Biology

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Open Access
Biologically Inspired Oral Inflammatory Load For Periodontal Applications
(2025-04-10) Soheili, Fatemeh; Ghafar-Zadeh, Ebrahim
Periodontal disease is a prevalent inflammatory condition affecting the supporting structures of teeth, including the gums, periodontal ligament, and alveolar bone. It is one of the leading causes of tooth loss in adults and has been linked to various systemic health issues, such as cardiovascular disease, diabetes, and respiratory conditions. Early detection and accurate diagnosis are critical for preventing disease progression and mitigating its broader health impacts. However, current diagnostic methods are labor-intensive, time-consuming, and require specialized clinical expertise. This dissertation presents an innovative approach that integrates bio-inspired cell isolation techniques with artificial intelligence (AI) to enhance the detection and quantification of oral inflammatory markers, specifically oral polymorphonuclear neutrophils (oPMNs), for periodontal diagnostics. Our method involves saliva sampling using a standardized 10 ml oral rinse collected from both healthy and periodontal subjects. We optimized and characterized a novel technique for isolating oPMNs from other cellular components in saliva, leveraging their unique adhesion properties. Hydrophilic materials were coated on surfaces to selectively capture and isolate oPMNs. The isolated cells were then analyzed using an AI server developed and trained specifically to detect and quantify oPMNs in both healthy and clinical samples. The AI model categorized the results into five distinct levels of periodontal disease, providing a detailed assessment of disease severity. The results demonstrated the effectiveness of the proposed method in isolating and quantifying oPMNs with high accuracy. Clinical validation on samples from a diverse cohort, ranging from healthy individuals to those with severe periodontitis, confirmed the method's functionality. The oral inflammatory load (OIL) assessment showed an error rate of less than 5% compared to standard laboratory-based methods, underscoring its precision and reliability. The integration of AI in this context significantly reduces the diagnostic workload for healthcare professionals while enhancing the accuracy and speed of assessments. The method offers a practical, scalable solution for periodontal disease diagnostics, enabling earlier and more precise identification of disease states. Beyond its clinical applications, the system has the potential to be developed into a point-of-care diagnostic tool, providing immediate results without the need for specialized laboratory equipment. This innovation could be particularly impactful in resource-limited settings, where access to advanced medical facilities is restricted. In conclusion, the combination of bio-inspired isolation techniques and AI-assisted analysis represents a significant advancement in periodontal diagnostics. This approach not only improves current diagnostic practices but also opens new possibilities for the future of periodontal healthcare, where rapid, accurate, and accessible diagnostics become the standard. Through this work, we aim to contribute to the development of innovative, patient-centered solutions for periodontal disease management, ultimately promoting better oral and systemic health outcomes.
Open Access
Tethered To Telomeres: Characterizing The Form And Dynamic Elasticity Of Tethers In Anaphase Crane-Fly Spermatocytes
(2025-04-10) Economopoulos, Demetra; Connor, Steven
Elastic tethers connect sister chromosomes during anaphase in a broad range of animal cells, likely aiding in communication and coordination of movement. Calyculin A prevents dephosphorylation of tethers by protein phosphatase 1 (PP1) and, consequently, causes them to remain elastic throughout anaphase, resulting in backward movement. In my thesis experiments, I further explore the composition and behaviour of tethers. I expand upon existing research with Calyculin A, elucidating an optimal working concentration of 10 nM for investigating the reversibility of this drug on backward movement when rinsed out at various stages. I show that PP1 is critical during the onset of anaphase and that backward movement is not readily reversible. I also support the existing notion that tethers are made of titin, disproving the hypothesis that tethers are made of DNA. These contributions further enhance our understanding of tether composition and regulation during a central mechanistic phase of cell division.
Open Access
Finding Common Ground: Methods For Sustaining Citizen Science Engagement That Increase Indigenous Plant Biodiversity In Southwestern Ontario
(2025-04-10) Bava, Julia Maria; Bazely, Dawn R. A.
