Genetics and Genomics Commons^™

Reconstruction Of Fox Transcription Factor-Regulated Subnetworks Mediating Cardiac Progenitor Cell Divisions, Md Rezaul Hasan

All-Inclusive List of Electronic Theses and Dissertations

Congenital heart disease (CHD) is the most common congenital anomaly worldwide, affecting approximately 1% of live births, corresponding to 1.35 million infants born with CHD each year, and remains a leading cause of infant mortality; therefore, it is urgent to understand the genetic and molecular mechanisms underlying CHD for advancing early diagnosis and treatment. Because many aspects of the Drosophila heart formation are highly reminiscent of vertebrate heart development, Drosophila melanogaster serves as a simple yet powerful model system for studying cardiac development and CHD. While at least eight Forkhead box (Fox) transcription factors (TFs) are required for proper cardiac …

The Rna-Binding Protein Pumilio Limits Polymodal Noiception In Drosophila Larvae, Sara Palega, Hannah Davenport, Rebeccah K. Stewart, Jessica Horton, Andrew Bellemer

Microbiology & Molecular Cell Biology Faculty Publications

Nociception is the process by which the nervous system detects and processes information about potentially harmful environmental stimuli to generate behavioral and physiological responses. The process of nociception undergoes plasticity in response to injury, inflammation, and infection to shape the sensitivity of nociceptive circuits and the behavioral responses they control. We are increasingly aware that post-transcriptional regulation of gene expression shapes the sensitivity and plasticity of nociceptive sensory neurons and nociceptive behavior. In Drosophila, the Pumilio RNA-binding protein interacts with diverse target mRNAs to regulate their abundance and translation in a wide range of contexts including the establishment of …

Picalm Alzheimer’S Risk Allele Causes Aberrant Lipid Droplets In Microglia, Alena Kozlova, Siwei Zhang, Ari Sudwarts, Hanwen Zhang, Stanislau Smirnou, Seul Kee Byeon, Christina Thapa, Xiaotong Sun, Kimberley Stephenson, Xiaojie Zhao, Brendan Jamison, Moorthi Ponnusamy, Xin He, Julie A Schneider, Akhilesh Pandey, David A Bennett, Zhiping P Pang, Alan R Sanders, Hugo J Bellen, Gopal Thinakaran, Jubao Duan

Faculty, Staff and Students Publications

Despite genome-wide association studies (GWAS) of late-onset Alzheimer’s disease (LOAD) having identified many genetic risk loci1–3, the underlying disease mechanisms remain largely unclear. Determining causal disease variants and their LOAD-relevant cellular phenotypes has been a challenge. Here, using our approach for identifying functional GWAS risk variants showing allele-specific open chromatin, we systematically identified putative causal LOAD-risk variants in human induced pluripotent stem (iPS)-cell-derived neurons, astrocytes and microglia, and linked a PICALM LOAD-risk allele to a microglial-specific role of PICALM in lipid droplet (LD) accumulation. Allele-specific open-chromatin mapping revealed functional risk variants for 26 LOAD-risk loci, mostly …

Gene Model For The Ortholog Of Glys In Drosophila Simulans, Madeline L. Gruys, Madison A. Sharp, Zachary Lill, Caroline Xiong, Amy T. Hark, James J. Youngblom, Chinmay P. Rele, Laura K. Reed

Faculty Journal Articles

Gene model for the ortholog of glycogen synthase ( Glys ) in the Drosophila simulans May 2017 (Princeton ASM75419v2/DsimGB2) Genome Assembly (GenBank Accession: GCA_000754195.3 ). This ortholog was characterized as part of a developing dataset to study the evolution of the Insulin/insulin-like growth factor signaling pathway (IIS) across the genus Drosophila using the Genomics Education Partnership gene annotation protocol for Course-based Undergraduate Research Experiences.

