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  • Undergraduate Poster Abstracts
  • Cell/Molecular Biology

    Room National Harbor 4

    ap003 CELL-TYPE SPECIFIC CHROMATIN REGULATION BY H2A VARIANTS

    • Londen Johnson ;
    • Dana Byrd ;
    • Diana Chu ;

    n/a

    CELL-TYPE SPECIFIC CHROMATIN REGULATION BY H2A VARIANTS

    Londen Johnson, Dana Byrd, Diana Chu.

    San Francisco State University, San Francisco, CA.

    Development is dependent on the accessibility and expression of genes at the right time and place. Accessibility of DNA for transcription is determined by how tightly DNA is wrapped around histones. Core histones are replaced by specialized histone variants, whose incorporation aids gene regulation by altering DNA accessibility. While some histone variants are ubiquitously expressed others are specialized in a tissue specific manner allowing us to study the mechanism behind cell-type specific regulation. For example, during C. elegans spermatogenesis canonical H2A is replaced by globally expressed HTZ-1 and sperm specific HTAS-1, which is incorporated during a period of high compaction in the germline. We aim to identify the transcriptional role of H2A variants in the germline. We hypothesized that HTZ-1 would assist in making genes more accessible for transcription while HTAS-1 would aid in repression. Through immunofluorescence and fluorescent in situ hybridization (FISH) assays we localized these variants to active and inactive chromatin. We found that both variants co-localize during later stages of spermatogenesis and are under-represented on the transcriptionally silent X-chromosome. Next, we test whether they are located on active or inactive extrachromosomal arrays. Preliminary results suggest that both variants are localized to the active array, implying that they are incorporated in transcriptionally active chromatin. Our results imply that both variants may aid in the transcriptional activation of chromatin during a period of global silencing. We expect that this research will correlate HTZ-1 and HTAS-1 incorporation with transcription and aid in understanding the mechanism behind cell-type specific gene regulation.

    ap004 THE ER DIVIDES ASYMMETRICALLY IN NEURAL PROGENITOR CELLS DURING EARLY DROSOPHILA DEVELOPMENT

    • Arturo Altamirano III ;

    n/a

    THE ER DIVIDES ASYMMETRICALLY IN NEURAL PROGENITOR CELLS DURING EARLY DROSOPHILA DEVELOPMENT

    Arturo Altamirano III1.

    1San Francisco State University, San Francisco, CA, 2Kobe University, Kobe, JP.

    Studies surrounding cell division are well documented; however, relatively little is known about how organelles are inherited during mitosis. In particular, the endoplasmic reticulum (ER) is essential for cell viability given its essential role in cellular function. Yet it remains unclear whether there is a mechanism in place to ensure proper ER inheritance or whether a cell can simply generate more ER if needed. Previous work has shown that the ER is highly dynamic during mitosis. Here, we hypothesize that dramatic changes in ER organization are important for development. This hypothesis is based on our striking observation that in the early Drosophila melanogaster embryo the ER divides asymmetrically in neural progenitor cells such that one daughter cell receives significantly more ER than its counterpart. Using immunostaining and confocal microscopy, we investigate the role that known cortical determinants play in these asymmetric divisions. We report that this phenomenon precedes the localization of prospero, aPKC, and inscutable. Furthermore, we examine the role of jagunal, a novel ER reorganization protein, in these asymmetric divisions. We find that knockdown of jagunal by RNAi abolishes this asymmetry, and that when jagunal localization is observed through live imaging it appears to divide asymmetrically as well. Our findings suggest that these asymmetric divisions of the ER are not under the control of these cortical determinants. Additionally, jagunal may be potentially involved in establishing this asymmetry and thus, that research into its involvement may further elucidate this unique ER organization mechanism.

    ap005 THE INTERACTION BETWEEN ARGININE METHYLATION AND SERINE PHOSPHORYLATION IN HISTONE H3

    • Mariel Grace Mendoza ;
    • Cecilia Zurita-Lopez ;

    n/a

    THE INTERACTION BETWEEN ARGININE METHYLATION AND SERINE PHOSPHORYLATION IN HISTONE H3

    Mariel Grace Mendoza, Cecilia Zurita-Lopez.

    California State University, Los Angeles, Los Angeles, CA.

