Biology Commons^™

Diet Analysis Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Virginia, Kristen Marie Volker

Biological Sciences Theses & Dissertations

This study describes the diet of bottlenose dolphins (Tursiops truncatus) stranded in Virginia via stomach content analysis and considers factors such as proportion of numerical abundance and reconstructed mass, frequency of occurrence, average reconstructed prey size, prey diversity and quantity, and otolith degradation code. Fish size was estimated via regression equations established from local fish collected during the study that derive wet weight directly from otolith length or width. Squid size is estimated from previously published equations. Soniferous fishes dominated the diet, especially Atlantic croaker, spot, and seatrout spp., adding evidence to the theory that bottlenose dolphins passively …

Bone Morphogenic Proteins Are Immunoregulatory Cytokines Controlling Foxp3+ TReg Cells, Lauren M. Browning, Caroline Miller, Michal Kuczma, Maciej Pietrzak, Yu Jing, Grzegorz Rempala, Pawel Muranski, Leszek Ignatowicz, Piotr Kraj

Bioelectrics Publications

Bone morphogenic proteins (BMPs) are members of the transforming growth factor β (TGF-β) cytokine family promoting differentiation, homeostasis, and self-renewal of multiple tissues. We show that signaling through the bone morphogenic protein receptor 1α (BMPR1α) sustains expression of FOXP3 in T_reg cells in peripheral lymphoid tissues. BMPR1α signaling promotes molecular circuits supporting acquisition and preservation of T_reg cell phenotype and inhibiting differentiation of pro-inflammatory effector Th1/Th17 CD4+ T cell. Mechanistically, increased expression of KDM6B (JMJD3) histone demethylase, an antagonist of the polycomb repressive complex 2, underlies lineage-specific changes of T cell phenotypes associated with abrogation of BMPR1α signaling. …

Evolutionary Determinism And Convergence Associated With Water Column Transitions In Marine Fishes, Melissa Rincon-Sandoval, Emmanuelle Duarte-Ribeiro, Aaron M. Davis, Aintzane Santaquiteria, Lily C. Hughes, Carole C. Baldwin, Luisángely Soto-Torres, Arturo Acero P., H.J. Walker Jr, Kent E. Carpenter, Marcus Sheaves, Guillermo Orti, Dahiana Arcila, Ricardo Betancur-R.

Biological Sciences Faculty Publications

Repeatable, convergent outcomes are prima facie evidence for determinism in evolutionary processes. Among fishes, well-known examples include microevolutionary habitat transitions into the water column, where freshwater populations (e.g., sticklebacks, cichlids, and whitefishes) recurrently diverge toward slender-bodied pelagic forms and deep-bodied benthic forms. However, the consequences of such processes at deeper macroevolutionary scales in the marine environment are less clear. We applied a phylogenomics-based integrative, comparative approach to test hypotheses about the scope and strength of convergence in a marine fish clade with a worldwide distribution (snappers and fusiliers, family Lutjanidae) featuring multiple water-column transitions over the past 45 million years. …

Apparent Resilience To Fire Of Native Bee (Hymenoptera: Apoidea) Communities From Upland Longleaf Pine Forests In Louisiana And Mississippi, Sara A. Simmons, Janice L. Bossart

Biological Sciences Faculty Publications

Controlled burning is an essential tool for restoration and management of Pinus palustris (Longleaf Pine) habitats, yet effects of controlled burning on insect species, including pollinators, are rarely considered in conservation planning. We used blue vane traps to sample native bees (Hymenoptera: Apoidea) at recently burned and unburned sites in 2 Longleaf Pine upland forests in Mississippi and Louisiana. Our objective was to quantify short-term effects of controlled burns given fire-return intervals of 1-2 years are now regularly employed to manage Longleaf Pine woodlands. We sampled during 2016 and 2017 and collected 1777 native bees, representing 43 species. Recent fire …

Correlates Of Bird Collisions With Buildings Across Three North American Countries, Jared A. Elmore, Stephen B. Hager, Bradley J. Cosentino, Nastasha Hagemeyer, Eric Walters, Scott R. Loss, Et Al.