Homozygous Missense Variants In Ykt6 Result In Loss Of Function And Are Associated With Developmental Delay, With Or Without Severe Infantile Liver Disease And Risk For Hepatocellular Carcinoma, Mengqi Ma, Mythily Ganapathi, Yiming Zheng, Kai-Li Tan, Oguz Kanca, Kevin E Bove, Norma Quintanilla, Sebnem O Sag, Sehime G Temel, Charles A Leduc, Amanda J Mcpartland, Elaine M Pereira, Yufeng Shen, Jacob Hagen, Christie P Thomas, Nhu Thao Nguyen Galván, Xueyang Pan, Shenzhao Lu, Jill A Rosenfeld, Daniel G Calame, Michael F Wangler, James R Lupski, Davut Pehlivan, Paula M Hertel, Wendy K Chung, Hugo J Bellen

Faculty, Staff and Students Publications

PURPOSE: YKT6 plays important roles in multiple intracellular vesicle trafficking events but has not been associated with Mendelian diseases.

METHODS: We report 3 unrelated individuals with rare homozygous missense variants in YKT6 who exhibited neurological disease with or without a progressive infantile liver disease. We modeled the variants in Drosophila. We generated wild-type and variant genomic rescue constructs of the fly ortholog dYkt6 and compared their ability in rescuing the loss-of-function phenotypes in mutant flies. We also generated a dYkt6

RESULTS: Two individuals are homozygous for YKT6 [NM_006555.3:c.554A>G p.(Tyr185Cys)] and exhibited normal prenatal course followed by failure to thrive, …

A Single Cell Rna Sequence Atlas Of The Early Drosophila Larval Eye, Komal Kumar Bollepogu Raja, Kelvin Yeung, Yumei Li, Rui Chen, Graeme Mardon

Faculty, Staff and Students Publications

The Drosophila eye has been an important model to understand principles of differentiation, proliferation, apoptosis and tissue morphogenesis. However, a single cell RNA sequence resource that captures gene expression dynamics from the initiation of differentiation to the specification of different cell types in the larval eye disc is lacking. Here, we report transcriptomic data from 13,000 cells that cover six developmental stages of the larval eye. Our data show cell clusters that correspond to all major cell types present in the eye disc ranging from the initiation of the morphogenetic furrow to the differentiation of each photoreceptor cell type as …

Screen For Beneficial Genetic And Chemical Modifiers In Drosophila Models Of Als And Traumatic Brain Injury, Will Bonderer

Biological Sciences Theses and Dissertations

The underlying molecular processes of aberrant protein expression in neurodegeneration are intricate and multifaceted, with ribosome-associated quality control (RQC) emerging as a promising avenue of exploration. Ribosome-associated quality control is integral to cellular function. Its evolutionarily conserved pathway encompasses a network of mechanisms designed to ensure the fidelity of protein synthesis, folding, and degradation within the cells of all eukaryotes. The ribosome, central to protein synthesis, plays a pivotal role in this quality control network, and its malfunction can lead to the accumulation of misfolded or aberrant proteins. In the context of neurodegenerative disorders, this dysfunction can have dire consequences. …

Identifying Key Evolving Residues That Drive Cid/Cal1 Incompatibility In Drosophila Species, Hayden Yuan, Barbara Mellone

Honors Scholar Theses

The centromere, an essential locus on the chromosome critically important for faithful chromosome segregation during cell division, requires the incorporation of centromere protein A (CENP-A/CID) orchestrated by the chaperone CAL1. This thesis investigates the structural requirements governing the interaction between CAL1 and CID, with a focus on two diverged Drosophila species. Using a combination of structural analysis prediction and cellular assays, I explored the compatibility between the N-terminal region of CAL1 and the L1 domain of CID. Previous results demonstrate species specific interactions between CAL1 and CID, with endogenous Drosophila melanogaster (mel) CAL1 efficiently depositing Drosophila melanogaster CID …

Regulation Of Intracellular Sorting Of The Bruno Protein In Drosophila Flight Muscles, Travis Main

Master's Theses

Understanding mechanisms of intracellular sorting is a fundamental inquiry of cell biology. We used the B-body and protein Bruno (Bru) as a model to study the formation of nuclear domains that are membraneless organelles inside the cell nucleus. Specifically, we sought to identify protein sequences that regulate Bru's affinity to B-bodies and protein aggregation. We generated various Bru mutants and subsequently tested them in vivo using fluorescence microscopy. We found that the protein solubility of Bru is determined through an interplay of RNA recognition motifs (RRMs) and intrinsically disordered regions (IDRs). Using truncation analysis, we identified a 31-amino acid region …

