Understanding the effects of chemical exposure is important for human health and environmental regulations. We are particularly interested in toxicity related to early development because embryos are often more sensitive to toxicity when compared to adult tissues. To address questions of embryonic toxicity, we use the zebrafish system to test how chemical exposure affects early development. I am currently training in lab techniques to use zebrafish for these types of experiments and also conducting literature analysis to define a chemical of interest for future experiments.
Poplar trees (Populus) provide vital ecosystem services for humans and are a critical species within their wide range of habitats. Our research goal was to investigate whether hybridization between Populus trichocharpa (Black Cottonwood) and P. balsamifera (Balsam Poplar) alters their resistance to a fungal pathogen Melampsora, or rust. Rust is apotential threat to proper development in many poplar species. Our garden is within a multi-institution poplar research project, consisting of 19 common gardens across North America with clones of 47 poplar genotypes. All genotypes exhibit a hybrid class, or percentage of DNA from the two focal species. Each garden collected general presence or absence of rust data. At our garden we conducted a detailed assessment of the proportion of leaves exhibiting rust damage. For our garden and across the larger project we used ANOVAs, linear models, and correlation tests to determine if there was a relationship between the presence of rust disease and genetic background. For both data sets, no significant relationships were found between rust presence and hybrid class. However, in the larger set, there was a significant relationship between rust and transect, or original location. Also, in our smaller set, rust was positively correlated with leaf area.
For early spring wildflowers in Wisconsin, global climate change may lead to warmer, drier climates with more day-to-day variability, which in turn can impact flower and pollinator phenology, plant-pollinator network structure, and reproductive security for plants and pollinators. Inter-annual changes to plant-pollinator interactions are often only noticeable with long-term data sets. Here, we present our goal to establish a multi-year study monitoring plant-pollinator interactions in early spring wildflowers in Putnam Park. We will use AutoPollS (Autonomous Pollinator Samplers) camera traps with temperature sensors to record flower visitors to early spring wildflowers. We will deploy six camera traps with four cameras from the start of bloom through mid-May, aiming to document all flowering species. After we collect images of flower visitors, we will filter out images with insects and use BeeMachine to identify flower visitors. To analyze our data, we will use bipartite plots to evaluate network dynamics and complexity and link temperature with pollinator activity and wildflower phenology. Over time, we will evaluate multi-year patterns and evidence of climate change-mediated shifts to plant-pollinator interactions. We expect as the climate warms, spring wildflowers will bloom earlier, bloom duration will decrease, and pollinators will shift their dietary preferences in response.
Global change is predicted to result in warmer and more variable temperatures, which may impact insect learning. Learning is critical to social insects, like bumble bees, where colony success relies on worker memory. We used a foraging arena to investigate whether bumble bee (Bombus impatiens) learning is influenced by temperature. We wanted the bees to learn that yellow flowers had a higher reward (50% sugar) than blue flowers (25% sugar). Bee colonies were connected to a training arena with half-blue, half-yellow flowers with ad-libitum nectar for one week, then individual workers were removed from the training arena to be tested in the foraging arena. Before foraging, bees were starved for six hours, then introduced to the foraging arena and allowed to forage for 10 minutes on two subsequent days. We recorded the color of the first flower visited, the duration foraging on both high- and low-reward flowers, and the number and type of each flower, per foraging visit. In total, we tested nine temperature combinations of 18, 25, and 32°C across days 1 and 2. As a control, we also evaluated whether bees had an innate preference for blue or yellow flowers when floral reward was equal (both 50% sugar).
Cortisol is a stress hormone essential for fetal development in humans. Increased prenatal cortisol exposure due to maternal stress can alter fetal neurodevelopment. Previous studies in our lab identified morphological changes in zebrafish larvae due to embryonic cortisol exposure. Cortisol primarily acts through two receptors, the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR), which are crucial to the regulation and development of many physiological processes. MRs are crucial to the regulation and development of many physiological processes. Deoxycorticosterone (DOC) is a synthetic glucocorticoid that binds selectively to the MR. In this study, we tested how activating the mineralocorticoid receptors affects the morphology of embryonic development in zebrafish. Zebrafish embryos were treated with different concentrations of DOC at 3 hours post fertilization (hpf). Embryos were then imaged at 72 hpf with brightfield microscopy. Images were scored for morphological phenotypes and the severity of phenotypes. Results show a dose-dependent change in morphological phenotypes due to DOC treatment. These experiments inform our understanding of how different corticosteroid receptors affect zebrafish morphology in embryonic development.
