Biology Commons^™

Impact Of Co-Culturing Bacteria Upon Antibiotic Production, Zora Westwalewicz

Senior Honors Theses and Projects

The lack of new antibiotics capable of treating the ever-increasing number of antibiotic-resistant bacterial infections reflects the difficulty of finding new antimicrobial compounds. Most antibiotics were originally discovered from microorganisms that were grown in isolation. The interspecies interactions involved in co-culturing microbes, growing two or more strains together, can impact the types and increase production levels of antimicrobial compounds compared to monocultures. The purpose of this study was to determine whether co-culturing antibacterial producers would result in increased antibiotic production. Mixed student samples from the EMU Tiny Earth lab were utilized for this study because there was a higher chance …

Decomposition Of Organic Matter Above And Below Dams, Olivia Muntz

Senior Honors Theses and Projects

Dams produce hydroelectric power and control flooding, but they also cause negative ecological consequences such as habitat fragmentation and altered water quality. The goal of this study was to determine whether dams alter rates of organic matter decomposition. Decomposition rates in impoundments and in free-flowing sections of the Huron River were measured using the cotton strip assay. We hypothesized that if water temperature is the main driver of decomposition rates, then higher rates of decomposition would be expected behind dams due to anticipated warmer water temperatures in the impoundment. If oxygen concentrations are a main driver of decomposition rates, lower …

Vocal Analysis Of The Newly Described Atlantic Coast Leopard Frog, Carrie J. Kosiba

Senior Honors Theses and Projects

Urbanization alters animal behaviors and especially impacts amphibians due to their sensitivity to environmental change, small home ranges, and reliance on acoustic communication to locate mates. A newly discovered leopard frog species, Rana kauffeldi, was recently described from the New York City metro area. This species was previously characterized as R. sphenocephala due to their nearly identical morphology, but the two species are distinguished based on genetics and calling characteristics. The goal of this project was to document calling intensity and phenology (timing) differences between urban and rural populations of R. kauffeldi, as well as describe variation across …

Understanding The Effects Of Embryonic Hyperglycemia On Retinal Development And Maintenance, Kayla Titialii-Torres

Theses and Dissertations--Biology

Hundreds of millions of people are affected by diabetes worldwide. Whether they are diagnosed with prediabetes or Type I or II diabetes, there are a variety of mechanisms in the pathogenesis of diabetes. Diabetes is a disease which consists of recurring states of hyperglycemia that can be difficult to manage due to either lack of insulin production or improper utilization of insulin. While these mechanisms of action differ, complications induced by diabetes occur in both poorly regulated Type I and II. Common complications of diabetes include nerve damage, kidney damage, and eye damage. Eye damage specifically is called diabetic retinopathy …

Modeling Als-Associated Matrin-3 Toxicity In Yeast, Widad El-Zein

Browse all Theses and Dissertations

ALS is a neurodegenerative disease characterized by degeneration of upper and lower motor neurons in the brain and spinal cord leading to progressive paralysis and ultimately death. Perturbations in RNA metabolism and RNA binding proteins have emerged as underlying defects in ALS pathogenesis. Matrin-3 is a multifunctional RNA binding protein that has been linked to familial and sporadic ALS. Matrin-3 is normally found in the nucleus, but mutations in the gene cause mislocalization of the protein from the nucleus into the cytoplasm of neuronal cells where it forms protein aggregates. In this study, we show that over-expressing human MATR3 in …

Increased Signal Complexity Is Associated With Increased Mating Success, Noori Choi, Matt Adams, Kasey Fowler-Finn, Elise Knowlton, Malcolm Rosenthal, Aaron Rundus, Roger D. Santer, Dustin J. Wilgers, Eileen Hebets

Eileen Hebets Publications

The evolution of complex signals has often been explored by testing multiple functional hypotheses regarding how independent signal components provide selective benefits to offset the costs of their production. In the present study, we take a different approach by exploring the function of complexity per se. We test the hypothesis that increased vibratory signal complexity— based on both proportional and temporal patterning—provides selective benefits to courting male Schizocosa stridulans wolf spiders. In support of this hypothesis, all of our quantified metrics of vibratory signal complexity predicted the mating success of male S. stridulans. The rate of visual signalling, which is …

Description Of The Courtship And Copulation Behaviours Of The Wall Spider Oecobius Concinnus (Oecobiidae), Diego Solano-Brenes, Laura Segura-Hernández, Gilbert Barrantes

