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Assessing Patterns Of Hybridization And Multiple Mechanisms Of Reproductive Isolation Between Erythronium Albidum And Its Congener E. Mesochoreum, Kathy Roccaforte

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

Although there are approximately 250,000 extant angiosperm species, we still have much to learn about the speciation process, including the ways in which species boundaries are maintained among closely related taxa. Species are formed when populations become reproductively isolated from each other via genetic and morphological barriers that act before hybrid formation (prezygotic) or after hybrids are formed (postzygotic).

Erythronium albidum Nutt. and Erythronium mesochoreum Knerr (Liliaceae) differ in ploidy, are likely sister species, and have been reported to hybridize, making them well-suited for assessing the strength of multiple reproductive barriers. First, I assessed the frequency of hybrid occurrence at …

Pseudoscorpion Mitochondria Show Rearranged Genes And Genome-Wide Reductions Of Rna Gene Sizes And Inferred Structures, Yet Typical Nucleotide Composition Bias, Sergey Ovchinnikov, Susan E. Masta

Biology Faculty Publications and Presentations

Pseudoscorpions are chelicerates and have historically been viewed as being most closely related to solifuges, harvestmen, and scorpions. No mitochondrial genomes of pseudoscorpions have been published, but the mitochondrial genomes of some lineages of Chelicerata possess unusual features, including short rRNA genes and tRNA genes that lack sequence to encode arms of the canonical cloverleaf-shaped tRNA. Additionally, some chelicerates possess an atypical guanine-thymine nucleotide bias on the major coding strand of their mitochondrial genomes.

We sequenced the mitochondrial genomes of two divergent taxa from the chelicerate order Pseudoscorpiones. We find that these genomes possess unusually short tRNA genes that do …

Effects Of The Manipulation Of Aboveground Plant Diversity In Restoration Management On The Diversity Of Belowground Arthropod Assemblage, Claire E. Gilmore

College of Science and Health Theses and Dissertations

A missing element in restoring belowground soil systems to a relatively healthy state may lie in promoting microarthropod diversity. By contributing to healthy nutrient cycling and assisting in the breakdown of leaf litter a diverse microarthropod population helps improve the overall soil quality. My study evaluated how current restoration practices aimed at maintaining aboveground diversity affects belowground microarthropod populations. I examined how the aboveground manipulation of plant diversity in restoration management practices affects the hyperdiverse assemblage of belowground arthropod communities. Additionally, I examined the relationship between soil nutrient content and microarthropod diversity. This study was conducted within the boundaries of …

Computer Simulation And Mathematical Models Of The Noncentrosomal Plant Cortical Microtubule Cytoskeleton, Ezgi Can Eren, Natarajan Gautam, Ram Dixit

Biology Faculty Research

There is rising interest in modeling the noncentrosomal cortical microtubule cytoskeleton of plant cells, particularly its organization into ordered arrays and the mechanisms that facilitate this organization. In this review, we discuss quantitative models of this highly complex and dynamic structure both at a cellular and molecular level. We report differences in methodologies and assumptions of different models as well as their controversial results. Our review provides insights for future studies to resolve these controversies, in addition to underlining the common results between various models. We also highlight the need to compare the results from simulation and mathematical models with …

The Chicken Challenge – What Contemporary Studies Of Fowl Mean For Science And Ethics, Carolynn L. Smith, Jane Johnson

Between the Species

Studies with captive fowl have revealed that they possess greater cognitive capacities than previously thought. We now know that fowl have sophisticated cognitive and communicative skills, which had hitherto been associated only with certain primates. Several theories have been advanced to explain the evolution of such complex behavior. Central to these theories is the enlargement of the brain in species with greater mental capacities. Fowl present us with a conundrum, however, because they show the behaviors anticipated by the theories but do not have the expected changes in the brain. Consequently fowl present two challenges of interest to us here. …

A Putative P-Type Atpase Required For Virulence And Resistance To Haem Toxicity In Listeria Monocytogenes, Rosemary Rea, Roy D. Sleator, Et. Al.

