Biology Commons^™

Creating A Georgia Southern Spider Collection: Can Dna Barcoding Help?, Guy B. Hobbs

College of Graduate Studies: Theses & Dissertations

With over 280 spider (Araneae) species recorded within the State of Georgia, USA, the need for a well-documented natural history collection with a usable voucher system is critical to continually assess spider diversity and their future ecological impact in this region. Spider identification can be daunting for the inexperienced taxonomist; it is time consuming and sometimes requires destructive procedures. Previous works have successfully used an alternative method, DNA barcoding, to correctly identify spider species while preserving their morphology. This study set forth to create the core of a well-documented spider collection within Georgia Southern University’s Institute for Coastal Plain Science …

Complete Genome Sequence Of Rickettsia Parkeri Strain Black Gap, Sandor E. Karpathy, Christopher D. Paddock, Stephanie L. Grizzard, Dhwani Batra, Lori A. Rowe, David T. Gauthier

Biological Sciences Faculty Publications

A unique genotype of Rickettsia parkeri, designated R. parkeri strain Black Gap, has thus far been associated exclusively with the North American tick, Dermacentor parumapertus. The compete genome consists of a single circular chromosome with 1,329,522 bp and a G+C content of 32.5%.

Functional Genetic Approaches To Provide Evidence For The Role Of Toolkit Genes In The Evolution Of Complex Color Patterns In Drosophila Guttifera, Mujeeb Olushola Shittu

Dissertations, Master's Theses and Master's Reports

Toolkit genes are set of genes that orchestrate the development of basic body plan of animals, and they are highly conserved in all animals. The co-option of the toolkit genes into the pigmentation pathway has led to the evolution of novel species. This study focuses on understanding how the complex color patterns in animals develop by using the Drosophila species in the quinaria group as models. We developed an mRNA in situ hybridization (ISH) protocol, which allowed us to study gene expression patterns in the abdomen of developing pupae of non-model Drosophila species (Chapter 2). Through ISH, we found that …

Composition And Homology In The Taxonomic Classification Of Escherichia Coli, Tanya Irani

Theses and Dissertations (Comprehensive)

As new techniques have been introduced, specifically the possibility of complete genome sequencing, better methods of defining bacterial species have also been proposed. One of the most recently proposed methods, using bioinformatic techniques, is to calculate the average nucleotide identity (ANI) between the homologous genome segments of different isolates. Another method for species discrimination that has been tested successfully is the similarity of DNA compositional signatures. However, in a recent update, DNA signatures split the available Escherichia coli complete genomes into three groups. To check if this result was consistent with such genomes belonging to different species, we tested methods …

Ogre-Faced, Net-Casting Spiders Use Auditory Cues To Detect Airborne Prey, Jay A. Stafstrom, Gil Menda, Eya I. Nitzany, Eileen A. Hebets, Ronald R. Hoy

Eileen Hebets Publications

Prey-capture behavior among spiders varies greatly from passive entrapment in webs to running down prey items on foot. Somewhere in the middle are the ogre-faced, net-casting spiders (Deinopidae: Deinopis) that actively capture prey while being suspended within a frame web. Using a net held between their front four legs, these spiders lunge downward to ensnare prey from off the ground beneath them. This “forward strike” is sensorially mediated by a massive pair of hypersensitive, night-vision eyes. Deinopids can also intercept flying insects with a “backward strike,” a ballistically rapid, overhead back-twist, that seems not to rely on visual cues. Past …

A Cophylogenetic Analysis Of Fungus Gardening Ants And Their Symbiotic Fungi, Katherine Beigel

Biology Theses

Fungus-growing ants (Tribe Attini) and their fungal cultivars share a 50-million-year coevolutionary history. Large scale phylogenetic analyses depict a strong co-phyletic signal among ants and their farmed fungi yet fungus sharing among unrelated ant lineages is somewhat widespread. An overview of sharing has been hampered by a lack of genetic markers that exhibit intraspecific variation and surveys across geographic regions. For example, previous studies have shown similar sequences of the internal transcribed spacer (ITS) region of fungus in different species of Trachymyrmex, suggesting that these ant species are farming the same fungal clone. To examine whether this was a …

