Using dry plants and DNA to unravel the story ferns have to tell

Type: Graduate
Author(s): Lucia Vargas Biology
Advisor(s): Matt Hale Biology Alejandra Vasco Biology
Location: Basement, Table 1, Position 3, 11:30-1:30

Understanding and documenting the diversity and distribution of species on Earth is crucial, especially in the face of habitat loss and species extinction. Without this knowledge, we risk losing valuable understanding of the natural world, including species with ecological, medicinal, or economic significance. Ferns, one of the oldest lineages of land plants, still hold many scientific mysteries, particularly in tropical regions where diversity is high and under-explored.
Herbarium specimens—dried plants collected and preserved over centuries—serve as critical windows into the past, allowing botanists to study plant diversity across time and space. When combined with modern tools such as imaging and DNA analyses, these collections become powerful data sources for unraveling evolutionary relationships, discovering new species, and improving our understanding of biodiversity. Our research focuses on Elaphoglossum, one of the most diverse and taxonomically challenging fern genera. Using herbarium specimens, powerful microscopes, and molecular phylogenetic studies, we are conducting a systematic review of the Elaphoglossum dendricola clade, a group of Andean ferns. Our aims are to clarify species boundaries, uncover undescribed species, reconstruct evolutionary relationships, and evaluate the conservation status of these ferns.
This poster presents preliminary results and outlines future directions of our research in tropical ferns, highlighting the importance of integrating collections-based taxonomy and molecular phylogenetics to explore and preserve tropical fern diversity.

The Impact of Shoreline Distance on the Proportion of Aquatic Insects in Arctic Wolf Spider Diets

Type: Undergraduate
Author(s): Lance Viscioni-Wilson Biology Charlie Duethman Biology Sydney Hill Biology Ramsey Jennings Biology Chidi Mbagwu Biology Cami Middlebrooks Biology Ben Strang Biology David Wright Biology
Advisor(s): Matt Chumchal Biology
Location: SecondFloor, Table 6, Position 3, 1:45-3:45

Arctic wolf spiders (Pardosa glacialis) are dominant terrestrial predators in the High Arctic, yet the extent to which their diets are influenced by aquatic subsidies remains uncertain. Previous research suggests that aquatic insects do serve as a key food source for shoreline predators, transferring both nutrients and contaminants such at mercury (THg) from aquatic to terrestrial ecosystems. Aquatic insects have unique carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic signatures that differentiate them from terrestrial insects that allow for identification of aquatic-derived energy in terrestrial food webs. The purpose of this case study is to examine the stable isotope composition of P. glacialis collected at varying distances (0, 10m, and 35m) near a pond located in northwest Greenland to establish local food web dynamics and assess potential pathways of contaminant transfer. Understanding these dynamics will provide insight into how THg is distributed among trophic levels and across distances in riparian environments. P. glacialis were collected in traps placed at three distances from pond shoreline (0, 10m, and 35m). The specimens were then analyzed for THg and stable isotope ratios. We hypothesized that spiders collected closer to the shoreline will display isotopic values indicative of a more aquatic-based diet as well as higher THg concentrations. Conversely, with increasing distances from pond shoreline, we expect to see isotopic signatures suggestive of a more terrestrial diet and lower THg. Given mercury’s neurotoxic and bio accumulative properties, results of this study will provide insight not only into aquatic-terrestrial linkages in Arctic ecosystems but also the potential threats that the trophic movement of contaminants may pose to wildlife.

WHEN CANCER CELLS GO TO THE WARBURG EFFECT, WHERE DOES LACTATE GO? Exploring Lactate Metabolism in Cancer Cells

Type: Undergraduate
Author(s): Kha Vu Biology Xin Cai Biology Gurveer Kaur Biology
Advisor(s): Giridhar Akkaraju Biology
Location: Basement, Table 7, Position 1, 11:30-1:30

Metabolic reprogramming is a hallmark of cancer, allowing tumor cells to sustain proliferation under varying nutrient and oxygen conditions. One of the most well-known adaptations is the Warburg effect, wherein cancer cells preferentially utilize glycolysis to generate ATP and produce lactate, even in the presence of oxygen. While lactate has long been considered a metabolic waste product, emerging studies suggest that it may have regulatory functions beyond energy production. In this study, we investigate how lactate influences the metabolic enzyme malate dehydrogenase 1 (MDH1), a key component of the malate-aspartate shuttle and a contributor to cytosolic NAD⁺ regeneration. Using CRISPR-mediated MDH1 knockout models, cell proliferation assays, a cell-free mitochondrial system, and direct enzymatic activity measurements, we demonstrate that lactate—both L- and D-enantiomers—activates MDH1. This activation is independent of lactate’s conventional metabolic conversion via lactate dehydrogenase. Notably, D-lactate, which mammalian cells cannot metabolize, produced similar effects to L-lactate, indicating a non-metabolic, potentially signaling-based mechanism. Structural modeling using AlphaFold2 further supports the presence of a putative lactate-binding site on MDH1. These findings suggest a novel paradigm in which lactate directly regulates mitochondrial metabolism, redefining its role in the Warburg effect and its contribution to cancer cell proliferation.