Methylmercury (MeHg) is a common water pollutant in the Great Lakes region with known toxicity in wildlife and humans. The glutathione (GSH) pathway plays a crucial role in detoxifying cells from substances like MeHg. While variants in GSH genotypes have been linked to differential MeHg retention and toxicity in adult tissues, less is known about these gene-environment interactions during embryonic development. To investigate this context, a mutant line of zebrafish was created utilizing CRISPR techniques targeting the gclm gene, a gene involved in the GSH pathway. In this study, we characterized the mutant allele in the F3 generation using high-resolution melting analysis (HRMA) along with PCR + restriction enzyme digestion. Suspected mutant zebrafish were genotyped to detect a change in DNA sequence at the CRISPR target area using PCR + restriction enzyme digestion with gel electrophoresis. Gel extraction of the altered PCR fragment and subsequent DNA sequencing revealed a consistent deletion at the CRISPR target area. Subsequent analysis of predicted protein products of the mutant sequences indicated a loss-of-function allele. Characterizing the functional impact of this mutant gclm allele will help clarify how the gclm gene contributes to MeHg detoxification in the context of embryonic development.
Kin selection theory (Hamilton 1964) is a widely invoked explanation for the evolution of cooperation in animal societies. A major assumption of this theory is that individuals must discriminate among individuals based on genetic relationships to bias helpful behaviors toward kin. In the context of alarm calls, a common danger signal, kin selection is expected to favor inclusive fitness through increased attention to closely related (indirect benefits) and reliable (direct benefits) callers. Here we quantified individual differences in acoustic properties of alarm calls (i.e., chatters) for members of two long-term populations of California ground squirrels. We used Raven Pro to measure the acoustic properties of chatters produced by marked individual squirrels over time. As expected, the acoustic properties of calls were explained by the age, sex, and location of callers. Beyond this, individuals’ calls were repeatable across the study, providing evidence for individuality in call structure. Our findings suggest these animals have the potential to discriminate among individual callers based on acoustic information produced in alarm calls. These findings are important because individuals could support a suite of other behavioral processes important for social animals that include parent-offspring interactions, mate choice, and recognition of social partners.
Understanding why some individuals within populations are more prone to harbor parasites (and diseases) than others is an important biological question. Repeated measures on marked individuals over time are required to assess the extent to which individual identity, age, sex, or year of study most strongly shape prevalence in nature. Here, we studied the potential for age and sex to structure parasite prevalence in the California ground squirrel (Otospermophilus beecheyi). This native rodent is common across California and frequently interacts with humans. Its fleas have been studied extensively in the context of bubonic plague, but their endoparasites have not been the subject of systematic study. As part of a long-term study, we collected fleas in 70% ethanol and fecal samples in formalin from live-trapped individual ground squirrels of known ages and sexes in situ for two consecutive years. We microscopically identified parasite prevalence in the lab. We explored individual squirrels’ parasitic profiles for members of two study populations that vary in levels of human disturbance. Our findings offer an in-depth understanding of how identity, age, and sex of hosts influence parasite prevalence in our two study populations but also have implications for understanding zoonotic diseases in human-altered landscapes.
Cortisol is a stress hormone that is vital to human development. Previous studies in the lab have found that embryonic exposure to cortisol alters morphological development in zebrafish. Cortisol primarily acts through two receptors, the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR), which are crucial to the regulation and development of many physiological processes. Dexamethasone is a synthetic glucocorticoid that binds selectively to the GR. This study aimed to identify the lowest observable adverse effect limit (LOAEL) of exposure on embryonic zebrafish in order to better understand which developmental effects may be directly related to GR activation. Zebrafish embryos were exposed to various concentrations of dexamethasone between 3 and 72 hours post fertilization (hpf) and then imaged with a brightfield microscope to qualitatively evaluate any observable phenotypic abnormalities. Preliminary results showed morphological phenotypes increased as the concentration of dexamethasone increased. These data suggest that an excess of GR regulation results in developmental abnormalities. Additional experiments are needed to determine the LOAEL and confirm the results with statistical analyses. These experiments inform our understanding of how corticosteroid receptors affect zebrafish morphology in embryonic development.
This study explored patterns of spatial and temporal variability in the structure of coral reef fish assemblages around San Salvador Island, The Bahamas. For 25 years, students from the University of Wisconsin–Eau Claire have conducted reef surveys, generating a long-term dataset that provides a unique opportunity to assess reef fish community changes in response to ecological disturbances. Surveys across six reefs were conducted in 2000, 2004, 2006, 2008, 2014, and 2025, generating quantitative presence-absence data. These surveys captured the effects of two major stressors: the invasion of Pterois volitans (lionfish) in 2007 and a severe coral bleaching event in 2023. The six reefs varied in size, depth, and visitation patterns, enabling comparisons of fish assemblages across different environmental conditions. All observed fish species were recorded during snorkeling surveys, and multivariate analyses were applied to assess changes in fish community composition over time and across reef sites. Coral bleaching was quantified using a standardized assessment protocol. By examining how reef fish communities respond to disturbances, this study enhances our understanding of reef resilience and ecosystem shifts.
