About the Pre-Release: 

MSURJ presents its first Pre-Release Abstracts compilation! This features a preview of the Special Issue: Proceedings of the Seventh Annual McGill Undergraduate Science Showcase, highlighting the work of some of our most dedicated science students. 

Head over to the OSE's Undergraduate Science Showcase on March 25th to catch a glimpse of our official proceedings!

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Title: Variation in the status of Acropora palmata coral in relation to environmental factors along the west coast of Barbados

Authors: Hana Kaloudis¹, Eleanore Lukas¹, Faye Dryden¹, Lindsey Myhre¹, Atisha Lloyd¹, Virginie Millien¹

Affiliations:
¹Faculty of Science, McGill University, Montreal, QC, Canada
²Faculty of Science and Technology, University of the West Indies at Cave Hill, Saint Michael, Barbados

Keywords: Acropora palmata; Barbados; Breakwater; Coral health index; Latitude; Runoff output

Abstract: Acropora palmata is a critically endangered Caribbean coral whose decline threatens both coastal ecosystems and shoreline protection. Barbados once supported extensive A. palmata colonies along its west coast, yet the environmental drivers shaping current patterns of colony health and distribution remain unclear. We re-surveyed twelve sites in 2025, five of which were also assessed in 2024 and all originally mapped in 2015, to evaluate temporal changes in colony abundance, size, and condition, and to test how spatial and environmental gradients influence A. palmata health. Average colony height increased from 2015 to 2024, but declined sharply in 2025, consistent with fragmentation following heavy wave action and Hurricane Beryl in 2024. Despite this size reduction, health index scores improved significantly from 2024 to 2025, indicating rapid recovery in live tissue and pigmentation since the 2024 bleaching and hurricane events. Lack of pattern in count across study years suggests that varying environmental conditions across sites had different impacts on abundance. Our PCA results revealed four distinct habitat groupings across the coastline, with strong environmental gradients associated with latitude, distance to breakwaters and runoff outputs, depth, and distance from shore. Percent dead tissue was significantly related to a depth/distance to shoreline gradient, colony abundance was strongly structured by latitude, and total colony area increased significantly along the same gradient. Distances to individual anthropogenic structures were not associated with colony condition once broader spatial gradients were considered. Collectively, these results indicate that A. palmata conditions along Barbados’s west coast are shaped primarily by latitudinal environmental variation rather than direct proximity to runoff outputs or breakwaters. These findings provide an updated baseline for restoration planning and highlight the importance of spatial context in the management of recovering A. palmata populations.

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Title: Engineering SPEF1 Fusion Proteins for Improved Microtubule Seam Alignment for Cryo-Electron Microscopy

Authors: Helena Goodey-Parfitt¹, Tina Alagha¹, Hayley Rose Blythe¹, Thibault Legal¹, Khanh Huy Bui¹

Affiliations: ¹Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada

Keywords: Computational protein design; Cryo-electron microscopy; Fusion proteins; Microtubule seam; Microtubules; Sperm flagellar protein 1 (SPEF1)