The Anti-Diabetic Drug Metformin Disrupts Feeding And Sleeping Behaviors In Drosophila Melanogaster., Lucas Fitzgerald

College of Arts & Sciences Senior Theses

Dimethylbiguanide, also known as metformin, is the single most prescribed oral treatment for non-insulin dependent diabetes mellitus, or type 2 diabetes, in Western countries. The primary mechanism of action that metformin acts through is the activation of AMP kinase, an important regulator of energy homeostasis. While the anti-diabetic effects of metformin are well documented, its effects on feeding and sleeping behaviors are not well characterized. Using the model organism Drosophila melanogaster, the mean daily quantity of food consumed was measured and compared between groups treated with several dosages of metformin. Feeding interactions such as meal frequency and length were …

Cdk8/Cdk19 Promotes Mitochondrial Fission Through Drp1 Phosphorylation And Can Phenotypically Suppress Pink1 Deficiency In Drosophila, Jenny Zhe Liao, Hyung-Lok Chung, Claire Shih, Kenneth Kin Lam Wong, Debdeep Dutta, Zelha Nil, Catherine Grace Burns, Oguz Kanca, Ye-Jin Park, Zhongyuan Zuo, Paul C Marcogliese, Katherine Sew, Hugo J Bellen, Esther M Verheyen

Faculty, Staff and Students Publications

Cdk8 in Drosophila is the orthologue of vertebrate CDK8 and CDK19. These proteins have been shown to modulate transcriptional control by RNA polymerase II. We found that neuronal loss of Cdk8 severely reduces fly lifespan and causes bang sensitivity. Remarkably, these defects can be rescued by expression of human CDK19, found in the cytoplasm of neurons, suggesting a non-nuclear function of CDK19/Cdk8. Here we show that Cdk8 plays a critical role in the cytoplasm, with its loss causing elongated mitochondria in both muscles and neurons. We find that endogenous GFP-tagged Cdk8 can be found in both the cytoplasm and nucleus. …

De Novo Variants In Fryl Are Associated With Developmental Delay, Intellectual Disability, And Dysmorphic Features, Xueyang Pan, Alice M Tao, Shenzhao Lu, Mengqi Ma, Shabab B Hannan, Rachel Slaugh, Sarah Drewes Williams, Lauren O'Grady, Oguz Kanca, Richard Person, Melissa T Carter, Konrad Platzer, Franziska Schnabel, Rami Abou Jamra, Amy E Roberts, Jane W Newburger, Anya Revah-Politi, Jorge L Granadillo, Alexander P A Stegmann, Margje Sinnema, Andrea Accogli, Vincenzo Salpietro, Valeria Capra, Lina Ghaloul-Gonzalez, Martina Brueckner, Marleen E H Simon, David A Sweetser, Kevin E Glinton, Susan E Kirk, Baylor College Of Medicine Center For Precision Medicine Models, Michael F Wangler, Shinya Yamamoto, Wendy K Chung, Hugo J Bellen

Faculty, Staff and Students Publications

FRY-like transcription coactivator (FRYL) belongs to a Furry protein family that is evolutionarily conserved from yeast to humans. The functions of FRYL in mammals are largely unknown, and variants in FRYL have not previously been associated with a Mendelian disease. Here, we report fourteen individuals with heterozygous variants in FRYL who present with developmental delay, intellectual disability, dysmorphic features, and other congenital anomalies in multiple systems. The variants are confirmed de novo in all individuals except one. Human genetic data suggest that FRYL is intolerant to loss of function (LoF). We find that the fly FRYL ortholog, furry (fry), is …

Identifying Potential Dietary Treatments For Inherited Metabolic Disorders Using Drosophila Nutrigenomics, Felipe Martelli, Jiayi Lin, Sarah Mele, Wendy Imlach, Oguz Kanca, Christopher K Barlow, Jefferson Paril, Ralf B Schittenhelm, John Christodoulou, Hugo J Bellen, Matthew D W Piper, Travis K Johnson