    Specific combinations of posttranslational modifications on the N-terminal tail of histone proteins can determine patterns of gene expression. It has been demonstrated that protein arginine methyltransferases methylate arginine residues in FOXO1 and BAD proteins, and this modification blocks Akt-mediated serine phosphorylation. We expect that a similar crosstalk is occurring in histone H3, where adjacent arginine 8 (H3R8) and serine 10 (H3S10) residues are methylated and phosphorylated, respectively. We propose that arginine methylation can inhibit phosphorylation of neighboring serine residues regardless of the kinase phosphorylating the substrate. Through this mechanism, H3R8 methylation can serve as an inhibitory modification that is capable of regulating gene expression by impeding phosphorylation. In vitro studies using peptides based on histone H3 and full-length recombinant H3 will be used to demonstrate this interplay. Specific methylated H3R8 and phosphorylated H3S10 will be detected via immunoblot analyses, mass spectrometry, and radioactive assays. Investigating the crosstalk between posttranslational modifications on histone proteins provides a deeper understanding of gene regulation, and can potentially serve as a novel therapeutic target for drug development.

    ap006 INVESTIGATING THE ROLE OF MYOD IN THE REGULATION OF ID2 AND ID3 GENES DURING MYOGENESIS

    • Carlos Aguirre ;
    • Sandra Sharp ;

    n/a

    INVESTIGATING THE ROLE OF MYOD IN THE REGULATION OF ID2 AND ID3 GENES DURING MYOGENESIS

    Carlos Aguirre, Sandra Sharp.

    California State University, Los Angeles, Los Angeles, CA.

    During myogenesis, specific transcription factors are crucial at different developmental stages. MyoD is such a transcription factor and is expressed during both proliferation and differentiation of myogenic cells; however, it is found bound at different sites in the DNA during the 2 cell phases. During differentiation, MyoD binds to and induces the expression of muscle-specific genes. Id proteins, which are expressed in proliferating cells, are negative regulators of MyoD binding, resulting in the inhibition of differentiation. Surprisingly it has been found that MyoD binds to regulatory regions of Id2 and Id3 genes during proliferation. We hypothesize that MyoD contributes to the transient upregulation of Id2 and Id3 during transition from growth to early differentiation. We have confirmed the MyoD expression and differentiation capacities of stably transfected Balb 10(1) +/- MyoD and untransfected fibroblast cell lines. Using these lines, RNA will be extracted over a time course from the proliferating phase to the differentiating phase. qRT-PCR will be conducted in order to determine accumulation of MyoD, Id2 and Id3 mRNAs. ChIP will be conducted in order to identify MyoD binding sites at the Id2 and Id3 regulatory regions. Data will be analyzed to determine levels of Id2 and Id3 in the presence and absence of MyoD during myogenesis. Investigating the mechanisms of myogenesis is paramount for discovering cures for skeletal muscle diseases. In addition, the ways in which the Id genes are regulated is of primary interest to cancer researchers, as these genes are often found overexpressed in cancers.

    ap007 EPIGENETIC REGULATION OF TRANSFORMING GROWTH FACTOR BETA 2 IN THE GLAUCOMA TRABECULAR MESHWORK

    • Jaclyn Bermudez ;
    • Yi-Qiang Cheng ;
    • Abbot Clark ;
    • Weiming Mao ;

    n/a

    EPIGENETIC REGULATION OF TRANSFORMING GROWTH FACTOR BETA 2 IN THE GLAUCOMA TRABECULAR MESHWORK

    Jaclyn Bermudez1Hannah Webber1, Yi-Qiang Cheng, Abbot Clark, Weiming Mao.

    University of North Texas Health Science Center, Fort Worth, TX.

    The role of epigenetic regulation in glaucoma, an age-related neurodegenerative disease that leads to vision loss and irreversible blindness in millions worldwide, is unknown. The most important risk factor of primary open angle glaucoma (POAG), is elevated intraocular pressure (IOP). IOP elevation in glaucoma patients is due to compromised trabecular meshwork (TM) function. In the glaucoma TM (GTM), transforming growth factor β2 (TGFβ2) is elevated, which disrupts TM homeostasis. We hypothesize that histone acetylation, an epigenetic regulatory mechanism, is responsible for the increased expression of TGFβ2 in the GTM. To test our hypothesis, we treated TM cells with 10 nM thailandepsin-A (TDP-A), a histone deacetylase inhibitor (HDACi), or DMSO (vehicle control) for 4 days. Q-PCR was used to compare gene expression. We also perfusion cultured bovine anterior segments with DMSO or TDP-A for 7 to 10 days. Some eyes were treated with TDP-A or TDP-A plus TGFβ2 associated pathway inhibitor. The IOPs of the bovine eyes were continuously monitored. We found that TDP-A elevated the expression of TGFβ2 in TM cell cultures (n = 6, p < 0.05). Also, TDP-A significantly elevated IOP in perfusion cultured bovine eyes (n = 8, p < 0.05). Furthermore, use of the pathway inhibitor decreased TDP-A induced ocular hypertension. Therefore, we believe histone acetylation may play an important role in the dysregulation of TGFβ2 in the GTM. This mechanism provides a unique opportunity to elucidate the etiology of POAG. We also showed that TDP-A is a potent HDACi that can be used as a powerful tool in glaucoma research.

