Life Sciences Commons^™

Genetic Diversity Of Kemp's Ridley (Lepidochelys Kempii) Sea Turtles On South Padre Island, Texas, Hilary R. Frandsen

Theses and Dissertations

In 2010, researchers observed an abrupt decline in nesting numbers of the Kemp’s ridley following 35 years of positive growth. In wake of this halt, and subsequent lowered nesting averages, evaluation of the genetic diversity of remaining individuals is relevant to investigate the plausibility of a genetic bottleneck, and determine the reproductive stability of the Kemp’s ridley.

Here, I evaluate the genetic diversity within a sampling of the Kemp’s ridleys on South Padre Island using two methods: targeting the mitochondrial control region and targeting the complete mitochondrial genome. Opportunistic samples were donated from juvenile ridleys on the East coast, and …

Phylogeography Of An Estuarian Calanoid Copepod; Acartia Tonsa In The Texas Gulf Of Mexico, Nicole J. Figueroa

Theses and Dissertations

The calanoid copepod, Acartia tonsa is one of the most abundant and well-studied estuarian species. However, the idea that this cosmopolitan species has unrestricted dispersal and high gene flow has been challenged. In this study, a more holistic picture of the phylogeography of A. tonsa was developed using the mitochondrial gene cytochrome oxidase one (mtCOI). Multiple new lineages were found in the Texas Gulf of Mexico that are basal to Northeastern Atlantic lineages. Connectivity was also observed between Brazil and the Texas Gulf of Mexico. The revised phylogeny shows a clear pattern of cryptic speciation as the species made a …

Foxo3 Regulation Of Stem Cell Markers Oct4 And Sox2 In Pten-Null Glioblastomas, Eduardo Martinez

Theses and Dissertations

The PI3K pathway controls many cellular processes such as cell growth, survival, metabolism, apoptosis, and differentiation. Canonically, PI3K activates AKT leading to subsequent nuclear exportation of FOXO transcription factors. Dysregulation of the PI3K pathway is a hallmark in many cancers and often is attributable to a null mutation in PTEN. PTEN is a phosphatase that reverses the reactions catalyzed by PI3K. Loss of PTEN leads to constitutive inactivation of tumor suppressor FOXO proteins. However, there is increasing evidence that FOXO may still reside and promote transcriptional activity in the nucleus despite high PI3K output within certain advance cancers and …

Morganella Morganii (Enterobacteriales: Enterobacteriaceae) Is A Lethal Pathogen Of Mexican Fruit Fly (Diptera: Tephritidae) Larvae, Bacilio Salas, Hugh E. Conway, Erin Schuenzel, Kristen Hopperstad, Christopher Vitek, Don C. Vacek

Biology Faculty Publications and Presentations

Tephritid pests, such as the Mexican fruit fly, Anastrepha ludens (Loew), represent a major threat to fruit production worldwide. In order to control these pests, sterile insect technique is used to suppress and eradicate wild populations. For this control method to be successful, hundreds of millions of flies must be produced weekly in mass rearing facilities. The large quantity of artificial diet and close proximity of flies at various life stages allows bacteria from family Enterobacteriaceae, Bacillaceae, Pseudomonadaceae, and others to multiply and spread more easily. In this study, bacteria with a possible pathogenic effect were isolated from Mexican fruit …

Gastrin Induces Nuclear Export And Proteasomal Degradation Of Menin In Enteric Glial Cells, Sinju Sundaresan, Cameron A. Meininger, Anthony J. Kang, Amanda L. Photenhauer, Michael M. Hayes, Nirakar Sahoo, Jolanda Lindenberg, Jolanta Grembecka, Tomasz Cierpicki, Lin Ding

Biology Faculty Publications and Presentations

Background & aims: The multiple endocrine neoplasia, type 1 (MEN1) locus encodes the nuclear protein and tumor suppressor menin. MEN1 mutations frequently cause neuroendocrine tumors such as gastrinomas, characterized by their predominant duodenal location and local metastasis at time of diagnosis. Diffuse gastrin cell hyperplasia precedes the appearance of MEN1 gastrinomas, which develop within submucosal Brunner's glands. We investigated how menin regulates expression of the gastrin gene and induces generation of submucosal gastrin-expressing cell hyperplasia.