Faculty, Staff and Students Publications

Inherited metabolic disorders are a group of genetic conditions that can cause severe neurological impairment and child mortality. Uniquely, these disorders respond to dietary treatment; however, this option remains largely unexplored because of low disorder prevalence and the lack of a suitable paradigm for testing diets. Here, we screened 35 Drosophila amino acid disorder models for disease-diet interactions and found 26 with diet-altered development and/or survival. Using a targeted multi-nutrient array, we examine the interaction in a model of isolated sulfite oxidase deficiency, an infant-lethal disorder. We show that dietary cysteine depletion normalizes their metabolic profile and rescues development, neurophysiology, …

Loss Of The Endoplasmic Reticulum Protein Tmem208 Affects Cell Polarity, Development, And Viability, Debdeep Dutta, Oguz Kanca, Rishi V Shridharan, Paul C Marcogliese, Benjamin Steger, Marie Morimoto, F Graeme Frost, Ellen Macnamara, Michael F Wangler, Shinya Yamamoto, Andreas Jenny, David Adams, May C Malicdan, Hugo J Bellen

Faculty, Staff and Students Publications

Nascent proteins destined for the cell membrane and the secretory pathway are targeted to the endoplasmic reticulum (ER) either posttranslationally or cotranslationally. The signal-independent pathway, containing the protein TMEM208, is one of three pathways that facilitates the translocation of nascent proteins into the ER. The in vivo function of this protein is ill characterized in multicellular organisms. Here, we generated a CRISPR-induced null allele of the fruit fly ortholog

A Zika Virus Protein Expression Screen In Drosophila To Investigate Targeted Host Pathways During Development, Nichole Link, J Michael Harnish, Brooke Hull, Shelley Gibson, Miranda Dietze, Uchechukwu E Mgbike, Silvia Medina-Balcazar, Priya S Shah, Shinya Yamamoto

Faculty, Staff and Students Publications

In the past decade, Zika virus (ZIKV) emerged as a global public health concern. Although adult infections are typically mild, maternal infection can lead to adverse fetal outcomes. Understanding how ZIKV proteins disrupt development can provide insights into the molecular mechanisms of disease caused by this virus, which includes microcephaly. In this study, we generated a toolkit to ectopically express ZIKV proteins in vivo in Drosophila melanogaster in a tissue-specific manner using the GAL4/UAS system. We used this toolkit to identify phenotypes and potential host pathways targeted by the virus. Our work identified that expression of most ZIKV proteins caused …

Integrative Genomic Analyses Reveal Putative Cell Type-Specific Targets Of The Drosophila Ets Transcription Factor Pointed, Komal Kumar Bollepogu Raja, Kelvin Yeung, Yoon-Kyung Shim, Graeme Mardon

Faculty, Staff and Students Publications

The Ets domain transcription factors direct diverse biological processes throughout all metazoans and are implicated in development as well as in tumor initiation, progression and metastasis. The Drosophila Ets transcription factor Pointed (Pnt) is the downstream effector of the Epidermal growth factor receptor (Egfr) pathway and is required for cell cycle progression, specification, and differentiation of most cell types in the larval eye disc. Despite its critical role in development, very few targets of Pnt have been reported previously. Here, we employed an integrated approach by combining genome-wide single cell and bulk data to identify putative cell type-specific Pnt targets. …

A Syndromic Neurodevelopmental Disorder Caused By Rare Variants In Ppfia3, Maimuna S Paul, Sydney L Michener, Hongling Pan, Hiuling Chan, Jessica M Pfliger, Jill A Rosenfeld, Vanesa C Lerma, Alyssa Tran, Megan A Longley, Richard A Lewis, Monika Weisz-Hubshman, Mir Reza Bekheirnia, Nasim Bekheirnia, Lauren Massingham, Michael Zech, Matias Wagner, Hartmut Engels, Kirsten Cremer, Elisabeth Mangold, Sophia Peters, Jessica Trautmann, Jessica L Mester, Maria J Guillen Sacoto, Richard Person, Pamela P Mcdonnell, Stacey R Cohen, Laina Lusk, Ana S A Cohen, Jean-Baptiste Le Pichon, Tomi Pastinen, Dihong Zhou, Kendra Engleman, Caroline Racine, Laurence Faivre, Sébastien Moutton, Anne-Sophie Denommé-Pichon, Hyun Yong Koh, Annapurna Poduri, Jeffrey Bolton, Cordula Knopp, Dong Sun Julia Suh, Andrea Maier, Mehran Beiraghi Toosi, Ehsan Ghayoor Karimiani, Reza Maroofian, Gerald Bradley Schaefer, Vijayalakshmi Ramakumaran, Pradeep Vasudevan, Chitra Prasad, Matthew Osmond, Sarah Schuhmann, Georgia Vasileiou, Sophie Russ-Hall, Ingrid E Scheffer, Gemma L Carvill, Heather Mefford, Undiagnosed Diseases Network, Carlos A Bacino, Brendan H Lee, Hsiao-Tuan Chao

