Life Sciences Commons^™

Manipulations Of The Caenorhabditis Elegans Microbiome Reveal Influences Of Detrimental Members On Host Life History Traits, Ashley Elizabeth Foltz

Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–

Microbiomes are a fundamental part of eukaryotic organisms and play a role in both host health and fitness. Although microbiomes are often associated with health and positive effects on the host, certain microbiome compositions are also associated with disease. We used Caenorhabditis elegans and its experimental microbiome, CeMbio to explore the interactions that individual microbiome members have with other microbes, with the host, and how the entire microbiome community interacts with the host. We found that individual CeMbio members have varying effects on host health and fitness compared to the whole community. This suggested that there is synergy occurring in …

Investigation Of How A Kinesin-1 Mutation Affects The Synaptic Localization Of The Periactive Zone Protein Apt-4, Ian Harden

Honors College

Dysfunctional or loss of synaptic transmission is a major contributing factor to many neurological and neurodevelopmental diseases, such as Alzheimer’s disease. To develop novel approaches to treating these diseases, understanding the structures and proteins related to synaptic development and function is essential. Within the synapse is the presynaptic site, containing the active and periactive zones, at which synaptic vesicles containing neurotransmitters are released. The active zone’s primary role is mediating neurotransmitter release via exocytosis, and the periactive zone sorts and recycles synaptic vesicles via endocytosis. However, how periactive zone proteins localize to the presynapse and how they interact with the …

Transcriptomic Clues To Protein Homeostasis, Anna Byquist, Lina Dahlberg

WWU Honors College Senior Projects

Protein misfolding is associated with many different diseases such as Alzheimer’s disease, Parkinson’s disease, and cystic fibrosis. Cells prevent the accumulation of misfolded proteins through conserved pathways, including Endoplasmic Reticulum Associated Degradation (ERAD). In the absence of proper ERAD function, cellular homeostasis is disrupted, and cells can become stressed. The ERAD mechanism is not fully understood, but it is becoming clear that the intersection of gene regulation and protein degradation are tightly linked (1). We approached this intersection using a strain of C. elegans that is lacking the gene F26F4.9, which encodes a putative ortholog of the mammalian ERAD gene …

Neuronal Npr-15 Modulates Molecular And Behavioral Immune Responses Via The Amphid Sensory Neuron-Intestinal Axis In C Elegans, Benson Otarigho, Anna Frances Butts, Alejandro Aballay

Student and Faculty Publications

The survival of hosts during infections relies on their ability to mount effective molecular and behavioral immune responses. Despite extensive research on these defense strategies in various species, including the model organism

Engaging Students In A Genetics Course-Based Undergraduate Research Experience Utilizing Caenorhabditis Elegans In Hybrid Learning To Explore Human Disease Gene Variants, Natalie Forte, Virginia Veasey, Bethany Christie, Amira Carter, Marli Hanks, Alan Holderfield, Taylor Houston, Anil Challa, Ashley Turner

Research, Publications & Creative Work

Genetic analysis in model systems using bioinformatic approaches provides a rich context for a concrete and conceptual understanding of gene structure and function. With the intent to engage students in research and explore disease biology utilizing the nematode Caenorhabditis elegans model, we developed a semester-long course-based undergraduate research experience (CURE) in a hybrid (online/in-person) learning environment—the gene-editing and evolutionary nematode exploration CURE (GENE-CURE). Using a combination of bioinformatic and molecular genetic tools, students performed structure-function analysis of disease-associated variants of uncertain significance (VUS) in human orthologs. With the aid of a series of workshop-style research sessions, students worked in teams …

Editorial: C. Elegans Hostmicrobiome Interactions: From Medical To Ecological And Evolutionary Model, Michael A. Herman, Javier E. Irazoqui, Buck S. Samuel, Nic Vega

School of Biological Sciences: Faculty Publications

No abstract provided.