Diagnosis And Distribution Of Florida Sand Darter, Ammocrypta Bifascia (Teleostei; Percidae), In The Flint River, Georgia, Camm C. Swift, Gregory R. Moyer, Christine E. Fallon, Brett Albanese

Southeastern Fishes Council Proceedings

Abstract: In 2013, we observed the presence of an undocumented Ammocrypta species in the lower Flint River, Georgia. The occurrence represents the first record of the genus in Georgia. Subsequent surveys at 24 sites, using seining or snorkeling, documented additional specimens from mainstem sites (n = 3) between Albany and Bainbridge and from Ichawaynochaway Creek (n = 5 sites), a large tributary to the Flint River. We used morphological and genetic data to identify specimens to species. Morphological examination included 23 morphometric and 8 meristic characters from fifteen specimens that were compared to specimens from Williams (1975). For genetic analyses, …

Innate Pathogenic Traits In Oral Yeasts, Ayat Ibrahiem Esmaeel Al-Laaeiby, Adnan A. Al-Mousawi, Inaam M.N. Alrubayae, Abdullah Al-Saadoon, Maysoon Almayahi

Karbala International Journal of Modern Science

The normal flora community plays a significant role in both healthy and patient individual’s bodies. It has improved its ability to change from beneficial to opportunistic organisms causing crucial infections in immunocompromised patients. This study was conducted to identify the community of yeast species, and to investigate potential virulence factors. Saliva samples were collected from healthy individuals, yeast species were isolated and identified using both traditional and advance molecular genetics technique. The results revealed that Candida albicans was the dominant isolate, while Meyerozyma caribbica was the least. The phylogenetic tree was constructed for 13 species using the Neighbour-Joining method, which …

Ultracontinuous Single Haplotype Genome Assemblies For The Domestic Cat (Felis Catus) And Asian Leopard Cat (Prionailurus Bengalensis), Kevin R. Bredemeyer, Andrew J. Harris, Gang Li, Le Zhao, Nicole M. Foley, Melody E. Roelke-Parker, Stephen James O'Brien, Leslie A. Lyons, Wesley C. Warren, William J. Murphy

Biology Faculty Articles

In addition to including one of the most popular companion animals, species from the cat family Felidae serve as a powerful system for genetic analysis of inherited and infectious disease, as well as for the study of phenotypic evolution and speciation. Previous diploid-based genome assemblies for the domestic cat have served as the primary reference for genomic studies within the cat family. However, these versions suffered from poor resolution of complex and highly repetitive regions, with substantial amounts of unplaced sequence that is polymorphic or copy number variable. We sequenced the genome of a female F1 Bengal hybrid cat, the …

Karyotype Evolution In 10 Pinniped Species: Variability Of Heterochromatin Versus High Conservatism Of Euchromatin As Revealed By Comparative Molecular Cytogenetics, Violetta R. Beklemisheva, Polina L. Perelman, Natalya A. Lemskaya, Anastasiya A. Proskuryakova, Natalya A. Serdyukova, Vladimir N. Burkanov, Maksim B. Gorshunov, Oliver A. Ryder, Mary Thompson, Gina Lento, Stephen James O'Brien, Alexander S. Graphodatsky

Biology Faculty Articles

Pinnipedia karyotype evolution was studied here using human, domestic dog, and stone marten whole-chromosome painting probes to obtain comparative chromosome maps among species of Odobenidae (Odobenus rosmarus), Phocidae (Phoca vitulina, Phoca largha, Phoca hispida, Pusa sibirica, Erignathus barbatus), and Otariidae (Eumetopias jubatus, Callorhinus ursinus, Phocarctos hookeri, and Arctocephalus forsteri). Structural and functional chromosomal features were assessed with telomere repeat and ribosomal-DNA probes and by CBG (C-bands revealed by barium hydroxide treatment followed by Giemsa staining) and CDAG (Chromomycin A3-DAPI after G-banding) methods. We demonstrated diversity of heterochromatin among pinniped karyotypes in terms of localization, …

