The Competition Between Splicing And 3′ Processing Shapes The Human Transcriptome, Lindsey V. Soles, Shuangyu Li, Liang Liu, Kristianna S.K. Sarkan, Erik G. Alvstad, Lusong Tian, Yoseop Yoon, Marielle Valdez, Ivan Marazzi, Yongsheng Shi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Eukaryotic pre-mRNA processing steps, including splicing and 3′ processing, are tightly coordinated, yet the underlying mechanisms remain incompletely understood. U1 snRNP has been proposed to inhibit 3′ processing at intronic polyadenylation (IPA) sites through a splicing-independent mechanism termed telescripting. In contrast, we discovered that disrupting splicing by using six different methods—targeting various key components such as U1 snRNP, U2 snRNP, U2AF, and SF3b—activates 3′ processing at thousands of IPA sites. Notably, splicing inhibition, especially of U1 snRNP, induced widespread premature transcription termination within gene bodies through both IPA-coupled and IPA-independent mechanisms. Inhibition of different splicing factors activated overlapping and distinct …

Characterizing The Molecular Response Of Embryonic Zebra Finch To Acute Sound Playback, Saidat O. Adeniran-Obey Miss

All Theses

Auditory stimuli are important cues that influence developmental plasticity in animals and are important for development and adaptation to an ever-changing environment. In the zebra finch (Taeniopygia guttata), there is evidence of adaptive developmental reprogramming in response to a prenatal ‘heat call’. Embryos exposed to this heat call exhibit changes in growth rate post-hatch, increased heat resistance, and enhanced reproductive success at maturity. However, it has long been assumed that embryonic zebra finches cannot respond to sound due to the immaturity of their auditory system. These findings raise the critical question of whether late-stage zebra finch embryos can, …

The Genetics Of Sex, Fortis Brown

The Agora

Sex is a complex biological process that begins in the womb and lasts into puberty and beyond. It is often presented to society as a binary, chromosome-based system where XX means female and XY means male. In reality, chromosomes are just the beginning of a lifelong process involving hormones that influence biological changes. This process becomes apparent with its errors, known as Differences in Sexual Development (DSDs). DSDs can be caused in two main ways: through changes in either meiosis or in gene expression. While many consider these changes as ‘errors’, the processes that cause them to have been intentionally …

Comparing Gngt1 Expression In Eye Tissue Of Polymorphic Salamander Species Through Development, Fiona Coulbourne, Camila Cardozo, Macarena Machado, Ruben Tovar

Posters - 2026

The effect of the environment on organisms and their adaptations is widely studied. When exposed to different environmental niches, phenotypic adaptation is observed even within species. Animals that live in dark cave environments show a loss of their eyesight, since this sense is no longer useful to keep. Previous research has studied salamanders of the clade Eurycea and compared gene expression to subterranean and surface phenotypes1. E.pterophila is observed to express these two phenotypes depending on its environment, either Preserve Cave (subterranean) or Comal Springs (surface). Subterranean variant shows reduced eye volume and assumes to have decreased eyesight. Utilizing RNASeq …

Identifying Rna Splicing Changes During Alcohol Withdrawal Using An Optimized Rna-Seq Analysis Pipeline, Yasaswi Veera, Luana Martins De Carvalho, Amy Lasek

UROP Posters

Alcohol use disorder (AUD) causes long-lasting changes in brain gene expression and RNA splicing, particularly in the ventral hippocampus. This study analyzes RNA-Seq data from rats exposed to chronic alcohol and withdrawal to identify transcript-level and splicing alterations. An optimized RNA-Seq pipeline using STAR, FeatureCounts, edgeR, and WGCNA improved efficiency by 25-40% while maintaining consistency across 25 datasets. Results reveal changes in neural signaling and stress-response pathways associated with withdrawal. This work provides both biological insight into AUD and a reproducible computational framework for transcriptomic analysis.

Microarray Analysis Of Human Abdominal Aortic Aneurysm With Emphasis On Cardiovascular Genes Revealed Differentially Expressed Genes, Song Lu, Li Ping Li, John V. White, Xiaoying Zhang, Ifeyinwa Nwaneshiudu, Adaobi Nwaneshiudu, Nectaria Ntaoula, John Gaughan, Dimitri S. Monos, Wan-Lu Lin, Charalambos C. Solomides, Emilia L. Oleszak, Chris D. Platsoucas

Biological Sciences Faculty Publications

Background/Aim: We examined gene expression profiles in abdominal aortic aneurysm (AAA) lesions vs. normal aortas by cDNA microarray and real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR).