Editorial: C. Elegans Host-Microbiome Interactions: From Medical To Ecological And Evolutionary Model, Michael A. Herman, Javier E. Irazoqui, Buck S. Samuel, Nic Vega

School of Biological Sciences: Faculty Publications

Microbiomes often form specific functional associations with their hosts. Correlations between microbiome membership and states of host health and disease abound in many systems. However, there are few systems that allow for in depth functional studies that include precise manipulation and interrogation of both microbiome composition and host function. Recently the nematode Caenorhabditis elegans - an excellent genetic model organism for studying many fields of biology, including neurobiology and behavior, development, cell biology, and innate immunity - has proven to be a robust system to probe microbiome interactions and their effect on host physiology.

Cold Shock Induces A Terminal Investment Reproductive Response In C. Elegans, Leah Gulyas, Jennifer R. Powell

Biology Faculty Publications

Challenges from environmental stressors have a profound impact on many life-history traits of an organism, including reproductive strategy. Examples across multiple taxa have demonstrated that maternal reproductive investment resulting from stress can improve offspring survival; a form of matricidal provisioning when death appears imminent is known as terminal investment. Here we report a reproductive response in the nematode Caenorhabditis elegans upon exposure to acute cold shock at 2 °C, whereby vitellogenic lipid movement from the soma to the germline appears to be massively upregulated at the expense of parental survival. This response is dependent on functional TAX-2; TAX-4 cGMP-gated channels …

Research Proposal: Clarifying Any Interactions Between Cytoskeletal Proteins And The Aminopeptidase Pam-1, Alexis Ayala

Biology Presentations

Caenorhabditis elegans is a transparent roundworm that functions as an ideal model organism for studying the complex processes that occur during embryonic cell division. The cell division process is comprised of distinct phases that ensure the development of a healthy and robust embryo. The cytokinesis phase is characterized by the formation of a contractile ring near the middle of the embryo. When this contractile ring constricts, the embryo can effectively divide into two cells. Recent work in the Lyczak laboratory has focused on better understanding how the aminopeptidase PAM-1 works in conjunction with cytoskeletal proteins to regulate the actomyosin cytoskeleton. …

Long-Term Memory For Associative Conditioning And Glutamate Receptor Expression, Kaitlyn Dybing, Waleed Faruqi, Janie Aguilera, Roma Zakos, Lina Dahlberg, Jacqueline K. Rose

WWU Honors College Senior Projects

This poster demonstrates the unique methodology used in Dr. Jacqueline Rose's lab at Western Washington University to study the impact of glutamate receptors on long-term memory in C. elegans. The poster includes a description of the purpose of the study, reasons for use of C. elegans, the methods used, as well as the data and interpretation of the results.

A Conserved Neuropeptide System Links Head And Body Motor Circuits To Enable Adaptive Behavior, Shankar Ramachandran, Navonil Banerjee, Raja Bhattacharya, Michele L. Lemons, Jeremy Florman, Christopher M. Lambert, Denis Touroutine, Kellianne Alexander, Liliane Schoofs, Mark J. Alkema, Isabel Beets, Michael M. Francis

Biological and Physical Sciences Department Faculty Works

Neuromodulators promote adaptive behaviors that are often complex and involve concerted activity changes across circuits that are often not physically connected. It is not well understood how neuromodulatory systems accomplish these tasks. Here, we show that the Caenorhabditis elegans NLP-12 neuropeptide system shapes responses to food availability by modulating the activity of head and body wall motor neurons through alternate G-protein coupled receptor (GPCR) targets, CKR-1 and CKR-2. We show ckr-2 deletion reduces body bend depth during movement under basal conditions. We demonstrate CKR-1 is a functional NLP-12 receptor and define its expression in the nervous system. In contrast to …

Integrins Have Cell-Type-Specific Roles In The Development Of Motor Neuron Connectivity, Devyn Oliver, Emily Norman, Heather Bates, Rachel Avard, Monika Rettler, Claire Y. Bénard, Michael M. Francis, Michele L. Lemons