Biological Sciences Faculty Publications

Collisions with buildings cause up to 1 billion bird fatalities annually in North America. Bird-building collisions have recently received increased conservation, research, and policy attention. However, efforts to reduce collisions would benefit from studies conducted at large spatial scales across multiple study sites, with standardized methods, and with consideration of species- and life history-related variation and correlates of collisions. We addressed these research needs with a coordinated data collection effort at 40 sites across North America. We estimated collision vulnerability for 40 bird species by accounting for their North American population abundance, distribution overlap with study sites, and sampling effort. …

Small-Scale Population Connectivity And Genetic Structure In Canada Thistle (Cirsium Arvense), Mahboubeh Hosseinalizadeh Nobarinezhad, Lavanya Challagundla, Lisa E. Wallace

Biological Sciences Faculty Publications

Premise of research. Population connectivity, the exchange of genes among geographically separated subpopulations, is thought to be a key process for the maintenance of genetic diversity and the survival of invasive species in newly colonized areas. Plant populations' degree of genetic connectivity, which occurs via pollen and seed dispersal, leads to different degrees of genetic admixture and genetic structure. Environmental barriers and differential selection pressures that are variable across time and space tend to alter genetic structure within and among populations via restriction or facilitation of gene flow. Canada thistle, an invasive species of the United States and Canada, is …

Science, Diplomacy, And The Red Sea's Unique Coral Reef: It's Time For Action, Karine Kleinhaus, Ali Al-Sawalmih, Daniel J. Barshis, Amatzia Genin, Lola N. Grace, Ove Hoegh-Guldberg, Yossi Loya, Anders Meiborn, Eslam O. Osman, Jean-Daniel Ruch, Yonathan Shaked, Christian R. Voolstra, Assaf Zvuloni, Maoz Fine

Biological Sciences Faculty Publications

Rapid ocean warming due to climate change poses a serious risk to the survival of coral reefs. It is estimated that 70–90 percent of all reefs will be severely degraded by mid-century even if the 1.5°C goal of the Paris Climate Agreement is achieved. However, one coral reef ecosystem seems to be more resilient to rising sea temperatures than most others. The Red Sea’s reef ecosystem is one of the longest continuous living reefs in the world, and its northernmost portion extends into the Gulf of Aqaba. The scleractinian corals in the Gulf have an unusually high tolerance for the …

In Vitro And In Vivio Evaluation Of A Moisture Treatment Cream Containing Three Critical Elements Of Natural Skin Moisturization, David H. Mcdaniel, Jeffrey S. Dover, Mitchell Wortzman, Diane B. Nelson

Biological Sciences Faculty Publications

Objectives

To evaluate skin barrier and hydration effects of a new rebalancing moisture treatment (TRMT) and to assess efficacy and tolerability in subjects with photodamaged skin.

Methods

In an epidermal skin model, tissues (n = 5/group) were topically treated with 25 µL of TRMT, 25 µL of a market‐leading moisturizer (MLM), or untreated for 60 minutes. Hydration was measured at 0, 15, and 30 minutes. Tissues were harvested for gene expression analysis of markers associated with skin barrier and hydration: Claudin (CLD), Aquaporin (AQP), Hyaluronic Acid Syntheses (HAS), and Hyaluronidase (HYAL). A clinical study evaluated twice‐daily application of TRMT, assessing …

An Efficient Microinjection Method To Generate Human Anaplasmosis Agent Anaplasma Phagocytophilum-Infected Ticks, Vikas Taank, Ellango Ramasamy, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks are important vectors that transmit several pathogens including human anaplasmosis agent, Anaplasma phagocytophilum. This bacterium is an obligate intracellular rickettsial pathogen. An infected reservoir animal host is often required for maintenance of this bacterial colony and as a source for blood to perform needle inoculations in naïve animals for tick feeding studies. In this study, we report an efficient microinjection method to generate A. phagocytophilum-infected ticks in laboratory conditions. The dense-core (DC) form of A. phagocytophilum was isolated from in vitro cultures and injected into the anal pore of unfed uninfected Ixodes scapularis nymphal ticks. These ticks …

Conserving Spawning Stocks Through Harvest Slot Limits And No-Take Protected Areas, Gaya Gnanalingam, Holly Gaff, Mark J. Butler Iv