Materials and Methods: Phosphorus (32P)-labeled cDNA from AAA specimens (mean AAA size 6.65 cm) and normal aortas were hybridized with a 588-gene microarray primarily of the cardiovascular system. The results were validated by qRT-PCR.

Results: A total of 35 out of the 588 genes were differentially expressed, with either log2 ratio of AAAs/controls ≥1 (upregulated; 20 genes) or ≤−1 (downregulated; 15 genes) in AAA lesions vs. normal aorta, and 25 of these were significantly …

A Persistent Homology Framework For Scrna-Seq: Assessing Clustering Robustness And Quantifying Preprocessing And Integration Effects On Topological Features., Jonah Daneshmand

Electronic Theses and Dissertations

As single-cell RNA sequencing (scRNA-seq) data expands, robust methods for integrating diverse datasets are critical. This dissertation applies Persistent Homology (PH), a technique from Topological Data Analysis (TDA), to a collection of scRNA-seq datasets spanning eight tissue types to quantify how data integration affects topological features and biological interpretability. We assessed global topological structure using Betti curves, Euler characteristics, and persistence landscapes across raw, normalized, and integrated data representations. Our analysis revealed a performance inversion: while conventional methods excelled on unintegrated data, high-granularity topological methods, particularly those sensitive to global data structure, became superior after integration. This suggests a synergy …

Foxo Factors’ Ability In Binding To And Inducing Tcf7 In Glioblastoma Cells, Stephanie Oyervides

Theses and Dissertations

Glioblastoma Multiforme (GBM) is an aggressive astrocytoma tumor type with a poor prognosis and limited immunotherapeutic options for those inflicted. Stem gene expression of this cancer indicates a direct relationship with the transcription factors, Forkhead box subfamily O (FOXO-1, -3 and - 4). These transcription factors are evolutionarily conserved, partially redundant. They are involved in diverse and fundamental biological processes such as cell survival, stem cell homeostasis, cell fate determination, cell cycle maintenance, metabolism, and apoptosis. Increasing evidence suggests interconnectivity between the WNT Pathway and FOXO transcription factors; however, the mechanism and full extent to which these interactions play a …

Rnai Pathway Homeostasis Is Essential For Longevity In C. Elegans., Sejal Dulal

2025 Spring Honors Capstone Projects - Archive

RNA interference (RNAi) is a gene regulatory mechanism that is conserved across all animal species, including humans and the microscopic nematode, Caenorhabditis elegans. Many studies have identified the RNAi pathway factors and dissected the regulatory mechanisms of RNAi pathways, but there is little understanding of how the RNAi pathways themselves are regulated. Previously, Rogers and Phillips identified a feedback loop mediated by a pair of small RNA sensors, Sensor of siRNAs-1 (sosi-1) and eri-6[e-f], embedded within the genomic locus of a small RNA biogenesis factor, ERI-6/7. In this feedback motif, loss of small RNA-mediated silencing of …

Highly Targeted Metabolomics Coupled With Gene Expression Analysis By Rt–Qpcr Improves Beef Separation Based On Grass, Grain, Or Grape Supplemented Diet, Lucas Krusinski, Chloe Castanon, Rosalee S. Hellberg, Isabella C. F. Maciel, Muhammad Ahsin, Stephan Van Vliet, Jason E. Rowntree, Jennifer I. Fenton

Food Science Faculty Articles and Research

The objective of this study was to use a multi-omics (i.e., gene expression quantification, metabolomics, and fatty acid [FA] profiling) approach to separate and authenticate beef from three different dietary groups. In this 2-year study, Red Angus steers (n = 54) were randomly allocated to one of three treatments: (1) complex biodiverse pasture (GRASS), (2) total mixed ration (TMR) in feedlot (GRAIN), or (3) TMR in feedlot supplemented with 5% (dry matter) grapeseed extract for the last 30 days (GRAPE). FAs were measured by gas chromatography-mass spectrometry (GC–MS), secondary metabolites were identified using ultra-high-performance liquid chromatography tandem mass spectrometry …

