Life Sciences Commons^™

Alterations In Ether Lipid Metabolism In Obesity Revealed By Systems Genomics Of Multi-Omics Datasets, Yvette Schooneveldt, Sudip Paul, Kevin Huynh, Habtamu B. Beyene, Natalie A. Mellett, Gerald F. Watts, Joseph Hung, Jennie Hui, John Beilby, John Blangero

Human Genetics Publications

Ratios between two metabolites are sensitive indicators of metabolic changes. Lipidomic profiling studies have revealed that plasma ether lipids, a class of glycero- and glycerophospho-lipids with reported health benefits, are negatively associated with obesity. Here, we utilized lipid ratios as surrogate markers of lipid metabolism to explore the processes underlying the inverse relationship between ether lipid metabolism and obesity. Plasma lipidomics data from two independent human cohorts (n = 10,339 and n = 4,492) were integrated to assess the associations between 82 lipid ratios and obesity-related markers in males and females. Results were externally validated using mouse transcriptomics data …

Identification, Abundance, And Behavior Of North American Bobcat (Lynx Rufus) Along Road Mitigation Structures Designed For Endangered Species In South Texas, Victoria Hanley, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Integrative Biological & Chemical Sciences Faculty Publications

Endangered species are increasingly used as the target species in implementing and constructing new wildlife crossing structures (WCS). Highways in South Texas fragment the landscape and result in high road mortality for endangered species such as ocelots (Leopardus pardalis, a medium-sized spotted wild cat). In response, the Texas Department of Transportation constructed nine WCS on Farm-to-Market 106 (FM 106), a road which bisects Laguna Atascosa National Wildlife Refuge in Cameron County, Texas. With ocelots being rare and elusive, bobcats (Lynx rufus) are often used as a surrogate species to study felid behavior at road mitigation structures …

Native Ticks As A Model For The Effectiveness Of Fire As A Tool For The Management Of Cattle Fever Ticks In South Texas, Lauren P. Maestas, Sarah E. Mays Maestas, Kathleen M. Yeater, Manuel Zavala, Reyes Garcia, John A. Goolsby

School of Integrative Biological & Chemical Sciences Faculty Publications

The species of cattle fever ticks (CFT) present in North America, Rhipicephalus (=Boophilus) annulatus, and R. microplus, remain an important agricultural and economic burden. The use of acaricides to control CFT has been a common practice over the past half century. However, alternative strategies for control are needed to improve the options for sustainable pest control. Fire is a tool to manage vegetation, and some evidence supports its potential for use to control ticks. We evaluated the effectiveness of fire as a management tool for ticks in South Texas. Our site was a 28.2-ha property in Cameron …

Asymmetric Fgf Receptor Dimerization: Implications For Fgf23 Biology And Drug Discovery, Mohammed S. Razzaque, Moosa Mohammadi

School of Medicine Publications

Fibroblast growth factor 23 (FGF23) requires both αKlotho and heparan sulfate proteoglycans (HSPGs) as obligatory coreceptors to bind, dimerize, and activate its FGF receptors (FGFRs) in the kidney, thereby regulating mineral ion and vitamin D homeostasis. Cryogenic electron microscopy studies reveal that FGF23 signaling proceeds through an asymmetric 1:2:1:1 FGF23–FGFR–αKlotho–HS assembly. According to this structural model, αKlotho simultaneously anchors FGF23 and one FGFR chain, referred to as the primary receptor (FGFRP), to form a 1:1:1 FGF23-FGFRP-αKlotho triplex, which boosts FGF23-FGFRP interaction. Subsequently, the HS coreceptor aids the triplex in recruiting a second FGFR chain, or secondary receptor (FGFRS), leading to …

Efficacy Of Lactobacillus Rhamnosus And Its Metabolites To Mitigate The Risk Of Foodborne Pathogens In Hydroponic Nutrient Solution, Esther Oginni, Robin A. Choudhury, Veerachandra Yemmireddy

School of Earth, Environmental, & Marine Sciences Faculty Publications

Hydroponic nutrient solution (HNS) has been established as an ideal conduit for pathogen contamination and proliferation. This study evaluated the efficacy of lactic acid bacteria and their metabolites in mitigating the risk of foodborne pathogens in HNS when compared to conventional chemical treatments. Hoagland’s HNS were prepared according to the manufacturer’s instructions and inoculated with Salmonella Typhimurium, Escherichia coli 0157:H7, and Listeria innocua at 105 CFU/mL cell concentration. These nutrient solutions were subjected to treatment with various concentrations of Lactobacillus rhamnosus live cells, a cell-free extract (CFE) of L. rhamnosus metabolites, sodium hypochlorite and peroxyacetic acid at 22 ± 1 …