Methods: Primary enteric glial cultures were generated from the VillinCre:Men1FL/FL:Sst-/- mice or C57BL/6 mice (controls), with or without inhibition of gastric acid by omeprazole. Primary …

Utilizing Accelerometer Telemetry Tags To Compare Red Snapper (Lutjanus Campechanus) Behavior On Artificial And Natural Reefs, Ethan T. Getz

Theses and Dissertations

The Texas Parks and Wildlife Department Artificial Reef Program has deployed over 2,800 hectares of reefing area composed of petroleum platforms, steel vessels, and concrete. Artificial reefs have been shown to support many important reef fishes such as red snapper (Lutjanus campechanus), however, few studies have compared fish behavior on artificial reefs and natural habitats. We examined activity levels, behavioral patterns and habitat preferences of red snapper over natural reefs, oil platforms and submerged ships. Telemetry tags (Sonotronics model MTT) with tri-axial acceleration range, average depth, and average temperature were programmed to optimize data collection and tag life. …

Co-Independent Modification Of K+ Channels By Tricarbonyldichlororuthenium(Ii) Dimer (Corm-2), Guido Gessner, Nirakar Sahoo, Sandip M. Swain, Gianna Hirth, Roland Schönherr, Ralf Mede, Matthias Westerhausen, Hans Henning Brewitz, Pascal Heimer, Diana Imhof

Biology Faculty Publications and Presentations

Although toxic when inhaled in high concentrations, the gas carbon monoxide (CO) is endogenously produced in mammals, and various beneficial effects are reported. For potential medicinal applications and studying the molecular processes underlying the pharmacological action of CO, so-called CO-releasing molecules (CORMs), such as tricabonyldichlororuthenium(II) dimer (CORM-2), have been developed and widely used. Yet, it is not readily discriminated whether an observed effect of a CORM is caused by the released CO gas, the CORM itself, or any of its intermediate or final breakdown products. Focusing on Ca2+- and voltage-dependent K+ channels (KCa1.1) and voltage-gated K+ channels (Kv1.5, Kv11.1) relevant …

A Metadata Reporting Framework (Frames) For Synthesis Of Ecohydrological Observations, Danielle S. Christianson, Charuleka Varadharajan, Bradley O. Christoffersen, Matteo Detto, Boris Faybishenko, Bruno O. Gimenez, Val Hendrix, Kolby J. Jardine, Robinson Negron-Juarez, Gilberto Z. Pastorello

Biology Faculty Publications and Presentations

Metadata describe the ancillary information needed for data preservation and independent interpretation, comparison across heterogeneous datasets, and quality assessment and quality control (QA/QC). Environmental observations are vastly diverse in type and structure, can be taken across a wide range of spatiotemporal scales in a variety of measurement settings and approaches, and saved in multiple formats. Thus, well-organized, consistent metadata are required to produce usable data products from diverse environmental observations collected across field sites. However, existing metadata reporting protocols do not support the complex data synthesis and model-data integration needs of interdisciplinary earth system research. We developed a metadata reporting …

Filtering Out Parasites: Sand Crabs (Lepidopa Benedicti) Are Infected By More Parasites Than Sympatric Mole Crabs (Emerita Benedicti), Zen Faulkes

Biology Faculty Publications and Presentations

Two digging decapod crustaceans, the sand crab species Lepidopa benedicti and the mole crab species Emerita benedicti, both live in the swash zone of fine sand beaches. They were examined for two parasites that infect decapod crustaceans in the region, an unidentified nematode previously shown to infect L. benedicti, and cestode tapeworm larvae, Polypocephalus sp., previously shown to infect shrimp (Litopenaeus setiferus). Lepidopa benedicti were almost always infected with both parasite species, while E. benedicti were rarely infected with either parasite species. This difference in infection pattern suggests that tapeworms are ingested during sediment feeding in …

T6ss Intraspecific Competition Orchestrates Vibrio Cholerae Genotypic Diversity, Benjamin Kostiuk, Daniel Unterweger, Daniele Provenzano, Stefan Pukatzki

Biology Faculty Publications and Presentations

Vibrio cholerae is a diverse species that inhabits a wide range of environments from copepods in brackish water to the intestines of humans. In order to remain competitive, V. cholerae uses the versatile type-VI secretion system (T6SS) to secrete anti-prokaryotic and anti-eukaryotic effectors. In addition to competing with other bacterial species, V. cholerae strains also compete with one another. Some strains are able to coexist, and are referred to as belonging to the same compatibility group. Challenged by diverse competitors in various environments, different V. choleare strains secrete different combination of effectors - presumably to best suit their niche. Interestingly, …