Nature-based solutions to address biodiversity loss require supports that reach beyond government grants. The Conservation Impact Bond (CIB) developed by Southwestern Ontario regional conservation charity, Carolinian Canada Coalition, is an example of a novel financial tool to incentivize biodiversity conservation by supporting citizen science. My research evaluated Carolinian Canada’s In The Zone Tracker and its allied programs. A systematic review of the literature about Canadian citizen science projects provided context. (1) The ITZ Program reversed plant biodiversity loss at a local level through planting projects that generated a self-reported increase in native species. (2) Information about citizen science projects was difficult to discover. Academic research into citizen science projects published in peer-reviewed literature creates a more permanent record than web-based, grey literature. (3) Citizen science projects do not necessarily improve science literacy. Rather, the ITZ tracker helped people to find common values and make positive, evidence-informed differences in their communities.
Open Access
Effects And Interactions Of Antibiotic, Butyrate, And Temperature On Sailfin Molly (Poecilia Latipinna) Metabolism And Gut Microbiota
(2025-04-10) Trovato, James; Bucking, Carol
Understanding the complex interactions between environmental factors, dietary supplements, and microbiome dynamics is crucial for optimizing fish health and growth, particularly in aquaculture settings. This study examines the effects of antibiotic, butyrate, and temperature treatments on the metabolism and gut microbiota of sailfin molly (Poecilia latipinna) alone and in combination. The results indicate that butyrate successfully restored the growth rates due to antibiotic exposure but had little effect when supplied to controls. Interestingly, while elevated temperature has been shown to promote growth through increased metabolic rates growth was not observed, possibly due to stress. Notably, there was a decrease in diversity in the microbiome because of antibiotic treatment. Further, both antibiotics and increased temperature lead to a decrease in the predicted functional capabilities of bacteria related to metabolism and health pathways after using PICRUSt analyses. While butyrate ameliorated the impacts on growth and metabolism caused by antibiotics, the microbiome was mostly unaffected, indicating that butyrate exerts its effects through the host directly. These findings suggest that butyrate could mitigate some negative impacts of antibiotics on fish growth and gut health as well as highlight some of the concerning effects of increasing environmental temperatures and antibiotic use. These insights may help develop strategies in fish population management and aquaculture practices, particularly those involving antibiotics and butyrate supplementation.
Open Access
Understanding Bumble Bee Community Changes And Floral Use In Southern Ontario.
(2025-04-10) Kerekes, Taylor; Colla, Sheila
Multiple wild bee species, including bumble bees, are in global decline due to habitat loss, reduced floral resources, and competition with managed honey bees. Monitoring previously surveyed sites is essential to assess ongoing impacts on bumble bee populations and identify trends over time. This research revisited areas in southern Ontario to examine changes in bumble bee abundance, diversity, and floral use (Chapter 1) and explored potential competition for floral resources between bumble bees and honey bees (Chapter 2). Results indicate that while some bumble bee species have increased over the last 50 years, many have declined, leading to an overall loss of diversity. Findings also reveal significant niche overlap between bumble bees and honey bees, suggesting competition for floral resources. This work informs conservation strategies, identifies species requiring focused efforts, and emphasizes the importance of maintaining diverse floral resources to support bumble bee populations.