Comparing DC1s and DC2s Immune Response Against Cryptococcus neoformans

Type: Undergraduate
Author(s): Elizabeth West Biology
Advisor(s): Floyd Wormley Biology Natalia Castro Biology

Comparing DC1s and DC2s Immune Response Against Cryptococcus neoformans

Elizabeth West*, Natalia Castro Lopez, Floyd Wormley Jr.
Department of Biology, Texas Christian University, Fort Worth, TX, USA

Abstract

Cryptococcus neoformans is a fungal pathogen that poses a threat to immunocompromised individuals, and there is currently no vaccine. Dendritic Cells (DCs) play a crucial role in the cell’s immune response and will be studied to determine an effective treatment. In this study, we will analyze the immune response of two groups of conventional dendritic cells (cDCs), cDC1s (CD103+, driven from GM-CSF + FLT3) and cDC2s (CD11B+, driven from GM-CSF) to determine their ability to produce a protective immune response against Cryptococcus neoformans. We grew bone marrow dendritic cells in the conditions stated above and then exposed to IFN-ɣ, cell wall extract (CWE), or both. After, we used a calcineurin (cna) knockout strain to simulate exposure to the wild-type strain, which allows us to analyze the cell’s immune response. RNA purification technique will be performed to isolate the RNA, which will then be analyzed via RT-PCR. We will analyze DC1s and DC2s responses by evaluating the transcripts, including NOS2, Arg1, and IL-2. This study will help us understand the role of DCs in the protective immune response. We hypothesize that DC1s (CD103+) will elicit a stronger Th1 response, increased by IFN-γ treatment compared to DC2s eliciting a different immune response. By comparing transcript expression levels of DC1s and DC2s, we can study the role of dendritic cell subsets in producing memory for protective immune response against Cryptococcus neoformans.

Fishy fear: the development of a predator avoidance assay for fathead minnows

Type: Graduate
Author(s): Catherine Wise Biology Kate Davis Environmental Sciences Lilli Gonzales Biology Justin Hunt Biology Zoie Munoz Biology Marisa Ross Psychology
Advisor(s): Marlo Jeffries Biology
Location: FirstFloor, Table 2, Position 2, 11:30-1:30

The fathead minnows (Pimephales promelas; FHMs) have been the most utilized small fish model in North American ecotoxicity assessments for decades. However, the behavior of FHMs across their lifespan remains poorly characterized relative to other small fish models. Given the growing recognition of the importance of evaluating ecologically-relevant behavioral endpoints in environmental monitoring, aquaculture, and ecotoxicology, there is a need to develop assays to assess such behaviors in fish across multiple life stages. One class of ecologically-relevant behaviors is predator avoidance behaviors, which hold importance for the survival and propagation of fish populations. While the predator avoidance behaviors of adult FHMs (e.g., shelter seeking/hiding, freezing) have been well documented, there has yet to be a comprehensive study characterizing the responses of larval FHMs to chemical predator stimuli. Thus, the present study aimed to develop a behavioral assay that assesses predator avoidance behaviors of FHMs across multiple life stages. The specific predator stimulus was alarm cue, a chemical released from damaged or injured epidermal club cells of FHMs to signal conspecifics of a predator attack. In turn, the objectives were to 1) verify that the use of alarm cue collected from pond-reared donors induced predator avoidance behaviors, as measured via ToxTrac, an open-source tracking software, in adult fathead minnows, and 2) develop a predator avoidance assay for use in 14 days post-hatch (dph) larval FHMs using the alarm cue from pond-reared donors verified in adult FHMs. Exposure of adult FHMs to alarm cue collected from pond-reared donors induced significant changes in the predator avoidance behaviors detected by ToxTrac, verifying its use as a predator stimulus for lab-reared FHMs. Moreover, this study represents the first characterization of the behavioral response of 14 dph FHMs to alarm cue from pond-reared donors, providing insight into the maturation of predator avoidance behaviors of FHMs. Future work may investigate the sensitivity of the larval predator avoidance assay to chemicals with known neurological effects to validate its use as an ecologically-relevant behavioral assay in an aquaculture, ecotoxicity, or environmental management context.

