Master of Sciences, Case Western Reserve University, 2018, Biology

The Drosophila blastoderm embryo is patterned by morphogens, molecules that inform cells to adopt specific fates in a threshold-dependent fashion. The morphogen Bicoid subdivides the antero-posterior axis into head, thorax and abdomen, whereas the morphogens Dorsal/NFk-B and Decapentaplegic/BMP-4 regulate cell fates along the dorso-ventral axis and subdivide the embryo into three germ layers (mesoderm, neuroectoderm and ectoderm). Together, the concentration gradients produced by these morphogens form a coordinate system along the main embryonic axes and cell fate is influenced depending on where a cell falls inside this system. For several years, the blastoderm was considered to be a static stage due to the lack of mitotic divisions or any major gastrulation movements. However, recent work demonstrated that a stereotyped movement of cells towards the dorsal midline from the lateral regions and the poles of the embryo takes place. As a result, by the end of the blastoderm stage, there is a higher density of cells in the dorsal region of the embryo and a lower density of cells in the ventral region. Results from our lab and others suggest that Decapentaplegic and Dorsal are required for these stereotyped cell movements. In this work, we tested whether the candidate gene frazzled (fra) we identified in a bioinformatics screening is a downstream regulator responsible for directing cells towards the dorsal region of the embryo. fra encodes a transmembrane receptor previously implicated in glial cell migration during late embryonic stages. The function of fra in the early blastoderm is unknown. In this work, we show that in embryos mutant for fra, cells lose their migration direction towards the dorsal midline and display an increased density within the ventral side compared to wild type embryos. We have also observed that FRA protein is located on the dorsal side of the Drosophila embryo and is localized on the apical surface of the cell vertices. Our findings suggest (open full item for complete abstract)

Committee: Claudia Mizutani (Advisor); Sarah Diamond (Committee Chair); Dianne Kube (Committee Member); Emmitt Jolly (Committee Member) Subjects: Biology; Developmental Biology; Genetics

Doctor of Philosophy, The Ohio State University, 1974, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Master of Science (M.S.), University of Dayton, 2025, Biology

Among the general hallmarks of cancer are dysregulated proliferative signaling and tumor heterogeneity, with diverse genetic alterations inducing the activity of various interconnected signaling pathways and ultimately posing a significant challenge to targeted pharmacological treatment. Colorectal cancer (CRC) stands as the third-most diagnosed malignancy, and invasive surgical intervention remains the predominant method of treatment. CRC is characterized by high co-occurrence of mutations in the tumor suppressor gene APC, the proto-oncogene KRAS, and the dual tumor suppressor and proto-oncogene TP53. These genetic lesions implicate the Wnt, Ras-MAPK, and DNA damage repair pathways in the initiation and progression of neoplastic growth in the intestinal epithelium, raising questions regarding how these pathways and others such as JNK and Hippo interact in the aberrant control of cellular proliferation, cell cycle progression, growth, and cell death. Using the Drosophila intestine as a model, this study sought to investigate the signaling interactions underlying initiation and progression of CRC in the context of dominant-negative p53, oncogenic RasG12V, and loss-of-function APC. The mosaic analysis with a repressible cell marker (MARCM) technique was used alongside escargot-GAL4 to drive the expression of these mutant transgenes specifically in intestinal stem cells in early larvae and adults. Through the generation of one-hit, two-hit, and three-hit models of CRC expressing p53DN, RasV12, and APC-/-, we tested for alterations in signaling activity that ultimately drive abnormal proliferation and cell cycle progression in CRC. Molecular phenotypes, including gene expression changes and alterations in growth-regulating pathways, were assessed via dissection of third instar larvae and mature adult flies and immunohistochemistry. Our results support that the expression of dominant-negative p53, oncogenic RasV12, and loss-of-function APC in the larval intestine is suff (open full item for complete abstract)

Committee: Madhuri Kango-Singh (Advisor); Thomas Williams (Committee Member); Amit Singh (Committee Member) Subjects: Biology; Biomedical Research; Cellular Biology; Genetics; Molecular Biology; Oncology