Modeling Neurofibromatosis Type Ii In Zebrafish, Hannah Nuszen

University Honors Program Senior Projects

Neurofibromatosis Type 2 (NF2) is a rare genetic disorder, classified as a neurocutaneous syndrome inherited through an autosomal dominant genetic mutation or deletion of the NF2 gene in humans. The tumor suppressor gene NF2 encodes the cytoskeletal protein MERLIN to promote apoptosis and inhibit abnormal cellular proliferation. Mutations in NF2 lead to a deficiency of functional MERLIN in humans and can result in hearing loss, disability, and premature death. These symptoms are due to uncontrollable growth of schwann cells generating bilateral benign tumors (schwannomas) within the nerve sheath of cranial nerve VIII. Here we seek to understand the function of …

Draft Genome Of The Common Snapping Turtle, Chelydra Serpentina, A Model For Phenotypic Plasticity In Reptiles, Debojyoti Das, Sunil Kumar Singh, Jacob Bierstedt, Alyssa Erickson, Gina L. J. Galli, Dane A. Crossley Ii, Turk Rhen

Biology Faculty Publications

Turtles are iconic reptiles that inhabit a range of ecosystems from oceans to deserts and climates from the tropics to northern temperate regions. Yet, we have little understanding of the genetic adaptations that allow turtles to survive and reproduce in such diverse environments. Common snapping turtles, Chelydra serpentina, are an ideal model species for studying adaptation to climate because they are widely distributed from tropical to northern temperate zones in North America. They are also easy to maintain and breed in captivity and produce large clutch sizes, which makes them amenable to quantitative genetic and molecular genetic studies of …

Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing

Master's Theses

The Critically Endangered Largetooth Sawfish, Pristis pristis, experienced global declines in range and abundance over the past century and Australia is now their last stronghold. This research aimed to understand whether these declines have been accompanied by a reduction in levels of genetic diversity. Using P. pristis tissue samples sourced from natural history specimens, three fragments (616-bp, 386-bp, 141-bp) in the mitochondrial DNA (mtDNA) control region were PCR-amplified. At each fragment, significant genetic structure was found in P. pristis overall (Φ_ST=0.946, N=9; 0.813, N=54; 0.771, N=99). The Indo-West Pacific and Atlantic/Eastern Pacific each harbor genetically distinct lineages of …

The Design And Validation Of A Qpcr-Based Approach To Cell Quantification Of Fungal-Algal Symbioses, Isabelle Katherine Garlotte

Honors Theses

Symbiotic relationships are extremely common in virtually all species. These relationships between organisms, particularly mutualistic symbioses, can have an incredibly large impact and can greatly affect the evolution of the species involved. Of particular interest is the suspected mutualistic relationship between green algae and fungi that may hold key evidence of how terrestrial plants evolved. In this experiment we established a method of quantifying the cells of each species involved in these symbioses through qPCR analysis to determine if the relationships are truly mutualistic. We developed a system for using DNA copies as a proxy for cell count in co-cultures …

Neogene And Quaternary Events Shaped Diversification And Speciation In Bhutanese Rheophilic Fishes Of The Family Nemacheilidae (Cypriniformes) And Sisoridae (Siluriformes), Karma Wangchuk

Graduate Theses and Dissertations

Biogeography of the Himalayan region [to include the Qinghai-Tibetan Plateau (QTP)] evolved over a ~30M year span, catalyzed by the collision of the Indian and Eurasian plates. The resulting uplift produced major ecological and climatic effects, that in turn drove the diversification of biodiversity. As a result, the QTP is designated as a global biodiversity hotspot particularly vulnerable to cumulative climatic effects, including shrinking distributions, declining numbers, and local extinctions. Understanding how the biodiversity within the Himalaya/ QTP was established and maintained is a necessary first step in prioritizing conservation efforts.

