sediment samples (15 to 35 cm deep) were collected from areas of active methane ebullition or areas where methane hydrates occurred. The samples were diluted into enrichment medium with formate, acetate or trimethylamine as catabolic substrate. After 2 years of incubation at 4 °C to 15 …


Contributions Of Heterosis And Epistasis To Hybrid Fitness, Mitchell B. Cruzan Nov 2005

Contributions Of Heterosis And Epistasis To Hybrid Fitness, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

Early-generation hybrid fitness is difficult to interpret because heterosis can obscure the effects of hybrid breakdown. We used controlled reciprocal crosses and common garden experiments to distinguish between effects of heterosis and nuclear and cytonuclear epistasis among morphotypes and advanced-generation hybrid derivative populations in the Piriqueta caroliniana (Turneraceae) plant complex. Seed germination, growth, and sexual reproduction of first-generation hybrids, inbred parental lines, and outbred parental lines were compared under field conditions. Average vegetative performance was greater for hybrids than for inbred lines, and firstseason growth was similar for hybrids and outbred parental lines. Hybrid survival surpassed that of inbred lines …


Patterns Of Fitness And Fluctuating Asymmetry Across A Broad Hybrid Zone, Mitchell B. Cruzan Nov 2004

Patterns Of Fitness And Fluctuating Asymmetry Across A Broad Hybrid Zone, Mitchell B. Cruzan

Biology Faculty Publications and Presentations

We estimated levels of developmental instability in leaves, as indicated by fluctuating asymmetry (i.e., random deviations from perfect bilateral symmetry), across a broad hybrid zone between two taxa in the Piriqueta caroliniana complex. Previous studies have indicated that this hybrid zone was initiated in southern Florida and has expanded northward. We found that plants from the hybrid zone generally had higher levels of leaf developmental instability than plants from allopatric regions, but the increase in asymmetry was not substantial. Although it is usually assumed that developmental instability is associated with lower fitness, these Piriqueta hybrids from central Florida are similar …


Importance Of Outcrossing For Fruit Production In Slickspot Peppergrass, Lepidium Papilliferum L. (Brassicaceae), Ian Robertson Apr 2004

Importance Of Outcrossing For Fruit Production In Slickspot Peppergrass, Lepidium Papilliferum L. (Brassicaceae), Ian Robertson

Biology Faculty Publications and Presentations

Plants with insect-mediated pollination are often assumed to be obligate outcrossers; i.e., pollen must be supplied from flowers of other individuals for pollination and subsequent fruit production. Indeed, many flowers with insect-mediated pollination exhibit incompatibility to their own pollen or have a separation in time between pollen production and maturation of the stigma on a given flower (Proctor et al. 1996). However, because the breeding systems of plants are diverse and include varying levels of outcrossing and selfing, experiments are required to determine whether pollination in a particular species occurs via outcrossing, self-pollination, or both. Here I report the results …


Wing Shape In House Finches Differs Relative To Migratory Habit In Eastern And Western North America, Jeremy R. Egbert, James R. Belthoff Nov 2003

Wing Shape In House Finches Differs Relative To Migratory Habit In Eastern And Western North America, Jeremy R. Egbert, James R. Belthoff

Biology Faculty Publications and Presentations

We investigated whether wing morphology differed between the sedentary House Finches (Carpodacus mexicanus) of western North America and the introduced population of eastern North America, as the latter has developed migratory behavior since its inception. Wing morphology differed between eastern and western House Finches. Eastern House Finches had shorter proximal primaries and a longer outer primary, perhaps reflecting a thinner and more pointed wing, although no disparity in wing length was detected. Since we interpret these differences in wing shape as modifications for flight capability, we believe that initial evidence for morphological divergence relative to migratory habit between eastern and …


The Hyperthermophilic Archaeon Sulfolobus: From Exploration To Exploitation, Stan J.J. Brouns, Thijs J.G. Ettema, Kenneth M. Stedman, Jasper Walther, Hauke Smith, Ambrosius P.L. Snijders, Mark Young, Rolf Bernander, Phillip C. Wright, Betina Siebers, John Van Der Oost Oct 2003

The Hyperthermophilic Archaeon Sulfolobus: From Exploration To Exploitation, Stan J.J. Brouns, Thijs J.G. Ettema, Kenneth M. Stedman, Jasper Walther, Hauke Smith, Ambrosius P.L. Snijders, Mark Young, Rolf Bernander, Phillip C. Wright, Betina Siebers, John Van Der Oost

Biology Faculty Publications and Presentations

In the early 1970s, Sulfolobus was first isolated by Thomas Brock and co-workers from sulfur-rich acidic hot springs in Yellowstone National Park. Sulfolobus became one of the model organisms of Archaea in general, and of Crenarchaea in particular. Many of its unusual physiological characteristics have been investigated, and several of its thermostable enzymes have been studied in considerable detail. For fundamental reasons, and because of its potential for industrial applications, Sulfolobus has been selected for a genome sequence project. The recent completion of the Sulfolobus solfataricus genome has set the stage for a series of postgenome research lines that will …


Insect-Mediated Pollination In Slickspot Peppergrass, Lepidium Papilliferum L. (Brassicaceae), And Its Implications For Population Viability, Ian Robertson, Danielle Klemash Jul 2003

Insect-Mediated Pollination In Slickspot Peppergrass, Lepidium Papilliferum L. (Brassicaceae), And Its Implications For Population Viability, Ian Robertson, Danielle Klemash

Biology Faculty Publications and Presentations

Field experiments on the pollination biology of slickspot peppergrass, Lepidium papilliferum L. (Brassicaceae), a rare species endemic to microsites in sagebrush-steppe habitat in southwestern Idaho, were conducted at 2 sites from May to July 2001. Site KB contained over 10,000 plants, whereas site WG contained less than 150 plants. Insect exclusion experiments revealed that seed production in L. papilliferum is dependent on insect-mediated pollination; median percent seed set dropped from 70% to 2% when insects were excluded from flowers. A total of 25 insect families from 5 orders visited L. papilliferum flowers: 24 families at KB and 11 families at …