Oxidative Insults Disrupt Mitochondrial Dynamics, Iraselia A. Garcia

Theses and Dissertations

Mitochondria form an organellar network to provide ATP to the cell. Mitochondrial DNA (mtDNA) combines with nuclear DNA to encode polypeptides critical to forming the complexes of oxidative phosphorylation in the mitochondrial inner membrane, which generate a transmembrane potential (ΔΨm) to synthesize ATP. This ΔΨm is required to maintain mitochondria fission/fusion dynamics: organellar fusion (mediated by OPA1) and fission events (mediated by DRP1) coordinately regulate mitochondrial dynamics. While oxidative stress correlates with mitochondrial dysfunction, it is unclear how oxidants affect mitochondrial structure/function homeostasis. This project seeks to establish and examine the impact of reactive oxygen species (ROS) on mitochondrial dynamics. …

Central Precocious Puberty Alters The Mammary Gland Epithelial Landscape In Female Rats, Alina M. Hamilton

Theses and Dissertations

Precocious puberty (PP) is a serious endocrine disorder associated with an increased risk for development of breast cancer (BC) later in life. However, the lack of a strong in vivo model has made it difficult to study this relationship. Our group has established manganese (Mn) as a non-toxic activator of the pubertal process. Recently we demonstrated that Mn-induced precocious puberty (MnPP) accelerates E2-regulated mammary gland (MG) development in prepubertal female rats, resulting in persistent proliferation and adult hyperplasia. Using this model, I demonstrate that precocious puberty alters steroidal regulation of proliferation in both the prepubertal and adult virgin MG, altering …

Effectiveness Of The Flipped Classroom Model In Anatomy And Physiology Laboratory Courses At A Hispanic Serving Institution, Gerardo Sanchez

Theses and Dissertations

A flipped laboratory model involves significant preparation by the students on lab material prior to entry to the laboratory. This allows laboratory time to be focused on active learning through experiments. The aim of this study was to observe changes in student performance through the transition from a traditional laboratory format, to a flipped format. The data showed that for both Anatomy and Physiology (I and II) laboratories a more normal distribution of grades was observed once labs were flipped and lecture grade averages increased. Chi square and analysis of variance tests showed grade changes to a statistically significant degree, …

Linking Plant Hydraulics And Beta Diversity In Tropical Forests, Bradley O. Christoffersen, Patrick Meir, Nate G. Mcdowell

Biology Faculty Publications and Presentations

This article is a Commentary on Cosme et al., 215: 113–125.

Resaca Supports Range Expansion Of Invasive Apple Snails (Pomacea Maculata Perry, 1810; Caenogastropoda: Ampullariidae) To The Rio Grande Valley, Texas, Kathryn E. Perez, Victoria Garcia Gamboa, Caitlin M. Schneider, Romi L. Burks

Biology Faculty Publications and Presentations

Resacas, or oxbow lakes, form from old river channels. In the Rio Grande, resacas provide habitat for diverse wildlife, including native and non-native species. Biologists unexpectedly found pink egg masses on emergent vegetation (November 2015) and later adult apple snails (May 2016) within a resaca at a former fish hatchery in Brownsville, Texas. This report extends the non-native range of Pomacea maculata Perry, 1810 by 429 km southeast in Texas. Our findings imply that abandoned waterbodies, such as fish hatcheries, can act as unrecognized conduits for non-native invasive species.

Decomposition Of Black Mangrove (Avicennia Germinans ) Leaf Litter: Calibrating Estuarine Indicators Of Functional Recovery, Leticia Martinez Contreras

Theses and Dissertations

Decomposition of plant material produced by mangroves and other macrophytes in estuaries occurs in both sediments and the water column. Early and intense processing could be more common in the water. In a previous study, in situ decomposition rates of Black Mangrove (Avicennia germinans ) leaf litter suspended in the water column differed among three estuaries in south Texas with moderate differences in salinity, water temperature, available nitrogen (N), and tidal flow. A series of microcosm experiments were conducted to determine the influence, within observed ranges in the estuaries, of these water variables on mass loss of Black Mangrove …

The Vocal Babbling Behavior And Its Sibling Effects In A Wild Parrot, Tatiana Dolgushina

Theses and Dissertations

Vocal learning is a rare trait in the animal kingdom, defined as the sensorimotor imitation of sounds, and is only found in select groups of birds and mammals. Parrots are a behaviorally complex group of birds, famous for their ability to mimic social companions, but how they develop this ability in the wild has received little attention. The vocal learning period consists of a complex vocal babbling stage, a crucial developmental precursor for imitation of adult vocalizations in humans and songbirds, but has not been described in any of the 360+ parrot species. This project quantifies potential individual variation in …

Applications Of Side Scan And Parametric Echosounders For Mapping Shallow Seagrass Habitats And Their Associated Organic Carbon, Austin L. Greene