Abstract: Microtubules are dynamic polymers of α-β tubulin heterodimers that support cell structure and contribute to processes including cell division, intracellular transport, and cilia stability. Their functions are modulated by microtubule-associated proteins (MAPs), which regulate microtubule assembly, stability, organization, and interactions with other cellular components. Accurate identification of the microtubule seam, where heterotypic α-β interactions replace homotypic α-α and β-β contacts, is essential for cryo-electron microscopy (cryo-EM) reconstruction. Current seam-alignment strategies employ kinesin motor domains that generate alignment contrast but mask lattice features and limit compatibility with many MAPs. The Bui lab identified Sperm Flagellar Protein 1 (SPEF1) as a seam-binding alternative, though its small size limits reliable visualization. We hypothesised that engineering larger SPEF1 fusion proteins would improve seam contrast and alignment while preserving microtubule binding. Fusion constructs were designed using RoseTTAFold Diffusion to append structured domains to the SPEF1 microtubule-binding region while preserving predicted folding and function. Constructs were cloned, sequence-verified, and expressed in Escherichia coli, with several designs demonstrating strong expression and yielding soluble protein after purification. Using a microtubule co-sedimentation assay, the engineered construct SPEF1 (1-120)-300AA demonstrated effective binding to polymerized microtubules, supporting its suitability for further microtubule seam-targeting studies, although cryo-EM validation remains ongoing. These results position engineered SPEF1 fusion proteins as promising seam-alignment tools that provide a broadly compatible and experimentally validated strategy for advancing cryo-EM studies of microtubule architecture and enabling direct evaluation of seam localization without masking lattice features or disrupting lattice-binding protein interactions, thereby overcoming limitations imposed by existing seam-alignment strategies.

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Title: Impact of human-like knock-in mutation on glomerular structure in a mouse model of Sanfilippo Syndrome (MPS IIIC)

Authors: Emily Pun¹, Dr. Lorena Carvelli¹, Dr. Alexey V. Pshezhetsky¹, Dr. Carlos R. Morales¹

Affiliations:  ¹Department of Anatomy and Cell Biology, McGill University

Keywords: Heparan sulfate; Lysosomal storage disorder; Renal pathology; Sanfilippo syndrome C

Abstract: Mucopolysaccharidosis type IIIC, also known as Sanfilippo syndrome type C, is a lysosomal storage disease caused by a deficiency of heparan sulfate acetyl-CoA: alpha glucosaminide N-acetyltransferase (HGSNAT). HGSNAT is one of the key enzymes involved in the degradation of heparan sulfate, a glycosaminoglycan present in proteoglycans and basement membranes. The absence of HGSNAT activity leads to an accumulation of heparan sulfate in lysosomes, causing cellular dysfunction and progressive neurological degeneration. This study examined the glomerular renal pathology in a CRISPR-Cas9-generated knock-in mouse model expressing the Pro304Leu HGSNAT variant, which replicates the human Pro311Leu mutation. The model showed early-onset MPS IIIC with dominant-negative effects and stress on the endoplasmic reticulum and lysosomes. Wild type (WT, n=3, 7 months old) and HGSNAT knock-in (KI, n=3, 7 months old) mice were used for each experiment. Kidneys were collected and processed for histological and ultrastructural analysis by light and electron microscopy. ImageJ was used to quantify the stained area of the mesangial matrix. Compared with WT, KI mice exhibited a more intense Periodic acid Schiff staining of the glomerular mesangial matrix, an accumulation of empty vesicles in the podocytes, distorted mesangial cells, and severely affected podocytes filled with lysosomes and enlarged pedicels. In conclusion, the increased deposition of heparan sulfate in the mesangial matrix is associated with glomerular distortion and mesangial proliferation, findings that could be consistent with the development of mesangial proliferative glomerulonephritis.

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Title: Understanding the impact of antigen-specific regulatory T cells on anergy induction in vivo

Authors: Sophie Courville¹, Stefanie F. Valbon^2,3, Marilaine Fournier³, Heather J. Melichar^3,4

Affiliations:
¹Department of Physiology, McGill University, Montreal, QC, Canada
²Department of Microbiology, Immunology and Infectious Disease, Université de Montréal, Montreal, QC, Canada
³Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, Canada
⁴Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada

Keywords: Adoptive cell transfer; Antigen-specific regulatory T cells; Peripheral tolerance; Single-cell RNA sequencing; T Cell Anergy