Profiling Brain Morphology For Autism Spectrum Disorder With Two Cross-Culture Large-Scale Consortia, Xue-Ru Fan, Ye He, Yin-Shan Wang, Lei Li, Lifespan Brain Chart Consortium (Lbcc), China Autism Brain Imaging Consortium (Cabic), Xujun Duan, Xi-Nian Zuo, John Blangero

Human Genetics Publications

We explore neurodevelopmental heterogeneity in Autism Spectrum Disorder (ASD) through normative modeling of cross-cultural cohorts. By leveraging large-scale datasets from Autism Brain Imaging Data Exchange (ABIDE) and China Autism Brain Imaging Consortium (CABIC), our model identifies two ASD subgroups with distinct brain morphological abnormalities: subgroup “L” is characterized by generally smaller brain region volumes and higher rates of abnormality, while subgroup “H” exhibits larger volumes with less pronounced deviations in specific areas. Key areas, such as the isthmus cingulate and transverse temporal gyrus, were identified as critical for subgroup differentiation and ASD trait correlations. In subgroup H, the regional volume …

Acute Exposure Of American Oyster (Crassostrea Virginica) To Selected Antidepressant Drug: Histological, Biochemical, And Immunohistochemical Assessments, Md. Faisal Amin

Theses and Dissertations

The rapid increase in pharmaceutical use has brought significant health benefits to humans. Studies have shown that many pharmaceuticals, such as antidepressants, are often detected in surface waters, groundwater, and even drinking water. These pharmaceuticals in aquatic environments threaten marine life seriously. Marine bivalves are vital source of seafood for people worldwide. In this study, we examined the effects of short-term exposure to fluoxetine, an antidepressant used to treat depression, at low (0.5 μg/L) and high (5 μg/L) doses over a one-week period on American oysters (Crassostrea virginica) under controlled laboratory conditions. Histological analysis revealed atrophy in the gills and …

Assessment Of Floral Resources From Three Tamaulipan Thornscrub Communities Of The Lower Rio Grande Valley, Gracie Makenna Granados

Theses and Dissertations

The Tamaulipan thornscrub is a transition zone between the neotropics and the temperate regions, harboring high biodiversity. This habitat supports a diverse insect community, including many pollinators of native and cultivated plants in Texas and northeastern Mexico. This ecosystem has been extensively degraded and lost; only 5% of its original cover remains north of the Rio Grande. Restoration of the Tamaulipan thornscrub has been ongoing for over three decades, but the important roles of pollinators in the success of such efforts and the functioning of the restored ecosystem have rarely been considered in restoration efforts. The purpose of this study …

Arginine Vasotocin And Corticosterone In Nesting And Non-Nesting Loggerhead Sea Turtles In X’Cacel-X’Cacelito Sanctuary, Krista Blair Reed

Theses and Dissertations

Sea turtles exhibit distinct behaviors before and after egg laying, however, not all individuals successfully oviposit. Some females display disruptions in their typical nesting behavior, returning to the water without laying eggs, which is referred to as a non-nesting emergence (NNE). NNEs can be due to external disturbances on the beach, but why they occur is often unclear. Arginine vasotocin (AVT) is a neuropeptide involved in various physiological processes, including stimulating smooth muscle contraction of the oviduct to facilitate egg deposition in nesting sea turtles. On the other hand, corticosterone is the primary stress hormone in sea turtles and is …

Computational And Experimental Analysis Of Knee Kinematics And Gait Variability: The Effects Of Load, Speed, And Fatigue On Human Motion, Alfirio Trejo Jr.