Fishes in global montane regions, such as the Himalaya, …

Evaluation Of The Xpert Carba-R Nxg Assay For Detection Of Carbapenemase Genes In A Global Challenge Set Of Pseudomonas Aeruginosa Isolates, Fred C. Tenover, Christian M. Gill, Tomefa E. Asempa, Isabella A. Tickler, Caitlin M. Dela Cruz, David P. Nicolau

Biology Faculty Publications

The growing prevalence and diversity of carbapenemase producers among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates warrants an expansion of detection capabilities. The purpose of this study was to evaluate the performance of the commercially available Xpert Carba-R (Carba-R) and the research-use-only Xpert Carba-R NxG (Carba-R NxG) in a global collection of P. aeruginosa. The challenge set included 123 P. aeruginosa clinical isolates from 12 countries. Isolates were previously categorized via PCR or whole-genome sequencing. Carbapenemase classes tested include VIM, IMP, NDM, SPM, KPC, and GES. Non-carbapenemase (non-CP)-harboring isolates were also tested (negative control). Isolates were tested using the Carba-R NxG and …

Quantifying Structure And Variation In Complex Phylogenetic Data, Genevieve Geraldine Mount

LSU Doctoral Dissertations

Identifying the source and structure of variation in nature is crucial to understanding fundamental aspects of evolution. Despite a recent plethora of genetic and morphological data, many interesting questions about the relationships between different groups remain unresolved. My dissertation evaluates three approaches for identifying and quantifying the variation within phylogenetic datasets. Characterizing variation within datasets and across analytical methods gives insight into biologically interesting characters, unusual evolutionary processes, and areas for model improvement.

Network-based community detection approaches offer a powerful tool to describe variation in phylogenetic signal across the genome (i.e., gene tree variation). In Chapter 2, I investigate the …

Spatio-Temporal Dynamics Of Fungal Communities And Their Effects On Plants, Kel Cook

Biology ETDs

Fungi perform several critical functions in the environment. Spatiotemporal distributions of fungal communities will mediate when and where these functions happen and how they vary across the landscape. I first explored tropical tree canopy fungal community variation at small spatial scales and documented near total turnover of fungi across sub-meter distances and among adjacent substrates. The second chapter analyzed fungal turnover over the course of three years, where community stability was driven primarily by abundant fungi. In the third chapter, I tested effects of the environment, including host plant and habitat, on canopy fungal communities and found only small effects, …

Identification Of Novel Host Genes Required For Antiviral Immunity And Viral Genome Replication In C. Elegans, Fei Meng

LSU Doctoral Dissertations

RNA interference (RNAi) is a wide-spread gene silencing mechanism that control diverse biological functions and triggered by small interfering RNAs (siRNAs) processed from the viral genome or its replication intermediates. Mechanistic studies of antiviral RNAi in Caenorhabditis elegans has led to the identification of several critical factors involved in the process. As a result, whether antiviral RNAi requires additional novel genes remains to be an open question.

Viruses are intracellular parasites that rely on host products for reproduction. Disrupting their interaction with host factors can significantly compromise their replication and keep them under control. Thus, identification of host genes …

The Nature Of Genes Expressed Differently After Environmental Drug Exposure, Nicci Siffel

Scholars Week

The Nature of Genes Expressed Differently after Environmental Drug Exposure

N. Siffel, S. Anderson, B. Subedi, D.R. Hammond-Weinberger

Drug use, of prescription or illicit varieties, alter bodily functions in different ways, especially in the nervous system. These drugs are found in sources of drinking water because they are not removed by wastewater treatment facilities. To investigate the effects of these drugs as they appear in mixtures, we exposed groups of zebrafish embryos to cocktails of drugs and screened for genes that were differentially expressed between the experimental and control groups and could thus give more insight into their biological functions. …

Exploring A Novel Substrate-Borne Vibratory Signal In The Wolf Spider Schizocosa Floridana, Malcolm F. Rosenthal, Eileen Hebets, Rowan H. Mcginley, Cody Raiza, James Starrett, Lin Yan, Damian O. Elias