Theses and Dissertations

Despite a global valuation of $1.9 trillion seagrass habitats world-wide are in decline—directly impacting the large soil carbon stocks associated with seagrasses. Many methods exist to measure the health of seagrass habitats, yet few apply to shallow coastal ecosystems. Those that do lack spatial resolution (satellite surveys) or do not provide continuous data across large areas (point-based surveys). Furthermore, carbon content of these ecosystems is largely limited to destructive and time-consuming soil core sampling. Side scan and parametric acoustics represent a unique technological opportunity to study habitat coverage and carbon content of vegetated coastal habitats (< 3 m depth). This study presents proof of concept for applications of recreational side scan and parametric sub-bottom profiling sonars in mapping both habitat coverage and organic carbon distribution in shallow seagrass habitats, and explores how these methods might be improved in future applications.

Increasing Marine Debris Awareness Through Public Education And Analyzing Fish For Microplastic And Pollutant Contamination, Stephanie R. Dubois

Theses and Dissertations

Marine debris is any persistent solid material that is manmade and then disposed of into the world’s oceans. Outreach and education was used in combination with biological research using an indicator fish species to raise awareness about the impacts of marine debris and encourage change in behavior to reduce marine debris. Pre and post surveys were administered during marine debris education tours for K-12 students at the Coastal Studies Lab on South Padre Island, Texas to determine change in knowledge and behavior regarding marine debris. Pinfish were collected from Laguna Madre and stomachs and livers removed for microplastics content and …

Multifunctionality Of Cover Crops On Organic Vegetable Farms In South Texas, Savannah M. Rugg

Theses and Dissertations

Situated in deep South Texas, the Lower Rio Grande Valley (LRGV) is considered one the most productive agricultural regions in the southern US. With the highest concentration of organic farms in the state (Hidalgo county), finding management practices that comply with organic certification is increasingly pertinent. Cover cropping can serve multiple functions in an agroecosystem such as: suppressing weeds, increasing soil organic matter (SOM), increasing soil nitrates, and enhancing soil biodiversity. The four cover crops (lablab, sunn hemp, sudangrass, and pearl millet) were assessed to see their potential to increase soil nitrogen, to increase soil organic matter, and to suppress …

Genetic Variation In Two Economically Important Arthropod Vectors Of Citrus Diseases, Alejandra Fuentes

Theses and Dissertations

Arthropod vectors are agriculturally and ecologically important because they transmit numerous plant pathogens. Commonly, control strategies for vector-borne plant pathogens focus on suppression of vector populations. Genetic variation studies in pest populations provide useful information for biological control, understanding pesticide resistance, and inferring global movement patterns. In chapter I, genetic variation of worldwide populations of Diaphorina citri, the vector of Citrus greening disease, was examined to assess potential sites of origin of invasive populations. The results showed population structure at regional levels, suggesting limited gene flow and revealing patterns of invasion. In chapter II, I explored the community of …

Assessment Of Long-Term Effects Of Woody Plants Expansion In Humid, Tropical Grassland Of Venezuela, Soraya A. Delgado

Theses and Dissertations

The invasion of woody plants into grassland communities, or shrub encroachment, is a worldwide phenomenon usually attributed to anthropogenic interference. Most studies have focused on temperate and arctic biomes. Less is known about how shrub encroachment is affecting humid tropical grasslands, which have different climates, higher levels of biodiversity and different histories of human land use. This project quantifies the rate of woody vegetation change in a humid tropical grassland of Venezuela using remote sensing over the past quarter century and ground based measurements of selected individual species. Results of remote sensing indicate high rates of conversion of grasslands to …

The Phenology Of Sand Crabs, Lepidopa Benedicti (Decapoda: Albuneidae), Zen Faulkes

Biology Faculty Publications and Presentations

Albuneid sand crabs are widespread on sandy beaches around the world, but because they conceal themselves by digging in sand and are often found at low densities, little is known about their basic biology. Lepidopa species were collected from the beaches of South Padre Island, Texas, on the western coast of Gulf of Mexico, a location that had previously been suggested to act as a population sink. The site contained Lepidopa benedicti and L. websteri, although the latter was extremely rare (collected three times in 5 years). There was significant variation in abundance across the year, with higher densities …

The Role Of Language In Anatomy And Physiology Instruction, Angela M. Chapman, Hsuying C. Ward, Ashwini Tiwari, Amy Weimer, Jaime B. Duran, Federico Guerra, Robert Paul Sale