Theses and Dissertations

This thesis investigates the biomechanical behavior of the human knee under varying conditions of motion, load, and fatigue, with a focus on clinical angle analysis and gait stability. Four studies were conducted using motion capture data and a modified Grood and Suntay Joint Coordinate System (JCS) to evaluate knee joint kinematics—specifically flexion-extension, abduction-adduction, and internal-external rotation. The first study examined the effects of incremental weight loads during isolated knee extension exercises, revealing dose-dependent increases in abduction and internal rotation that may contribute to joint stress. The second study assessed the impact of walking speed and asymmetric loading on gait, showing …

Exploring Transcriptional Stress Responses In Sorghum And Evolutionary Insights Into Yth Domain Proteins Across Plants, Shikha Bharti

Theses and Dissertations

Understanding how plants respond to abiotic stress is crucial for enhancing crop resilience in the face of climate change. This thesis explores plant stress adaptation mechanisms through two interlinked studies that address different aspects of gene regulation. The first study investigates the transcriptional dynamics of Sorghum bicolor under drought and heat stress at 1-hour and 6-hour time points. By employing 3'-end RNA sequencing, this study provides a comprehensive temporal view of gene expression changes, revealing stress-responsive transcription factors, hormone-associated pathways, and chromatin regulators. The comparative analysis highlights both common and distinct molecular responses between drought and heat stress, providing insights …

Biological, Histological, And Immunohistochemical Responses To Heat Stress In Common Goldfish, Carassius Auratus, Ngozichukwu Francis Ngozichukwu

Theses and Dissertations

Global climate change has led to rising temperatures, posing significant challenges to aquatic ecosystems and the health of ectothermic species such as goldfish (Carassius auratus) This thesis investigated the effects of heat stress on growth performance, histological alterations, and molecular stress responses in the gill and kidney tissues of goldfish Fish were exposed to control (24°C), medium (28°C), and high (32°C) temperatures for two weeks Growth parameters, including instantaneous growth rate (IGR), absolute growth rate (AGR), body value gain (BVG), and condition factor, were evaluated alongside histological and immunohistochemical markers of stress Results revealed that high temperature significantly reduced AGR …

Opa1-Mediated Mitochondrial Dynamics In Myogenic Differentiation Of C2c12 Myoblasts, Daniel Eloy Bazan

Theses and Dissertations

Mitochondria play a pivotal role in metabolic energy production, cellular signaling, and apoptosis. To carry out these key cellular roles, mitochondria dynamically balance their organization through opposing including fusion and fission processes. The balance between mitochondrial fusion and fission is regulated by key proteins such as OPA1 (optic atrophy 1) and OMA1 (overlapping activity with metalloprotease). More recently, mitochondria have been increasingly revealed to play key roles in cellular differentiation, where metabolic demands are reprogrammed. This study aims to elucidate the specific roles of OPA1 and OMA1 in the differentiation of C2C12 myoblast cells into myotubes.

Our data demonstrates that …

Phenotypic Plasticity In Response To Abiotic Factors In Silverleaf Nightshade (Solanum Elaeagnifolium), And The Effectiveness Of North American Lacebug (Gargaphia Arizonica Drake And Calvo) As A Biocontrol, Marco Andre Silguero

Theses and Dissertations

Silverleaf nightshade (Solanum elaeagnifolium) is a widespread invasive weed in South Texas and other arid regions, where it reduces crop productivity, competes with native vegetation, and resists conventional control methods. Its ability to thrive across different environments is linked to phenotypic plasticity, allowing it to adjust growth and physiology in response to light and water availability. In this thesis, I examine the role of plasticity in S. elaeagnifolium under field conditions and evaluate the potential of the North American lacebug (Gargaphia arizonica) as a biological control agent. Field observations were used to measure plant traits such as height, stem thickness, …

Molecular And Clinical Insights Into Role Of Gper In Hepatocellular Carcinoma (Hcc), Hossain Ahmed

Theses and Dissertations

Metabolic dysfunction–associated steatotic liver disease (MASLD), encompassing stages from steatosis (MASLD) to steatohepatitis (MASH), cirrhosis, and hepatocellular carcinoma (HCC), is the most prevalent chronic liver disease worldwide, yet molecular markers of progression remain limited. The G protein–coupled estrogen receptor (GPER), a non-genomic estrogen receptor with metabolic and anti-inflammatory roles, emerges as a candidate regulator in hepatic pathophysiology. In this Dissertation thesis, we have delineated for the first time clinicopathological assessment of liver biopsies across MASLD stages revealing a robust inverse correlation between GPER expression and disease severity. Higher GPER levels in early MASLD associated with favorable metabolic and biochemical profiles, …

Transcriptomic Study On The Effect Of Salt Stress In Sorghum Bicolor Seedlings, Joshwa A. Gandy