Biological Sciences Faculty Publications

The key to the conservation of harvested species is the maintenance of reproductive success. Yet for many marine species large, old individuals are targeted despite their disproportionate contribution to reproduction. We hypothesized that a combination of no-take marine protected areas (MPAs) and harvest slot limits (maximum and minimum size limits) would result in the conservation of large spawning individuals under heavy harvest. We tested this approach under different harvest intensities with a 2-sex, stage-structured metapopulation model for the Caribbean spiny lobster (Panulirus argus). P. argus is intensively harvested in the Caribbean, and in many localities large, mature individuals no longer …

Factors Affecting The Microbiome Of Ixodes Scapularis And Amblyomma Americanum, R. Jory Brinkerhoff, Chris Clark, Kelly Ocasio, David T. Gauthier, Wayne L. Hynes

Biological Sciences Faculty Publications

The microbial community composition of disease vectors can impact pathogen establishment and transmission as well as on vector behavior and fitness. While data on vector microbiota are accumulating quickly, determinants of the variation in disease vector microbial communities are incompletely understood. We explored the microbiome of two human-biting tick species abundant in eastern North America (Amblyomma americanum and Ixodes scapularis) to identify the relative contribution of tick species, tick life stage, tick sex, environmental context and vertical transmission to the richness, diversity, and species composition of the tick microbiome. We sampled 89 adult and nymphal Ixodes scapularis (N …

Phenotypic Variation Of Partridge Pea (Chamaecrista Fasciculata) From Mississippi Persists In A Common Garden, Lisa E. Wallace, Mahboubeh Hosseinalizadeh-Nobarinezhad, Robert Coltharp

Biological Sciences Faculty Publications

Intraspecific phenotypic variation occurs for many different reasons and understanding its basis has applications in taxonomy, ecology, and evolution. Chamaecrista fasciculata (partridge pea) is a widely distributed species with much phenotypic variation and varied interactions with other species in communities where it grows. Botanists have often noted that phenotypic variation in some traits of this species increases from north to south in the eastern United States. In this study, we grew seeds collected from five Mississippi populations in a common greenhouse environment to determine if the observed variation in leaf and stem traits is maintained in this environment. Interpopulation variation …

Squids Use Multiple Escape Jet Patterns Throughout Ontogeny, Carly A. York, Ian K. Bartol, Paul S. Krueger, Joseph T. Thompson

Biological Sciences Faculty Publications

Throughout their lives, squids are both predators and prey for a multitude of animals, many of which are at the top of ocean food webs, making them an integral component of the trophic structure of marine ecosystems. The escape jet, which is produced by the rapid expulsion of water from the mantle cavity through a funnel, is central to a cephalopod's ability to avoid predation throughout its life. Although squid undergo morphological and behavioral changes and experience remarkably different Reynolds number regimes throughout their development, little is known about the dynamics and propulsive efficiency of escape jets throughout ontogeny. We …

Tick-Borne Flavivirus Inhibits Sphingomyelinase (Issmase), A Venomous Spider Ortholog To Increase Sphingomyelin Lipid Levels For Its Survival In Ixodes Scapularis Ticks, Pravesh Regmi, Supreet Khanal, Girish Neelakanta, Hameda Sultana

Biological Sciences Faculty Publications

Our previous study showed that cells from medically important arthropods, such as ticks, secrete extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Understanding the molecular determinants and mechanism(s) of arthropod-borne flavivirus transmission via exosome biogenesis is very important. In this current study, we showed that in the presence of tick-borne Langat Virus (LGTV; a member of tick-borne encephalitis virus complex), the expression of arthropod IsSMase, a sphingomyelinase D (SMase D) that catalyzes the hydrolytic cleavage of substrates like sphingomyelin (SM) lipids, was significantly reduced in both Ixodes scapularis ticks (in vivo) …

Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick-Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che-Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Ticks secrete various anti-coagulatory, anti-vasoconstrictory, anti-inflammatory, and anti-platelet aggregation factors in their saliva at the bite site during feeding to evade host immunological surveillance and responses. For the first time, we report successful isolation of exosomes (small membrane-bound extracellular signaling vesicles) from saliva and salivary glands of partially fed or unfed ixodid ticks. Our data showed a novel role of these in vivo exosomes in the inhibition of wound healing via downregulation of C-X-C motif chemokine ligand 12 (CXCL12) and upregulation of interleukin-8 (IL-8). Cryo-electron microscopy (cryo-EM) analysis revealed that tick saliva and salivary glands are composed of heterogeneous populations …