Department of Biological Sciences Publications

Regulation of iron homeostasis in many pathogens is principally mediated by the ferric uptake regulator, Fur. Since acquisition of iron from the host is essential for the intracellular pathogen Listeria monocytogenes, we predicted the existence of Fur-regulated systems that support infection. We examined the contribution of nine Fur-regulated loci to the pathogenicity of L. monocytogenes in a murine model of infection. While mutating the majority of the genes failed to affect virulence, three mutants exhibited a significantly compromised virulence potential. Most striking was the role of the membrane protein we designate FrvA (Fur regulated virulence factor A; encoded by …

Overexpression Of Fatty Acid Amide Hydrolase Induces Early Flowering In Arabidopsis Thaliana, Neal D. Teaster, Jantana Keereetaweep, Aruna Kilaru, Yuh-Shuh Wang, Yuhong Tang, Christopher N.-Q. Tran, Brian G. Ayre, Kent D. Chapman, Elison B. Blancaflor

ETSU Faculty Works

N-Acylethanolamines (NAEs) are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE). In animal systems this reaction is part of the “endocannabinoid” signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH), which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440) lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA), enhanced …

Matrix Metalloproteinase Genes Are Transcriptionally Regulated By E2f Transcription Factors: A Link Between Cell Cycle Control And Metastatic Progression, Jacqueline Lea Johnson

USF Tampa Graduate Theses and Dissertations

The RbµE2F transcriptional regulatory pathway plays a critical role in the cell cycle. Rb is inactivated through multiple waves of phosphorylation, mediated mainly by cyclin D and cyclin E associated kinases. Once Rb is inactivated, cells can enter Sµphase. Collectively, three Rb family members and ten E2F proteins coordinate every additional stage of the cell cycle, from quiescence to mitosis. However the RbµE2F pathway is frequently altered in cancer. Aside from cell proliferation, the RbµE2F pathway regulates other essential cellular processes including apoptosis, cell differentiation, angiogenesis and DNA damage repair pathways, but its role in invasion and cancer progression is …

Evolution Of Plant Sucrose Uptake Transporters, Anke Reinders, Alicia B. Sivitz, John M. Ward

Dartmouth Scholarship

In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were …

Characterization Of Aquaporin 4 Protein Expression And Localization In Tissues Of The Dogfish (Squalus Acanthias), Christopher P. Cutler, Sheena Harmon, Jonathan Walsh, Kia Burch

Biology: Faculty Publications

The role of aquaporin water channels such as aquaporin 4 (Aqp4) in elasmobranchs such as the dogfish Squalus acanthias is completely unknown. This investigation set out to determine the expression and cellular and sub-cellular localization of Aqp4 protein in dogfish tissues. Two polyclonal antibodies were generated (AQP4/1 and AQP4/2) and these showed somewhat different characteristics in Western blotting and immunohistochemistry. Western blots using the AQP4/1 antibody showed two bands (35.5 and 49.5 kDa) in most tissues in a similar fashion to mammals. Liver had an additional band of 57 kDa and rectal gland two further faint bands of 37.5 and …

University Of South Florida St. Petersburg Student Research Journal, Vol. 1, Issue 1, Article 5 : Geometric Probability Of Mating Success For The Greater Short-Nosed Fruit Bat, Cynopterus Sphinx, Krista Ford, Leon Hardy, Deby L. Cassill

USF St. Petersburg Campus Faculty Publications

In the bat Cynopterus sphinx, the random probability of mating success was calculated to be 4%. A combination of several adaptations dramatically increases their mating success to nearly 100%. First, the male and female hang upside down in a front-to-back mount. From behind, the male positions his penis dorsoventral toward the female's genitalia. The male maintains a tight hold on the female by biting the scruff on her neck and by holding her wings with his thumbs, allowing the pair to move forwards and backwards uninterruptedly and rhythmically. The male inserts the glans of his penis while the female bends …

Foraging Alters Resilience/Vulnerability To Sleep Disruption And Starvation In Drosophila, Jeffrey Donlea, Averi Leahy, Matthew S. Thimgan, Yasuko Suzuki, Bryon N. Hughson, Marla B. Sokolowski, Paul J. Shaw

Biological Sciences Faculty Research & Creative Works

Recent human studies suggest that genetic polymorphisms allow an individual to maintain optimal cognitive functioning during sleep deprivation. If such polymorphisms were not associated with additional costs, selective pressures would allow these alleles to spread through the population such that an evolutionary alternative to sleep would emerge. To determine whether there are indeed costs associated with resiliency to sleep loss, we challenged natural allelic variants of the foraging gene (for) with either sleep deprivation or starvation. Flies with high levels of Protein Kinase G (PKG) (for^R) do not display deficits in short-term memory following 12 …

Dobzhansky's Dictum: An Object Lesson For Critical Thinking, William D. Stansfield

Biological Sciences

A creationist has called Dobzhansky's dictum a myth. Discussion of this debate could be used as an object lesson for critical thinking.