Open Access
The Relative Importance Of Microclimatic Heterogeneity On Plant And Animal Communities In Deserts Of Southern California, U.S.A
(2025-04-10) Ghaziantafrishi, Nargol; MacDonald, Suzanne
This dissertation examines the intricate relationships between facilitation, environmental heterogeneity, and artificial habitat constructions in arid ecosystems, focusing on plant-animal and plant-plant interactions. By leveraging ecological principles, it explores the role of foundation plant species like Ephedra californica and Larrea tridentata in fostering ecosystem resilience and biodiversity under adverse conditions due to climate change, land use, and desertification. The study starts with an overview of facilitation theory, highlighting its importance in mitigating the negative effects of abiotic stressors in arid and semi-arid regions. It highlights the Stress Gradient Hypothesis (SGH) as a framework for understanding how competitive interactions can shift towards facilitation under harsh conditions, thus promoting the survival of diverse flora and fauna. The dissertation then delves into environmental heterogeneity, explaining its complex influence on ecosystem dynamics, species composition, and microclimatic regulation. Chapter 2 provides a detailed analysis of camera trapping techniques, offering optimal sampling design strategies for accurately estimating vertebrate abundance and richness. Chapter 3 examines the effects of artificial canopies on microclimate regulation. This chapter evaluates various eco-friendly fabrics, such as natural burlap, cotton, and nursery seedling fabric, in buffering microclimate through lab experiments measuring understory temperature, relative humidity, and radiation. Chapters 4 and 5 investigate how climatic variations and vegetation structure contribute to spatial and environmental heterogeneity, shaping flora and fauna diversity and abundance. A key aspect of the study is evaluating the effectiveness of artificial habitat construction as a conservation and restoration strategy in arid landscapes. Field experiments assess the microclimatic buffering capabilities of artificial shelters compared to natural vegetation in supporting vertebrate populations amid desertification in the Southwestern U.S.A. Overall, this dissertation enhances our understanding of the complex interplay between facilitation, environmental heterogeneity, and habitat modification in arid ecosystems. By uncovering the mechanisms behind these ecological processes, it provides valuable insights for conservation, management, and restoration efforts in regions vulnerable to anthropogenic disturbances and climate change.
Open Access
Examining The Role Of Lysyl Oxidase Enzymes In Atrial Fibrillation Induced By Volume Overload
(2025-04-10) Sherrard, Dana Evelyn; Backx, Peter
Atrial fibrillation (AF), the most prevalent cardiac arrhythmia, is linked to atrial electrical and structural remodelling. AF is associated with fibrosis; however, in models imposing atrial stretch, this occurs without changes in collagen transcription, suggesting fibrosis results from collagen stabilization by the Lysyl Oxidases (LOX) family of enzymes. To investigate this relationship, we established a murine aortic regurgitation (AR) model, which induces atrial stretch. AR mice exhibited increased AF susceptibility, decreased atrial refractoriness (AERP), elevated left atria (LA) fibrosis, and macrophage infiltration 2-fold compared to sham mice. LOXL2 inhibitor PXS-5382 reduced AF inducibility, shortened AF duration and attenuated fibrosis without affecting AERP. In contrast, the broader LOX inhibitor PXS-5505 prevented fibrosis without reducing AF inducibility in AR mice but exacerbated AF and fibrosis in sham mice. These results highlight LOXL2's critical role in atrial structural remodelling and AR-induced AF, suggesting it may be a promising therapeutic target for AF.
Open Access
Estimating Broad-Sense Heritability Of The Gut Microbiome In Western Honey Bees (Apis Mellifera)
(2025-04-10) Subramanian, Aishwarya; Zayed, Amro
The honey bee gut microbiome, crucial for bee health, may be shaped by both environmental and genetic factors. While differences in microbiomes exist between honey bee subspecies, it is unclear if genetic variation within a population influences this variation. This study estimated the broad-sense heritability of gut microbiome traits to explore patriline effects. We analyzed 500 workers from two colonies using 16S rRNA sequencing for microbiome characterization and genotyped them at 11 microsatellite loci. Results showed that patriline genetics marginally influenced the relative abundance of dominant microbiome taxa (18% to 24%) but did not significantly impact presence/absence of bacterial taxa or alpha and beta diversity. These findings suggest that environmental factors play a more substantial role in shaping the honey bee gut microbiome, indicating that microbiome-based interventions could benefit honey bees across populations.