Eileen Hebets Publications

Courtship and copulation behaviours are yet scantily described in many spider families, and this lack of information limits our understanding of the evolution of such behaviours within and across families. Here, we provide a detailed description of both courtship and copulation behaviour for Oecobius concinnus Simon, 1893. A striking characteristic of the male courtship is the construction of a tubular web (mating web) in which most courtship and copulation occurs. This web likely functions to restrain the female in a reduced space and as a substrate for male pheromones. The courtship consists of a complex web of interactions between both …

Reconstructed Evolutionary Patterns For Crocodile-Line Archosaurs Demonstrate Impact Of Failure To Log-Transform Body Size Data, Roger B. J. Benson, Pedro Godoy, Mario Bronzati, Richard J. Butler, William Gearty

School of Biological Sciences: Faculty Publications

No abstract provided.

Pea Aphid Winged And Wingless Males Exhibit Reproductive, Gene Expression, And Lipid Metabolism Differences, Omid Saleh Ziabari, Qingyi Zhong, Swapna R. Purandare, Joel Reiter, Anthony J. Zera, Jennifer A. Brisson

School of Biological Sciences: Faculty Publications

Alternative, intraspecific phenotypes offer an opportunity to identify the mechanistic basis of differences asso- ciated with distinctive life history strategies. Wing dimorphic insects, in which both flight-capable and flight- incapable individuals occur in the same population, are particularly well-studied in terms of why and how the morphs trade offflight for reproduction. Yet despite a wealth of studies examining the differences between fe- male morphs, little is known about male differences, which could arise from different causes than those acting on females. Here we examined reproductive, gene expression, and biochemical differences between pea aphid ( Acyrthosiphon pisum ) winged and wingless …

Social Networks In The Single Cell, Moira Rodriguez, Ana Martinez-Hottovy, Alan C. Christensen

School of Biological Sciences: Faculty Publications

Plant mitochondrial DNA (mtDNA) can become damaged in many ways. A major repair mechanism is homologous recombination, which requires an undamaged DNA template. Presumably, this template comes from a different mitochondrion in the same cell. Plant mitochondria undergo fission and fusion to form transient networks which could allow the exchange of genetic information. To test this hypothesis, Chustecki et al. (2022) used msh1 mutants with defective DNA repair, and showed that mitochondrial interactions increased, revealing a link between the physical and genetic behavior of mitochondria.

Towards An Integrative View Of Virus Phenotypes, John P. Delong, Maitham A. Al-Sammak, Zeina Al-Ameeli, David Dunigan, Kyle F. Edwards, Jeffry J. Fuhrmann, Jason P. Gleghorn, Hanqun Li, Kona Haramoto, Amelia O. Harrison, Marcia F. Marston, Ryan M. Moore, Shawn W. Polson, Barbra D. Ferrell, Miranda E. Salsbery, Christopher R. Schvarcz, Jasmine Shirazi, Grieg F. Steward, James L. Van Etten, K. Eric Wommack

School of Biological Sciences: Faculty Publications

Understanding how phenotypes emerge from genotypes is a foundational goal in biology. As challenging as this task is when considering cellular life, it is further complicated in the case of viruses. During replication, a virus as a discrete entity (the virion) disappears and manifests itself as a metabolic amalgam between the virus and the host (the virocell). Identifying traits that unambiguously constitute a virus’s phenotype is straightforward for the virion, less so for the virocell. Here, we present a framework for categorizing virus phenotypes that encompasses both virion and virocell stages and considers functional and performance traits of viruses in …

Arctic Stream Characteristics And Diet Analysis Choice Impact Condition And Diet Estimates Of Ninespine Stickleback (Pungitius Pungitius), Adam Kuhrt

Theses and Dissertations (Comprehensive)

Ninespine stickleback (Pungitius pungitius) are ubiquitous in circumpolar freshwaters, but their ecological role is not well understood. Little research has been conducted on the influence of environmental variables on ninespine stickleback in stream environments, and while they are understood to be generalist feeders, their diet in stream environments is equally understudied. Determining diet is difficult due to biases inherent in all standard diet analysis methods. Morphological gut-content analysis (M-GCA), DNA metabarcoding of gut contents (D-GCA), and stable isotope analysis (SIA) are currently three of the most frequently conducted diet analyses; and while combinations of these methods are commonly …

Effects Of 17Α-Ethinylestradiol (Ee2) On Gonadal Development And Gene Expression In Larval Mummichog (Fundulus Heteroclitus), Carly Sing-Judge

Theses and Dissertations (Comprehensive)