Abstract: In order to properly function, the immune system must achieve a fine balance between attacking foreign invaders while avoiding damage to healthy (self) tissue. One way it maintains this balance is through the induction of T cell anergy. Anergy is a key tolerance mechanism that renders self-reactive T cells hyporesponsive, thereby preventing the development of autoimmune diseases. T cell anergy is typically induced under steady state conditions when antigen recognition occurs without co-stimulation, such as in the absence of inflammation. Regulatory T (Treg) cell-mediated suppression of self-reactive T cells may contribute to anergy induction, but their specific role remains poorly defined. In this study, we investigate how antigen-specific Tregs influence the generation and accumulation of anergic CD8 T cells <em>in vivo</em>. To test this, we generated Tregs <em>ex vivo</em> from OVA-specific OT-II CD4 T cells. We injected OVA-specific OT-I CD8 T cells with or without OT-II Tregs into mice expressing OVA as a model self-antigen. After fourteen days, we observed an increase in the proportion of OT-I T cells in the spleen of mice co-adoptively transferred with OT-II Tregs as compared to mice injected with OT-I T cells alone. We confirmed, via <em>ex vivo</em> re-stimulation, that OT-I T cells induced in the presence of OT-II Tregs remained anergic. Interestingly, single-cell RNA-sequencing revealed that levels of antigen-specific Tregs correlate with transcriptional heterogeneity among anergic CD8 T cells <em>in vivo</em>. These findings suggest that antigen-specific Tregs promote the accumulation of anergic CD8 T cells. This work contributes to a broader effort to define mechanisms of peripheral tolerance, providing a foundation for their potential use in therapeutic interventions to prevent autoimmune disease.

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Title: Computational Model of the Hippocampus Supports Exploratory Behaviour in Reinforcement Learning Agents

Authors: Sabrina Du¹, Adel Halawa^1,2, Aleksei Efremov^1,2, Adrien Peyrache¹, Daniel Levenstein³, Blake Richards^1,2,3,4,5

Affiliations:
¹Montreal Neurological Institute, McGill University, Montreal, QC, Canada
²Mila – Quebec Artificial Intelligence Institute, Montreal, QC, Canada
³Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
⁴School of Computer Science, McGill University, Montreal, QC, Canada
⁴Learning in Machines and Brains Program, CIFAR, Toronto, ON, Canada

Keywords: Hippocampus; Cognitive maps; Intrinsic reinforcement learning; Curiosity-driven exploration

Abstract: The hippocampus supports spatial navigation, memory, and planning through the formation of cognitive maps—structured environmental representations reflected in neural activity. These neural dynamics can be modeled computationally using recurrent neural networks (RNNs) to provide insights into how cognitive maps guide behavior. However, these RNNs are typically trained via reinforcement learning (RL) using external rewards, failing to capture the intrinsic drive of freely exploring animals in the absence of external rewards. Instead, reward-free RL models, which rely on internal environmental representations, are better candidates to study novelty-seeking and exploratory behaviour. This study aims to investigate whether an RNN exhibiting hippocampal-like activity builds spatial representations sufficient to support exploratory behavior in reward-free RL agents. We leveraged an existing RNN trained for sensory sequence prediction, which exhibits hippocampal-like activity patterns, and used its prediction error as the intrinsic reward to train an Actor-Critic agent. Performance was evaluated using a Novel Object Recognition task to quantify its preference for novel versus familiar stimuli. The RL agent occupied the region of interest (defined as a 3-unit radius around the novel object) significantly more often than a random agent across multiple episodes and novel object locations. The RL agent’s performance was also measured in a multi-room environment, where its visitation frequency to novel rooms was significantly higher than a random control. This work demonstrates that hippocampal-like representations can support autonomous exploratory behaviour, and provides a framework for investigating how cognitive maps guide exploration and navigation.