Theses and Dissertations

The global impact and reliance on cereal crops, and sorghum in particular, is paramount for worldwide food security and for the livelihood of hundreds of millions of people. The detrimental effects of salt stress on crop plants and the huge economic losses it causes by affecting agricultural output worldwide is a devastating issue with huge impacts, which have prompted research to combat salinity in numerous ways. Understanding how cereals respond to the negative effects of salt stress is crucial for enhancing their salt tolerance. In this study of sorghum, we used a 3’-end RNA sequencing approach to elucidate major salt …

Insights Gained From Applying Molecular Techniques To Gray Triggerfish (Balistes Capriscus Gmelin, 1789) In The Mexican Caribbean, The Southern And Northwestern Gulf Of Mexico, Geaceli G. Orive

Theses and Dissertations

This study focuses on Balistes capriscus (Gray Triggerfish), a reef-associated species dependent on hard-bottom habitats in the Gulf of Mexico (GOM). Using mitochondrial DNA barcoding and phylogenetic analyses, genetic structure across four sites was assessed: Rio Grande Valley (RGV), Veracruz, Chinchorro Bank, and Xahuayxol. Samples from RGV and Veracruz exhibited limited haplotype diversity, minimal nucleotide divergence, and weak genetic differentiation-patterns consistent with recent population expansion and ongoing connectivity within the GOM. While the study centered on B. capriscus, all individuals from Chinchorro and Xahuayxol unexpectedly grouped with Canthidermis maculata (Spotted Oceanic Triggerfish), suggesting misidentification, cryptic diversity, or taxonomic uncertainty in …

Analyzing How Taste And Nutrition Impact Learning And Memory In Honey Bees Through Olfactory Associative Conditioning, Alessandra Elizabeth Perry

Theses and Dissertations

Honey bees detect sweet nectar, but not all sweet-tasting sugars provide nutrition. Unlike fruit flies, which can learn to avoid non-nutritious sweet foods, bees may lack this ability. To test if bees form caloric frustration memory (CFM), we conditioned them using odors paired with L-glucose (sweet but non-nutritious) or D-glucose (sweet and nutritious). Bees rewarded with L-glucose showed lower learning and long-term memory compared to D-glucose. Bees cannot differentiate between an odor associated with rewards containing malaise-causing compounds and an odor associated with a reward alone during differential conditioning. Therefore, we used differential conditioning to determine if lower acquisition in …

Comparison Of Recovery Methods After Resistance Exercise For Power Performance, Isaac D. Huerta

Theses and Dissertations

Elite athletes engage in intense training to secure marginal performance advantages, placing considerable physical strain on their bodies. Effective recovery techniques are critical to rapidly restore physical function. Conventional methods like ice baths, hydrotherapy, and massages are often impractical due to cost and logistical barriers. This study examined the efficacy of voluntary deep slow breathing (VDSB) as a cost-effective recovery method compared to static stretching (SS) and no recovery method (control) in untrained male athletes aged 18–26. Using a within-subjects, randomized crossover design over four weeks, participants visited the lab seven times to complete a standardized full-body workout involving plyometric …

Cucurbit Plant Defenses Against Aboveground Or Belowground Insect Herbivores Are Distinct And Shaped By Eco-Evolutionary Factors, Morgan N. Thompson, Emily M. Russavage, Jeremy G. Garces, B. Jack Bradford, Danielle Merrell, Charles P.-C. Suh, Anjel M. Helms

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Plant defense strategies against insect herbivores are classified broadly as resistance or tolerance. Resistance deters insect growth or feeding, while tolerance mitigates negative effects of herbivory on plant fitness. Plant investment into resistance or tolerance strategies likely falls along a continuum that has been shaped by eco-evolutionary factors, such as plant domestication or coexistence histories with herbivores. Relatively little is known about how general defense strategies differ against aboveground foliar herbivores and belowground root herbivores. In the current study, we investigated defense strategies of plant species in the gourd family (Cucurbitaceae) against aboveground squash bug (Anasa tristis) or …

Health Patterns Of Dementia Caregivers With Chronic Pain: Latent Profile Analysis Of The Promis-29 Measure, Shelbie G. Turner, Dakota D. Witzel, Shana Garza, Karl Pillemer, M Carrington Reid