We investigated how stress (low moisture and mineral nutrients) influences how functional community assembly differs from random drift assembly. Plant strategy theory suggests that stressful habitats should be dominated by short species with adaptations for conserving resources. The “stress-dominance hypothesis” suggests that stressful habitats should have low functional diversity, and both have been confirmed in European grasslands. We sampled plants at 19 locations along well-known moisture gradients from dry prairies to wet sedge meadows. At each location, three nested sample plots were established using three grain sizes (0.1 m^2, 1.0 m^2, 10 m^2). Four functional traits (two size traits and two leaf economics traits) were measured in every instance of each plant species. We used Monte Carlo simulations to estimate the standardized effect size of abundance-weighted mean and functional diversity using the observed species. Results for weighted mean traits were consistent with strategy theory in terms of size traits only. Results for functional diversity were consistent with the stress-dominance hypothesis in terms of leaf economics traits, while the results for plant height were opposite of theory. We know of no other study that has observed these alternative patterns across the two main axes of plant functional traits.
Microbial species that fix atmospheric nitrogen can benefit plants by colonizing the area around the roots or internal plant tissues and increasing nutrient availability. This process can reduce the need for synthetic fertilizers, therefore maintaining healthy soil and promoting environmental sustainability. Three endophytic bacterial species (Herbaspirillum, Gluconacetobacter, Methylobacterium) are gaining attention as potentially effective plant growth promoters when applied to the leaves directly, whereas an associative species Azospirillum is conventionally applied to soil. This field study investigated the impact of the foliar application of these four bacterial species independently and in combination, on the growth, physiological performance, and yield of corn and soybean. Overall, corn plants treated with the endophytic bacteria had increased leaf nitrogen content, chlorophyll, and greater reproductive yield compared to the untreated plants. However, the associative Azospirillum showed no growth benefits. In soybean, chlorophyll content was enhanced when all microbe species were combined in mixture, while seed mass was increased under only some of the endophytic microbes compared to the control. These results suggest that foliar treatments could be effective when using bacterial species classified as endophytic for boosting crop productivity, offering a more environmentally friendly way to supply nitrogen to plants than conventional synthetic fertilizers.
Introgression is the incorporation of genetic material from one species into another and can contribute to evolution. The goal of this research was to detect if introgression occurred in population of three sunflower species in Wisconsin, Helianthus giganteus, H. grosseserratus, and H. maximiliani. Previous studies have detected introgression in other sunflower species and there are both historical records of morphological intermediates and evidence for hybridization from crossing experiments for these species. I used the bioinformatics pipeline ipyrad on raw RADseq data from 357 samples to clean, align, and detect SNPs across the dataset. I then used TreeMix to create a maximum likelihood phylogenetic tree for the set of populations to look for evidence for introgression. I found no detectable introgression among the sunflower populations in this study. Instead, it appears that two samples of unknown populations are not of hybrid origin, and instead likely belong to Helianthus giganteus.
The ongoing rise of antibiotic-resistant microbes is a major concern in the medical field. Many pathogenic bacteria that were once vulnerable to common antibiotics have developed resistance, posing significant challenges to medicine and public health. Infections caused by these resistant bacteria are both expensive and challenging to treat. To address this growing crisis, we aim to identify new antibiotic-producing microbes isolated from soil samples obtained from beneath a wood pile. Following the collection of the soil, testing was done to determine the presence of any substances produced that either inhibit or kill any of the tester strains used (Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis). We have identified three strains of microbes that show evidence of producing an antimicrobial substance. We are working to identify these strains and determine if the antimicrobial substance they are producing is novel.
Mangrove communities play a significant role in shaping coastal communities such as San Salvador Island, Bahamas. Communities consisting of red, black, white, and buttonwood trees are commonly divided into specific regions of growth through the process of zonation with red mangroves growing along the coast, black mangroves along the muddy soils, white mangroves farther inland, and buttonwood located the farthest inland, which is dependent on soil salinity concentrations. Our goal was to define how salinity stress impacts the four mangrove species and their current health. We collected data across two sites: a high salinity body of water and a low salinity body of water. We expected an inverse relationship between salinity concentrations with tree diameter at breast height (DBH) and height. We also predicted chlorophyll content, specific leaf area (SLA), and stomata density would be greater for trees with lower salinity. Contrary to our predictions, DBH, height, and SLA did not depend on the salinity of the soil. White mangroves and buttonwoods from both sites differed in stomatal density (p-value < 0.001); however, stomatal density was not affected by salinity between sites. There was a higher chlorophyll content in higher salinity conditions compared to lower (p-value < 0.001).