Inhibitors Of Membranous Adenylyl Cyclases, Roland Seifert, Gerald H. Lushington, Tung-Chung Mou, Andreas Gille, Stephen R. Sprang

Biological Sciences Faculty Publications

Membranous adenylyl cyclases (mACs) constitute a family of nine isoforms with different expression patterns. Studies with mAC gene knockout mice provide evidence for the notion that AC isoforms play distinct (patho)physiological roles. Consequently, there is substantial interest in the development of isoform-selective mAC inhibitors. Here, we review the current literature on mAC inhibitors. Structurally diverse inhibitors targeting the catalytic site and allosteric sites (e.g. the diterpene site) have been identified. The catalytic site of mACs accommodates both purine and pyrimidine nucleotides, with a hydrophobic pocket constituting a major affinity-conferring domain for substituents at the 2'- and 3'-O-ribosyl position of nucleotides. …

Predicting The Physiological Performance Of Ectotherms In Fluctuating Thermal Environments, Michael W. Sears, A C. Niehaus, M J. Angilletta, C E. Franklin, R S. Wilson

Publications

Physiological ecologists have long sought to understand the plasticity of organisms in environments that vary widely among years, seasons and even hours. This is now even more important because human-induced climate change is predicted to affect both the mean and variability of the thermal environment. Although environmental change occurs ubiquitously, relatively few researchers have studied the effects of fluctuating environments on the performance of developing organisms. Even fewer have tried to validate a framework for predicting performance in fluctuating environments. Here, we determined whether reaction norms based on performance at constant temperatures (18, 22, 26, 30 and 34°C) could be …

Pten Regulation Of Local And Long-Range Connections In Mouse Auditory Cortex, Qiaojie Xiong, Hysell V. Oviedo, Lloyd C. Trotman, Anthony M. Zador

Publications and Research

Autism spectrum disorders (ASDs) are highly heritable developmental disorders caused by a heterogeneous collection of genetic lesions. Here we use a mouse model to study the effect on cortical connectivity of disrupting the ASD candidate gene PTEN (phosphatase and tensin homolog deleted on chromosome 10). Through Cre-mediated recombination, we conditionally knocked out PTEN expression in a subset of auditory cortical neurons. Analysis of long-range connectivity using channelrhodopsin-2 revealed that the strength of synaptic inputs from both the contralateral auditory cortex and from the thalamus onto PTEN-cko neurons was enhanced compared with nearby neurons with normal PTEN expression. Laser-scanning photostimulation showed …

Distribution, Population Size, And Structure Of Himalayan Grey Goral Naemorhedus Goral Bedfordi (Cetartiodactyla: Bovidae) In Pakistan, Fakhar -I- Abbas, Kathreen E. Ruckstuhl, Afsar Mian, Tanveer Akhtar, Thomas P. Rooney

Biological Sciences Faculty Publications

Himalayan grey goral (Naemorhedus goral bedfordi) is a Red List (Near Threatened) member of Caprinae endemic to Asia, occupying the south-facing slopes of the Himalaya Mountains. The species is listed as Vulnerable on the National Pakistan Red List, but the distribution and abundance of the species within the nation is poorly known. We conducted a national census of Himalayan grey goral in Pakistan during 2002 – 2004, with the objective of documenting the geographic locations of populations, estimating population size, and describing group sizes and sex ratios. We conducted a direct count census in 98 sites distributed over …

Environmentally Realistic Exposure To The Herbicide Atrazine Alters Some Sexually Selected Traits In Male Guppies, Kausalya Shenoy

Biology Faculty Publications

Male mating signals, including ornaments and courtship displays, and other sexually selected traits, like male-male aggression, are largely controlled by sex hormones. Environmental pollutants, notably endocrine disrupting compounds, can interfere with the proper functioning of hormones, thereby impacting the expression of hormonally regulated traits. Atrazine, one of the most widely used herbicides, can alter sex hormone levels in exposed animals. I tested the effects of environmentally relevant atrazine exposures on mating signals and behaviors in male guppies, a sexually dimorphic freshwater fish. Prolonged atrazine exposure reduced the expression of two honest signals: the area of orange spots (ornaments) and the …

The Giant Danio (D. Aequipinnatus) As A Model Of Cardiac Remodeling And Regeneration, Pascal J. Lafontant, Jamie A. Grivas, Mary A. Lesch, Lala Tanmoy Das, Tyler D. Frounfelter