A Simple, Inexpensive Method For Mark-Recapture Of Ixodid Ticks, Alexis White, Robin Minch, Lindsey Bidder, Holly Gaff

Biological Sciences Faculty Publications

Mark-recapture techniques have been widely used and specialized to study organisms throughout the field of biology. To mark-recapture ticks (Ixodida), we have created a simple method to mark ticks using nail polish applied with an insect pin secured in a pencil that allows for a variety of questions to be answered. For measuring tick control efficacy, estimating population estimates, or measuring movement of ticks, this inexpensive mark-recapture method has been easily applied in the field and in the lab to provide useful data to answer a variety of questions about ticks.

The Natural History Of The Marsh Rice Rat, Oryzomys Palustris, In Eastern Virginia, Robert K. Rose

Biological Sciences Faculty Publications

The marsh rice rat, Oryzomys palustris, is a common rodent in tidal marshes of eastern Virginia, including those on the barrier islands. It also is present in grassy old fields in upland habitats in the coastal plain and parts of the piedmont of Virginia. This report summarizes what has been learned in recent decades about the population biology of this species in Virginia, including aspects of behavior, density, diet, distribution, genetics, habitats, mammal associates, and reproduction.

A Survey Of The Reptiles And Amphibians At The University Of Georgia Costa Rica Field Station In San Luis De Monteverde, Costa Rica, John David Curlis, Elliot Convery Fisher, W. Kody Muhic, James Moy, Martha Garro-Cruz, José Joaquín Montero-Ramírez

Biological Sciences Faculty Publications

Reptiles and amphibians are experiencing declines across the globe. In Monteverde, Costa Rica, these declines and their underlying causes have been relatively well studied since the early 1990s, and many protected areas have been set aside to conserve these species. However, thorough surveys of the herpetofaunal diversity in these areas have been scarce over the last 20 years. We conducted a survey of all reptile and amphibian species at the University of Georgia Costa Rica (UGACR), a field station in San Luis de Monteverde. Herein, we present an annotated checklist of the 48 species (35 reptiles and 13 amphibians) that …

Translating Globally Threatened Marine Species Information Into Regional Guidance For The Gulf Of Mexico, Kyle Strongin, Beth Polidoro, Christi Linardich, Gina Ralph, Kent Carpenter

Biological Sciences Faculty Publications

A comprehensive understanding of the status of marine organisms in the Gulf of Mexico is critical to the conservation and improved management of marine biodiversity in the region. Threats and extinction risk, based on application of the IUCN Red List Categories and Criteria at the global level, were analyzed for 1,300 Gulf of Mexico marine species. These species include all known marine mammals, sea birds, marine reptiles, cartilaginous fishes, bony shorefishes, corals, mangroves, seagrasses and complete clades of select invertebrates. Analyses showed that 6% of these species are threatened, 2% Near Threatened, 9% Data Deficient, and 83% Least Concern. However, …

Ecosystem Services And Disservices Of Mangrove Forests And Salt Marshes, Daniel A. Friess, Erik S. Yando, Jahson B. Alemu I, Lynn-Wei Wong, Sasha D. Soto, Natasha Bhatia, S. J. Hawkins (Ed.), A. L. Allcock (Ed.), A. E. Bates (Ed.), A.J. Evans (Ed.), L. B. Firth (Ed.), C. D. Mcquaid (Ed.), B. D. Russell (Ed.), I. P. Smith (Ed.), S. E. Swearer (Ed.), P. A. Todd (Ed.)