The mummichog (Fundulus heteroclitus) is a small-bodied estuarine fish that inhabits the North American east coast and is often used as a model adult saltwater fish in environmental bioassays. This study aimed to describe gonadal development and gene expression levels in five-week-old mummichog under control conditions and following 17α-ethinylestradiol (EE₂) treatment in order to better understand the susceptibility of sex determination (SD) and gonadal differentiation (GD) processes following contaminant exposure. In the first experiment, eggs were fertilized, collected and incubated in the laboratory for three weeks, then yolk-sac larvae were grown out for five weeks and …

Toxicity Of The Technology Critical Elements Germanium And Yttrium To Daphnia Magna And Hyalella Azteca And The Influence Of Toxicity Modifying Factors, Rashid Shah

Theses and Dissertations (Comprehensive)

Technology critical elements (TCEs) are increasingly used in high and green technologies but there is little aquatic toxicity data for TCEs, particularly in fresh water. The objective of this study was to investigate the toxicity of two TCEs, Ge and Y, to Daphnia magna and Hyalella azteca and to understand the role of natural organic matter and cations on toxicity modification. Testing followed standard methods. The 48 h EC50 for D. magna was 11.6 (95% CI of 9.64-13.8) mg Ge/L based on measured dissolved concentrations at test end. The addition of NOM at 10 mg DOC/L resulted in a significant …

Assessment Of Temperature Optimum Signatures Of Corals At Both Latitudinal Extremes Of The Red Sea, Guilhem Banc-Prandi, Nicolas R. Evensen, Daniel J. Barshis, Gabriela Perna, Youssouf Moussa Omar, Maoz Fine

Biological Sciences Faculty Publications

Rising ocean temperatures are pushing reef-building corals beyond their temperature optima (T_opt), resulting in reduced physiological performances and increased risk of bleaching. Identifying refugia with thermally resistant corals and understanding their thermal adaptation strategy is therefore urgent to guide conservation actions. The Gulf of Aqaba (GoA, northern Red Sea) is considered a climate refuge, hosting corals that may originate from populations selected for thermal resistance in the warmer waters of the Gulf of Tadjoura (GoT, entrance to the Red Sea and 2000 km south of the GoA). To better understand the thermal adaptation strategy of GoA corals, …

Determinants Of Population Genetic Structure In Chamaecrista Fasciculata (Michx.) Greene (Fabaceae) In The Southeastern United States, Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace

Biological Sciences Faculty Publications

Chamaecrista fasciculata is a widely distributed, phenotypically variable species in the eastern U.S. Whereas studies have demonstrated genetic structure and local adaptation in northern areas of its distribution, there has been no comparison of genetic variability among populations at the southern extent where phenotypic variation is more complex. We characterized genetic variation at 14 microsatellite loci for populations in Mississippi and Alabama and compared this to variation in a phenotypic trait, leaf pubescence. Geographic distance, climatic variables, and elevation were evaluated as factors to explain the observed patterns of genetic diversity. A significant amount of variation (19%) resided among populations, …

The Challenges Of Growing Orchids From Seeds For Conservation: An Assessment Of Asymbiotic Techniques, Devani Jolman, Martín I. Batalla, Alexis Hungerford, Pryce Norwood, Noah Tait, Lisa E. Wallace

Biological Sciences Faculty Publications

Lewis Knudson first successfully germinated orchid seeds asymbiotically on artificial medium in 1922. While many orchid species have since been grown asymbiotically, the tremendous variation in how species respond to artificial medium and growth conditions ex situ has also become apparent in the past century. In this study, we reviewed published journal articles on asymbiotic orchid seed germination to provide a summary of techniques used and to evaluate if these differ between terrestrial and epiphytic species, to identify areas where additional research is needed, and to evaluate whether asymbiotic germination could be used more often in ex situ conservation. We …

Effects Of Elevated Temperature, Reduced Hydroperiod, And Invasive Bullfrog Larvae On Pacific Chorus Frog Larvae, Bailey R. Tasker, Karli Honebein, Allie M. Erickson, Julia E. Misslin, Paul Hurst, Sarah Cooney, Skylar Riley, Scott A. Griffith, Betsy A. Bancroft

Biology Faculty Scholarship

Climate change and invasive species threaten many ecosystems, including surface freshwater systems. Increasing temperatures and reduced hydroperiod due to climate change may promote the persistence of invasive species and facilitate new invasions due to potentially higher tolerance to environmental stress in successful invaders. Amphibians demonstrate high levels of plasticity in life history characteristics, particularly those species which inhabit both ephemeral and permanent water bodies. We tested the influence of two projected effects of climate change (increased temperature and reduced hydroperiod) on Pacific chorus frog (Pseudacris regilla) tadpoles alone and in combination with the presence of tadpoles of a …