    ap008 REGULATION OF C. ELEGANS SPERM MOTILITY BY PROTEASE SIGNALING

    • Daniela Chavez ;
    • Gillian Stanfield ;

    n/a

    REGULATION OF C. ELEGANS SPERM MOTILITY BY PROTEASE SIGNALING

    Daniela Chavez, Gillian Stanfield.

    The University of Utah, Salt Lake City, UT.

    For many cell types, the ability to migrate is essential to their function and requires dynamic changes in morphology. To understand how cellular rearrangements are regulated, we are using C. elegans sperm activation as a model. During activation, C. elegans sperm respond to extracellular signals and undergo morphogenesis to develop a pseudopod used for crawling toward oocytes. Sperm activation is regulated by the serine protease, TRY-5 and the serine protease inhibitor, SWM-1. In swm-1 mutant males, sperm become prematurely activated and are inefficiently transferred to hermaphrodites during mating, resulting in reduced male fertility. TRY-5 is a seminal fluid protease transferred to hermaphrodites during mating and has the characteristics of a male sperm activation factor. Previous studies have lead us to a model in which SWM-1 inhibits activation by inhibiting TRY-5 protease activity from cleaving sperm cell membrane factors to initiate activation. In support of the model, we have shown that swm-1 is co-expressed with try-5 in a subset of vas deferens cells. Furthermore, SWM-1::mCherry and TRY-5::GFP colocalize in vesicles within vas deferens cells, suggesting that SWM-1 may directly inhibit TRY-5 protease activity. Additionally, we have found that swm-1 is expressed in somatic cells near the seminal vesicle, suggesting an alternative model where SWM-1 indirectly inhibits TRY-5, by regulating the release of TRY-5. In ongoing studies, we are further testing our models by expressing swm-1 and try-5 in a tissue-specific manner and probing the functional domains of SWM-1 and TRY-5.

    ap009 FUNCTIONAL CHARACTERIZATION OF A HEMOCYANION-LIKE PROTEIN IN THE FRESHWATER SNAIL BIOMPHALARIA GLABRATA, INTERMEDIATE HOST FOR THE HUMAN PARASITE SCHISTOSOMA MANSONI

    • Janeth Peña ;
    • Coenraad Adema ;

    n/a

    FUNCTIONAL CHARACTERIZATION OF A HEMOCYANION-LIKE PROTEIN IN THE FRESHWATER SNAIL BIOMPHALARIA GLABRATA, INTERMEDIATE HOST FOR THE HUMAN PARASITE SCHISTOSOMA MANSONI

    Janeth Peña, Coenraad Adema.

    Center for Evolutionary and Theoretical Immunology, The University of New Mexico, Albuquerque, NM.

    Biomphalaria glabrata is an aquatic snail pivotal to transmission of intestinal schistosomiasis because it sustains the life cycle of the parasitic flatworm Schistosoma mansoni. Continued study of the unique biology of B. glabrata is needed to aid in efforts to identify alternative controls method to counter schistosomiasis transmission. Initial EST-based gene discovery guided sequencing of two B. glabrata (BB02 strain) genomic BAC clones to reveal a full hemocyanin-like gene (hcl-1). Hemocyanin is blue blood pigment employed as an oxygen carrier in some arthropods and mollusks. The presence of hcl-1 is unusual because B. glabrata has red-pigmented blood as a result of using hemoglobin as an oxygen carrier. Toward functional characterization, hcl-1 transcript sequences were confirmed from 4 separate B. glabrata strains. Dissected tissues subjected to RT-PCR and (tandem) mass spectrometry revealed that hcl-1 expression and synthesis occurs in the albumen gland (AG), an immune- and reproduction-relevant organ. Proteomic work also identified hcl-1-derived peptides in the egg mass fluid surrounding developing snail embryos. Ontogenetic studies revealed that hcl-1 expression is age-dependent, associating with reproductive maturity in B. glabrata (shell diameter 10 - 12 mm). qRT-PCR demonstrated an increase in hcl-1 expression in response to bacterial pathogen exposure. These results suggest that hcl-1 plays a role in protection and/or development of B. glabrata eggs.