In this project we evaluated the distribution, diversity, and activity patterns of bat communities on San Salvador Island in The Bahamas. This study is important because bat populations on the island were last studied 30 years ago. The goal of this study was to get updated information on different species previously encountered on the island, including: Erophylla sezikorni (buffy flower bat), Natalus tumidifrons (Bahamian funnel eared bat), Eptesicus fuscus (big brown bat), Tadarida brasiliensis (Brazilian free-tailed bat), and Macrotus waterhousii (big eared bat). Four Audiomoth sensors were deployed in various locations around the island over a period of seven days in January 2025. Each sensor recorded data for 12 hours each day, from dusk to dawn. From these recordings, we obtained data on the presence/absence of bat species, as well as the timing of their activity. Due to the variability in bat populations from day to day, our focus was on identifying species rather than counting the exact number of individuals in any specific area. Additionally, the team collected observational data in two caves where bats were visibly present. We also evaluated the correlation between bat activity patterns and the locations of the deployed sensors.
Plants have evolved a sophisticated set of pathways to detect and respond to light which allows them to adjust their development in response to changing conditions. The plant Arabidopsis thaliana contains three genes LRB1, LRB2, and LRB3 (Light-Response BTB 1, 2, and 3) that encode similar proteins functioning as target adaptors in E3 ubiquitin-ligase complexes. These complexes select target proteins for degradation. Plants containing mutations in the LRB1 and 2 genes are hypersensitive to red light due to reduced degradation of phytochromes, receptors for red and far-red light. Initial investigation of plants with disruption of the LRB3 gene suggested it does not participate in red-light response like LRB1 and 2. Previously, the laboratory performed genetic screens to identify enhancer mutations which exaggerate the effect of the LRB1/LRB2 mutations. Two of these enhancer mutations are in the Phytochrome B gene. Each of the mutations increases sensitivity to red light and in each case this hypersensitivity is increased when LRB1 and LRB2 are disrupted. To further investigate whether LRB3 might play a role in red light response, we created a line with one of the enhancer mutations in combination with disruption of LRB3. Data from analysis of these mutants will be presented.
We will evaluate the cytotoxic effects of ginger oil on cultured MCF-7 human breast cancer cells. Essential oils, commonly used through topical application or aromatherapy, have been explored for their potential to alleviate the adverse effects of cancer and its treatments, such as chemotherapy. Previous research has demonstrated that ginger oil can trigger cell death in cervical cancer cells within hours in vitro. In our study, MCF-7 cells will be exposed to varying concentrations of ginger oil for two hours, and cytotoxicity will be assessed by measuring lactate dehydrogenase (LDH) levels in the culture medium We hypothesize that ginger oil will exhibit dose-dependent cytotoxic effects on breast cancer cells.
Given the rapid expansion of human presence across the globe, coping with humans is an important aspect of life in the modern world for most animals. The California ground squirrel (Otospermophilus beecheyi) is a facultatively social rodent that has a long evolutionary history of residing near humans. While it is well understood that humans disrupt their foraging and social behavior, the role of humans and dogs on the stress physiology of these animals is unclear. As part of a long-term study, we live-trapped and released California ground squirrels and measured “stress” levels from fecal glucocorticoid metabolites (FGMs) using a fully validated enzyme-linked immunoassay (ELISA). Drawing from 12 years of data, we show that FGM levels vary across years but are elevated in areas with high exposure to humans and dogs. These patterns tracked variation in human activity across a gradient from high to low disturbance across our study site (from the south to the north). FGMs were repeatable for individual squirrels within and between years. Our findings offer insights into the relationships between anthropogenic disturbance and stress physiology over small temporal and spatial scales.
Light is important for plants as an energy source for photosynthesis, as a measure of day/night and seasonal cycles, and as information about the surrounding environment. For this reason, plants have evolved a sophisticated set of pathways to detect and respond to light, which allows them to adjust their development in response to changing conditions. Red and far-red light are detected by photoreceptors called phytochromes. A genetic screen for Arabidopsis thaliana mutants altered in red-light response conducted by the Gingerich lab identified mutations in PHYB, the gene encoding the major phytochrome involved in red-light responses. We have found that one of these mutations, which is predicted to alter a single amino acid in the phyB protein, increases sensitivity to not only red-light but also blue. Furthermore, this increased blue sensitivity is exacerbated when the genes LRB1 and LRB2 (which encode proteins functioning in complexes that initiate red-induced degradation of the phytochromes) are disrupted. This suggests a previously unrecognized interaction between blue-light response and the red-light phytochrome response pathway. Characterization of the blue-light response of this mutant will be presented.