Understanding The Cellular And Physiological Mechanisms Of Fertilization And Early-Stage Seed Development, Mohammad Foteh Ali

Theses and Dissertations--Plant and Soil Sciences

Flowering plants have evolved a unique double-fertilization process. Two sperm cells fuse with two female gametophytic cells, the egg and central cells within the ovule, giving rise to the embryo and endosperm, respectively. Sperm cells in flowering plants are nonmotile and delivered in close proximity to the egg and central cells by the pollen tube. Flowering plants have established filamentous actin (F-actin) based sperm nuclear migration system for successful fertilization. Prior to fertilization, the female gamete forms a mesh-like structure of F-actin that shows constant inward movement from the plasma membrane periphery to the center of the cell where the …

The Role Of Rna Helicase Rhau In Immunoglobulin Class Switch Recombination, Sabine Jean Guillaume

Dissertations and Theses

B cells alter the expression of immunoglobulin isotypes through a process known as class switch recombination (CSR). In these cells, activation induced cytidine deaminase (AID) binds Gquadruplex (G4) switch transcripts, which serve as guide RNAs to target AID to the immunoglobulin heavy chain switch (S) regions in the DNA for CSR. Sequence alignment revealed homology between the AID G4 binding domain and the RNA helicase associated with AU-rich element (RHAU) specific motif (RSM), which allows RHAU binding to G4 RNAs and subsequent unwinding of G4 RNA into single-stranded transcripts. We hypothesize that RHAU functions in CSR by binding G4 S …

Exosome- And Microrna-Based Therapeutic Approach For Tendinopathy, Angela Wang Ilaltdinov

Dissertations and Theses

Tendinopathy, characterized by degeneration and chronic inflammation, is a significant clinical burden. Current treatments focus on symptom management but do not sufficiently address its underlying pathology; however, stem cell-based approaches aimed at repairing diseased tissues may overcome this limitation. Therapeutic effects of stem cells may be due in part to paracrine actions, including some mediated by exosomes – extracellular vesicles secreted by cells that play a role in cell communication. MicroRNA (miRNA), small non-coding RNA carried by exosomes, are likely responsible for many exosome effects. Exosomes and miRNA therapies show promise in treating diseases such as cancer and arthritis, but …

Response Of Antarctic Soil Fauna To Climate-Driven Changes Since The Last Glacial Maximum, Andre L.C. Franco, Byron J. Adams, Melisa A. Diaz, Nathan P. Lemoine, Nicholas B. Dragone, Noah Fierer, W. Berry Lyons, Ian Hogg, Diana H. Wall

Biological Sciences Faculty Research and Publications

Understanding how terrestrial biotic communities have responded to glacial recession since the Last Glacial Maximum (LGM) can inform present and future responses of biota to climate change. In Antarctica, the Transantarctic Mountains (TAM) have experienced massive environmental changes associated with glacial retreat since the LGM, yet we have few clues as to how its soil invertebrate-dominated animal communities have responded. Here, we surveyed soil invertebrate fauna from above and below proposed LGM elevations along transects located at 12 features across the Shackleton Glacier region. Our transects captured gradients of surface ages possibly up to 4.5 million years and the soils …

Coupled Structure-Function Responses To Disturbance: High Structural Complexity Resistance Supports Primary Production Resistance, Kerstin M. Niedermaier

Theses and Dissertations

The capacity of forests to resist structural change and retain material legacies–the biotic and abiotic resources that persist through disturbance–is crucial to sustaining ecosystem functioning after disturbance. However, the role of forest structure as both a material legacy and feature supporting carbon (C) cycling stability following disturbance has not been widely investigated. We used a large-scale disturbance manipulation to ask whether LiDAR-derived canopy structures as material legacies drive 3-year responses of NPP to a range of disturbance severity levels. As part of the Forest Resilience Threshold Experiment (FoRTE) in northern Michigan, USA we simulated phloem-disrupting disturbances at a range of …

Advancing Forest Structure-Function Relationships: Linking Above- And Belowground Structure To Soil Respiration, Laura J. Hickey

Theses and Dissertations

Variation in the soil-to-atmosphere C flux, or soil respiration (Rs), is influenced by a suite of biotic and abiotic factors, including soil temperature, soil moisture, and root biomass. However, whether canopy structure is tied to soil respiration through its simultaneous influence over these drivers is not known. We assessed relationships between measures of above- and belowground vegetation density and complexity, and evaluated whether Rs is linked to remotely sensed canopy structure through pathways mediated by established biotic and abiotic mechanisms. Our results revealed that, at stand-scale, canopy rugosity–a measure of complexity–and vegetation area index were coupled to soil respiration through …