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Title: Introducing Ultrasound-Guided Peripheral IV Catheter Insertion to Nursing Students Through a Student-Led Workshop

Authors: Rawane Soboh^1,2, Dohee Kim^1,2, Melanie Xie^1,2, Juan Avila Amariles^1,2, Marc-Alexandre Bourget^1,2, Mélodie Lewis^1,2, Andrea Lian^1,2, Chloe Luu^1,2, Mélanie Gauthier^1,2, Caroline Marchionni^1,2, and William Landry^1,2

Affiliations:
¹McGill University, Ingram School of Nursing,
²McGill Vascular Access Student Club

Keywords: Ultrasound-guided (USG); Nursing students; Difficult Intravenous Access (DIVA); Peripheral intravenous insertion (PIV insertion)

Abstract: Patients with difficult intravenous access (DIVA) pose a significant challenge in clinical settings, often leading to delayed care and complications such as pain, phlebitis, and increased infection risk due to multiple insertion attempts. Although evidence supports ultrasound-guided peripheral intravenous catheter (USGPIVC) insertion as a superior approach for DIVA patients, this technique remains largely absent from undergraduate nursing curricula and is typically accessed through post-registration certification, creating workflow inefficiencies and potential delays in care. To address this gap, McGill’s Vascular Access Student Club (VASC) organized a workshop to introduce USGPIVC insertion to nursing students through both theoretical and hands-on learning. Participants completed pre- and post-workshop surveys assessing familiarity with USGPIVC insertions and confidence in managing DIVA patients. Among 24 Bachelor of Nursing (Integrated) (BNI) and Bachelor of Science in Nursing (BScN) participants, 66.7% were in their first year of undergraduate studies. Second- and third-year students reported low baseline confidence in IV insertion for DIVA patients, with 95.4% reporting "not confident at all" or "slightly confident." Although 36.4% had observed USGPIVC insertions, none had received formal training. Post-workshop feedback was overwhelmingly positive: 100% rated the session as beneficial, and 62.5% advocated for training prior to clinical practice. More than 90% of participants expressed interest in advanced training. This student-led initiative reveals a critical gap in undergraduate curriculum and a strong demand for structured ultrasound-guided vascular access training. Integrating these skills early may enhance nursing preparedness for DIVA patients and lead to improved patient care.

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Title: Building Confidence Through Practice: Evaluating a Student-Led Flu Vaccination Clinic Using Retractable Safety Needles

Authors: Rawane Soboh^1,2, Andrea Lian^1,2, Mélodie Lewis^1,2, Juan Avila Amariles^1,2, Marc-Alexandre Bourget^1,2, Dohee Kim^1,2, Chloe Luu^1,2, Melanie Xie^1,2, William Landry^1,2, Mélanie Gauthier^1,2, and Caroline Marchionni^1,2

Affiliations:
¹McGill University, Ingram School of Nursing,
²McGill Vascular Access Student Club

Keywords: Vaccination clinic; Nursing students; Retractable safety needles; Influenza; Nursing

Abstract: Nursing students often graduate with limited experience vaccinating. Low-fidelity simulations using task trainers are effective for skill development, but are not realistic and, when used alone, limit engagement with the interpersonal and clinical aspects of care. The introduction of retractable safety syringes designed to minimize needlestick injuries has advanced clinical practice, yet students have limited exposure to them. McGill’s Vascular Access Student Club organised a vaccination clinic at the Sakoto Shibata Clinical Nursing Laboratories to bridge this gap by assessing the impact of retractable safety syringes on patient experience and the skills and confidence of student vaccinators. Vaccinated participants included 87 nursing students and laboratory staff who completed a post-vaccination survey rating their experience. Most rated 5/5 in terms of “safety” and “comfort”, with a median pain score of 1/10. Professionalism and technical skills were rated 5/5 by 89% of respondents, while 92% were “very likely” to recommend the clinic. Vaccinators were graduating students who underwent mandatory training. Of 11 student vaccinators, 80% had no prior experience vaccinating with safety needles, and 60% reported “very high confidence,” up from 0% pre-event. 70% felt more comfortable using safety syringes than non-safety syringes, and 90% reported that vaccinating real patients was “different” or “very different” from simulated practice. Results showed that this student-led clinic using retractable safety syringes improved patient experiences, boosted student confidence and skills, and transferred the learning from low-fidelity training to a clinical practice.