Eileen Hebets Publications

Animals communicate using a diversity of signals produced by a wide array of physical structures. Determining how a signal is produced provides key insights into signal evolution. Here, we examine a complex vibratory mating display produced by male Schizocosa floridana wolf spiders. This display contains three discrete substrate-borne acoustic components (known as “thumps”, “taps”, and “chirps”), each of which is anecdotally associated with the movement of a different body part (the pedipalps, legs, and abdomen respectively). In order to determine the method of production, we employ a combination of high-speed video/audio recordings and SEM imaging of possible sound-producing structures. Previous …

Testing The Hypothesized Antipredator Defence Function Of Stridulation In The Spiny Orb-Weaving Spider, Micrathena Gracilis, Tyler B. Corey, Eileen A. Hebets

Eileen Hebets Publications

The observable diversity of antipredator defenses across organisms demonstrates predation’s impact on trait evolution. The functions of many traits that are presumed to have an antipredator function have never been directly tested. The spiny orb-weaving spider, Micrathena gracilis, for example, stridulates when grasped. While stridulation was first hypothesized to be an antipredator defense nearly 50 years ago, no data exist to support this hypothesis. To explore the form and function of M. gracilis stridulation, we first quantified the behavioral and acoustical properties of sound production. Next, using laboratory assays, we directly tested the effect of stridulation on survival with …

Inheritability Of Ciprofloxacin-Induced Mitochondrial Mutations From Parental To Offspring Generation Using Quantitative Polymerase Chain Reaction, Rose Mccoy

Honors Program: Senior Projects (Public)

In all eukaryotes, mitochondria are known as the powerhouse of the cell (Siekevitz, 1957). In plants, however, their mitochondrial genome is especially strange. Plant mitochondrial genomes are extremely large and contain both linear and circular subgenomic DNA fragments. Plant mitochondrial genomes undergo a significant amount of mutations in the form of rearrangements. However, it is not known how often these rearrangements are inherited by the next generation. It is thought that plant cells that are still dividing have higher rates of DNA repair, such as double-strand break repair, to ensure the quality of that plant lineage. As follows, it is …

Identification And Characterization Of Novel Genes And Genetic Interactions That Influence Iba Metabolism, Vanessica Jawahir

Dissertations

Indole-3-butyric acid (IBA) is an endogenous storage auxin important for maintaining appropriate indole-3-acetic acid (IAA) levels that influences primary root elongation and lateral root development. IBA is metabolized into free IAA in the peroxisome in a multistep process similar to fatty acid β-oxidation. Although many components specific to IBA metabolism and peroxisome function have been identified, our understanding is incomplete. I sought to identify novel components of IBA metabolism or peroxisome function by conducting a forward genetic screen for Arabidopsis thaliana plants with enhanced resistance to IBA. I identified Long chain acyl-CoA synthetase 4 (LACS4) as a novel gene functioning …

Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Temperate forests of eastern North America are subject to multiple invasions from non-native species that have the potential to drive long-term dynamics in biodiversity. Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) is an invasive plant in many deciduous forests, and management efforts often focus on removing this species to initiate native species restoration. Agrilus planipennis Fairmaire (emerald ash borer; Coleoptera: Buprestidae) is a non-native insect pest that has caused substantial loss of ash trees (Fraxinus spp. L.) in North America. Our goal was to understand how the herbaceous layer in an old-growth forest responded to the removal of …

Mechanistic Insights Into Strigolactone Biosynthesis, Signaling And Regulation During Plant Growth And Development, Kaiser Iqbal Wani, Andleeb Zehra, Sadaf Choudhary, M Naeem, M. Masroor A. Khan, Christian Danve Castroverde, Tariq Aftab

Biology Faculty Publications

Strigolactones (SLs) constitute a group of carotenoid-derived phytohormones with butenolide moieties. These hormones are involved in various functions, including regulation of secondary growth, shoot branching and hypocotyl elongation, and stimulation of seed germination. SLs also control hyphal branching of arbuscular mycorrhizal (AM) fungi, and mediate responses to both abiotic and biotic cues. Most of these functions stem from the interplay of SLs with other hormones, enabling plants to appropriately respond to changing environmental conditions. This dynamic interplay provides opportunities for phytohormones to modulate and augment one another. In this article, we review our current mechanistic understanding of SL biosynthesis, receptors …