Biology Faculty publications

The paucity of mammalian adult cardiac myocytes (CM) proliferation following myocardial infarction (MI) and the remodeling of the necrotic tissue that ensues, result in non-regenerative repair. In contrast, zebrafish (ZF) can regenerate after an apical resection or cryoinjury of the heart. There is considerable interest in models where regeneration proceeds in the presence of necrotic tissue. We have developed and characterized a cautery injury model in the giant danio (GD), a species closely related to ZF, where necrotic tissue remains part of the ventricle, yet regeneration occurs. By light and transmission electron microscopy (TEM), we have documented four temporally overlapping …

Two New Species Of Trigonotylus (Hemiptera: Heteroptera: Miridae: Stenodemini) From Western Canada And Northwestern United States, G G.E. Scudder, Michael D. Schwartz

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Time Of Day Regulates Subcellular Trafficking, Tripartite Synaptic Localization, And Polyadenylation Of The Astrocytic Fabp7 Mrna, Jason R. Gerstner, William M. Vanderheyden, Timothy Lavaute, Cara J. Westmark, Labib Rouhana, Allan I. Pack, Marvin Wickens, Charles F. Landry

Biological Sciences Faculty Publications

The astrocyte brain fatty acid binding protein (Fabp7) has previously been shown to have a coordinated diurnal regulation of mRNA and protein throughout mouse brain, and an age-dependent decline in protein expression within synaptoneurosomal fractions. Mechanisms that control time-of-day changes in expression and trafficking Fabp7 to the perisynaptic process are not known. In this study, we confirmed an enrichment of Fabp7 mRNA and protein in the astrocytic perisynaptic compartment, and observed a diurnal change in the intracellular distribution of Fabp7 mRNA in molecular layers of hippocampus. Northern blotting revealed a coordinated time-of-day-dependent oscillation for the Fabp7 mRNA poly(A) tail throughout …

Expression Of 14-3-3 Protein Isoforms In Mouse Oocytes, Eggs And Ovarian Follicular Development, Santanu De, Jennifer Marcinkiewicz, Srinivasan Vijayaraghavan, Douglas Kline

Biology Faculty Articles

Background

The 14-3-3 (YWHA) proteins are a highly conserved, ubiquitously expressed family of proteins. Seven mammalian isoforms of 14-3-3 are known (β, γ, ε, ζ, η, τ and, σ). These proteins associate with many intracellular proteins involved in a variety of cellular processes including regulation of the cell cycle, metabolism and protein trafficking. We are particularly interested in the role of 14-3-3 in meiosis in mammalian eggs and the role 14-3-3 proteins may play in ovarian function. Therefore, we examined the expression of 14-3-3 proteins in mouse oocyte and egg extracts by Western blotting after polyacrylamide gel electrophoresis, viewed fixed …

Effect Of Wine And Vinegar Processing Of Rhizoma Corydalis On The Tissue Distribution Of Tetrahydropalmatine, Protopine And Dehydrocorydaline In Rats, Zhiying Dou, Kefeng Li, Ping Wang, Liu Cao

Michigan Tech Publications, Part 1

Vinegar and wine processing of medicinal plants are two traditional pharmaceutical techniques which have been used for thousands of years in China. Tetrahydropalmatine (THP), dehydrocorydaline (DHC) and protopine are three major bioactive molecules in Rhizoma Corydalis. In this study, a simple and reliable HPLC method was developed for simultaneous analysis of THP, DHC and protopine in rat tissues after gastric gavage administration of Rhizoma Corydalis. The validated HPLC method was successfully applied to investigate the effect of wine and vinegar processing on the compounds’ distribution in rat tissues. Our results showed that processing mainly affect the T_max and mean …

High Altitude Diving In River Otters: Coping With Combined Hypoxic Stresses, Jamie R. Crait, Henry D. Prange, Noah A. Marshall, Henry J. Harlow, Clark Cotton, Merav Ben-David

Biology Faculty Publications

River otters (Lontra canadensis) are highly active, semi-aquatic mammals indigenous to a range of elevations and represent an appropriate model for assessing the physiological responses to diving at altitude. In this study, we performed blood gas analyses and compared blood chemistry of river otters from a high-elevation (2357 m) population at Yellowstone Lake with a sea-level population along the Pacific coast. Comparisons of oxygen dissociation curves (ODC) revealed no significant difference in hemoglobin-oxygen (Hb-O₂) binding affinity between the two populations - potentially because of demands for tissue oxygenation. Instead, high-elevation otters had greater Hb concentrations (18.7 …

Investigating The Spectrum Of Biological Activity Of Substituted Quinoline-2-Carboxamides And Their Isosteres, Jiahui Guo, Et. Al.