Open Access
Elucidating Anthropogenic Impacts On Water Quality Through Spatial Heterogeneity In The Laurentian Great Lakes And The Global Fast Fashion Industry
(2025-04-10) Bailey, Kerrice Kesaynoi; Sharma, Sapna
Freshwater resources are vital for human survival including for consumption, transportation, and production of goods. We explore the impact of anthropogenic activity on water quality through: 1) the spatial heterogeneity in the northern nearshore regions of the Canadian Great Lakes and 2) the state of fast fashion in the top garment producing countries: China, Bangladesh, Vietnam, Turkey, India, and Indonesia. Water quality conditions varied spatially from oligotrophic conditions in Lake Superior to eutrophic conditions with elevated concentrations of nutrients and chlorophyll-a in Lake Erie. Further, we found that policy, sustainability and wastewater are key research areas in the top garment-producing countries. However, there was variation in the number of publications, terminology, knowledge gaps, and barriers that impede more sustainable garment production in the top garment-producing countries. We suggest investments in management and education to protect and use our freshwater resources more sustainably.
Open Access
The Evolutionary History Of The Cleptoparasitic Bee Genus Nomada With An Emphasis On The Species Of Eastern North America
(2024-11-07) Odanaka, Katherine Akemi; Rehan, Sandra
Approximately 12% of all bee species found in North America are brood parasitic. Of the different genera of cleptoparasitic bees, the most diverse and taxonomically challenging is the genus Nomada, which has approximately 800 species and is found on every continent except Antarctica. Little is known regarding Nomada biology, evolution, and population dynamics and further complicating studying Nomada is inconsistency in species concepts due to variation within and between species and the lack of updated taxonomic tools needed to identify species. This dissertation aims to address gaps pertaining to the evolutionary history, biogeography, and population dynamics of Nomada at both a global and North American level. The first global phylogeny and biogeography for the genus is presented here. Nomada was found to have a Holarctic origin around 65 million years ago and subsequently dispersed into the southern hemisphere at least three times while also dispersing throughout the Nearctic and Palearctic multiple times over various land bridges. To explore phylogeographic patterns and population genetic structure and diversity, the North American endemic species Nomada articulata was used as a model, a first for a cleptoparasitic bee. It is suggested that the Wisconsinan glaciation influenced N. articulata populations by dividing the species along an east-west gradient but over time, these populations dispersed, creating a single panmictic population that persists to the present. Furthermore, N. articulata is suggested to be a species complex with two possible new and unknown species in the southern United States. Lastly, newly updated keys are provided with the aim to help remedy the lack of updated species level keys for the genus in eastern North America. As a result, fully illustrated keys are provided for five of the seven Nomada species groups found in eastern Canada and the United States covering male and female characters for 15 different species. Additionally, one new synonymy is presented and updated information pertaining to the biology, evolution, and taxonomy is included. The research presented here provides an important first step towards understanding the evolution and diversification of Nomada and how, more broadly, cleptoparasitic bees became one of the most successful groups of bees.