Bachelor of Science (BS), Ohio University, 2025, Biological Sciences

Neurodegenerative disorders account for millions of deaths per year, but the mechanisms behind them remain somewhat misunderstood. In motor related diseases such as Parkinson's disease (PD) and Lewy body dementia (LBD) degeneration is partially attributed to the misfolding of proteins including alpha-synuclein (α-syn) in the synapse. When synaptic health declines in these disorders so does mitochondrial health because normal energy production is interrupted by oxidative stress and increased numbers of free radical species that damage cellular components. Is there a way disease-related mitochondrial damage could be recovered or prevented? In my project I aimed to answer this question in three parts. First, I used a protocol for the analysis and quantification of mitochondria to assess standard size and count of mitochondria signals in the NMJs of Drosophila melanogaster larvae, an established model for the study of neurodegeneration. Then, I utilized the UAS-Gal4 system to introduce human α-syn into the F1 generation of an experimental cross and model synucleinopathies. Using immunofluorescence, I observed a decrease in mitochondria signal count and mitochondria signal size on average for these larvae indicating a decline in synaptic mitochondrial health overall in the presence of human α-syn. Finally, I supplemented the standard fly food recipe with an antioxidant that had potential to improve synaptic mitochondrial health by neutralizing some of the α-syn induced oxidative stress. I chose to use the polymethoxyflavone GardeninA (GA) as my antioxidant. In α-syn+ larvae that were fed a GA+ diet, I saw a significant increase in synaptic mitochondrial health across the NMJ when compared to α-syn+ larvae with no exposure to GA. This suggests that dietary antioxidant GA could have neuroprotective effects against the kind of α-syn induced mitochondrial damage common in many neurodegenerative disorders.

Committee: Daewoo Lee (Advisor) Subjects: Biology; Biomedical Research; Cellular Biology; Genetics; Molecular Biology; Neurobiology; Neurology

Master of Science, The Ohio State University, 1967, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1965, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1961, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1970, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1960, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science (M.S.), University of Dayton, 2024, Biology

This thesis sought to advance the understanding of a gene regulatory network (GRN) that is responsible for the development of a male-specific (dimorphic) pattern of pigmentation on the 5th and 6th (A5 & A6) abdomen segments of the fruit fly species Drosophila (D.) melanogaster. The A5 and A6 protective cuticle tergites are fully black in color from the melanin pigment deposited from the underlying epidermal cells. These black tergites differ from the non-melanic A1-A4 tergites, and the A5 and A6 tergites of females. Previous studies identified 18 transcription factor genes whose functions are needed for this dimorphic pattern of tergite pigmentation. They also found the cis-regulatory elements (CREs) that control the epidermis expression of four “realizator” genes that encode enzymes for pigment metabolism (Ddc, tan, yellow, and ebony), and one CRE that controls expression of the bab paralog (bab1 and bab2) genes which encode key transcription factors that shape sex-specific patterns of pigmentation gene expression. Here, the activity of these CREs were assessed in genetic backgrounds in which RNA-interference (RNA-i) turned down the expression of these 18 genes one by one, and were imaged utilizing confocal microscopy. On the low end, the activity of the Ddc gene's MEE1 CRE and the bab dimorphic element CRE were impacted by eight of the 18 transcription factors. On the high end, the e_AMS CRE of ebony and the t_MSE2 CRE for tan were impacted by 12 transcription factors. Among the nuances of these numerous CRE interactions were transcription factors like bab (bab1 and bab2) and grh whose expressions were required for the proper activity of the CREs for all five of the analyzed genes. In contrast, the transcription factor pdm3 was found to regulate the expression of a single gene, ebony. A second objective of this thesis was to see whether any of the regulatory relationships between transcription factors and CREs might involve direct physical interactions. To this (open full item for complete abstract)

Committee: Thomas Williams (Advisor); Yvonne Sun (Committee Chair); Pothitos Pitychoutis (Committee Chair) Subjects: Biology; Developmental Biology; Evolution and Development; Genetics