Neuroinflammatory Signaling And Immune Cell Infiltration Differ In Brains Of Rats Exposed To Space Radiation And Social Isolation, Austin M. Adkins, Zachary N. M. Luyo, Alea F. Boden, Riley S. Heerbrandt, Richard A. Britten, Laurie L. Wellman, Larry D. Sanford

Center for Integrative Neuroscience and Inflammatory Diseases (CINID) Faculty Publications

Astronauts on the proposed Mars missions will be exposed to extended periods of social isolation (SI) and space radiation (SR). SI and SR-induced immune dysregulation can result in persistent neuroinflammation and neuronal damage which could negatively impact an astronaut’s health and ability to maintain adequate levels of performance. The synergistic effects of combined SI and SR on immune system functionality and the brain remain unknown. Determining how single and combined inflight stressors modulate the immune system is crucial for fully understanding pathways impacting astronaut health and performance. We used ground-based analogs of SI and SR in rodent models to investigate …

Electrochemical Strategies For Microrna Quantification Leveraging Amplification And Nanomaterials: A Review, Alexander Hunt, Gymama Slaughter

Center for Bioelectronics Publications

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression and have emerged as critical biomarkers in various diseases, including cancer. Their stability in bodily fluids and role as oncogenes or tumor suppressors make them attractive targets for non-invasive diagnostics. However, conventional detection methods, such as Northern blotting, RT-PCR, and microarrays, are limited by low sensitivity, lengthy protocols, and limited specificity. Electrochemical biosensors offer a promising alternative, providing high sensitivity, rapid response times, portability, and cost-effectiveness. These biosensors translate miRNA hybridization events into quantifiable electrochemical signals, often leveraging redox-active labels, mediators, or intercalators. Recent advancements in nanomaterials and signal amplification …

Heterogeneous Clustering Of Multiomics Data For Breast Cancer Subgroup Classification And Detection, Joseph Pateras, Musaddiq Lodi, Pratip Rana, Preetam Ghosh

Computer Science Faculty Publications

The rapid growth of diverse -omics datasets has made multiomics data integration crucial in cancer research. This study adapts the expectation–maximization routine for the joint latent variable modeling of multiomics patient profiles. By combining this approach with traditional biological feature selection methods, this study optimizes latent distribution, enabling efficient patient clustering from well-studied cancer types with reduced computational expense. The proposed optimization subroutines enhance survival analysis and improve runtime performance. This article presents a framework for distinguishing cancer subtypes and identifying potential biomarkers for breast cancer. Key insights into individual subtype expression and function were obtained through differentially expressed gene …

Environmental Magnesium Ion Affects Global Gene Expression, Motility, Biofilm Formation And Virulence Of Vibrio Parahaemolyticus, Xue Li, Xiaobai Zhang, Miaomiao Zhang, Xi Luo, Tingting Zhang, Xianjin Liu, Renfei Lu, Yiquan Zhang

Faculty, Staff and Student Publications

No abstract provided.

Characterizing The Expression Of The Sphingosine 1-Phosphate Pathway In Injury And Post-Traumatic Fibrosis, Nicole Cubbage

Masters Theses, 2020-current

Following injury, tissue repair allows for the restoration of the architecture and function of the injured tissue, while tissue replacement is characterized by severely damaged or non-regenerable tissue that is repaired by the laying down of extensive connective tissue, also known as fibrosis. The fibrotic process should be arrested at its early stage to have the greatest impact on preventing or reversing associate sequelae and promoting the regeneration of normal tissue. Sphingosine 1-phosphate (S1P), a metabolic product of cell membrane sphingolipids, has emerged as a pathway that may be involved in fibrosis. Most of S1P’s actions are mediated through the …

Towards Understanding The Function Of An Ets-Like Gene In Nematostella Vectensis: Generation Of A Knockout Mutant Line And A Transgenic Reporter Line, Emily Bullock

Biological Sciences Undergraduate Honors Theses

Due to their unique phylogenic position as sister to Bilateria, Cnidaria are often credited with the utility of allowing for reconstruction of ancestral biology based on characteristics shared with bilaterians and other animals. This factor makes investigation into the nervous systems of cnidarians critical in understanding early neural evolution. Wamides, a class of neuropeptides, have been shown to play a regulatory role in life cycle transitions across many different species. The cnidarian specific Wamide neuropeptide, GLWamide, has previously been identified to play an accelerator role in the metamorphic timing of a specific species of sea anemone, Nematostella vectensis. However, …