Open Access
An examination of facilitative interactions between shrubs and local desert organisms within the desert ecosystems of southern California
(2024-11-07) Zuliani, Mario; MacDonald, Suzanne
In recent decades, facilitative interactions have been the focus of ecological studies, specifically those with foundational shrubs within drylands. However, little has been done to analyze how the density of shrubs influence the frequency of these interactions. Here, I aim to establish shrub density as a crucial measure in ecology and facilitative interactions. I begin with a systematic review and meta-analysis (Chapter 2) to quantify the current understanding of shrub density on local animal abundance. A full text review of shrub density and animal abundance was conducted with 113 unique observations utilized in the meta-analysis. Shrub density positively predicted animal abundance, specifically within grassland and desert ecosystems. I conducted a greenhouse experiment to examine the effects of temperature on native and invasive plant species germination (Chapter 3). Temperatures were manipulated to simulate cooler microclimates and high temperature extremes. Increasing temperatures reduced germination, establishment, and biomass of all plant species, with the invasive species suffering more than natives. I conducted a telemetry experiment to determine the effects of shrub densities on an endangered species (Chapter 4). Telemetry data was combined with satellite-based counts of shrub density. Increasing shrub densities positively predicted the presence of G. sila individuals above ground. A field experiment comparing high and no shrub densities across aridity ecosystems in Southern California was conducted (Chapter 5). Camera traps were used at distinct ecosystems across southern California to determine vertebrate association. Areas of high shrub density influenced the richness and evenness of vertebrate species, while increasing temperatures negatively impacted vertebrate abundance, richness, and evenness. Finally, I tested if facilitative associations could be replicated with artificial structures (Chapter 6). Mimics were deployed within California drylands. Camera traps were utilized to estimate vertebrate communities, with temperature pendants used to contrast microclimates. Shrubs and mimics had similar microclimates, reducing the temperature underneath their canopy. Mimics displayed a higher vertebrate abundance and richness than open areas. These findings illustrate that facilitation between shrubs and dryland communities are crucial interactions. These findings suggest that shrub density is a critical measure, increasing the likelihood of interactions and possible benefits associated with shrubs.
Open Access
Potential Roles Of Circska3 In Epithelial Ovarian Cancer Development
(2024-11-07) Agbede, Oluwatobi Michael; Chun Peng
Ovarian cancer (OC) is the deadliest gynecologic cancer, of which epithelial ovarian cancer (EOC) is the most prevalent and aggressive form. Circular RNAs (circRNAs) have emerged as potential therapeutic targets and biomarkers in various cancers, including EOC. This study investigated circSKA3, which was identified to be overexpressed in high-grade serous carcinoma (HGSC). Using qRT-PCR, we confirmed upregulation in HGSC tissues compared to less aggressive subtypes. Functional assays revealed circSKA3's tumor-promoting effects in HGSC cell lines, enhancing proliferation, migration, and clonogenicity. We identified its possible involvement in epithelial-mesenchymal transition (EMT) and dysregulation of cellular metabolism, contributing to increased aggressiveness in HGSC. Protein pulldown assays and mass spectrometry analysis also identified potential interacting proteins. We then predicted circSKA3-miRNA-mRNA network to explore potential miRNA-mRNA crosstalk dysregulated by circSKA3. These findings suggest that circSKA3, via a complex regulatory interplay of proteins and miRNA interactions, modulates EMT and cellular metabolism to drive HGSC malignancy.
Open Access
Using Fecal Hormones to Determine Reproductive State and Female Choice in Wild Vervet Monkeys (Chlorocebus pygerythrus)
(2024-11-07) Rademacher, Lina Ann; Schoof, Valerie
This study aimed to assess the feasibility of using fecal hormones to identify female reproductive state in wild vervet monkeys (Chlorocebus pygerythrus) in order to gain insight on changes in female mate choice. We followed a single study group with 16 adult/subadult females at Lake Nabugabo, Uganda over a 5-month field season in 2022. During this time, 248 fecal samples and 309 hours of behavioral observations were collected and used in analyses. Mean gestation length from hormonal data was 164.33 ± 18.09 days (range 134 – 187 days) based on six females that conceived during the study. However, gaps in fecal sample collection highlight that, while feasible, greater sampling effort is needed in future studies using fecal hormones. Generally, behavioral results indicate females displayed more proceptive and receptive behaviors towards males while ovulatory and appeared to prefer high-ranking males. However, there was no effect of female dominance rank on mate choice.