A Summary Of Current Research Into Neurodegenerative Disorders Using Drosophila Melanogaster, Chase Cortese

Honors Theses

Neurodegenerative disorders such as Alzheimer’s disease are characterized by damage to neural cells causing widespread neurological deficits. Historically, these diseases were deemed as inevitable declines in cognitive and neurological function that occurred with aging. Recent research has revealed, however, that these diseases have molecular bases allowing potential clinical intervention. The groundbreaking discoveries have been made using differing model organisms, which can replicate the phenotype and physiological cause of these disorders. One major model organism that has been used is the fruit fly, Drosophila melanogaster. They have served various roles in elucidating gene pathways and neurophysiological bases seen in these diseases. …

Does The Presence Of Multiple Β-Lactamases In Gram-Negative Bacilli Impact The Results Of Antimicrobial Susceptibility Tests And Extended-Spectrum Β-Lactamase And Carbapenemase Confirmation Methods?, Fred C. Tenover, Caitlin M. Dela Cruz, Scott Dewell, Victoria M. Le, Isabella A. Tickler

Biology Faculty Publications

Objectives: Many multidrug-resistant Gram-negative bacilli (MDR-GNB) harbour multiple β-lactamases. The aim of this study was to assess the impact of multiple β-lactamase carriage on the accuracy of susceptibility tests and extended-spectrum β-lactamase (ESBL) and carbapenemase confirmation methods.

Methods: A total of 50 MDR-GNB, of which 29 carried multiple β-lactamases, underwent broth microdilution (BMD) and disk diffusion (DD) testing as well as confirmation tests for ESBLs and carbapenemases. Whole-genome sequencing (WGS) was used for β-lactamase gene identification.

Results: Categorical agreement of BMD and DD testing results ranged from 86.5 to 97.7% for 10 β-lactam agents. BMD and DD algorithms for ESBL …

Analyses Of The Expression, Immunohistochemical Properties And Serodiagnostic Potential Of Schistosoma Japonicum Peroxiredoxin-4, Minh-Anh Dang-Trinh, Jose Ma. M. Angeles, Kharleezelle J. Moendeg, Adrian Miki C. Macalanda, Thu-Thuy Nguyen, Luna Higuchi, Shotaro Nakagun, Masahi Kirinoki, Yuichi Chigusa, Yasuyuki Goto, Shin-Ichiro Kawazu

Biology Faculty Publications

Background

Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense mechanism during their intra-mammalian stages. To counteract this host immune attack, the parasite utilizes their antioxidant system for survival inside the host. Peroxiredoxins (Prxs), thiol-specific antioxidant proteins, play an essential role for protecting the parasite against oxidative stress by reducing hydrogen peroxide to water. Only three types of 2-Cys Prxs have been previously characterized in S. japonicum whereas a fourth Prx has been identified for Schistosoma mansoni as Prx-4. A sequence …

The Influence Of Riparian Invasion By The Terrestrial Shrub Lonicera Maackii On Aquatic Macroinvertebrates In Temperate Forest Headwater Streams, Michelle N. Little, Kevin W. Custer, Eric B. Borth, Julia I. Chapman, Mitchell J. Kukla, Corey Kuminecz, Margaret E. Maloney, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

The ecology of headwater streams is tightly linked to the riparian zone through organic matter subsidies which are highly susceptible to alteration due to biological invasion. Lonicera maackii is a non-native shrub that is a highly successful invader of headwater stream riparian zones in the American Midwest. We assessed effects on benthic macroinvertebrates across a gradient of invasion intensity from references sites with minimal invasion to a site that had a very heavy invasion. Benthic macroinvertebrates were sampled throughout the year and compositional differences were assessed using Non-metric Multidimensional Scaling ordination, and by comparing the prevalence of sensitive (Ephemeroptera, Plectoptera, …