Biological and Physical Sciences Department Faculty Works

Formation of the nervous system requires a complex series of events including proper extension and guidance of neuronal axons and dendrites. Here we investigate the requirement for integrins, a class of transmembrane cell adhesion receptors, in regulating these processes across classes of C. elegans motor neurons. We show α integrin/ina-1 is expressed by both GABAergic and cholinergic motor neurons. Despite this, our analysis of hypomorphic ina-1(gm144) mutants indicates preferential involvement of α integrin/ina-1 in GABAergic commissural development, without obvious involvement in cholinergic commissural development. The defects in GABAergic commissures of ina-1(gm144) mutants included both premature termination and guidance …

Immobilization Nematodes For Live Imaging Using An Agarose Pad Produced With A Vinyl Record, Katherine A. Rivera Gomez, Mara Schvarzstein

Publications and Research

Numerous microfluidic systems have been developed and used for live imaging of Caenorhabditis nematodes (Allen et al., 2008; Zhang et al., 2008; Krajniak and Lu, 2010; Krajniak et al., 2013; Cornaglia et al., 2015). These systems can be costly, complex to set up, or require high-maintenance between uses. In addition, microfluidic rigs can be thick, preventing live imaging of worms from strains expressing low fluorescence fusion proteins. In the absence of elaborate microfluidic rigs, most live imaging protocols utilize flat agarose pads along with anesthetics and/or microbeads to immobilize the nematodes (Kim et al., 2013). Since this method does not …

The Molecular Chaperone Hsp90 Promotes Notch Signaling In The Germline Of Caenorhabditis Elegans, James L. Lissemore, Elyse Connors, Ying Liu, Li Qiao, Bing Yang, Mark L. Edgley, Stephane Flibotte, Jon Taylor, Vinci Au, Donald G. Moerman, Eleanor M. Maine

2018 Faculty Bibliography

In a genetic screen to identify genes that promote GLP-1/Notch signaling in Caenorhabditis elegans germline stem cells, we found a single mutation, om40, defining a gene called ego-3. ego-3(om40) causes several defects in the soma and the germline, including paralysis during larval development, sterility, delayed proliferation of germline stem cells, and ectopic germline stem cell proliferation. Whole genome sequencing identified om40 as an allele of hsp-90, previously known as daf-21, which encodes the C. elegans ortholog of the cytosolic form of HSP90. This protein is a molecular chaperone with a central position in the protein homeostasis network, which is responsible …

The Folic Acid Metabolism Gene Mel-32/Shmt Is Required For Normal Cell Cycle Lengths In Caenorhabditis Elegans, Kalin D. Konrad, Raquel A. Campbell, Vanessa Thiel, Jessica Sullivan-Brown

Biology Faculty Publications

Neural tube defects are common and serious birth defects in which the brain and/or spinal cord are exposed outside the body. Supplementation of foods with folic acid, an essential vitamin, is linked to a lower risk of neural tube defects; however, the mechanisms by which folic acid influence neural tube defect risk are unclear. Our research seeks to identify the basic cellular roles of known folic acid metabolism genes during morphogenesis using the roundworm Caenorhabditis elegans (C. elegans) as a simple model system. Here, we used live imaging to characterize defects in embryonic development when mel-32 is depleted. mel-32 is …

Glutamylation Regulates Transport, Specializes Function, And Sculpts The Structure Of Cilia, Robert O'Hagan, Malan Silva, Ken Cq Nguyen, Winnie Zhang, Sebastian Bellotti, Yasmin Ramadan, David Hall, Maureen M. Barr

Department of Biology Faculty Scholarship and Creative Works

Ciliary microtubules (MTs) are extensively decorated with post-translational modifications (PTMs), such as glutamylation of tubulin tails. PTMs and tubulin isotype diversity act as a “Tubulin Code” that regulates cytoskeletal stability and the activity of MT-associated proteins such as kinesins. We previously showed that, in C. elegans cilia, the deglutamylase CCPP-1 affects ciliary ultrastructure, localization of the TRP channel PKD-2 and the kinesin-3 KLP-6, and velocity of kinesin-2 OSM-3/KIF17, while a cell-specific α-tubulin isotype regulates ciliary ultrastructure, intraflagellar transport, and ciliary functions of extracellular vesicle (EV)-releasing neurons. Here, we examine the role of PTMs and the Tubulin Code in the cililary …