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Title: The Bi-functional Role of BMP in mid Regulation in Drosophila

Authors: Chihao Xu

Keywords: Drosophila; Embryogenesis; Genetic mosaic analysis; Intracellular signal; Transcription regulation

Abstract: During early embryogenesis, intracellular signals determine whether follicle cells differentiate towards  anterior or posterior fate. Bone Morphogenetic Protein (BMP) is one of the regulatory proteins repressing mid, a transcription factor induces the posterior pattern formation in Drosophila. BMP regulates mid expression via binding to the intron segment of the mid gene, known as mid-in. Previous work using the lacZ reporter in mid-in has shown that  mid-,requires BMP expression in some cases, presenting a potential bi-functional role of BMP. We hypothesize that such a property might be determined by the availability of schnurri, a well-known co-repressor of BMP. We examined lacZ fused with mid-in in three groups of Drosophila (over expression of BMP, knock-down of schnurri, and the combination of both genotypes). Each group contained 40 samples  and was analyzed using genetic mosaic analysis.  We found that reporter expression decreased substantially when schnurri was present and BMP was over expressed. In contrast,  the reporter was ectopically expressed when schnurri was absent and BMP signalling was overactivated. However, because schnurri was only knocked down using schnurri RNAi in this experiment, the activation phenotype was not strong. Future experiments could repeat this analysis using Drosophila a with schnurri gene mutation instead. Overall, these results demonstrate the bifunctional property of BMP pathway in the regulation of the mid-in reporter. Future work may focus on identifying the locations of the BMP activation and repression motif within the mid-in sequence.

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Title: Gestational Exposure to Nanoplastics and its Effect on Maternal Behaviour, Progeny Outcome, and Sex Ratio: A Literature Review

Authors: Ella Domingo¹, Caroline Fei¹, Yu Chen Nan¹, and Lan Yun Wu¹

Affiliations: ¹Department of Pharmacology, McGill University, Montreal, QC, Canada

Keywords: Microplastics; Plastic nanoparticles; Gestational exposure; Maternal behavior; Progeny outcome; Sex ratio

Abstract: 

Exposure to plastic nanoparticles has been investigated since the late 1980s and has become a growing public health concern over recent years. Among these concerns are their potential impact on fertility and reproduction, as the small size of plastic nanoparticles allows for their entry into the systemic circulation and translocation across the placental barrier, potentially affecting and disrupting reproductive processes. This literature review aims to examine how gestational exposure to plastic nanoparticles and the substances they carry can influence or alter maternal behaviour, progeny outcome, and sex ratio. We hypothesized that gestational exposure to plastic nanoparticles disrupts neuroendocrine pathways regulating maternal behaviour and offspring development. After synthesizing data from in vitro and in vivo studies in PubMed, a comprehensive review of the current scientific literature was conducted. Overall, study findings suggest that nanoparticle exposure during pregnancy can reduce oxytocin levels in both the plasma and the hypothalamus, correlating with decreased observable maternal behaviours in affected mice. Additionally, adverse outcomes have been reported in exposed progeny, including thinning of the cerebral cortex in Sprague Dawley rats and transgenerational changes in population fitness in D. Magna plankton. Specific sex-based vulnerabilities were identified, with some studies suggesting a potential skewing of the male-to-female ratio, with male embryos being more severely impacted. However, current evidence more strongly implicates general environmental pollution rather than nanoparticles specifically. Moreover, contemporary scientific information is limited by a stronger focus on oxytocin. While the link between environmental pollutants and oxytocin is well-documented, other critical regulators of maternal behaviour, such as placental lactogen and prolactin, remain understudied and yield conflicting data regarding nanoparticle interference. The importance of this investigative literature review lies in the urgency to understand the mechanisms by which nanoplastics impact reproductive health, and to prevent the adverse effects of nanoparticle exposure on our ecosystems and our future generations.