Faculty, Staff and Students Publications

PPFIA3 encodes the protein-tyrosine phosphatase, receptor-type, F-polypeptide-interacting-protein-alpha-3 (PPFIA3), which is a member of the LAR-protein-tyrosine phosphatase-interacting-protein (liprin) family involved in synapse formation and function, synaptic vesicle transport, and presynaptic active zone assembly. The protein structure and function are evolutionarily well conserved, but human diseases related to PPFIA3 dysfunction are not yet reported in OMIM. Here, we report 20 individuals with rare PPFIA3 variants (19 heterozygous and 1 compound heterozygous) presenting with developmental delay, intellectual disability, hypotonia, dysmorphisms, microcephaly or macrocephaly, autistic features, and epilepsy with reduced penetrance. Seventeen unique PPFIA3 variants were detected in 18 families. To determine the pathogenicity …

Comparative Exploration Of Mammalian Deafness Gene Homologues In The Drosophila Auditory Organ Shows Genetic Correlation Between Insect And Vertebrate Hearing, Daniel C Sutton, Jonathan C Andrews, Dylan M Dolezal, Ye Jin Park, Hongjie Li, Daniel F Eberl, Shinya Yamamoto, Andrew K Groves

Faculty, Staff and Students Publications

Johnston's organ, the Drosophila auditory organ, is anatomically very different from the mammalian organ of Corti. However, recent evidence indicates significant cellular and molecular similarities exist between vertebrate and invertebrate hearing, suggesting that Drosophila may be a useful platform to determine the function of the many mammalian deafness genes whose underlying biological mechanisms are poorly characterized. Our goal was a comprehensive screen of all known orthologues of mammalian deafness genes in the fruit fly to better understand conservation of hearing mechanisms between the insect and the fly and ultimately gain insight into human hereditary deafness. We used bioinformatic comparisons to …

Allelic Strengths Of Encephalopathy-Associated Uba5 Variants Correlate Between In Vivo And In Vitro Assays, Xueyang Pan, Albert N Alvarez, Mengqi Ma, Shenzhao Lu, Michael W Crawford, Lauren C Briere, Oguz Kanca, Shinya Yamamoto, David A Sweetser, Jenny L Wilson, Ruth J Napier, Jonathan N Pruneda, Hugo J Bellen

Faculty, Staff and Students Publications

Protein UFMylation downstream of the E1 enzyme UBA5 plays essential roles in development and endoplasmic reticulum stress. Variants in the UBA5 gene are associated with developmental and epileptic encephalopathy 44 (DEE44), an autosomal recessive disorder characterized by early-onset encephalopathy, movement abnormalities, global developmental delay, intellectual disability, and seizures. DEE44 is caused by at least 12 different missense variants described as loss of function (LoF), but the relationships between genotypes and molecular or clinical phenotypes remain to be established. We developed a humanized UBA5 fly model and biochemical activity assays in order to describe in vivo and in vitro genotype–phenotype relationships …

A Single Cell Genomics Atlas Of The Drosophila Larval Eye Reveals Distinct Photoreceptor Developmental Timelines, Komal Kumar Bollepogu Raja, Kelvin Yeung, Yoon-Kyung Shim, Yumei Li, Rui Chen, Graeme Mardon