Systems Biology Approach To Late-Onset Alzheimer's Disease Genome-Wide Association Study Identifies Novel Candidate Genes Validated Using Brain Expression Data And Caenorhabditis Elegans Experiments, Shubhabrata Mukherjee, Joshua C. Russell, Daniel T. Carr, Jeremy D. Burgess, Mariet Allen, Daniel J. Serie, Kevin L. Boehme, John S. K. Kauwe, Adam C. Naj, David W. Fardo, Dennis W. Dickson, Thomas J. Montine, Nilufer Ertekin-Taner, Matt R. Kaeberlein, Paul K. Crane

Biostatistics Faculty Publications

Introduction—We sought to determine whether a systems biology approach may identify novel late-onset Alzheimer's disease (LOAD) loci.

Methods—We performed gene-wide association analyses and integrated results with human protein-protein interaction data using network analyses. We performed functional validation on novel genes using a transgenic Caenorhabditis elegans Aβ proteotoxicity model and evaluated novel genes using brain expression data from people with LOAD and other neurodegenerative conditions.

Results—We identified 13 novel candidate LOAD genes outside chromosome 19. Of those, RNA interference knockdowns of the C. elegans orthologs of UBC, NDUFS3, EGR1, and ATP5H were associated with Aβ …

Functional Analysis Of Microrna Pathway Genes In The Somatic Gonad And Germ Cells During Ovulation In C. Elegans, Carmela Rios, David Warren, Benjamin Olson, Allison L. Abbott

Biological Sciences Faculty Research and Publications

MicroRNAs (miRNAs) are post-transcriptional regulators of gene expression that play critical roles in animal development and physiology, though functions for most miRNAs remain unknown. Worms with reduced miRNA biogenesis due to loss of Drosha or Pasha/DGCR8 activity are sterile and fail to ovulate, indicating that miRNAs are required for the process of oocyte maturation and ovulation. Starting with this penetrant sterile phenotype and using new strains created to perform tissue specific RNAi, we characterized the roles of the C. elegans Pasha, pash-1, and two miRNA-specific Argonautes, alg-1 and alg-2, in somatic gonad cells and in germ cells in the regulation …

Stage-Specific Timing Of The Microrna Regulation Of Lin-28 By The Heterochronic Gene Lin-14 In Caenorhabditis Elegans, Jennifer Tsialikas, Mitchell A. Romens, Allison L. Abbott, Eric G. Moss

Biological Sciences Faculty Research and Publications

In normal development, the order and synchrony of diverse developmental events must be explicitly controlled. In the nematode Caenorhabditis elegans, the timing of larval events is regulated by hierarchy of proteins and microRNAs (miRNAs) known as the heterochronic pathway. These regulators are organized in feedforward and feedback interactions to form a robust mechanism for specifying the timing and execution of cell fates at successive stages. One member of this pathway is the RNA binding protein LIN-28, which promotes pluripotency and cell fate decisions in successive stages. Two genetic circuits control LIN-28 abundance: it is negatively regulated by the miRNA …

Assessment Of Daf-19 Related Behavioral Defects, Loraina A. Stinson

Lawrence University Honors Projects

The daf-19 gene encodes the only RFX transcription factors in C. elegans, producing at least four related protein isoforms, one of which, DAF-19C, is responsible for ciliogenesis. Previous work by Senti and Swoboda (2008) demonstrated that adult worms deficient in all four DAF-19 proteins have extremely aberrant dwelling and roaming behavior on bacterial food. Most intriguingly, the addition of cDNA encoding the DAF-19C isoform restores cilia formation, but does not fully restore wild-type dwelling and roaming behavior. We are suggesting that additional neuron functions are needed to properly execute behaviors and these neuron functions require the activity of other …

Activation Of Target Gene Expression In Neurons By The C. Elegans Rfx Transcription Factor, Daf-19, Katherine P. Mueller