Biologists have long recognized the importance of two native rodent species – California ground squirrels and voles – as important ecosystem engineers and prey for a suite of predators in California ecosystems. However, in the twelfth year of studying California ground squirrels at Briones Regional Park, for the first time, we observed ground squirrels shifting their diets from primarily granivorous to actively consuming vole prey. In 2024, our team documented a total of 74 events involving the hunting, killing, and/or consuming of voles by ground squirrels. Here we explored associations between vole density and these events. First, we extracted iNaturalist data to quantify vole numbers. Vole sightings in 2024 were regionally high at our site and seven times greater than the 10-year average statewide. Second, we created heat maps to show that vole-squirrel events occurred mostly where vole and ground squirrel burrows were the closest at our site. Our findings reveal important associations between this unusual peak in vole numbers, close spatial proximity between voles and squirrels, and the emergence of novel carnivorous behaviors by squirrels. Thus, spatial overlap with a locally abundant prey in a boom year likely contributed to the emergence of unusual dietary shift by a granivorous mammal.
Natural selection is expected to favor foraging behaviors that allow animals to maximize energy gain in novel situations. Whereas many species are known to regularly hunt prey and eat meat, squirrels are largely considered to be flexible omnivores that consume mainly grasses and seeds. However, our team recently documented the widespread hunting of California voles (Microtus californicus) by California ground squirrels (Otospermophilus beecheyi). This novel behavior is unusual for the species and has not been studied before. Here, we analyze the behavior of ground squirrels during these predation events (N=22 events). We characterized the hunting sequence for the first time in the California ground squirrel. We define hunting as the active pursuit of prey. We know that some mammalian hunters (cursors) chase prey over distances whereas sit-and-wait predators use stealth to ambush prey. We found that California ground squirrels were successful in 59% of their hunts, typically chasing, pouncing, and then biting the neck or head of the vole before consuming it. Revealing these opportunistic patterns of behavior contributes to our broader understanding of mammalian hunting styles.
Anthropogenic changes are expected to influence behavior, stress physiology, and ultimately, lifetime fitness of animals. For social animals, external stressors imposed by human activities may interact with the social environment to either exacerbate or buffer stressors. In the context of human-induced rapid environmental change, long-term data on individually recognized social mammals has the potential to offer novel insights into the extent to which organisms can cope with social and ecological stressors. In this research, we established a new project focused on the behavioral ecology of North American beavers (Castor canadensis), a native ecosystem engineer, through monitoring using camera traps. We surveyed various public lands and identified several active family groups of beavers in West-Central Wisconsin. Our camera trap data indicate that the behavioral patterns and their interactions with other local fauna vary temporally within days and across seasons. Future research will focus on their social behaviors, including their monogamous lifestyles, dominance structures, communication systems, and movement ecology. The plethora of wildlife we monitored on our camera traps illustrates how beavers play a key role in shaping diverse and healthy wetland ecosystems. This research therefore has important implications for the management of wetlands and conservation of beaver populations in the region.
Mosquitoes are harmful, disease-carrying vectors that pose significant publichealth risks worldwide. Aedes aegypti, known for transmitting Zika Virus, Dengue, andyellow fever, poses a threat in various climates, while Aedes triseriatus—native toWisconsin—transmits the La Crosse virus.While much is known about adult mosquito behavior, less is understood about thesensory behaviors of mosquito larvae. To address this gap, our lab is investigating thechemosensory behaviors of Ae. aegypti and Ae. triseriatus larvae, particularly in relation toforaging. We have refined protocols using the InVision device, a high-resolution camerasystem designed for tracking aquatic invertebrates, to monitor and quantify the behavior ofmosquito larvae in response to chemical gradients emitted from a point source.With these methodologies, our research now focuses on sensory behaviorvariations across all mosquito larval and pupal stages. The mosquito life cycle consists offour instar (larval) stages, followed by a pupal stage before emerging into adulthood. Ourprevious findings suggest that L1 Ae. triseriatus and Ae. aegypti larvae do not rely onchemosensory modalities to locate food. Preliminary results indicate that foragingbehavior increases in L2-L4 instars, suggesting a developmental shift in foraging strategiesas larvae progress through these stages.
