Life Sciences Commons^™

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …

Late Pleistocene Range Expansion Of North American Topminnows Accompanied By Admixture And Introgression, David D. Duvernell, Eric Westhafer, Jacob F. Schaefer

Faculty Publications

Aim: We used genome‐scale sampling to assess the phylogeography of a group of topminnows in the Fundulus notatus species complex. Two of the species have undergone extensive range expansions resulting in broadly overlapping distributions, and sympatry within drainages has provided opportunities for hybridization and introgression. We assessed the timing and pattern of range expansion in the context of late Pleistocene–Holocene drainage events and evaluated the evidence for introgressive hybridization between species.

Location: Central and southern United States including drainages of the Gulf of Mexico Coastal Plain and portions of the Mississippi River drainage in and around the Central …

Preliminary Investigation Of A Diverse Megafossil Floral Assemblage From The Middle Miocene Of Southern Mississippi, Usa, Daniel M. Mcnair, Debra Z. Stults, Brian Axsmith, Mac H. Alford, James E. Starnes

Faculty Publications

Our understanding of Miocene floras in eastern North America is hampered by the rarity of megafossil sites. An early report from the middle Miocene Hattiesburg Formation in Mississippi included palms and Ulmus. A later report listed Taxodium, Salix, either Morus or Celtis, and monocot fragments. The floral assemblage described here was recently recovered from along the Bouie River in southern Mississippi. Ferns are represented by complete Salvinia specimens including attached sporocarps, Woodwardia, and Osmunda. Conifers are represented by branchlets of Taxodium. Angiosperms include leaves attributable to the Lauraceae. Platanus is known from leaves, stipules, and fruits. …

Scale Dependence Of Sex-Specific Movement In A Small-Bodied Stream Fish, Scott R. Clark, Brian R. Kreiser, Jacob F. Schraefer, Laura K. Stewart

Faculty Publications

1. Animal movement at localised scales is often modulated by competing pressures such as avoiding predators while acquiring resources and mates. The relative magnitude of these trade‐offs may affect males and females differently, often resulting in sex‐specific differences in movement.
2. Sex‐biases in movement have been linked to mating systems (e.g. monogamy or polygamy) in birds and mammals; however, this relationship has received less attention among fishes. Using passive integrated transponder tags and a series of stationary antennas, we evaluated the movement dynamics of a small‐bodied, sexually dimorphic stream fish Fundulus olivaceus over a 30‐day period in a fourth‐order tributary to the …

Linking Nutrient Stoichiometry To Zika Virus Transmission In A Mosquito, Andrew S. Paige, Shawna K. Bellamy, Barry W. Alto, Catherine L. Dean, Donald A. Yee

Faculty Publications

Food quality and quantity serve as the basis for cycling of key chemical elements in trophic interactions; yet the role of nutrient stoichiometry in shaping host–pathogen interactions is under appreciated. Most of the emergent mosquito-borne viruses affecting human health are transmitted by mosquitoes that inhabit container systems during their immature stages, where allochthonous input of detritus serves as the basal nutrients. Quantity and type of detritus (animal and plant) were manipulated in microcosms containing newly hatched Aedes aegypti mosquito larvae. Adult mosquitoes derived from these microcosms were allowed to ingest Zika virus-infected blood and then tested for disseminated infection, transmission, …

Discovery And Characterization Of Bacteriophage Luckybarnes, Savannah L. Underwood, Amanda Foto, Amanda F. Ray, Alexander E. Nelms, Keyshawn L. Kennedy, Shelby G. Hartley, Logan M. Ryals, Chandan Gurung, William A. D'Angelo, Welkin H. Pope, Dmitri V. Mavrodi

Faculty Publications

Here, we report the genome sequence of LuckyBarnes, a newly isolated singleton siphovirus that infects Brevibacterium iodinum ATCC 15728 and has a 50,774-bp genome with 67 predicted genes.

Repurposing Of Glycine-Rich Proteins In Abiotic And Biotic Stresses In The Lone-Star Tick (Amblyomma Americanum), Rebekah Bullard, Surendra Raj Sharma, Pradipta Kumar Das, Sarah E. Morgan, Shahid Karim

Faculty Publications

Tick feeding requires the secretion of a huge number of pharmacologically dynamic proteins and other molecules which are vital for the formation of the cement cone, the establishment of the blood pool and to counter against the host immune response. Glycine-rich proteins (GRP) are found in many organisms and can function in a variety of cellular processes and structures. The functional characterization of the GRPs in the tick salivary glands has not been elucidated. GRPs have been found to play a role in the formation of the cement cone; however, new evidence suggests repurposing of GRPs in the tick physiology. …

Linking Water Quality To Aedes Aegypti And Zika In Flood-Prone Neighborhoods, Susan Harrell Yee, Donald A. Yee, Rebeca De Jesus Crespo, Autumn Oczkowski, Fengwei Bai, Stephanie Friedman

Faculty Publications

The ability of ecosystems to regulate water quality and flood events has been linked to health outcomes, including mosquito-borne illnesses. In the San Juan Bay Estuary watershed of Puerto Rico, habitat alterations and land-use development have disrupted watershed hydrology, exacerbating wastewater discharges and subjecting some neighborhoods to frequent flooding events. In 2016, the mosquito-borne illness Zika became a new cause for concern. We hypothesized that nutrient-enriched flood water could provide pulses of supplemental nutrients to local mosquito populations. We conducted a field study in six neighborhoods adjacent to the estuary to assess whether environmental variability of nutrient inputs could be …

Is Selenoprotein K Required For Borrelia Burgdorferi Infection Within The Tick Vector Ixodes Scapularis?, Deepak Kumar, Monica Embers, Thomas N. Mather, Shahid Karim

Faculty Publications

Background: Tick selenoproteins are involved in regulating oxidative and endoplasmic reticulum stress during prolonged tick feeding on mammalian hosts. How selenoproteins are activated upon tick-borne pathogen infection is yet to be defined.