Faculty, Staff and Students Publications

The Drosophila eye is a powerful model system to study the dynamics of cell differentiation, cell state transitions, cell maturation, and pattern formation. However, a high-resolution single cell genomics resource that accurately profiles all major cell types of the larval eye disc and their spatiotemporal relationships is lacking. Here, we report transcriptomic and chromatin accessibility data for all known cell types in the developing eye. Photoreceptors appear as strands of cells that represent their dynamic developmental timelines. As photoreceptor subtypes mature, they appear to assume a common transcriptomic profile that is dominated by genes involved in axon function. We identify …

Rare De Novo Gain-Of-Function Missense Variants In Dot1l Are Associated With Developmental Delay And Congenital Anomalies, Zelha Nil, Ashish R Deshwar, Yan Huang, Scott Barish, Xi Zhang, Sanaa Choufani, Polona Le Quesne Stabej, Ian Hayes, Patrick Yap, Chad Haldeman-Englert, Carolyn Wilson, Trine Prescott, Kristian Tveten, Arve Vøllo, Devon Haynes, Patricia G Wheeler, Jessica Zon, Cheryl Cytrynbaum, Rebekah Jobling, Moira Blyth, Siddharth Banka, Alexandra Afenjar, Cyril Mignot, Florence Robin-Renaldo, Boris Keren, Oguz Kanca, Xiao Mao, Daniel J Wegner, Kathleen Sisco, Marwan Shinawi, Undiagnosed Disease Network, Michael F Wangler, Rosanna Weksberg, Shinya Yamamoto, Gregory Costain, Hugo J Bellen

Faculty, Staff and Students Publications

Misregulation of histone lysine methylation is associated with several human cancers and with human developmental disorders. DOT1L is an evolutionarily conserved gene encoding a lysine methyltransferase (KMT) that methylates histone 3 lysine-79 (H3K79) and was not previously associated with a Mendelian disease in OMIM. We have identified nine unrelated individuals with seven different de novo heterozygous missense variants in DOT1L through the Undiagnosed Disease Network (UDN), the SickKids Complex Care genomics project, and GeneMatcher. All probands had some degree of global developmental delay/intellectual disability, and most had one or more major congenital anomalies. To assess the pathogenicity of the DOT1L …

Biomechanical Origins Of Proprioceptor Feature Selectivity And Topographic Maps In The Drosophila Leg, Akira Mamiya, Anne Sustar, Igor Siwanowicz, Yanyan Qi, Tzu-Chiao Lu, Pralaksha Gurung, Chenghao Chen, Jasper S Phelps, Aaron T Kuan, Alexandra Pacureanu, Wei-Chung Allen Lee, Hongjie Li, Natasha Mhatre, John C Tuthill

Faculty, Staff and Students Publications

Our ability to sense and move our bodies relies on proprioceptors, sensory neurons that detect mechanical forces within the body. Different subtypes of proprioceptors detect different kinematic features, such as joint position, movement, and vibration, but the mechanisms that underlie proprioceptor feature selectivity remain poorly understood. Using single-nucleus RNA sequencing (RNA-seq), we found that proprioceptor subtypes in the Drosophila leg lack differential expression of mechanosensitive ion channels. However, anatomical reconstruction of the proprioceptors and connected tendons revealed major biomechanical differences between subtypes. We built a model of the proprioceptors and tendons that identified a biomechanical mechanism for joint angle selectivity …

Gut Barrier Defects, Intestinal Immune Hyperactivation And Enhanced Lipid Catabolism Drive Lethality In Ngly1-Deficient Drosophila, Ashutosh Pandey, Antonio Galeone, Seung Yeop Han, Benjamin A Story, Gaia Consonni, William F Mueller, Lars M Steinmetz, Thomas Vaccari, Hamed Jafar-Nejad

Faculty, Staff and Students Publications

Intestinal barrier dysfunction leads to inflammation and associated metabolic changes. However, the relative impact of gut bacteria versus non-bacterial insults on animal health in the context of barrier dysfunction is not well understood. Here, we establish that loss of Drosophila N-glycanase 1 (Pngl) in a specific intestinal cell type leads to gut barrier defects, causing starvation and JNK overactivation. These abnormalities, along with loss of Pngl in enterocytes and fat body, result in Foxo overactivation, leading to hyperactive innate immune response and lipid catabolism and thereby contributing to lethality. Germ-free rearing of Pngl mutants rescued their developmental delay but not …