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Title: Automated Microtubule Detection for Subtomogram Averaging in Cryo-Electron Tomography

Authors: Molly Yu¹, Khanh Huy Bui²

Affiliations:
¹Department of Computer Science and Department of Biology, McGill University, Montreal, QC, Canada,
²Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada

Keywords: Cryo-electron tomography; Filament detection; Microtubules; Structural cell biology; Subtomogram averaging

Abstract: Cryo-electron tomography enables three-dimensional visualization of macromolecular structures within intact cells. Filamentous structures such as microtubules are essential for intracellular transport, structural stability, and cell division. Structural analysis of microtubules often relies on subtomogram averaging, a process that requires manual or semi-manual filament picking and alignment. These steps are time-consuming, computationally demanding, and can introduce user bias, making it difficult to handle large datasets efficiently. We developed an automated pipeline for microtubule detection and particle orientation prediction to improve efficiency and consistency in subtomogram averaging workflows. The pipeline integrates filament tracing, line connection analysis, and geometric modeling to detect microtubules and predict particle angles prior to alignment. Quality control measures were incorporated to identify elliptical distortions, misaligned particles, and outliers in dense datasets. Performance was evaluated by comparing pipeline outputs with manually processed datasets, examining particle ordering, angular consistency, alignment behavior, resolution, and processing time. Automated picking preserved expected structural organization and produced angle predictions consistent with refined alignment parameters while reducing analysis time. However, performance may vary depending on tomogram quality and filament density. These findings demonstrate that automated filament detection can reduce manual effort and support efficient structural analysis in cryo-electron tomography. Further improvements may increase reliability across different cellular contexts. 

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Title: Impact of Salt Identity, Concentration, and Buffer Composition on Hierarchically Structured Protein Fibers from Recombinant Tobacco Mosaic Virus Self-Assembling Capsids

Authors: Louise Mussard¹, Guido M. Merino², Amy S. Blum²

Affiliations:
¹Department of Physics, McGill University, Montreal, QC, Canada
²Department of Chemistry, McGill University, Montreal, QC, Canada

Keywords: Tobacco Mosaic Virus, Virus-Like Particle, Self-assembly, Hierarchal Structure, Protein Fibers

Abstract: Biological organisms have mastered the self-assembly of proteins into multifunctional materials, achieving remarkable properties through complex molecular organization at the macroscopic scale. However, replicating this level of hierarchical organization in man-made materials remains a persistent challenge. Tobacco Mosaic Virus coat proteins (TMVcp) can self-assemble into different conformations (helical rods, disks, stacked disks) through variation of solution ionic strength and pH. Recent data from the Blum group suggests that TMVcp are able to form macroscale hierarchically structured protein fibers. The objective of this study was to investigate the effect of exogenous salt concentration and buffer identity on the hierarchical structure of the TMVcp fibers. Four salts were introduced at concentrations ranging from 1mM to 100mM and six buffer systems were evaluated, varying in both cation and anion identity. The fibers were characterized through Polarized Light Microscopy (PLM), which revealed the presence of birefringence that indicates a hierarchical structure, and Small Angle Xray Scattering (SAXS), which was used to characterize the organization and spacing between the helical rods within a fiber. Results indicate an optimal added salt concentration range which significantly enhanced birefringence and internal hierarchical order. Notably, citrate-based buffers demonstrated superior self-assembly efficiency compared to other buffer systems, as evidenced by distinct features in the SAXS spectra. Furthermore, Scherrer analysis confirmed that the rods pack into an hexagonal lattice, a consistent feature across all fibers formed with 25mM added salt, regardless of salt identity. This work highlights the influence of ionic strength and buffer composition on the hierarchical structure of the TMVcp fibers, opening new pathways for tuning the self-assembly of viral capsids via environmental control.