Chronic Adolescent Stress As A Predictive Factor For The Risk Of Developing Ptsd-Like Symptoms In Adulthood, Grace K. Young

Theses and Dissertations

Post-traumatic stress disorder is a stress and trauma based psychological disorder that is defined by the DSM-IV as an anxiety disorder that affects approximately 7.8% of people in the United States. PTSD is when those who suffer a traumatic event have intense and distressing feelings, emotions, and memories for a prolonged period of time after the event. A prominent feature of PTSD is the impaired ability to properly extinguish a fear response after a dangerous trigger or stressor is no longer present, also known as safety learning. Stressors are threats perceived within the environment that activate a response within the …

Biotic Characteristics Of Managed And Unmanaged Coastal Dunes In The Outer Banks, North Carolina, Andrew E. White

Theses and Dissertations

Under future climate change and sea level rise scenarios, Natural and Nature-Based Features (e.g., dunes) that protect coastal habitat and infrastructure will be exposed to increased wave energy and storm surge. Understanding how these forces will impact coastal dunes is necessary for their continued use as protective features. Coastal dunes develop through feedback between vegetation and sediment deposition, a process complicated by species-specific growth rates and responses to burial. Wave flume studies have tested the effects of dune vegetation on erosion and found multiple plant organs across several functional types to be important for resisting erosion. Although dune building and …

Stomatal Conductance And Reed Canary Grass Suppression Traits Of Native Michigan Trees, David E. Martinez, Dave Warners

Student Papers and Reports

Reed canary grass (Phalaris arundinacea), a prominent invasive understory species, threatens native Michigan biodiversity statewide. A notable affected area includes a stretch of agricultural land along Schooley Drain in Caledonia, MI, located in the headwaters of the Plaster Creek watershed. Our study pursues the following questions: “Do native trees provide enough shade to reduce the growth of Reed canary grass?” and “Which native trees best transpire water from a floodplain?”: To answer these questions, we continued the evaluation of seven different species of native Michigan trees to investigate which species best inhibits the growth of reed canary grass …

The Emma Cole Project: Reevaluating The Flora Of Grand Rapids, William Hofmann, Hayden Janssen, Martin Vanderschoot, Garrett Crow, Dave Warners

Student Papers and Reports

In 1901, botanist and teacher Emma Cole published an account of all the vascular plants in the Grand Rapids area, which is the most comprehensive documentation of the flora in the area today. The vicinity of Grand Rapids has been developed significantly since then, and with it the surrounding natural spaces have also been greatly altered. Over the past 7 years, Calvin University’s Emma Cole Project has been inventorying the flora of greater Grand Rapids and comparing modern plant life with the flora during Cole’s time 120 years ago. This project strives to both verify species’ presence around Grand Rapids …

Plaster Creek Stewards - Urban Habitat Restoration With Green Team, Jia Luchs, Clare Doss, Rachel Warners, Dave Warners, Deanna Geelhoed

Student Papers and Reports

Plaster Creek, though its watershed is home to many potential stewards in Grand Rapids, is the most polluted creek in West Michigan. The Green Team, a branch of Plaster Creek Stewards, is a group of students that work during the summer with a focus on research, education, and working directly to restore the Plaster Creek Watershed. The Green Team works toward this goal through urban green infrastructure, utilizing native plants to manage stormwater. Two Calvin students, Jia Luchs and Clare Doss, and twenty high school students living in the Plaster Creek watershed were hired by Plaster Creek Stewards this summer …

Urban Insect Biodiversity - Effects Of Native Landscaping, Caedmon Morgret, Dave Warners

Student Papers and Reports

Urban development comes with the cost of destroyed natural habitats. Urban infrastructure flattens entire ecosystems, replacing them with impervious, life-inhibiting constructions.

Alleviating the impacts of urbanization is possible. Green infrastructure mitigates habitat loss by restoring native habitats within urbanized areas. One benefit of green infrastructure is the reestablishment of biodiversity, benefitting plants, animals, and insects alike. Biodiversity creates a healthier habitat and location than urban infrastructure –and lack of biodiversity –does.

To investigate this benefit we performed a pilot study, sampling lawns and curb-cut rain gardens (CCRGs). We compared biodiversity between restored and unrestored urban habitats.