Lawrence University Honors Projects

DAF-19, the only RFX transcription factor found in C. elegans, is required for the formation of neuronal sensory cilia. Four isoforms of the DAF-19 protein have been reported, and the m86 nonsense (null) mutation affecting all four isoforms has been shown to prevent cilia formation. Transcriptome analyses employing microarrays of L1 and adult stage worms were completed using RNA from daf-19(m86) worms and an isogenic wild type strain to identify additional putative DAF-19 target genes. Using transcriptional fusions with GFP, we compared the expression patterns of several potential gene targets using fluorescence confocal microscopy. Expression patterns were characterized in …

Efn-4 Functions In Lad-2-Mediated Axon Guidance In Caenorhabditis Elegans, Alicia A. Schwieterman, Cory J. Donelson, Jonathan L. Mcmurry, Martin L. Hudson

Faculty Articles

During development of the nervous system, growing axons rely on guidance molecules to direct axon pathfinding. A well-characterized family of guidance molecules are the membrane-associated ephrins, which together with their cognate Eph receptors, direct axon navigation in a contact-mediated fashion. InC. elegans, the ephrin-Eph signaling system is conserved and is best characterized for their roles in neuroblast migration during early embryogenesis. This study demonstrates a role for theC. elegansephrin EFN-4 in axon guidance. We provide both genetic and biochemical evidence that is consistent with theC. elegansdivergent L1 cell adhesion molecule LAD-2 acting as a non-canonical ephrin receptor to EFN-4 to …

Wormguides: An Interactive Single Cell Developmental Atlas And Tool For Collaborative Multidimensional Data Exploration., James C. Schaff, William A. Mohler

UCHC Articles - Research

Abstract

BACKGROUND:

Imaging and image analysis advances are yielding increasingly complete and complicated records of cellular events in tissues and whole embryos. The ability to follow hundreds to thousands of cells at the individual level demands a spatio-temporal data infrastructure: tools to assemble and collate knowledge about development spatially in a manner analogous to geographic information systems (GIS). Just as GIS indexes items or events based on their spatio-temporal or 4D location on the Earth these tools would organize knowledge based on location within the tissues or embryos. Developmental processes are highly context-specific, but the complexity of the 4D environment …

Dynamically-Expressed Prion-Like Proteins Form A Cuticle In The Pharynx Of Caenorhabditis Elegans, Julia B. George-Raizen, Keith R. Shockley, Nicholas F. Trojanowski, Annesia L. Lamb, David M. Raizen

Publications and Research

In molting animals, a cuticular extracellular matrix forms the first barrier to infection and other environmental insults. In the nematode Caenorhabditis elegans there are two types of cuticle: a wellstudied collagenous cuticle lines the body, and a poorly-understood chitinous cuticle lines the pharynx. In the posterior end of the pharynx is the grinder, a tooth-like cuticular specialization that crushes food prior to transport to the intestine for digestion. We here show that the grinder increases in size only during the molt. To gain molecular insight into the structure of the grinder and pharyngeal cuticle, we performed a microarray analysis to …

Using Rnai In C. Elegans To Demonstrate Gene Knockdown Phenotypes In The Undergraduate Biology Lab Setting, Nicole M. Roy

Biology Faculty Publications

RNA interference (RNAi) is a powerful technology used to knock down genes in basic research and medicine. In 2006 RNAi technology using Caenorhabditis elegans (C. elegans) was awarded the Nobel Prize in medicine and thus students graduating in the biological sciences should have experience with this technology. However, students struggle conceptually with the molecular biology behind the RNAi technology and find the technology difficult to grasp. To this end, we have provided a simple, streamlined and inexpensive RNAi procedure using C. elegans that can be adopted in upper level biology classes. By using an unknown RNAi-producing bacteria, students perform novel …

The Branched Actin Nucleator Arp2/3 Promotes Nuclear Migrations And Cell Polarity In The C. Elegans Zygote, William A. Mohler