Quantifying the Impact: White Nose Syndrome and Bat Population Dynamics

Type: Graduate
Author(s): Hongzhen Wu Biology
Advisor(s): Jiao Jing Biology
Location: SecondFloor, Table 6, Position 3, 11:30-1:30

White-nose syndrome (WNS), caused by a fungus called Pseudogymnoascus destructans, has caused dramatic declines in North American bat populations, with mortality rates exceeding 90% in some species. WNS has spread widely, now to southern regions such as Texas, and presents new challenges for disease modeling due to differences in climate and bat hibernation behavior. This study developed a open patch epidemiological model integrating bat populations from the Northeastern United States to examine how migration and disease exposure affect population dynamics. By modifying a standard SIR model, we analyzed interactions between wild and robust bat genotypes at varying levels of migration and frequency of disease pulses. Preliminary findings suggest that increased migration favors robust genotypes, while frequent disease pulses initially favor robustness but may eventually penalize it if disease prevalence remains low. These insights enhance our understanding of regional disease dynamics and provide a framework for conservation strategies aimed at mitigating WNS-driven biodiversity loss.

DIRECT ARYLATION OF UNACTIVATED ARENE USING EARTH ABUNDANT IRON/TETRA-AZA MACROCYCLIC COMPLEX

Type: Graduate
Author(s): Tahmina Afroz Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry
Location: SecondFloor, Table 7, Position 3, 1:45-3:45

DIRECT ARYLATION OF UNACTIVATED ARENE USING EARTH ABUNDANT IRON/TETRA-AZA MACROCYCLIC COMPLEX
The development of sustainable catalytic systems for carbon–carbon bond formation is of critical importance in modern synthetic chemistry. This study presents an iron-based catalytic system employing tetra-aza macrocyclic ligands as a cost-effective and environmentally benign alternative to palladium in direct arylation reactions. Using [Fe²⁺L6(Cl)₂] as the catalyst and molecular oxygen as the terminal oxidant, the direct C(sp²)–C(sp²) coupling of pyrrole with substituted phenylboronic acids was achieved under mild conditions, yielding 2-phenylpyrrole and its derivatives with moderate efficiency (up to 62%). The catalyst displayed broad substrate scope and functional group tolerance, effectively accommodating halogen, nitro, alkyl, and methoxy substituents. Mechanistic studies excluded a radical-mediated pathway and instead supported a non-radical oxidative mechanism involving an iron(III)-hydroperoxo intermediate. These findings underscore the potential of earth-abundant iron complexes in sustainable cross-coupling chemistry and set the stage for further exploration in heterocycle functionalization and pharmaceutical scaffold development.

Towards a Comprehensive Benchmark of Quantum Mechanical pKa Prediction: Conformational Sampling, Model Solvent, Basis Set, Density Functional, and Empirical Corrections for the SAMPL7 Dataset

Type: Graduate
Author(s): Donatus Agbaglo Chemistry & Biochemistry Minh Ho Biology
Advisor(s): Benjamin Janesko Chemistry & Biochemistry

Fight Against Alzheimer’s: Developing a New Generation of Multifunctional Drug Therapeutics Using Pyridine-Containing Tetra-Aza Macrocycles

Type: Undergraduate
Author(s): Saba Anjum Chemistry & Biochemistry Shrikant Nilewar Chemistry & Biochemistry
Advisor(s): Kayla Green Chemistry & Biochemistry
Location: Basement, Table 1, Position 1, 11:30-1:30

Oxidative stress is associated with the development and progression of neurodegenerative diseases, including Alzheimer’s, but there are no approved drug therapeutics that effectively target oxidative stress in Alzheimer’s. The Green Research Group has previously synthesized and reported a pyridine-containing tetra-aza macrocycle, L2, which acts as a multifunctional antioxidant agent by targeting oxidative stress directly through radical scavenging and metal ion chelation as well as catalytically through activation of the Nrf2 pathway. While multiple preliminary studies conducted on L2 have confirmed its potent antioxidant activity, its high hydrophilicity results in reduced blood-brain barrier permeability, which is a concern when designing drug therapeutics for neurodegenerative diseases. It is hypothesized that incorporating a self-immolative linker onto L2 will result in increased blood-brain barrier permeability while maintaining antioxidant activity under physiological conditions.

Shape-shifting Molecules: The Search for Low Cost, Ring-shaped Drugs

Type: Undergraduate
Author(s): Grace Bobo Chemistry & Biochemistry Liam Claton Chemistry & Biochemistry
Advisor(s): Eric Simanek Chemistry & Biochemistry
Location: Third Floor, Table 10, Position 1, 11:30-1:30

The shape of a drug will determine how it interacts in the body. For it to work, it must dissolve, be absorbed into the bloodstream, avoid breakdown, enter the cell and bind to its target. Each of these steps likely requires a different shape. The pharmaceutical industry has historically only focused on the shape required to bind the target. This research has identified molecules that can readily adopt multiple shapes. These ring-shaped molecules (called macrocycles) represent a new model for drug design. Usual drugs (ie ibuprofen) are small and interact with a specific target to stop a chemical reaction. Macrocycles can work by an additional mechanism. They are larger and can interfere with interactions between proteins but are still small enough to travel the body. The preparation of these macrocycles is inexpensive and quick, properties that are important for the pharmaceutical industry. This poster describes the design and synthesis of a macrocycle and an analysis of the shapes that it adopts.