    ap010 DEVELOPING MORE EFFICIENT PROTECTIVE THERAPIES AGAINST HIV: COMBINING MEGATAL NUCLEASE-DRIVEN GENOME ENGINEERING WITH A RESISTANCE CASSETTE

    • Biswajit Paul ;
    • Guillermo Romano ;
    • David Rawlings ;
    • Hans-Peter Kiem ;

    n/a

    DEVELOPING MORE EFFICIENT PROTECTIVE THERAPIES AGAINST HIV: COMBINING MEGATAL NUCLEASE-DRIVEN GENOME ENGINEERING WITH A RESISTANCE CASSETTE

    Biswajit Paul1, Guillermo Romano2, David Rawlings3, Hans-Peter Kiem4.

    1University of Washington, Seattle, WA, 2Seattle Children's Hospital and Research Center, Seattle, WA, 3Seattle Children’s Research Institute, Seattle, WA, 4Fred Hutchinson Cancer Research Center, Seattle, WA.

    Human immunodeficiency virus (HIV) infection remains a substantial health problem worldwide. The human C-C chemokine receptor 5 (CCR5) gene, which encodes a co-receptor required for HIV entry into CD4+ T-cells, is a promising alternative therapeutic target. Clinical trials using CCR5-disrupting nucleases have demonstrated sustained functional control of HIV during antiretroviral treatment interruption. Our objective is to address the 2 limitations of current studies: the need for higher levels of CCR5-disruption in long-term memory cells and preferential selection of gene-modified cells protected from subsequent infection during transplant. We are coupling a novel nuclease, megaTAL, with drug selection in order to disrupt the CCR5 locus, and select modified CD4+ T cells to achieve therapeutically relevant levels of HIV-protected cells. The mutant human dihydrofolate reductase (DHFR) construct renders cells resistant to lymphotoxic concentrations of the drug methotrexate (MTX). For optimal cell viability we deliver nucleases via mRNA and selection-constructs via adeno-associated virus (AAV). Electroporation with megaTAL mRNA demonstrated robust CCR5 disruption: 95% in GHOST-Hi5 cell lines and 70 - 90% in human CD4+ T cells. Gene-modified human T cells were transplanted into NOD/SCID/γc-null humanized mice and subsequently challenged with HIV-1 infection. CCR5-null modified cells preferentially survived during active HIV infection in vivo (100-fold increase). HIV plasma viremia was significantly lower in the nuclease-treated mice but rebounded over time. We hope to address this by chemo-selectively transplanting only CCR5 disrupted cells. The CCR5-megaTAL nuclease produces the highest level of gene-modified CD4+ T cells reported and protects them from HIV infection in vivo.

    ap011 EPAC1-RAP1 SIGNALING ENHANCES AND RESTORES THE BLOOD-RETINAL BARRIER

    • Carla Ramos ;
    • David Antonetti ;

    n/a

    EPAC1-RAP1 SIGNALING ENHANCES AND RESTORES THE BLOOD-RETINAL BARRIER

    Carla Ramos, David Antonetti.

    University of Michigan, Ann Arbor, MI.