Teaching and Learning Faculty Publications and Presentations

Research indicates that student learning of science, student attitudes toward science, and their motivation to learn science and pursue science-related careers is related to classroom instruction. This study examined anatomy and physiology (A&P) classes in a south Texas high school where 97 percent of students are Hispanic bilingual learners. Classes were assigned to control or treatment groups, with the treatment group receiving instruction designed to help students develop a deeper understanding of anatomy vocabulary related to brain structures by making connections to these words in everyday life as well as to their understanding of Spanish. Main effects between group and …

Efectos Del Cambio Climático En La Interacción Planta-Hormiga: Una Mini Revisión Sobre La Tolerancia Térmica, Florencio Luna Castellanos, Mariana Cuautle, Teresa Patricia Feria-Arroyo, Citlalli Castillo Guevara

Biology Faculty Publications and Presentations

Sin duda alguna el clima está cambiando debido al aumento de la concentración de gases de efecto invernadero en la atmósfera provocado por la acción humana. Dichos cambios van a tener un efecto importante en algunas actividades humanas tales como la agricultura y también pueden afectar enormemente la distribución geográfica de los organismos vivos y por tanto sus interacciones. Las hormigas y las plantas tienen una larga historia evolutiva de interacción. La actividad de las hormigas y su relación con las plantas en los últimos años ha tenido un número creciente de estudios que están poniendo de relieve su papel …

Protective Effect Of Anti-Phosphatidylserine Antibody In A Guinea Pig Model Of Advanced Hemorrhagic Arenavirus Infection, John M. Thomas, Philip E. Thorpe

Biology Faculty Publications and Presentations

Objective: Host derived markers on virally infected cells or virions may provide targets for the generation of antiviral agents. Recently, we identified phosphatidylserine (PS) as a host marker of virions and virally-infected cells.

Methods and Materials: Under normal physiological conditions, PS is maintained on the inner leaflet of the plasma membrane facing the cytosol. Following viral infection, activation or pre-apoptotic changes cause PS to become externalized. We have previously shown that bavituximab, a chimeric human-mouse antibody that binds PS complexed with β2-glycoprotein I (β2GP1), protected rodents against lethal Pichinde virus and cytomegalovirus infections.

Results: Here, we determined the antiviral activity …

The Biological Flora Of Coastal Dunes And Wetlands: Avicennia Germinans (L.) L., Robert I. Lonard, Frank W. Judd, Kenneth R. Summy, Hudson R. Deyoe, Richard Stalter

Biology Faculty Publications and Presentations

Avicennia germinans (L.) L. is a pantropical, subtropical, and occasionally warm-temperate mangrove species that occurs on shorelines that have a broad horizontal tidal range. Also known as black mangrove, stands typically develop under anoxic, water-logged conditions in substrates of silt or clay. Black mangrove can tolerate salinity values ranging from 0 to 90 parts per thousand. Salt is excreted from salt glands on both leaf epidermal surfaces, and aerosol salt spray and salt crystals are frequently observed on the upper leaf epidermis. Avicennia germinans is viviparous. The embryos have no dormancy requirements, and there is no seed bank. This mangrove …

Survivorship And Growth Among Three Developmental Stages Of Black Mangrove (Avicennia Germinans) Seedlings In Southernmost Texas, Frank W. Judd, Kenneth R. Sunny, Robert I. Lonard, Ruben A. Mazariegos

Biology Faculty Publications and Presentations

Black mangrove is useful for shoreline stabilization in Texas and Mexico but there is insufficient information regarding propagule survivorship and seedling growth. We compared survivorship and growth of three develop-mental groups of black mangrove seedlings planted on three dredge spoil islands in the Lower Laguna Madre of Texas, to better understand optimum planting strategy. Each spoil island had 100 seedlings without emergent radicles, 100 seedlings with emergent radicles, and 75 head-started seedlings. Survivorship of seedlings with and with-out emergent radicles was low, (0-16%). Survivorship of head-started seedlings was higher, (60 – 62.7%). Varia-tion in survivorship among developmental categories was significant …

Fish Oil With Higher Dha Content And Voluntary Exercise Decreases Postmenopausal Bone Loss, Jameela Banu, Gabriel Fernandes

Biology Faculty Publications and Presentations

There is increasing evidence suggesting that fish oil (FO) decreases bone resorption by reducing osteoclastogenesis and regular exercise (EX) increases bone mass. EX is associated with increasing bone formation. Therefore, the combined effects of FO intake and EX may have additive effects by both increasing bone formation and decreasing bone resorption. To demonstrate this, we studied the effects of FO and EX on the bone of mice after an ovariectomyinduced bone loss.

Twelve months old C57BL/6 female mice were either sham operated or ovariectomized, divided into different dietary and EX group and maintained for 3 months before sacrifice.

The distal …