Open Access
Plant-pollinator relationships of culturally significant food and medicine plants in the Great Lakes Region
(2024-11-07) Gibson, Shelby Dawn; Colla, Shelia; Fitch, Gordon
Wild plant and pollinator populations have experienced declines globally in recent years. While species declines have often been examined for their impacts ecologically and economically, little is known about how species declines will impact humans culturally. All Indigenous cultures in North America use plant species for food and medicine. Plants considered important to a specific culture are known as cultural keystone species, meaning they are significant to cultural identity. With global declines in plant and pollinator species, this study aims to determine the role of wild pollinators to cultural keystone plant species. Availability of information on breeding systems and important pollinators is crucial information for management of plant species, especially if a plant species is experiencing population declines (e.g. at-risk, endangered). A literature review was conducted to determine what is known about the breeding systems of cultural keystone species in eastern North America. The results show 50% of the culturally significant plants lack any information regarding the breeding system. A plant-pollinator network was constructed based on observations in the field on the Three Sisters (corn, beans, squash) garden. The common eastern bumble bee (Bombus impatiens) and hoary squash bee (Xenoglossa pruinosa) were important pollinators in this system. A breeding experiment including diurnal and nocturnal video recording was conducted to determine the most frequent visitors of sacred Tobacco (Nicotiana rustica), and to determine the degree to which N. rustica relies on insect pollination. Lastly, a breeding experiment was conducted on common bearberry (Arctostaphylos uva-ursi) in eastern Ontario, Canada to determine the plant's reliance on insect pollination. In conclusion, wild pollinators are important to the continued success of cultural keystone species, and therefore to the cultures that use these plants. Including multiple ways of knowing and practicing ethical ecology in the future is part of ensuring biocultural conservation.
Open Access
Sumoylation of RNA Polymerase II Regulates Transcription in Saccharomyces cerevisiae
(2024-11-07) Bergey, Benjamin; Rosonina, Emanuel
Sumoylation is a post-translational modification that is involved in a host of cellular processes, including important roles in transcription. While it was previously reported that Rpb1, the largest subunit of RNA polymerase II (RNAPII), is sumoylated following UV-stress, our lab has shown that Rpb1 is also sumoylated under normal growth conditions. Here, we show that sumoylated Rpb1 is mostly associated with chromatin, providing further support for its role in transcriptional processes. We also show that the SUMO protease Ulp2 is important for supporting basal sumoylation of Rpb1, rather than merely as an instrument for desumoylation, which is an unexpected finding. Moreover, while impairing Rpb1 sumoylation at its major sumoylation site, K1487, has no apparent effect on growth, nascent transcription analysis from Global Run-on Sequencing (GROseq) reveals that a small number of genes are upregulated in this sumoylation-deficient Rpb1 mutant, a quarter of which are involved in the stress response.
Open Access
Characterization Of A Cysteine Protease From Phytolacca Americana And Its Association With Pokeweed Antiviral Protein
(2024-10-28) Audet, Annabelle; Hudak, Kathi
The plant apoplast, an essential extracellular space, contains diverse proteins crucial for plant defence. This study focuses on Phytolacca americana (American pokeweed), examining the interaction between the ribosome inactivating protein Pokeweed Antiviral Protein (PAP) and a putative papain-like cysteine protease, Phytolacca americana cysteine protease 1 (PaCP1). Bioinformatic predictions identified PaCP1 as a papain-like cysteine protease with conserved structural features, while enzymatic assays confirmed its functionality. Yeast-two hybrid assays validated the interaction between PAP and PaCP1, and localization studies indicated their extracellular co-localization in the apoplast. Enzymatic assays further demonstrated PaCP1's ability to cleave PAP, with mass spectrometry identifying the resulting degradation products. Differential expression studies under salicylic acid and Flg22 treatment revealed different patterns of expression for both PAP and PaCP1. This research enhances our understanding of PAP and its protein interactions as well as its potential role in the pokeweed apoplast.