Doctor of Philosophy (Ph.D.), University of Dayton, 2023, Biology

Alzheimer's disease (AD), a progressive neurodegenerative disorder characterized by cognitive decline, memory loss, and impaired daily functioning. It is the most common form of dementia, affecting millions worldwide. AD is characterized by the accumulation of amyloid-beta (Aβ42) plaques and neurofibrillary tangles in the brain. While the exact causes of AD are still unclear, a combination of genetic, environmental, and lifestyle factors is believed to contribute to its development. The Drosophila model has become a valuable tool for studying AD due to its genetic conservation with humans, short lifespan, simple nervous system, and available genetic tools. In this study, we utilized a Drosophila model expressing human Aβ42 in the developing retina to investigate the underlying mechanisms of Aβ42-induced neurodegeneration. We conducted a genetic screen and identified several modifiers that significantly affected Aβ42-induced neurodegeneration. One of the modifiers we identified is N-acetyltransferase 9 (Mnat9), known for its role in stabilizing microtubules and inhibiting the c-Jun-N-terminal kinase (JNK) signaling pathway. Overexpression of Mnat9 rescued the neurodegenerative phenotype caused by Aβ42 accumulation, while loss-of-function enhanced neurodegeneration. Importantly, we found that the neuroprotective function of Mnat9 was independent of its acetylation activity. The transgenic expression of human NAT9 (hNAT9) in Drosophila also suppressed Aβ42-mediated neurodegeneration, suggesting functional conservation between Mnat9 and hNAT9 in interacting with JNK-mediated neurodegeneration. These findings uncover a novel neuroprotective role of Mnat9 in downregulating the JNK pathway to ameliorate Aβ42-induced neurodegeneration. Another modifier we identified is miR-277 (hsa-miR-3660 in humans). Loss-of-function of miR-277 enhanced neurodegeneration, while its gain-of-function rescued the phenotype. Overexpression of miR-277 in the presence of Aβ42 reduced cell de (open full item for complete abstract)

Committee: Amit Singh Dr (Advisor); Madhuri Kango-Singh Dr (Committee Member); Potithos Pitychoutis Dr (Committee Member); Shirley Wright Dr (Committee Member); Shree Ram Singh Dr (Committee Member) Subjects: Biology; Genetics; Neurosciences

Master of Science (MS), Bowling Green State University, 2023, Biological Sciences

Within animal behavior studies, the actions of females have frequently been overlooked in a great many species (Ah-King, 2022). In order to more deeply understand the two way communication that necessarily occurs between males and females during courtship, the precise nature and functional meaning of acoustic signals need to be more closely examined. In the case of Drosophila melanogaster, acoustic studies have tended to focus on courtship or aggression. Within those contexts, female behavior has been characterized as simple compared to that of their male counterparts (Markow & Hanson, 1981). More recently, however, the active role of female D. melanogaster in courtship interactions has come to the forefront (Kerwin & Philipsborn, 2020; Swain & von Philipsborn, 2021). Sine song of D. melanogaster has been overlooked primarily due to the low amplitude and pure tone of the signal, as well as the limitations of technology. Sine song has a longer duration than does pulse, the other major part of the courtship song (Tauber & Eberl, 2003). Since being recognized as distinctly different from pulse, sine song has been described as serving various functions including attention getter (Ewing & Bennet-Clark, 1968; Tauber & Eberl, 2003; von Schilcher, 1976), primer to copulation (Alt et al., 1998; Aranha & Vasconcelos, 2018; Vijendravarma & Leopold, 2022), and bearer of fitness information (Vijendravarma & Leopold, 2022; (Swain & von Philipsborn, 2021; von Philipsborn et al., 2023a)). Through a series of playback experiments using stimuli reconstructed from laboratory recordings of full courtship song, varying duration, frequency, and song component order, we explored the extent to which male sine song functions as an attention getter, primes the female for copulation, or contains information contributing to female mate choice. The order of the song components made a difference to the female immobile response. While we found no significant difference in copulation success for t (open full item for complete abstract)

Committee: Moira van Staaden Ph.D. (Committee Chair); Robert Huber Ph.D. (Committee Member); Verner Bingman Ph.D. (Committee Member) Subjects: Animal Sciences; Animals; Biology; Biophysics