    Abnormalities in retinal vascular permeability are associated with diabetic retinopathy (DR), which is the leading cause of vision loss in working-age adults. Pathological changes in vascular permeability during DR are driven by growth factors such as vascular endothelial growth factor (VEGF) and pro-inflammatory cytokines. We are interested in understanding probarrier mechanisms that block vascular permeability and restore the blood-retinal barrier after VEGF signaling. Activation of Rap1 through the cAMP-dependent guanine nucleotide exchange factor (GEF) EPAC1 was reported to enhance barrier function in human umbilical endothelial cells. However, the role of EPAC1 in the retinal endothelial barrier and the relationship to VEGF-induced permeability is unknown. We hypothesize that EPAC1 activation inhibits VEGF-induced permeability in retinal endothelial cells. Primary bovine retinal endothelial cells (BREC) were used to model the blood-retinal barrier. The cAMP analog 8-pCPT-2-O-Me-cAMP-AM (8CPT) was used to specifically activate EPAC1. Cell monolayer permeability was measured by electrical resistance using the ECIS-Zϴ system or by measuring 70 kDa RITC dextran flux across transwell filters. Pre-treatment of BREC with 8CPT prevented VEGF-induced permeability to dextran and reduced electrical resistance. Importantly, treatment of BREC with VEGF followed by 8CPT treatment reversed VEGF-induced permeability to solute and ion flux. Our results demonstrate that activation of Rap1 in retinal endothelial cells through EPAC1 promotes barrier properties and inhibits VEGF-induced permeability. Importantly, EPAC1-Rap1 activation reversed VEGF-induced permeability. Collectively, our results suggest activation of EPAC1-Rap1 may provide a therapeutic means to restore barrier properties in diseases of increased retinal permeability.

    ap012 EVALUATION OF THE IN VIVO ROLE OF A COLD-INDUCIBLE RNA BINDING PROTEIN: IMPLICATIONS FOR BREAST DEVELOPMENT AND DISEASE

    • Daniel Lujan ;
    • Rebecca S. Hartley ;

    n/a

    EVALUATION OF THE IN VIVO ROLE OF A COLD-INDUCIBLE RNA BINDING PROTEIN: IMPLICATIONS FOR BREAST DEVELOPMENT AND DISEASE

    Daniel Lujan1, Rebecca S. Hartley2.

    1University of New Mexico Health Sciences Center, Albuquerque, NM. 2University of New Mexico Cancer Center, University of New Mexico School of Medicine, Albuquerque, NM.

    RNA binding proteins (RBPs) post-transcriptionally regulate gene expression at the mRNA level. Many RBPs associate with the regulatory sequences in the 5’ and 3’ untranslated regions (UTRs) of mRNA in order to regulate the expression of cancer-associated genes. Furthermore, dysfunction of several RBPs is associated with cancer; they regulate target genes that promote cell growth, survival and proliferation. Our current knowledge of RBPs and their role in regulating cancer-associated genes is largely based on in vitro studies. Our current study seeks to determine the in vivo role of a cold-inducible RBP (CIRP) that is overexpressed in breast cancer. In cultured cells, CIRP has displayed the ability to increase the expression of proteins that promote cell proliferation and survival. CIRP has also been demonstrated to inhibit apoptosis, all of which are hallmarks of cancer. We would like to assess the effects of CIRP overexpression on breast tumorigenesis in vivo. Contrary to previous in vitro studies, our current data suggest that CIRP may be inhibiting proliferation and suppressing early tumorigenesis in a breast cancer mouse model. These data may provide us with a more precise understanding of the in vivo function of CIRP.

    ap013 USING SYSTEMS BIOLOGY DATA INTEGRATION TO UNRAVEL THE PROTEOME OF ENDOTHELIAL CELLS INFECTED WITH AN ONCOGENIC HERPESVIRUS

    • Zoi Sychev ;
    • Michael Lagunoff ;

    n/a

    USING SYSTEMS BIOLOGY DATA INTEGRATION TO UNRAVEL THE PROTEOME OF ENDOTHELIAL CELLS INFECTED WITH AN ONCOGENIC HERPESVIRUS

    Zoi Sychev, Michael Lagunoff.

    University of Washington, Seattle, WA.

    Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS), an endothelial-based tumor. KS tumors are predominantly latently infected at around 90%, and less than 3% of cells are lytic. While viral lytic replication promotes KS malignancy, latency is strategic to maintain KS’ long-term infection. KSHV modulates many cell-signaling pathways. A major post-translational modification for cell signaling activation is mediated by phosphorylation. While the mechanisms of several signaling pathways have been characterized, the overall global signaling events from activation to gene expression have not been fully explored. We used systems biology applying mass spectrometry-based proteomics and high-throughput sequencing to elucidate the cellular responses during KSHV latent infection. Endothelial cells were mock and KSHV infected, and then harvested at 48 hours post infection followed by chemical labeling to quantify significant differences between mock and KSHV-infected endothelial cells. In parallel, we performed a transcriptomics analysis with deep sequencing coverage. To integrate these diverse datasets, we used the Steiner Forest algorithm based on protein-to-protein interaction-curated databases. This algorithm adds the minimal amount of nodes that can connect the target proteins to the target genes. Pathway analysis indicates that several pathways are altered including peroxisome and lysosome biogenesis. This comprehensive systems biology level of data-integration provided the first quantitative global proteome and phosphoproteome analysis of protein-to-protein interaction network in endothelial cells during KSHV latent virus infection and provided a number of novel pathways including unique hubs involved in the control of major signaling regulation activated by KSHV during latency.