Influence Of Maternal Supplementation With Vitamins, Minerals, And (Or) Protein/Energy On Placental Development And Angiogenic Factors In Beef Heifers During Pregnancy, Bethania J. Dávila Ruiz, Carl R. Dahlen, Kacie L. Mccathy, Joel S. Caton, Jennifer L. Hurlbert, Friederike Baumgaertner, Ana Clara B. Menezes, Wellison J. S. Diniz, Sarah R. Underdahl, James D. Kirsch, Kevin K. Sedivec, Kerri A. Bochantin, Pawel P. Borowicz, Sebastián Canovas, Lawrence P. Reynolds

Department of Animal Science: Faculty Publications

The effect of vitamins and minerals supplementation (VTM) and/or two rates of body weight gain (GAIN) on bovine placental vascular development and angiogenic factors gene expression were evaluated in two experiments: In Exp. 1, crossbred Angus heifers (n = 34) were assigned to VTM/NoVTM treatments at least 71 days before breeding to allow changes in the mineral status. At breeding, through artificial insemination (AI), heifers were assigned to low-gain (LG) 0.28 kg/d or moderate-gain (MG) 0.79 kg/d treatments, resulting in NoVTM-LG (Control; n = 8), NoVTM-MG (n = 8), VTM-LG (n = 9), and VTM-MG (n = …

Corals In Crisis: A Transcriptomic Investigation Of Stony Coral Tissue Loss Disease, Kelsey M. Beavers

Biology Dissertations - Archive

Coral reefs face existential threats due to climate change and human activities. The combined effects of ocean warming, overfishing, pollution, and habitat destruction have fundamentally altered the functionality of coral reefs and are driving a drastic increase in the prevalence and severity of coral disease outbreaks. Stony coral tissue loss disease (SCTLD) has emerged one of the most devastating disturbances to Caribbean reef ecosystems on record. Despite notable progress, the cellular mechanisms driving SCTLD pathogenesis remain poorly understood. To address this issue, my dissertation investigates the gene expression, histopathology, immune protein activity, and symbiont community dynamics involved in SCTLD progression …

The Effects Of Early Exposure To Prescription/Illicit Drugs And Drug Metabolites On Larval Zebrafish Behavioral And Motor Function Development, Jacob Thomas, Dena Weinberger, Bikram Subedi, Brandon Capps

Murray State Theses and Dissertations

THE EFFECTS OF EARLY EXPOSURE TO PRESCRIPTION/ILLICIT DRUGS AND DRUG METABOLITES ON LARVAL ZEBRAFISH BEHAVIORAL AND MOTOR FUNCTION DEVELOPMENT

A Thesis Presented to the Faculty of the Department of Biology

Murray State University

Murray, Kentucky

In Partial Fulfillment of the Requirements for the Degree of Masters In Science

By Jacob Thomas, B.S., Murray State University

December 2024

Acknowledgements

Brandon Capps, who pretty much did a whole third of the legwork on this project and saved me lots of headaches;

Chandler Maddox, one of the University of Kentucky’s finest undergrads who came in from the top rope with a folding chair …

Integrative Machine Learning Approaches For Enhanced Classification Of Genomic Sequences: A Next-Generation Sequencing Perspective, Sujatha Alla, Nagesh Bheesetty, Sai Gireesh Komaragiri, Prasanthi Chidipudi, Joshit Mohanty, Sathish Kumar Chintala, Jubin Thomas, Jayapal Vummadi, Hemanth Volikatla, Navin Kamuni

Engineering Management & Systems Engineering Faculty Publications

The advent of Next-Generation Sequencing (NGS) techniques has revolutionized genomic research by enabling the rapid sequencing of DNA and RNA. This data can be used for various applications, including genome sequencing, transcriptome profiling, metagenomics, and epigenetics studies. For this study, DNA classifier dataset was extracted from UCI repository of machine learning databases. This vast amount of genomic data necessitates the development of sophisticated machine learning (ML) models for effective classification and analysis. This study presents a comprehensive comparison of various ML models, including Support Vector Machines (SVM), Random Forests (RF), and Neural Networks (NNs), approaches, in classifying genomic data. We …