Dietary flexibility allows animals to respond adaptively to food pulses in the environment. Here we document the novel emergence of widespread hunting of California voles and carnivorous feeding behavior by California ground squirrels. Specifically, we aimed to investigate whether the age and sex of squirrels explained the extent to which they engaged in hunting, consumption, and/or competition over voles. This work is part of a long-term study at Briones Regional Park in California where squirrels of known ages and sexes are regularly live-trapped, marked, and released. In 2024, from June 10th to July 30th, we recorded all sightings of squirrels hunting, killing and/or consuming voles both opportunistically on trapping days and during formal behavioral observations. We found no significant difference in the age-sex composition of those individuals that engaged in any of these behaviors compared to those that did not hunt, consume, or compete over voles. Thus, juvenile and adult ground squirrels of both sexes depredate, consume, and/or compete over vole prey. Given that participation in hunting and consumption of voles was so widespread across members of the study population, future studies are required to understand whether these novel foraging behaviors were learned individually or spread socially throughout the study population.
Squirrels (Rodentia; Sciuridae) are a well-known and diverse group of rodents, including the charismatic ground-dwelling members of the Tribe Marmotini. In particular, the California ground squirrel (Otospermophilus beecheyi) is an emerging model system for the study of social and risk-sensitive behaviors in a rapidly changing world, as well as the physiology of resistance to snake venoms. To complement extensive natural history information for O. beecheyi, we provide a chromosome-scale genome to facilitate molecular studies focused on the genetic basis of ecologically important traits, population genetics, comparative genomics, and social evolution. The final scaffolded genome was 2.27 Gb contained in 9,960 contigs and placed into 28 1,383 scaffolds. The scaffold N50 was just over 125 Mb. We used the presence of 10,248 complete genes detected by BUSCO v5 specifically to compare broad patterns of chromosomal synteny between chromosomal scaffolds for O. beecheyi and two other sciurid rodents. The recovered pattern of synteny suggests several fusion and fission events for O. beecheyi to the other two species. This new information should advance our understanding of O. beecheyi, particularly concerning the study of social and risk-taking behaviors, and comparative studies of mammalian genomic biology and evolution.
Aging is a complex biological process influenced by a range of genetic, environmental, and physiological factors. Studying normal aging can help us better comprehend age related diseases and potentially lead to the identification of therapeutic targets. In this study, we use large transcriptomes collected from mouse and human brains (Tabula Muris and GTEx) to investigate genes, gene networks, and biological pathways that are selectively engaged at different biological ages through brain aging. We use a novel network biology platform called NetDecoder to determine which genes are highly utilized within brain specific biological networks; high utility genes are those that encode for important proteins that are crucial to a specific function, even if they are not differentially expressed. Our approach is unique because we can recover genes relating to the aging brain that are not differentially expressed, meaning they likely would not be pinpointed by other labs.
Cortisol is a hormone released in response to stress that is also vital to human development. Previous studies in lab have shown that cortisol exposure of zebrafish embryos resulted in hypolocomotion with increasing cortisol concentration. Cortisol acts through two receptors, the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). We tested if the activation of the GR receptor would produce similar effects on behavior to cortisol exposure. Dexamethasone is a synthetic gluccocorticoid that selectively binds to the GR. Zebrafish embryos were collected and treated with different concentrations of dexamethasone at 4-6 hours post-fertilization (hpf) in a 12-well plate. The resulting zebrafish were transferred at 5dpf to a 96-well plate, which was then measured in an 18-minute alternating light-dark assay to assess their locomotor behavior using a commercial motor tracking system. Two rounds of experiments, consisting of concentrations ranging from 100 to 1 uM showed differential relative behavioral phenotypes at different concentrations. These experiments inform our understanding of how corticosteroid receptors affect zebrafish behavior in embryonic development.
Glucocorticoids are steroid hormones vital to development and many physiological responses. The body’s primary glucocorticoid, cortisol, is released in response to stress and binds to two receptors: mineralocorticoid (MR) and glucocorticoid receptors (GR). Excess prenatal exposure to glucocorticoids has been linked to adverse effects on neurodevelopment. Previous work in the lab found that an increase in embryonic exposure to cortisol resulted in decreased swim behavior in zebrafish larvae 5 days post-fertilization (dpf). The goal of this study was to identify how selective MR exposure would affect behavior in larval zebrafish using deoxycorticosterone (DOC), a natural precursor to cortisol that binds to MR. Zebrafish embryos were treated with decreasing concentrations of DOC (1 µM, 0.3 µM, and 0.1 µM) at 4-6 hours post-fertilization (hpf) in a 12-well plate. Larvae were transferred at 5dpf to a 96-well plate and assayed using a commercial motor tracking system (Noldus DanioVision). Initial results indicate that the swim velocities for larvae exposed to 0.3 µM DOC were higher than control groups in the first dark cycle, but no other significant differences were observed. By investigating how DOC affects neurodevelopment in zebrafish, these results can inform future studies on the role of MR agonists in development.