    ap014 IDENTIFYING CANDIDATE SUBSTRATES OF THE LEUCINE RICH REPEAT KINASE 2 BY MASS SPECTROMETRY-BASED PROTEOMICS

    • William Edelman ;
    • Leo Pallanck ;
    • Judit Villen ;

    n/a

    IDENTIFYING CANDIDATE SUBSTRATES OF THE LEUCINE RICH REPEAT KINASE 2 BY MASS SPECTROMETRY-BASED PROTEOMICS

    William Edelman, Leo Pallanck, Judit Villen.

    University of Washington, Seattle, WA.

    Mutations in the human leucine-rich repeat kinase 2 (LRRK2) contribute to genetic forms of Parkinson’s disease (PD) in people and related phenotypes in model organisms. However, it is not yet known what the biologically relevant substrates are for LRRK2, and to what extent they play in cell signaling. In this work, we ask: what are the in vivo effectors of LRRK2 phosphorylation in a fly model of PD? We applied phosphopeptide enrichment, peptide fractionation, and quantitative mass-spectrometry to interrogate the neuronal proteome for direct and indirect effectors of LRRK2. We used a transgenic fly model to express wild-type human LRRK2 (hLRRK2-WT) or a hyperactive kinase mutant of human LRRK2 (hLRRK2-mutant) throughout the brain of the fly. We compared differences in protein abundance and phosphorylation of proteins. Increased phosphorylation on specific peptide sequences revealed candidate substrates for in vivo activity. Additionally, we presented an in vitro kinase reaction of LRRK2 on peptides to discover direct sites of LRRK2 phosphorylation on specific proteins. We identified over 15,000 unique peptides covering over 4,000 proteins extracted from fly heads. In this work, we applied fractionation methods to extract high-confidence proteome and phosphoproteome changes in response to expressing human WT-LRRK2. These proteins may play a role in signaling mediated by LRRK2 and provide insights into the mechanisms of LRRK2-related Parkinsonian phenotypes.

    ap015 ZINC DYNAMICS OF GERMLINE DEVELOPMENT IN CAENORHABDITIS ELEGANS

    • Adelita Mendoza ;
    • Cody Schiffer ;
    • Sandy Cheung ;
    • Sadie Wignall ;
    • Thomas O'Halloran ;

    n/a

    ZINC DYNAMICS OF GERMLINE DEVELOPMENT IN CAENORHABDITIS ELEGANS

    Adelita Mendoza, Cody Schiffer, Sandy Cheung, Sadie Wignall, Thomas O'Halloran.

    Northwestern University, Evanston, IL.

    Zinc fluxes are a key meiotic progression regulator in developing mammalian oocytes. When zinc fluxes are disrupted, meiosis is halted prematurely, and the developing oocyte becomes inviable. These findings established zinc as a crucial contributor to embryo viability and revealed a new role for zinc signaling within the specialized mammalian oocyte. Thus, we expanded studies into the soil nematode Caenorhabditis elegans to uncover if zinc fluxes are conserved. C. elegans are highly experimentally flexible for zinc studies. Early, broad studies on zinc insufficient hermaphrodites demonstrated that they possess smaller brood sizes, misshapen gonads, and fewer, larger oocytes compared to controls. Combined, these early findings suggest that zinc is involved in germline production. Based on this early data, we aimed to detect if zinc fluxes affect germline development, and hypothesized that zinc fluxes exist in C. elegans, and drive oocyte maturation. We examined the maturing oocyte using 2 main approaches. First, we mapped total zinc (all zinc found within the cell) using X-ray fluorescence microscopy, and second, we visualized labile zinc (zinc accessible to probes) using the zinc sensor ZincBy-1. We detected large-scale zinc fluxes throughout maturation. Interestingly, preliminary results probing labile zinc demonstrated that zinc is packaged in vesicles that exist throughout the cytoplasm in early meiosis I. At the end of meiosis I, they disappear. Combined, these results may indicate that total zinc acquisition is crucial for cell cycle progression and eggshell establishment. Future experiments are aimed at determining the identity of the vesicles containing zinc.