Methods: To examine the functional role of selenoprotein K in Borrelia burgdorferi infection within the tick host Ixodes scapularis, RNA interference (RNAi)-based gene silencing was performed.

Results: Selenoprotein K is an endoplasmic reticulum (ER)-resident protein and a component of the ERAD complex involved in ER homeostasis. A qRT-PCR assay revealed the significant upregulation of selenogene K (selenoK) expression in B. burgdorferi-infected …

The Incorporation Of Lipids Into The Cellular Membrane Of Salmonella, Betsy H. Redfern

Honors Theses

Salmonella is a gram negative, facultative anaerobic food borne pathogen and is the leading cause of deaths related to food borne illnesses. In order to establish an infection successfully, Salmonella must be able to survive in the presence of various stressors that it encounters, namely changes in pH, oxygen availability, osmolarity and bile. Previous research has shown that exposure to bile causes a shift in fatty acid composition in the cell membrane of the enteric bacterium Enterococcus faecalis. Thus, this led to the hypothesis that Salmonella incorporates fatty acids into its cellular membrane following exposure to bile and thereby protects …

Comparison Of Anthracnose Resistance With The Presence Of Two Scar Markers Associated With The Rca2 Gene In Strawberry, Melinda A. Miller-Butler, Barbara J. Smith, Brian R. Kreiser, Eugene K. Blythe

Faculty Publications

Strawberry anthracnose diseases are caused primarily by three Colletotrichum species: C. acutatum J.H. Simmonds, C. fragariae A.N. Brooks, and C. gloeosporioides (Penz.) Penz. & Sacc. Molecular markers are being used in breeding programs to identify alleles linked to disease resistance and other positive agronomic traits. In our study, strawberry cultivars and breeding germplasm with known anthracnose susceptibility or resistance to the three anthracnose-causing Colletotrichum species were screened for two sequence characterized amplified region (SCAR) markers linked to the Rca2 gene. The Rca2 resistant allele SCAR markers were associated with varying degrees of significance for a strawberry plant’s anthracnose resistance to …

Methylation-Specific Differentiation Of Vaginal Epithelial Cells For Forensic Tissue Typing By Bisulfite Conversion And Pyrosequencing, Elise Pood

Master's Theses

The identification of bodily fluids and tissues is often applied to criminal investigations to clarify events that may or may not have taken place. Current forensic techniques can identify blood, saliva, seminal fluid, and spermatozoa, but there is a clear absence of reliable testing to identify vaginal epithelial tissue. Though there are serological tests available for this purpose, tissue-specific methylation markers have recently been investigated as a candidate for the identification of blood, saliva, and spermatozoa.

In this study, tissue-specific methylation markers were analyzed to identify a set of markers for the differentiation of vaginal fluid from blood, saliva, and …

Algal-Mediated Priming Effects On The Ecological Stoichiometry Of Leaf Litter Decomposition: A Meta-Analysis, Halvor M. Halvorson, Steven N. Francoeur, Robert H. Findlay, Kevin A. Kuehn

Faculty Publications

In aquatic settings, periphytic algae exude labile carbon (C) that can significantly suppress or stimulate heterotrophic decomposition of recalcitrant C via priming effects. The magnitude and direction of priming effects may depend on the availability and stoichiometry of nutrients like nitrogen (N) and phosphorus (P), which can constrain algal and heterotrophic activity; in turn, priming may affect heterotrophic acquisition not only of recalcitrant C, but also N and P. In this study, we conducted a meta-analysis of algal-mediated priming across leaf litter decomposition experiments to investigate (1) bottom-up controls on priming intensity by dissolved N and P concentrations, and (2) …

The Strength Of Migratory Connectivity For Birds En Route To Breeding Through The Gulf Of Mexico, Emily B. Cohen, Clark R. Rushing, Frank R. Moore, Michael T. Hallworth, Jeffrey A. Hostetler, Mariamar Gutierrez Ramirez, Peter P. Marra

Faculty Publications

The strength of migratory connectivity is a measure of the cohesion of populations among phases of the annual cycle, including breeding, migration, and wintering. Many Nearctic‐Neotropical species have strong migratory connectivity between breeding and wintering phases of the annual cycle. It is less clear if this strength persists during migration when multiple endogenous and exogenous factors may decrease the cohesion of populations among routes or through time along the same routes. We sampled three bird species, American redstart Setophaga ruticilla, ovenbird Seiurus aurocapilla, and wood thrush Hylocichla mustelina, during spring migration through the Gulf of Mexico region …

Periphytic Algae Decouple Fungal Activity From Leaf Litter Decomposition Via Negative Priming, Halvor M. Halvorson, Jacob R. Barry, Matthew B. Lodato, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn

Faculty Publications

1. Well‐documented in terrestrial settings, priming effects describe stimulated heterotrophic microbial activity and decomposition of recalcitrant carbon by additions of labile carbon. In aquatic settings, algae produce labile exudates which may elicit priming during organic matter decomposition, yet the directions and mechanisms of aquatic priming effects remain poorly tested.

2. We tested algal‐induced priming during decomposition of two leaf species of contrasting recalcitrance, Liriodendron tulipifera and Quercus nigra, in experimental streams under light or dark conditions. We measured litter‐associated algal, bacterial, and fungal biomass and activity, stoichiometry, and litter decomposition rates over 43 days.

3. Light increased algal biomass and …