A Defect In Mitochondrial Fatty Acid Synthesis Impairs Iron Metabolism And Causes Elevated Ceramide Levels, Debdeep Dutta, Oguz Kanca, Seul Kee Byeon, Paul C Marcogliese, Zhongyuan Zuo, Rishi V Shridharan, Jun Hyoung Park, Undiagnosed Diseases Networ, Guang Lin, Ming Ge, Gali Heimer, Jennefer N Kohler, Matthew T Wheeler, Benny A Kaipparettu, Akhilesh Pandey, Hugo J Bellen

Faculty, Staff and Students Publications

In most eukaryotic cells, fatty acid synthesis (FAS) occurs in the cytoplasm and in mitochondria. However, the relative contribution of mitochondrial FAS (mtFAS) to the cellular lipidome is not well defined. Here we show that loss of function of Drosophila mitochondrial enoyl coenzyme A reductase (Mecr), which is the enzyme required for the last step of mtFAS, causes lethality, while neuronal loss of Mecr leads to progressive neurodegeneration. We observe a defect in Fe-S cluster biogenesis and increased iron levels in flies lacking mecr, leading to elevated ceramide levels. Reducing the levels of either iron or ceramide suppresses the neurodegenerative …

A Comprehensive Drosophila Resource To Identify Key Functional Interactions Between Sars-Cov-2 Factors And Host Proteins, Annabel Guichard, Shenzhao Lu, Oguz Kanca, Daniel Bressan, Yan Huang, Mengqi Ma, Sara Sanz Juste, Jonathan C Andrews, Kristy L Jay, Marketta Sneider, Ruth Schwartz, Mei-Chu Huang, Danqing Bei, Hongling Pan, Liwen Ma, Wen-Wen Lin, Ankush Auradkar, Pranjali Bhagwat, Soo Park, Kenneth H Wan, Takashi Ohsako, Toshiyuki Takano-Shimizu, Susan E Celniker, Michael F Wangler, Shinya Yamamoto, Hugo J Bellen, Ethan Bier

Faculty, Staff and Students Publications

Development of effective therapies against SARS-CoV-2 infections relies on mechanistic knowledge of virus-host interface. Abundant physical interactions between viral and host proteins have been identified, but few have been functionally characterized. Harnessing the power of fly genetics, we develop a comprehensive Drosophila COVID-19 resource (DCR) consisting of publicly available strains for conditional tissue-specific expression of all SARS-CoV-2 encoded proteins, UAS-human cDNA transgenic lines encoding established host-viral interacting factors, and GAL4 insertion lines disrupting fly homologs of SARS-CoV-2 human interacting proteins. We demonstrate the utility of the DCR to functionally assess SARS-CoV-2 genes and candidate human binding partners. We show that …

A De Novo Missense Variant In Ezh1 Associated With Developmental Delay Exhibits Functional Deficits In Drosophila Melanogaster, Sharayu V Jangam, Lauren C Briere, Kristy L Jay, Jonathan C Andrews, Melissa A Walker, Lance H Rodan, Frances A High, Undiagnosed Diseases Network, Shinya Yamamoto, David A Sweetser, Michael F Wangler

Faculty, Staff and Students Publications

EZH1, a polycomb repressive complex-2 component, is involved in a myriad of cellular processes. EZH1 represses transcription of downstream target genes through histone 3 lysine27 (H3K27) trimethylation (H3K27me3). Genetic variants in histone modifiers have been associated with developmental disorders, while EZH1 has not yet been linked to any human disease. However, the paralog EZH2 is associated with Weaver syndrome. Here we report a previously undiagnosed individual with a novel neurodevelopmental phenotype identified to have a de novo missense variant in EZH1 through exome sequencing. The individual presented in infancy with neurodevelopmental delay and hypotonia and was later noted to have …

Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer

Dartmouth College Ph.D Dissertations

The evolutionarily conserved Wnt/Wingless signal transduction pathway is critical for the proper development of all animals and implicated in numerous diseases in adulthood. Upon binding of the Wnt/Wingless ligand, a cascade of events culminates in inactivation of the destruction complex, a negative regulator of the pathway, and the subsequent formation of singalosomes which mediate pathway activation. A critical component of signalosome formation is the Wnt/Wingless receptor LRP6/Arrow. Upon canonical pathway activation, LRP6/Arrow undergoes activation via phosphorylation by several kinases and complexes with another Wnt/Wingless receptor Frizzled, along with several cytoplasmic components. While many studies have investigated the regulatory mechanisms of …

The Voltage-Gated Sodium Channel In Drosophila, Para, Localizes To Dendrites As Well As Axons In Mechanosensitive Chordotonal Neurons, Thomas A Ravenscroft, Ashleigh Jacobs, Mingxue Gu, Daniel F Eberl, Hugo J Bellen

Faculty, Staff and Students Publications

The fruit fly Drosophila melanogaster has provided important insights into how sensory information is transduced by transient receptor potential (TRP) channels in the peripheral nervous system (PNS). However, TRP channels alone have not been able to completely model mechanosensitive transduction in mechanoreceptive chordotonal neurons (CNs). Here, we show that, in addition to TRP channels, the sole voltage-gated sodium channel (NaV) in Drosophila, Para, is localized to the dendrites of CNs. Para is localized to the distal tip of the dendrites in all CNs, from embryos to adults, and is colocalized with the mechanosensitive TRP channels No mechanoreceptor potential C …

Tau Polarizes An Aging Transcriptional Signature To Excitatory Neurons And Glia, Timothy Wu, Jennifer M Deger, Hui Ye, Caiwei Guo, Justin Dhindsa, Brandon T Pekarek, Rami Al-Ouran, Zhandong Liu, Ismael Al-Ramahi, Juan Botas, Joshua M Shulman

Faculty, Staff and Students Publications

Aging is a major risk factor for Alzheimer’s disease (AD), and cell-type vulnerability underlies its characteristic clinical manifestations. We have performed longitudinal, single-cell RNA-sequencing in Drosophila with pan-neuronal expression of human tau, which forms AD neurofibrillary tangle pathology. Whereas tau- and aging-induced gene expression strongly overlap (93%), they differ in the affected cell types. In contrast to the broad impact of aging, tau-triggered changes are strongly polarized to excitatory neurons and glia. Further, tau can either activate or suppress innate immune gene expression signatures in a cell-type-specific manner. Integration of cellular abundance and gene expression pinpoints nuclear factor kappa B …

Bi-Allelic Variants In Ints11 Are Associated With A Complex Neurological Disorder, Burak Tepe, Erica L Macke, Marcello Niceta, Monika Weisz Hubshman, Oguz Kanca, Laura Schultz-Rogers, Yuri A Zarate, G Bradley Schaefer, Jorge Luis Granadillo De Luque, Daniel J Wegner, Benjamin Cogne, Brigitte Gilbert-Dussardier, Xavier Le Guillou, Eric J Wagner, Lynn S Pais, Jennifer E Neil, Ganeshwaran H Mochida, Christopher A Walsh, Nurit Magal, Valerie Drasinover, Mordechai Shohat, Tanya Schwab, Chris Schmitz, Karl Clark, Anthony Fine, Brendan Lanpher, Ralitza Gavrilova, Pierre Blanc, Lydie Burglen, Alexandra Afenjar, Dora Steel, Manju A Kurian, Prab Prabhakar, Sophie Gößwein, Nataliya Di Donato, Enrico S Bertini, Undiagnosed Diseases Network, Michael F Wangler, Shinya Yamamoto, Marco Tartaglia, Eric W Klee, Hugo J Bellen

Faculty, Staff and Students Publications

The Integrator complex is a multi-subunit protein complex that regulates the processing of nascent RNAs transcribed by RNA polymerase II (RNAPII), including small nuclear RNAs, enhancer RNAs, telomeric RNAs, viral RNAs, and protein-coding mRNAs. Integrator subunit 11 (INTS11) is the catalytic subunit that cleaves nascent RNAs, but, to date, mutations in this subunit have not been linked to human disease. Here, we describe 15 individuals from 10 unrelated families with bi-allelic variants in INTS11 who present with global developmental and language delay, intellectual disability, impaired motor development, and brain atrophy. Consistent with human observations, we find that the fly ortholog …