Genomic Studies Of The Equine Bloodworm, Strongylus Vulgaris, Nichol Ripley

Theses and Dissertations--Veterinary Science

Strongylus vulgaris is the most pathogenic nematode parasite of grazing horses worldwide. This gastrointestinal parasitic nematode is in the family Strongylidae under the subfamily Strongylinae, or Strongylins. While the epidemiology, complete life cycle, and high pathogenicity of the fourth and fifth larval stages of S. vulgaris are well established, we understand very little about its biology. This parasite is renowned for its unique life cycle and capacity to cause arterial damage, leading to significant health and economic impacts for the equine industry. It also is the most intensively documented Strongylin; however, S. vulgaris has yet to gain drug resistance as …

Sccad: Cluster Decomposition-Based Anomaly Detection For Rare Cell Identification In Single-Cell Expression Data, Yunpei Xu, Shaokai Wang, Qilong Feng, Jiazhi Xia, Yaohang Li, Hong-Dong Li, Jianxin Wang

Computer Science Faculty Publications

Single-cell RNA sequencing (scRNA-seq) technologies have become essential tools for characterizing cellular landscapes within complex tissues. Large-scale single-cell transcriptomics holds great potential for identifying rare cell types critical to the pathogenesis of diseases and biological processes. Existing methods for identifying rare cell types often rely on one-time clustering using partial or global gene expression. However, these rare cell types may be overlooked during the clustering phase, posing challenges for their accurate identification. In this paper, we propose a Cluster decomposition-based Anomaly Detection method (scCAD), which iteratively decomposes clusters based on the most differential signals in each cluster to effectively separate …

Multiple Rsv Strains Infecting Hep-2 And A549 Cells Reveal Cell Line-Dependent Differences In Resistance To Rsv Infection, Anubama Rajan, Felipe-Andres Piedra, Letisha Aideyan, Trevor Mcbride, Matthew Robertson, Hannah L. Johnson, Gina Marie Aloisio, David Henke, Cristian Coarfa, Fabio Stossi, Vipin Kumar Menon, Harshavardhan Doddapaneni, Donna Marie Muzny, Sara Joan Javornik Cregeen, Kristi Louise Hoffman, Joseph Petrosino, Richard A. Gibbs, Vasanthi Avadhanula, Pedro A. Piedra

Research Symposium

Background: Respiratory syncytial virus (RSV) is the major viral driver of a global pediatric respiratory disease burden disproportionately borne by the poor¹. Thus, RSV, like SARS-CoV-2, combines with congenital and environmental and host-history-dependent factors to create a spectrum of disease with greatest severity most frequently occurring in those least able to procure treatment.

Methods: Here we apply whole genome sequencing and a suite of other molecular biological techniques to survey host-virus dynamics in infections of two distinct cell lines (HEp2 and A549) with four strains representative of known RSV genetic diversity.

Results: We observed non-gradient patterns of RSV …

Modeling Nonsegmented Negative-Strand Rna Virus (Nnsv) Transcription With Ejective Polymerase Collisions And Biased Diffusion, Felipe-Andres Piedra

Research Symposium

Background: The textbook model of NNSV transcription predicts a gene expression gradient. However, multiple studies show non-gradient gene expression patterns or data inconsistent with a simple gradient. Regarding the latter, several studies show a dramatic decrease in gene expression over the last two genes of the respiratory syncytial virus (RSV) genome (a highly studied NNSV). The textbook model cannot explain these phenomena.

Methods: Computational models of RSV and vesicular stomatitis virus (VSV – another highly studied NNSV) transcription were written in the Python programming language using the Scientific Python Development Environment. The model code is freely available on GitHub: …

Gene Expression Effects On Productivity And Stress Tolerance In Polyclonal Plantings Of Populus Deltoides, Macy Gosselaar

Theses and Dissertations

Polyclonal plantings of Populus deltoides are expected to display increased site resource use, productivity, and tolerance to stress through plasticity changes leading to niche differentiation (i.e changes to crown/canopy structures). In the present study, P. deltoides Clones S7C8, 110412, and polyclonal plots were tested for differentially expressed genes and enriched biological pathways between planting schemes. Transcriptomic analysis of leaves revealed upregulation of an active growth gene and gene family members that play important roles in plant stress and stress tolerance in polyclonal plantings. A gene associated with oxidative stress was upregulated in polyclonal plantings across all treatments. Secondary metabolic pathways …

