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.

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.

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

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.

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.