Biological Sciences Faculty Publications

Coastal wetlands such as mangrove forests and salt marshes provide a range of important benefits to people, broadly defined as ecosystem services. These include provisioning services such as fuelwood and food, regulating services such as carbon sequestration and wave attenuation, and various tangible and intangible cultural services. However, strong negative perceptions of coastal wetlands also exist, often driven by the perceived or actual ecosystem disservices that they also produce. These can include odour, a sense of danger, and their real or perceived role in vector and disease transmission (e.g. malaria). This review provides an introduction to the ecosystem services and …

Can The Carbon And Nitrogen Isotope Values Of Offspring Be Used As A Proxy For Their Mother's Diet? Using Foetal Physiology To Interpret Bulk Tissue And Amino Acid Δ15N Values, Nico Lübcker, John P. Whiteman, Seth D. Newsome, Robert P. Millar, P.J. Nico De Bruyn

Biological Sciences Faculty Publications

The measurement of bulk tissue nitrogen (δ¹⁵N) and carbon isotope values (δ¹³C) chronologically along biologically inert tissues sampled from offspring can provide a longitudinal record of their mothers' foraging habits. This study tested the important assumption that mother-offspring stable isotope values are positively and linearly correlated. In addition, any change in the mother-offspring bulk tissues and individual amino acids that occurred during gestation was investigated. Whiskers sampled from southern elephant seal pups (Mirounga leonina) and temporally overlapping whiskers from their mothers were analyzed. This included n = 1895 chronologically subsampled whisker segments for bulk …

Metabolic Profiling Reveals Biochemical Pathways Responsible For Eelgrass Response To Elevated Co2 And Temperature, Carmen C. Zayas-Santiago, Albert Rivas-Ubach, Li-Jung Kuo, Nicholas D. Ward, Richard C. Zimmerman

OES Faculty Publications

As CO₂ levels in Earth’s atmosphere and oceans steadily rise, varying organismal responses may produce ecological losers and winners. Increased ocean CO₂ can enhance seagrass productivity and thermal tolerance, providing some compensation for climate warming. However, the metabolic shifts driving the positive response to elevated CO₂ by these important ecosystem engineers remain unknown. We analyzed whole-plant performance and metabolic profiles of two geographically distinct eelgrass (Zostera marina L.) populations in response to CO₂ enrichment. In addition to enhancing overall plant size, growth and survival, CO₂ enrichment increased the abundance of Calvin Cycle and …

Wandering Woodpeckers: Foray Behavior In A Social Bird, Sahas Barve, Natasha D. G. Hagemeyer, Russell E. Winter, Samuel D. Chamberlain, Walter D. Koenig, David W. Winkler, Eric L. Walters

Biological Sciences Faculty Publications

In many cooperatively breeding taxa, nonbreeding subordinates, or helpers, use extra-territorial forays to discover dispersal opportunities. Such forays are considered energetically costly and foraying birds face aggression from conspecific members of the territories they visit. In contrast, breeders in cooperatively breeding taxa are expected to foray seldomly. We used novel tracking technologies to follow 62 acorn woodpeckers (Melanerpes formicivorus), a cooperatively breeding bird, to study extra-territorial foray behavior. Both helpers and breeders engaged in extra-territorial forays routinely and often several times per day. Helpers forayed earlier in the day and invested more time when foraying to high-quality territories. …

Dormant Pathogenic Cd4(+) T Cells Are Prevalent In The Peripheral Repertoire Of Healthy Mice, Anna Cebula, Michal Kuczma, Edyta Szurek, Maciej Pietrzak, Natasha Savage, Wessam R. Elhefnawy, Grzegorz Rempala, Piotr Kraj, Leszek Ignatowicz

Computer Science Faculty Publications

Thymic central tolerance eliminates most immature T cells with autoreactive T cell receptors (TCR) that recognize self MHC/peptide complexes. Regardless, an unknown number of autoreactive CD4+Foxp3⁻ T cells escape negative selection and in the periphery require continuous suppression by CD4+Foxp3⁺ regulatory cells (Tregs). Here, we compare immune repertoires of Treg-deficient and Treg-sufficient mice to find Tregs continuously constraining one-third of mature CD4⁺Foxp3⁻ cells from converting to pathogenic effectors in healthy mice. These dormant pathogenic clones frequently express TCRs activatable by ubiquitous autoantigens presented by class II MHCs on conventional dendritic cells, including selfpeptides that select …

Global Conservation Status And Threat Patterns Of The World’S Most Prominent Forage Fishes (Teleostei, Clupeiformes), Tiffany L. Birge