Department of Biological Sciences Publications

In this study, a series of thirty-five substituted quinoline-2-carboxamides and thirty-three substituted naphthalene-2-carboxamides were prepared and characterized. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial species. N-Cycloheptylquinoline-2-carboxamide, N-cyclohexylquinoline-2-carboxamide and N-(2-phenylethyl)quinoline-2-carboxamide showed higher activity against M. tuberculosis than the standards isoniazid or pyrazinamide and 2-(pyrrolidin-1-ylcarbonyl)quinoline and 1-(2-naphthoyl)pyrrolidine expressed higher activity against M. kansasii and M. avium paratuberculosis than the standards isoniazid or pyrazinamide. The most effective antimycobacterial compounds demonstrated insignificant toxicity against the human …

Philopatry Drives Genetic Differentiation In An Island Archipelago: Comparative Population Genetics Of Galapagos Nazca Boobies (Sula Granti) And Great Frigatebirds (Fregata Minor), Iris Levin, Patricia Parker

Biology Department Faculty Works

Seabirds are considered highly mobile, able to fly great distances with few apparent barriers to dispersal. However, it is often the case that seabird populations exhibit strong population genetic structure despite their potential vagility. Here we show that Galapagos Nazca booby (Sula granti) populations are substantially differentiated, even within the small geographic scale of this archipelago. On the other hand, Galapagos great frigatebird (Fregata minor) populations do not show any genetic structure. We characterized the genetic differentiation by sampling five colonies of both species in the Galapagos archipelago and analyzing eight microsatellite loci and three mitochondrial genes. Using an F‐statistic …

Tumor Suppression By Cell Competition Through Regulation Of The Hippo Pathway, Chiao-Lin Chen, Molly C. Schroeder, Madhuri Kango-Singh, Chunyao Tao, Georg Halder

Biology Faculty Publications

Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene scribble (scrib) are eliminated from Drosophila imaginal discs. When all cells in imaginal discs are mutant for scrib, they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the scrib− cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does …

Aquaporin 4 Is A Ubiquitously Expressed Isoform In The Dogfish (Squalus Acanthias) Shark, Christopher P. Cutler, Bryce Maciver, Gordon Cramb, Mark L. Zeidel

Biology: Faculty Publications

The dogfish ortholog of aquaporin 4 (AQP4) was amplified from cDNA using degenerate PCR followed by cloning and sequencing. The complete coding region was then obtained using 5′ and 3′ RACE techniques. Alignment of the sequence with AQP4 amino acid sequences from other species showed that dogfish AQP4 has high levels (up to 65.3%) of homology with higher vertebrate sequences but lower levels of homology to Agnathan (38.2%) or teleost (57.5%) fish sequences. Northern blotting indicated that the dogfish mRNA was approximately 3.2 kb and was highly expressed in the rectal gland (a shark fluid secretory organ). Semi-quantitative PCR further …

Experimentally Altered Navigational Demands Induce Changes In The Cortical Forebrain Of Free-Ranging Northern Pacific Rattlesnakes (Crotalus O. Oreganus), Matthew L. Holding, Julius A. Frazier, Emily N. Taylor, Christine R. Strand

Biological Sciences

The hippocampus of birds and mammals plays a crucial role in spatial memory and navigation. The hippocampus exhibits plasticity in adulthood in response to diverse environmental factors associated with spatial demands placed on an animal. The medial and dorsal cortices of the telencephalon of squamate reptiles have been implicated as functional homologues to the hippocampus. This study sought to experimentally manipulate the navigational demands placed on free-ranging northern Pacific rattlesnakes (Crotalus o. oreganus) to provide direct evidence of the relationship between spatial demands and neuroplasticity in the cortical telencephalon of the squamate brain. Adult male rattlesnakes were radio-tracked for 2 …

The Number Of X Chromosomes Causes Sex Differences In Adiposity In Mice, Jenny Link, Xuqi Chen, Rebecca Mcclusky, Simon W. Beaven, Peter Tontonoz, Arthur P. Arnold, Karen Reue

Biology

Sexual dimorphism in body weight, fat distribution, and metabolic disease has been attributed largely to differential effects of male and female gonadal hormones. Here, we report that the number of X chromosomes within cells also contributes to these sex differences. We employed a unique mouse model, known as the “four core genotypes,” to distinguish between effects of gonadal sex (testes or ovaries) and sex chromosomes (XX or XY). With this model, we produced gonadal male and female mice carrying XX or XY sex chromosome complements. Mice were gonadectomized to remove the acute effects of gonadal hormones and to uncover effects …