Human Genetics Publications

We identified patterns of health and functioning in a national sample of dementia family caregivers experiencing chronic pain (N = 273). Utilizing latent profile analysis of the 29-item Patient-Reported Outcomes Measurement Information System (PROMIS-29), we identified three discrete groups: an average group (48%), a low health challenges group (30%), and a high health challenges group (22%). Women were more likely to be in the high (vs. low) health challenges group. There are discrete health patterns of caregivers with chronic pain, with over 20% reporting comorbid poor health and functioning that may negatively affect caregiving quality. Screening caregivers for high …

Transformation With Genes To Improve Lipid Production And Barcoding To Identify Unknown Algal Species, Michelle T. Rada

Theses and Dissertations

With the rising demand for alternative fuels, algal-based biofuels are a promising, sustainable source that meets commercial interest while producing lower greenhouse gas emissions compared to fossil fuels. This thesis explored two studies, evaluating microalgae for their future potential in lipid yield for biofuel production.

The first study involved developing a cost-efficient electroporation protocol that allowed for the genetic transformation of Chlamydomonas reinhardtii using the pChlamy_4 vector, which supports future cloning of genes to enhance lipid production. Parameters affecting DNA uptake and integration into algal genomes were studied: the effect of cell density, the settings of the electroporation device, and …

Perception Of Quality Of Life, Brain Regions, And Cognitive Performance In Hispanic Adults: A Canonical Correlation Approach, Juan C. Lopez-Alvarenga, Jesus D. Melgarejo, Jesus Rivera-Sanchez, Lorena Velazquez-Alvarez, Rosa V. Pirela, John Blangero, Jose E. Cavazos, Michael C. Mahaney, Joseph D. Terwilliger, Gladys E. Maestre

School of Medicine Publications

The quality of life (QoL) perception has been studied in neurological diseases; however, there is limited information linking brain morphological characteristics, QoL, and cognition. Human behavior and perception are associated with specific brain areas that interact through diffuse electrochemical networking. We used magnetic resonance imaging (MRI) to analyze the brain region volume (BRV) correlation with the scores of Rand’s 36-item Short Form Survey (SF-36) and cognitive domains (memory and dementia status). We analyzed data from 420 adult participants in the Maracaibo Aging Study (MAS). Principal component analysis with oblimin axis rotation was used to gather redundant information from brain parcels …

Longitudinal Changes In Infant Attention-Related Brain Networks And Fearful Temperament, Courtney A. Filippi, Alice Massera, Jiayin Xing, Hyung G. Park, Emilio A. Valadez, Jed T. Elison, Dana Kanel, Daniel Samuel Pine, Nathan A. Fox, Anderson M. Winkler

Human Genetics Publications

Background: Anxiety disorders may partly stem from altered neurodevelopment of attention-related networks. Neonatal alterations in resting-state functional connectivity (rsFC) among the dorsal attention network (DAN), frontoparietal network (FPN), salience network (SN), and default mode network (DMN) relate to fearful temperament, a risk marker for anxiety. Nevertheless, few studies have examined the development of these networks beyond the first months of life, particularly in fearful infants. In this study, we examined how changes in these networks during the first 2 years of life relate to fearful temperament.

Methods: Using data from the Baby Connectome Project (from 180 infants across 396 sessions), …

Spatiotemporal Responses To A Rural Highway By Four Mammal Species, Caitlin K. Brett, Anna Rose Mehner, John H. Young Jr., Sarah E. Lehnen, Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Roads can negatively impact the wildlife communities they transect. Road mortalities from wildlife-vehicle collisions are one direct effect, but roads may also indirectly affect wildlife behavior, movement, or local distribution. Quantifying the spatial extent of these road-effects is important for understanding how roads indirectly affect species of concern, identifying potential sources of disturbance, and for estimating the effectiveness of road mitigation structures. Farm-to-Market Road (FM)106, which transects part of the Laguna Atascosa National Wildlife Refuge in Cameron County, Texas, has been identified as a potential source of wildlife road mortalities, particularly for one of the two remaining breeding populations of …

Human Development, Inequality, And Their Associations With Brain Structure Across 29 Countries, Vicente Medel, Luz M. Alliende, Richard Bethlehem, Jakob Seidlitz, Grace Ringlein, Celso Arango, Aurina Arnatkevičiūtė, Laila Asmal, Mark Bellgrove, Anderson M. Winkler

Human Genetics Publications

Background: The macro-social and environmental conditions in which people live, such as the level of a country’s development or inequality, are associated with brain-related disorders. However, the relationship between these systemic environmental factors and the brain remains unclear. We here aimed to determine the association between the level of development and inequality of a country and the brain structure of healthy adults.