UCHC Articles - Research

Regulated movements of the nucleus are essential during zygote formation, cell migrations, and differentiation of neurons. The nucleus moves along microtubules (MTs) and is repositioned on F-actin at the cellular cortex. Two families of nuclear envelope proteins, SUN and KASH, link the nucleus to the actin and MT cytoskeletons during nuclear movements. However, the role of actin nucleators in nuclear migration and positioning is poorly understood. We show that the branched actin nucleator, Arp2/3, affects nuclear movements throughout embryonic and larval development in C. elegans, including nuclear migrations in epidermal cells and neuronal precursors. In one-cell embryos the migration …

The C. Elegans Snail Homolog Ces-1 Can Activate Gene Expression In Vivo And Share Targets With Bhlh Transcription Factors, John S. Reece-Hoyes, Bart Deplancke, M. Inmaculada Barrasa, Julia Hatzold, Ryan B. Smit, H Efsun Arda, Patricia A. Pope, Jeb Gaudet, Barbara Conradt, Albertga J.M. Walhout

Dartmouth Scholarship

Snail-type transcription factors (TFs) are found in numerous metazoan organisms and function in a plethora of cellular and developmental processes including mesoderm and neuronal development, apoptosis and cancer. So far, Snail-type TFs are exclusively known as transcriptional repressors. They repress gene expression by recruiting transcriptional co-repressors and/or by preventing DNA binding of activators from the basic helix-loop-helix (bHLH) family of TFs to CAGGTG E-box sequences. Here we report that the Caenorhabditis elegans Snail-type TF CES-1 can activate transcription in vivo. Moreover, we provide results that suggest that CES-1 can share its binding site with bHLH TFs, in different tissues, …

Analysis Of Wnt Signaling During Caenorhabditis Elegans Postembryonic Development, Samantha Van Hoffelen, Michael A. Herman

School of Biological Sciences: Faculty Publications

Wnts play a central role in the development of many cells and tissue types in all species studied to date. Like many other extracellular signaling pathways, secreted Wnt proteins are involved in many different processes; in C. elegans these include cell proliferation, differentiation, cell migration, control of cell polarity, axon outgrowth, and control of the stem cell niche. Perturbations in Wnt signaling are also key factors in cancer formation, and therefore of interest to oncobiologists. Wnts are secreted glycoproteins, which bind to Frizzled transmembrane receptors and signal either through, or independently of β-catenin. Both β-catenin-dependent (Wnt/β-catenin) and -independent pathways function …

The Bro1-Domain Protein, Ego-2, Promotes Notch Signaling In Caenorhabditis Elegans, Ying Liu, Eleanor M. Maine

Biology - All Scholarship

In Caenorhabditis elegans, as in other animals, Notch-type signaling mediates numerous inductive events during development. The mechanism of Notch-type signaling involves proteolytic cleavage of the receptor and subsequent transport of the receptor intracellular domain to the nucleus, where it acts as a transcriptional regulator. Notch-type signaling activity is modulated by post-translational modifications and endocytosis of ligand and receptor. We previously identified the ego-2 (enhancer of glp-1) gene as a positive regulator of germline proliferation that interacts genetically with the GLP-1/Notch signaling pathway in the germline. Here, we show that ego-2 positively regulates signaling in various tissues via both GLP-1 and …

Asymmetric Localizations Of Lin-17/Fz And Mig-5/Dsh Are Involved In The Asymmetric B Cell Division In C. Elegans, Mingfu Wu, Michael A. Herman

School of Biological Sciences: Faculty Publications

LIN-44/Wnt and LIN-17/Frizzled (Fz) function in a planar cell polarity (PCP)-like pathway to regulate the asymmetric B cell division in Caenorhabditis elegans. We observed asymmetric localization of LIN-17/Frizzled (Fz) and MIG-5/Disheveled (Dsh) during the B cell division. LIN-17∷GFP was asymmetrically localized within the B cell prior to and after the B cell division and correlated with B cell polarity. Asymmetric localization of LIN-17∷GFP was dependent upon LIN-44/Wnt and MIG-5/Dsh function. The LIN-17 transmembrane domain and a portion of the cysteine-rich domain (CRD) were required for LIN-17 function and asymmetric distribution to the B cell daughters, while the conserved KTXXXW …