Master of Science (M.S.), University of Dayton, 2023, Biology

How does a protein evolve while maintaining its function? Structure/function tests of the sperm tail protein β2-tubulin show that even small changes in the protein render it unable to generate a motile sperm tail, raising the question about how it evolved in the first place. In fact, it has not evolved in 60 million years in Drosophila melanogaster and its relatives. In previous work, additive and synergistic amino acid specializations of the β2 protein were identified. Synergism is of particular interest because it makes evolution path-dependent, slowing its progress and potentially contributing to the 60-million-year stasis of the β2 protein. Two amino acids, threonine 55 (Thr55) and alanine 57 (Ala57), were identified as potentially participating in a β2-specific synergism. Their function depends on amino acid contacts that are only present in β2, and their amino acid identities are unique to β2 in comparison to other β-tubulins. Here, the proposed hypothesis states that a third amino acid that is in contact with Thr55 and Ala57 in the folded protein, and is also unique to β2, cysteine 29 (Cys29), completes the synergism. The hypothesis will be tested by generating transgenic flies (called “CTA”) expressing a modified major β1 tubulin containing β2 identity Cys29, Thr55 and Ala57. Spermatogenesis and fertility were assessed in CTA/CTA β2 null/β2 null flies. CTA is able to support all post-mitotic tubulin function in the testis (cell division and shaping), except spermatogenesis. CTA flies generate short, immotile sperm and are sterile. No additional sperm-generating function was provided by cysteine 29 compared to the β1-β2 construct containing only threonine 55 and alanine 57. There are 13 remaining amino acid differences between β2-tubulin and the experimental CTA flies spread across the protein. Two differences, sites 37 and 80, are of particular interest due to their unique amino acid chemistry characteristics and can be tested in a β1-β2 chimeric protein. (open full item for complete abstract)

Committee: Mark Nielsen (Advisor); Ryan McEwan (Committee Member); Thomas Williams (Committee Member) Subjects: Biology; Evolution and Development; Genetics; Molecular Biology; Organismal Biology

Master of Science, Miami University, 2023, Biology

Enhancers are crucial for regulating gene expression; however, their discovery and validation are still difficult outside of well-studied model organisms. There is a growing number of insect species with fully-sequenced genomes, but few annotated enhancers within those species. SCRMshaw (Supervised cis-Regulatory Module discovery), a motif-blind enhancer discovery program, has been developed with the hypothesis that enhancers have common features not noticeable to the human eye or traditional alignment algorithms, but are recognizable through machine learning. The deep conservation of fundamental regulatory mechanisms could allow successful enhancer prediction across the holometabolous insect spectrum using previously identified D. melanogaster tissue- specific enhancers as training sets. This project evaluated the accuracy of SCRMshaw by functionally validating (i) novel enhancer predictions and (ii) predictions orthologous to previously identified D. melanogaster enhancers across three insect orders. We chose six genes important for wings, one of the best studied contexts in insects, and tested the activity of 19 predicted enhancers in a cross-species setting. We found over 70% success in predicting enhancers with tissue-specific activity. These outcomes offer SCRMshaw as a promising enhancer prediction tool for annotating the expanding number of fully- sequenced genomes.

Committee: Yoshinori Tomoyasu (Advisor); Dawn Blitz (Committee Member); Paul James (Committee Member) Subjects: Biology; Evolution and Development

Master of Arts (MA), Bowling Green State University, 1963, Biological Sciences

Committee: Everett C. Myers (Advisor) Subjects: Biology

Master of Science (MS), Bowling Green State University, 2022, Biological Sciences

The medical use of opioids and prescriptions is a major source that causes drug dependency in people raising concern worldwide. It is a major health crisis causing thousands of deaths every year. Morphine, an opioid, is used as anesthetics in clinics worldwide and is highly overused among different age groups. Prescribed opioid has become a major source of drug availability in the market reaching mostly young people. Adolescents are more prone to morphine overdose because of the euphoria that the drug provides causing gradual development of drug dependency and causing higher negative impacts than in adults. Our study focused on the effects of early morphine exposure on motor behavior at different time periods of life using Drosophila melanogaster which is a suitable animal model due to its small size and measurable behaviors [1]. We hypothesized that rearing fly larva by exposure to morphine shows motor behavioral abnormalities that progress to later stages of life. We compared three morphine exposure levels, 0(control), 0.025 mg/ml and 0.25 mg/ml. Fly larvae were reared with morphine and the locomotion and feeding behavior were observed in the late second or early third instar. The feeding behavior of male larva exposed to low and high drug doses differed significantly from the control group whereas locomotion was not affected. Behavioral assays were also performed on adult flies to observe the prolonged effects of morphine exposure. Startled-Induced Negative Geotaxis (SING) assay was used to observe the climbing behavior of adult flies that differed significantly between the control and low and high-dose females. Drug-treated flies showed a climbing preference in this assay. For further observation of motor behavior on adult flies, righting reflex assay (to observe the ability of flies to correct their position) and flight assay (to observe the ability of flies in maintaining steady elevation) were also run which showed no significant difference among any groups. (open full item for complete abstract)