Open Access
Probing Human Visual Strategies Using Interpretability Methods for Artificial Neural Networks
(2024-10-28) Kashef Alghetaa, Yousif Khalid Faeq; Kar, Kohitij
Unraveling human visual strategies during object recognition remains a challenge in vision science. Existing psychophysical methods used to investigate these strategies are limited in accurately interpreting human decisions. Recently, artificial neural network (ANN) models, which show remarkable similarities to human vision, provide a window into human visual strategies. However, inconsistencies among different techniques hinder the use of explainable AI (XAI) methods to interpret ANN decision-making. Here, we first develop and validate a novel surrogate method, in silico, using behavioral probes in ANNs with explanation-masked images to address these challenges. Finally, by identifying the XAI method and ANN with the highest human alignment, we provide a working hypothesis and an effective approach to explain human visual strategies during object recognition -- a framework relevant to many other behaviors.
Open Access
Studying The Effectiveness Of Large Language Models In Benchmark Biomedical Tasks
(2024-10-28) Jahan, Israt; Huang, Jimmy Xiangji
Recently, Large Language Models (LLMs) have demonstrated impressive capability to solve a wide range of tasks. However, despite their success across various tasks, no prior work has investigated their capability in the biomedical domain yet. To this end, this thesis aims to evaluate the performance of LLMs on benchmark biomedical tasks. For this purpose, a comprehensive evaluation of 4 popular LLMs in 6 diverse biomedical tasks across 26 datasets has been conducted. Interestingly, this evaluation shows that in biomedical datasets that have smaller training sets, zero-shot LLMs even outperform the current state-of-the-art models when they were fine-tuned only on the training set of these datasets. This suggests that pretraining on large text corpora makes LLMs quite specialized even in the biomedical domain. The findings also shows that not a single LLM can outperform other LLMs in all tasks, with the performance of different LLMs may vary depending on the task. While their performance is still quite poor in comparison to the biomedical models that were fine-tuned on large training sets, this study demonstrates that LLMs have the potential to be a valuable tool for various biomedical tasks that lack large annotated data.
Open Access
The Role of p107 in Myogenic Stem Cell DNA Methylation
(2024-07-18) Fine, Kyra Rachel; Scimè, Anthony
Myogenic stem cells have the potential to either self-renew or differentiate into muscle fibers. These stem cell fate choices are influenced by metabolic changes which affect the epigenetic landscape, including DNA methylation which alters gene expression patterns. Because we have found that a mitochondrial function of p107, a transcriptional co-repressor, is involved in regulating SC metabolism and fate decisions, we investigated whether p107 influences the mitochondrial DNA methylation signature. For this we used a portable long read sequencer MinION (Nanopore), to sequence and compare the mitochondria DNA methylation pattern of wildtype and p107 genetically deleted (p107KO) C2C12 myogenic cell line. We found that p107KO mitochondrial DNA had decreased methylation levels for OXPHOS genes compared to wild type. Thus, suggesting that p107 might suppress ND4 gene expression. We also compared a novel method of mtDNA isolation to three existing methods in order to determine the most efficient approach for sequencing.
Open Access
Role of MEKK2 Phosphorylation at Threonine 263 on SMYD3-Mediated Methylation of Lysine 260
(2024-07-18) Corridore, Rachel Nicole; Scheid, Michael
MEKK2 is a protein serine/threonine-kinase involved in the activation of many MAP-kinase signalling pathways. In a previous study, SMYD3-mediated methylation at K260 of MEKK2 was demonstrated to promote aberrant input downstream of oncogenic Ras-signaling, promoting Ras-driven PDAC and LAC progression. Our lab has previously characterized the role of MEKK2 phosphorylation at T283 and has recently discovered a novel second phosphorylation site at T263. We show that together, these sites form the bipartite binding group for 14-3-3 adapter proteins. This study focuses on characterizing T263 and T283 as regulatory phosphosites in K260 methylation and implicates 14-3-3 as a promoting factor in facilitating SMYD3-mediated methylation at K260. Our findings provide a potential mechanism of MEKK2 oncogenic function, whereby 14-3-3 preserves phosphorylation at T263 and T283, together promoting K260 methylation and MEKK2 activation. Our study characterizes T263 and T283 of MEKK2 and 14-3-3 phosphoadapter proteins as potential therapeutic targets in PDAC and LAC.