This study investigated the diversity, growth, and abundance of macroalgal species on reefs surrounding San Salvador Island, The Bahamas, amid ongoing ecological change. Coral reef ecosystems are undergoing significant shifts due to climate change, habitat degradation, and the spread of invasive species. Understanding macroalgal communities during this transition is critical, as these organisms play a key role in reef structure and function. We conducted quadrat sampling and photo surveys across three reefs representing different levels of degradation. Algal diversity, including variations in growth forms and color patterns, was estimated from photographic data collected at over 50 quadrat locations. A subset of samples was analyzed to confirm species identifications and to assess photosynthetic capacity and growth strategies through quantitative measurements of biomass and chlorophyll content. Reefs around San Salvador Island support a diverse macroalgal community, including calcareous algae (Halimeda spp.), fleshy browns (Dictyota spp.), greens (Udotea spp.), and filamentous species. This study establishes a valuable baseline for understanding macroalgal responses to environmental change and contributes to ongoing reef conservation efforts.
Schistosomes are parasitic flatworms that cause schistosomiasis, a highly prevalent neglected tropical disease impacting over 250-million people worldwide. Life cycle progression through a snail intermediate host during their first larval stage, which are called miracidia, is required for worms to become infective to humans. The mechanism miracidia use to locate snails is not known. However, a secreted snail peptide known as P12 has been shown to elicit responses from miracidia that suggest it may serve as a cue for them in locating their snail hosts. The objective of this study was to investigate the role and structural requirements of P12 in Schistosoma mansoni miracidia host-seeking. P12 was cloned and sequenced from five snail species, revealing natural variation at 7 key residues. Quantitative methods were employed to characterize miracidia behavioral responses to snail cues and synthesized P12 variants. Preliminary findings suggest that stimulant gradients are required to elicit behavioral changes in miracidia. Infection experiments with live snails were carried out to determine if P12-rich solutions can disrupt these gradients and dysregulate miracidia sensation. Miracidia dysregulation control strategies are an under-researched approach to reducing the prevalence of schistosomiasis, but they could have especially significant impacts in endemic regions of the world.
I'm a junior at UWEC majoring in microbiology. I am a researcher in the Wheeler lab here on campus (in the Biology Department). My research focuses on using quantitative methods to study parasite chemosensory behaviors. At CERCA, I'll be presenting a poster (Poster 036: Investigating... Read More →
Candida albicans is the most frequently isolated human fungal pathogen and is an important agent of hospital acquired infections. To determine if a gene encodes a protein that contributes to its ability to cause disease, both alleles of a gene are typically disrupted. Historically, gene disruption in C. albicans utilizes the URA3 gene as a selectable marker in a URA3 auxotrophic strain. It was discovered that some of the mutant strains created using the “URA-blaster” technique had reduced levels of URA3 expression that affected the phenotypes of the mutant strains. Previously, we created a mutant strain of Candida albicans in which the MBP1 gene has been disrupted using the “URA-blaster” technique. To determine if the mutant phenotype observed is due to the disruption of the MBP1 gene or is an artifact due to reduced levels of URA3 expression, we are assessing URA3 gene functionality by assaying for OMP decarboxylase activity using protein lysates from wild-type and MBP1 mutant strains. Currently, we are making protein lysates which will be assessed for URA3 activity. Once we obtain the results of this experiment it will help to clarify the significance of the phenotypes observed in the MBP1 null mutant strains.
The aim of this study is to understand how flatworms use their sensory capacities in their environments. Parasitic flatworms are a threat to human health globally. Understanding how these worms can find hosts to infect would help advance parasite control. This study focuses on Girardia dorotocephala, a species of free-living planaria we are developing as a flatworm model, uses chemoreceptors located in their auricles to sense their surroundings. While planaria are not parasites, they possess many of the same traits as parasites within the phylum. Both planaria and parasitic flatworms belong to the Platyhelminthes and have some of the same morphological features and molecular pathways. Because of the similarity between the two clades, we can use planaria as a model organism to better understand flatworm behavior. To initiate this project, we recorded and tracked planaria when placed in separate controlled environments. Experiment followed the planaria’s movements when placed in the presence or absence of food, or under different light conditions. We were also working on sequencing the genome to help identify genes potentially involved in sensation, setting up G. dorotocephala as a model flatworm for sensory experiments.