Committee: Larsen Raymond A Ph.D. (Committee Member); Huber Robert Ph.D. (Committee Member); Moira J van Staaden Ph.D. (Advisor) Subjects: Behavioral Sciences

Doctor of Philosophy, The Ohio State University, 2020, Molecular Genetics

Translational regulation plays an important role in gene expression. In this work, I focus on Nanos (Nos), a conserved RNA-binding protein that acts as a translational repressor to control a number of biological processes. In Chapter 1, I summarize current knowledge about the mechanism of action of Nos and briefly discuss the known regulatory targets of Nos. By utilizing Upf1-Nos chimera protein, I aimed to identify mRNA regulatory targets of Nos. As described in Chapter 2, I show that Nos potentially regulates approximately 32% of the transcriptome in the early embryo. I demonstrate that the majority of Upf1-Nos depleted mRNAs are likely regulated by the cooperative action of Nos and Pumilio (Pum) in Chapter 2. I identify molecular mechanisms for recognition of this diverse population of mRNAs in Chapter 3. In Chapter 4, I describe evidence suggesting that Bruno may be a novel partner that mediates a minor fraction of Nos activity in vivo. This work dramatically expands the list of potential Nos regulatory targets, from the previous number of 11 to 2554.

Committee: Robin Wharton Ph.D. (Advisor); Daniel Schoenberg Ph.D. (Committee Member); Helen Chamberlin Ph.D. (Committee Member); Guramrit Singh Ph.D. (Committee Member) Subjects: Biology; Developmental Biology; Genetics; Molecular Biology

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2020, Biological Sciences

Most mutations that occur within the autosomes of eukaryotic multicellular organisms are known to be mildly deleterious in effect, and are masked from selective pressures governing removal and fixation by their occurrence in the heterozygous state. Genetic drift, selection, and dominance all play a role in determining whether a mutation will be fixed or removed from a population, and affect the ultimate fitness of the organism possessing the new mutational variant. This understanding, however, applies primarily to mutational events occurring in autosomes during the adult phase of the organism's life cycle. The effect of a de novo mutations on organismal fitness can differ greatly however, depending upon when in the life cycle and the ploidy of the chromosome these mutations arise in. Mutations arising in the gender with a haploid sex chromosome are immediately expressed and exposed to selective pressures in the hemizygous state, whereas mutations arising in the gender possessing diploid sex chromosomes are concealed from expression and selective forces in the heterozygous state. Due to this heterozygous condition the diploid sex-chromosomes may accumulate a large number of mildly deleterious mutations over an organisms' life span, resulting in gender-based differences in fitness due to differences in expression and the number of mutations accumulated. Our expectations of how de novo mutations may affect organismal fitness can also be subverted by the effects of a single mutation arising in primordial germ cells (PGC) before they undergo sequestration. PGC's sequester and suspend almost all genetic processes for a period of time before migrating to their future site of development, and it is believed that part of the reason for this sequestration is to prevent single de novo mutations from developing into cluster mutations. In order to understand how new mutations affect population fitness in a variety of changing environmental conditions, a greater understanding of (open full item for complete abstract)

Committee: Ronny Woodruff Dr. (Advisor); Joshua Grubbs Dr. (Other); Maria Bidart Dr. (Committee Member); Paul Morris Dr. (Committee Member); Scott Rogers Dr. (Committee Member) Subjects: Biology; Evolution and Development; Genetics

Master of Sciences (Engineering), Case Western Reserve University, 2020, EMC - Mechanical Engineering

This manuscript describes neuromechanical modeling of the fruit fly, Drosophila melanogaster, in the form of a hexapod robot, Drosophibot. Drosophibot is a testbed for real-time dynamical neural controllers modeled after the anatomy and function of the insect nervous system. As such, Drosophibot has been designed to capture features of the animal's biomechanics in order to better test the neural controllers. These features include: Dynamically scaling the robot to match the fruit fly by designing its joint elasticity and movement speed; a biomimetic actuator control scheme that converts neural activity into motion in the same way as observed in insects; biomimetic sensing, including proprioception from all leg joints and strain sensing from all leg segments; and passively compliant tarsi that mimic the animal's passive compliance to the walking substrate. I incorporated these features into the robot's hardware and show that they successfully transfer to biological behavior on the physical robot.

Committee: Roger Quinn (Committee Chair); Daltorio Kathryn (Committee Member); Bachmann Richard (Committee Member) Subjects: Biomechanics; Mechanical Engineering; Robotics