Biological Sciences Theses & Dissertations

Conserving biodiversity is one of the greatest ethical responsibilities and challenges humans face. Understanding the conservation status of taxonomic groups provides a systematic way to prioritize efforts to combat biodiversity loss. The 405 species within the order Clupeiformes are the herrings, shads, sardines, anchovies, menhadens and relatives that include many of the most important marine forage fishes. These small, schooling fishes are economically, ecologically and culturally significant globally. Despite their contribution to global fisheries and our increasing reliance on these fishes for food and industrial commodities, they are generally poorly known with limited information regarding basic biology and population trends. …

Electrostatically Localized Proton Bioenergetics: Better Understanding Membrane Potential, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

In Mitchell's chemiosmotic theory, membrane potential Δψ was given as the electric potential difference across the membrane. However, its physical origin for membrane potential Δψ was not well explained. Using the Lee proton electrostatic localization model with a newly formulated equation for protonic motive force (pmf) that takes electrostatically localized protons into account, membrane potential has now been better understood as the voltage difference contributed by the localized surface charge density ([H-⁺_L] + ⁿΣ _i=1 [M⁽ⁱ⁺⁾_L]) at the liquid-membrane interface as in an electrostatically localized protons/cations-membrane-anions capacitor. That is, the origin of membrane …

Lipid Biomarkers Of Bering And Chukchi Sea Euphausiids And Their Application To Diet History, Rachel L. Pleuthner

OES Theses and Dissertations

In the eastern Bering Sea, Thysanoessa raschii are the most abundant krill species and a keystone trophic member that serve as both an important grazer and link to upper level consumers. In this system krill experience large annual variation in food resources, especially during ice advance and retreat; multiple lipid classes are used to temper the effects of those fluctuations, as well as to fuel reproduction and growth. Two shipboard feeding experiments that occurred during late spring and early summer of 2010, respectively, monitored the lipid retention in adult T. raschii and examined the fluctuation of specific lipid biomarkers under …

Host Genetics And Geography Influence Microbiome Composition In The Sponge Ircinia Campana, Sarah M. Griffiths, Rachael E. Antwis, Luca Lenzi, Anita Lucaci, Donald C. Behringer, Mark J. Butler, Richard F. Preziosi

Biological Sciences Faculty Publications

1. Marine sponges are host to large, diverse communities of microorganisms. These microbiomes are distinct among sponge species and from seawater bacterial communities, indicating a key role of host identity in shaping its resident microbial community. However, the factors governing intraspecific microbiome variability are underexplored, and may shed light on the evolutionary and ecological relationships between host and microbiome.

2. Here, we examined the influence of genetic variation and geographic location on the composition of the Ircinia campana microbiome.

3. We developed new microsatellite markers to genotype I. campana from two locations in the Florida Keys, USA, and characterised their …

In Hot Water: Thermal Acclimation Is Insufficient To Save Corals In The Anthropocene, Harmony Alise Martell

Biological Sciences Theses & Dissertations

Scleractinian corals are animal partners in exquisite symbioses with a suite of algal, microbial, fungal and viral associates comprising miniature ecosystems collectively referred to as a holobiont. In recent decades, ocean warming has jeopardized the delicate balance of the very symbioses that have enabled coral survival. Thermal stress causes a reduction of algal symbionts, a phenomenon referred to as ‘coral bleaching’ that represents dysbiosis in the holobiont and often leads to mortality. Current thermal acclimation theory states variation and gradual increases in temperature can ameliorate thermal stress. Indeed, there is evidence some coral species have some capacity to acclimatize to …

Targeting The Pin Domain Of Type Ii Toxins Is A Novel Approach To Treat Infections Caused By Nontypeable Haemophilus Influenzae, Ashley Lynne Molinaro

Biomedical Sciences Theses & Dissertations

Toxin-antitoxin (TA) gene pairs have been identified in nearly all bacterial genomes sequenced to date and are thought to facilitate persistence and antibiotic tolerance. TA loci are classified into various types based upon the characteristics of their antitoxins, with those in type II expressing proteic antitoxins. Many toxins from type II modules are ribonucleases that maintain a PilT N-terminus (PIN) domain containing conserved amino acids considered essential for activity. The vapBC (virulence associated protein) TA system is the largest subfamily in this class and has been linked to pathogenesis of nontypeable Haemophilus influenzae (NTHi). This dissertation presents three studies investigating …