Schistosomiasis, a neglected tropical disease caused by three parasitic flatworm species,including Schistosoma mansoni, relies on freshwater snails as intermediate hosts. Interrupting theparasite’s ability to locate snails could provide a novel strategy for disease control. Praziquantelis the current treatment of choice for human infections, and it exerts its effect by targetingtransient receptor potential (TRP) channels on the parasite, leading to death of the worm. Despiteits effectiveness in eliminating adult parasites, treated individuals remain susceptible toreinfection.In this study, a drug screening approach was used to identify compounds targeting the transientTRP receptors in miracidia, a larval stage of the parasite. A custom 96-well acrylic device wasdesigned; worms were added to each well and treated with 10 µM of drug.The impact of eachcompound on miracidia behavior was assessed to identify potential drug candidates. Toaccurately monitor their responses, a high-resolution recording device was utilized. This systemenabled precise observation of miracidia motility and orientation, allowing identification ofcompounds that disrupt general movement or host-seeking behavior. Preliminary findingssuggest that TRP channel modulators play a role in altering miracidia navigation, offering apromising avenue for disrupting the parasite’s life cycle.
I'm a junior at UWEC majoring in microbiology. I am a researcher in the Wheeler lab here on campus (in the Biology Department). My research focuses on using quantitative methods to study parasite chemosensory behaviors. At CERCA, I'll be presenting a poster (Poster 036: Investigating... Read More →
Schistosomiasis is a tropical disease caused by human-infective parasites of the genus Schistosoma. The larval stage, called miracidia, infects a snail intermediate host and matures into cercariae that are shed into water. Cercariae penetrate human skin and migrate to blood vessels connecting the intestines and liver. Here, mature parasites lay eggs that follow the flow of blood into the liver or against the flow into the intestines. Intestinal eggs will mature, be defecated into fresh water, and hatch to miracidia to continue the cycle of infection. In contrast, liver eggs have reached a dead end, but these are routinely harvested from rodent lab hosts for research use and maintenance of the life cycle. Previous evaluation of transcriptomic differences between the liver and intestine eggs revealed distinct functional differences, yet nothing is known about differences between miracidia derived from these eggs. We isolated distinct infected mice tissues and hatched miracidia. Using these miracidia, we performed RNA-seq analysis and found distinct transcriptomic clusters and differentially expressed genes between the samples. Future directions include experiments to test for differences between these miracidia in behavior and infection capacity. These findings will lead to deeper insights about relevant differences between miracidia from different tissues.
I'm a junior at UWEC majoring in microbiology. I am a researcher in the Wheeler lab here on campus (in the Biology Department). My research focuses on using quantitative methods to study parasite chemosensory behaviors. At CERCA, I'll be presenting a poster (Poster 036: Investigating... Read More →
In lakes, mosses are distributed in deeper waters than any other form of plant life. Little is known about these plant communities, and this ongoing study by Dr. Lonzarich and his students is the most comprehensive of its kind. Prior work in this lab has explored the distribution and factors affecting the occurrence of mosses from 70 lakes in Wisconsin. The objectives of this study were to identify the mosses collected from these lakes using a DNA barcoding approach, which involves DNA extraction, PCR amplification of the LTS gene (barcoding gene), and sequencing using the Sanger method. An altermative method using the RBCL gene and next-generation sequencing is also being used. By identifying the species through online gene databases, the study intends to unravel the geographic distribution patterns of deep-water moss species in the state. The study builds on previous work that found difficulties in identifying moss species based on morphological characteristics due to their unique growth forms in deep-water habitats. Initial indications from morphological assessments suggest the presence of distinct geographic patterns in the distribution of deep-water mosses within Wisconsin's lakes.
Mobile applications like PictureThis use artificial intelligence to identify plant species, providing a convenient tool for users without botanical expertise. However, the accuracy of these applications remains uncertain, which is particularly important in ecological and conservation contexts, as misidentifications can have serious consequences. This study evaluated the reliability of PictureThis by comparing its identifications with genetic sequencing results from plant samples collected on the University of Wisconsin–Eau Claire campus. Ninety-four plant samples were analyzed, with sixty-five yielding positive genetic identifications. Of these, thirty-three (51%) matched the species-level identification provided by PictureThis, while twelve (18%) were confirmed at the genus level and five (8%) at the family level. The remaining fifteen (23%) showed no correspondence between genetic sequencing and app-based identifications. Discrepancies may stem from the app’s inability to identify certain plants, such as grasses, or its reliance on superficial similarities. Notably, genetic analysis confirmed that twelve plants identified by the app as non-native were actually native to Wisconsin, indicating an overestimation of non-native species. These findings highlight the limitations of AI-based plant identification apps and emphasize the need to supplement such tools with scientific validation when making ecological or conservation decisions.