Methods: We conducted a cross-sectional study pooling brain imaging (T1-based) data from 145 magnetic resonance imaging (MRI) studies in 7,962 healthy adults (4,110 women) in 29 different countries. We used a meta-regression approach to relate the brain structure …

Low Premorbid Iq May Exacerbate The Cognitive Effects Of Apolipoprotein Ε4 (Apoe Ε4): A Multi-Ethnic Cross-Sectional Study From Habs-Hd, Lubnaa B. Abdullah, Zhengyang Zhou, Ney Alex Alliey, Robert Barber, James Hall, Sid O’Bryant

Psychological Science Faculty Publications

Introduction: Apolipoprotein allele 4 (APOE ε4) is associated with lower IQ scores during childhood and adolescence, but the influence of APOE ε4 and low IQ on late-life cognition is unknown. This study examines the association between APOE ε4 and cognitive outcomes based on premorbid intellectual ability (pIQ) and ethnic background.

Methods: Participants were drawn from the Health & Aging Brain Study–Health Disparities (HABS-HD), categorized by low (z ≤ −2.00) or average (z = 0.00 ± 1.00) pIQ based on word reading scores. Statistical analyses were conducted to evaluate whether APOE ε4 was associated with the cognitive domains of …

Fish Assemblages And Flow Regimes Upstream And Downstream Of Falcon Reservoir, Christopher J. Austin, Christopher Taylor

School of Integrative Biological & Chemical Sciences Faculty Publications

The lower Rio Grande is regulated by Falcon and Amistad dams, as well as series of smaller dams and rock weirs. Several native fish species that rely on a natural flow regime for habitat and spawning are imperiled in the region. We analyzed streamflow discharge above and below Falcon Reservoir to assess potential impacts of dam impoundment on the fishes and flow regime. Fish collections were conducted by seine, and river discharge data was provided by the International Boundaries and Water Commission. We found significant differences in fish assemblages above vs below Falcon Reservoir, and the flow regime was significantly …

Structural Brain Correlates Of Childhood Inhibited Temperament: An Enigma-Anxiety Mega-Analysis, Janna Marie Bas-Hoogendam, Rachel Bernstein, Brenda E. Benson, Samuel E. C. Frank, Kristin A. Buss, Koraly Pérez-Edgar, Giovanni A. Salum, Andrea P. Jackowski, Rodrigo A. Bressan, Anderson M. Winkler

Human Genetics Publications

Objective

Childhood inhibited temperament (cIT) is associated with an increased risk for developing internalizing psychopathology. Neurobiological characteristics identified by structural magnetic resonance imaging (MRI) may elucidate the neural substrates for cIT, but studies are scarce and often focus on particular regions of interest. Moreover, current findings lack replication. This preregistered analysis from the ENIGMA-Anxiety Working Group examined structural brain characteristics associated with cIT using a comprehensive whole-brain approach.

Method

Temperament assessments (behavioral observations, parent/teacher reports or self-reports on cIT before age 13 years) and MRI data (age at scan, 6-25 years) from international research sites (Europe, North America, South America) …

Vibrio Cholerae Endemic To The Lower Rio Grande Delta Segregate Into Urban And Rural Phylotypes, Daniele Provenzano, Jeffrey W. Turner, Jorge Duran-Gonzalez, David A. Laughlin, David Silva, Viviana Trevino, Miguel F. Gonzales, Boris Ermolinsky, Stefan Pukatzki

School of Integrative Biological & Chemical Sciences Faculty Publications

The lifestyle of Vibrio cholerae is primarily environmental, yet a chance encounter with a human host can lead to cholera, a potentially lethal form of diarrhea. Strains belonging to O1 and O139 serogroups have pandemic potential, but the contribution of non-O1/non-O139 serovars towards the genesis of cholera remains unclear. Endemic V. cholerae lineages were investigated given several historical accounts describing cholera epidemics and sporadic, contemporary cholera-like outbreaks along the lower Rio Grande Delta (LRGD). Seven isolates were recovered from an urban segment of the Rio Grande and six from a rural segment where the river empties into the Gulf of …