Structural Diversity And Stress Regulation Of The Plant Immunity-Associated Calmodulin-Binding Protein 60 (Cbp60) Family Of Transcription Factors In Solanum Lycopersicum (Tomato), Vanessa Shivnauth, Sonya Pretheepkumar, Eric J. R. Marchetta, Christina A. M. Rossi, Keaun Amani, Christian Castroverde

Biology Faculty Publications

Cellular signaling generates calcium (Ca2+) ions, which are ubiquitous secondary messengers decoded by calcium-dependent protein kinases, calcineurins, calreticulin, calmodulins (CAMs), and CAM-binding proteins. Previous studies in the model plant Arabidopsis thaliana have shown the critical roles of the CAM-BINDING PROTEIN 60 (CBP60) protein family in plant growth, stress responses, and immunity. Certain CBP60 factors can regulate plant immune responses, like pattern-triggered immunity, effector-triggered immunity, and synthesis of major plant immune-activating metabolites salicylic acid (SA) and N-hydroxypipecolic acid (NHP). Although homologous CBP60 sequences have been identified in the plant kingdom, their function and regulation in most species remain unclear. In …

Overexpressing Two Helicobacter Pylori Small Rnas From A Bacterial Pathogenicity-Related Chromosomal Region To Investigate Their Regulation Of Virulence Genes, Roxanne N. Mcpeck, Olivia F. Morgan, Andrea R. Castillo Phd

2023 Symposium

The bacterial pathogen Helicobacter pylori infects the stomachs of approximately 50% of humanity, causing symptomatic disease (e.g., stomach ulcers, gastric cancer, and MALT lymphoma) in 10-15% of the infected. Colonizing the acidic, inhospitable stomach requires H. pylori to tightly regulate gene expression despite lacking many common bacterial genetic regulatory elements. The pathogen may compensate by using abundant non-protein-coding small RNAs (sRNAs) to regulate gene expression, including of infection-intensifying virulence genes. Additionally, severe disease and cancer correlate with infection by H. pylori strains that contain a nonessential chromosomal region, the cytotoxin-associated gene pathogenicity island (cagPAI). This encodes powerful virulence …

Physiological And Transcriptomic Responses Of Two Artemisia Californica Populations To Drought: Implications For Restoring Drought-Resilient Native Communities, Hagop S. Atamian Dr., Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As climate change brings drier and more variable rainfall patterns to many arid and semi-arid regions, land managers must re-assemble appropriate plant communities for these conditions. Transcriptome sequencing can elucidate the molecular mechanisms underlying plant responses to changing environmental conditions, potentially enhancing our ability to screen suitable genotypes and species for restoration. We examined physiological and morphological traits and transcriptome sequences of coastal and inland populations of California sagebrush (Artemisia californica), a critical shrub used to restore coastal sage scrub vegetation communities, grown under low and high rainfall environments. The populations are located approximately 36 km apart but …

Analysis Of Ssa4 Reporter Expression By Q-Pcr, Susveen Sharanshi, Rebecca Adams

[Archive] Belmont University Research Symposium (BURS)

The synthesis of genome-encoded proteins via mRNA translation is integral to cell survival. In eukaryotes, such as S. cerevisiae, the mRNA that is produced in the nucleus must be exported to the cytoplasm for translation to occur, and this process is highly regulated. Specifically, the export of mRNA occurs via travel through nuclear pore complexes (NPCs), which are selective doorways embedded in the nuclear envelope. During cellular stress, such as heat shock, the cell needs to regulate gene expression to permit survival, and mRNA export is one step at which this occurs. At these high temperatures, a cell’s proteins …

Protocol To Identify The Core Gene Supported By An Essential Gene In E. Coli Bacteria Using A Genome-Wide Suppressor Screen, Isao Masuda, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

We describe here a genome-wide screening approach to identify the most critical core reaction among a network of many that are supported by an essential gene to establish cell viability. We describe steps for maintenance plasmid construction, knockout cell construction, and phenotype validation. We then detail isolation of suppressors, whole-genome sequencing analysis, and reconstruction of CRISPR mutants. We focus on E. coli trmD, which encodes an essential methyl transferase that synthesizes m1G37 on the 3'-side of the tRNA anticodon. For complete details on the use and execution of this protocol, please refer to Masuda et al. (2022).