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Yasuhara J, Manivannan SN, Majumdar U, Gordon DM, Lawrence PJ, Aljuhani M, Myers K, Stiver C, Bigelow AM, Galantowicz M, Yamagishi H, McBride KL, White P, Garg V. Novel pathogenic GATA6 variant associated with congenital heart disease, diabetes mellitus and necrotizing enterocolitis. Pediatr Res 2024; 95:146-155. [PMID: 37700164 DOI: 10.1038/s41390-023-02811-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/11/2023] [Accepted: 08/21/2023] [Indexed: 09/14/2023]
Abstract
BACKGROUND Pathogenic GATA6 variants have been associated with congenital heart disease (CHD) and a spectrum of extracardiac abnormalities, including pancreatic agenesis, congenital diaphragmatic hernia, and developmental delay. However, the comprehensive genotype-phenotype correlation of pathogenic GATA6 variation in humans remains to be fully understood. METHODS Exome sequencing was performed in a family where four members had CHD. In vitro functional analysis of the GATA6 variant was performed using immunofluorescence, western blot, and dual-luciferase reporter assay. RESULTS A novel, heterozygous missense variant in GATA6 (c.1403 G > A; p.Cys468Tyr) segregated with affected members in a family with CHD, including three with persistent truncus arteriosus. In addition, one member had childhood onset diabetes mellitus (DM), and another had necrotizing enterocolitis (NEC) with intestinal perforation. The p.Cys468Tyr variant was located in the c-terminal zinc finger domain encoded by exon 4. The mutant protein demonstrated an abnormal nuclear localization pattern with protein aggregation and decreased transcriptional activity. CONCLUSIONS We report a novel, familial GATA6 likely pathogenic variant associated with CHD, DM, and NEC with intestinal perforation. These findings expand the phenotypic spectrum of pathologic GATA6 variation to include intestinal abnormalities. IMPACT Exome sequencing identified a novel heterozygous GATA6 variant (p.Cys468Tyr) that segregated in a family with CHD including persistent truncus arteriosus, atrial septal defects and bicuspid aortic valve. Additionally, affected members displayed extracardiac findings including childhood-onset diabetes mellitus, and uniquely, necrotizing enterocolitis with intestinal perforation in the first four days of life. In vitro functional assays demonstrated that GATA6 p.Cys468Tyr variant leads to cellular localization defects and decreased transactivation activity. This work supports the importance of GATA6 as a causative gene for CHD and expands the phenotypic spectrum of pathogenic GATA6 variation, highlighting neonatal intestinal perforation as a novel extracardiac phenotype.
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Affiliation(s)
- Jun Yasuhara
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - Sathiya N Manivannan
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - Uddalak Majumdar
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - David M Gordon
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Patrick J Lawrence
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Mona Aljuhani
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - Katherine Myers
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - Corey Stiver
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Amee M Bigelow
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Mark Galantowicz
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
| | - Hiroyuki Yamagishi
- Division of Pediatric Cardiology, Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Kim L McBride
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
- Division of Genetic and Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
| | - Peter White
- Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Vidu Garg
- Center for Cardiovascular Research, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA.
- The Heart Center, Nationwide Children's Hospital, Columbus, OH, USA.
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA.
- Department of Molecular Genetics, The Ohio State University, Columbus, OH, USA.
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2
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Manivannan SN, Roovers J, Smal N, Myers CT, Turkdogan D, Roelens F, Kanca O, Chung HL, Scholz T, Hermann K, Bierhals T, Caglayan HS, Stamberger H, Mefford H, de Jonghe P, Yamamoto S, Weckhuysen S, Bellen HJ. De novo FZR1 loss-of-function variants cause developmental and epileptic encephalopathies. Brain 2022; 145:1684-1697. [PMID: 34788397 PMCID: PMC9166542 DOI: 10.1093/brain/awab409] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/21/2021] [Accepted: 10/18/2021] [Indexed: 01/18/2023] Open
Abstract
FZR1, which encodes the Cdh1 subunit of the anaphase-promoting complex, plays an important role in neurodevelopment by regulating the cell cycle and by its multiple post-mitotic functions in neurons. In this study, evaluation of 250 unrelated patients with developmental and epileptic encephalopathies and a connection on GeneMatcher led to the identification of three de novo missense variants in FZR1. Whole-exome sequencing in 39 patient-parent trios and subsequent targeted sequencing in an additional cohort of 211 patients was performed to identify novel genes involved in developmental and epileptic encephalopathy. Functional studies in Drosophila were performed using three different mutant alleles of the Drosophila homologue of FZR1 fzr. All three individuals carrying de novo variants in FZR1 had childhood-onset generalized epilepsy, intellectual disability, mild ataxia and normal head circumference. Two individuals were diagnosed with the developmental and epileptic encephalopathy subtype myoclonic atonic epilepsy. We provide genetic-association testing using two independent statistical tests to support FZR1 association with developmental and epileptic encephalopathies. Further, we provide functional evidence that the missense variants are loss-of-function alleles using Drosophila neurodevelopment assays. Using three fly mutant alleles of the Drosophila homologue fzr and overexpression studies, we show that patient variants can affect proper neurodevelopment. With the recent report of a patient with neonatal-onset with microcephaly who also carries a de novo FZR1 missense variant, our study consolidates the relationship between FZR1 and developmental and epileptic encephalopathy and expands the associated phenotype. We conclude that heterozygous loss-of-function of FZR1 leads to developmental and epileptic encephalopathies associated with a spectrum of neonatal to childhood-onset seizure types, developmental delay and mild ataxia. Microcephaly can be present but is not an essential feature of FZR1-encephalopathy. In summary, our approach of targeted sequencing using novel gene candidates and functional testing in Drosophila will help solve undiagnosed myoclonic atonic epilepsy or developmental and epileptic encephalopathy cases.
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Affiliation(s)
- Sathiya N Manivannan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston 77030, USA
| | - Jolien Roovers
- Neurogenetics Group, VIB Centre for Molecular Neurology, Antwerp 2610, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium
| | - Noor Smal
- Applied and Translational Neurogenomics Group, VIB Centre for Molecular Neurology, VIB, Antwerp 2610, Belgium
| | - Candace T Myers
- Center for Pediatric Neurological Disease Research, Department of Cell and Molecular Biology St. Jude Children's Research Hospital, Memphis, TN 30105, USA
| | - Dilsad Turkdogan
- Division of Child Neurology, Department of Paediatrics, Marmara University, Faculty of Medicine, Turkey
| | | | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston 77030, USA
| | - Hyung-Lok Chung
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston 77030, USA
| | - Tasja Scholz
- Institute of Human Genetics, University Medical Centre Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Katharina Hermann
- Department of Paediatrics, University Medical Centre Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Tatjana Bierhals
- Institute of Human Genetics, University Medical Centre Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Hande S Caglayan
- Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Turkey
| | - Hannah Stamberger
- Applied and Translational Neurogenomics Group, VIB Centre for Molecular Neurology, VIB, Antwerp 2610, Belgium.,Department of Neurology, University Hospital Antwerp, Antwerp 2650, Belgium
| | | | - Heather Mefford
- Center for Pediatric Neurological Disease Research, Department of Cell and Molecular Biology St. Jude Children's Research Hospital, Memphis, TN 30105, USA
| | - Peter de Jonghe
- Neurogenetics Group, VIB Centre for Molecular Neurology, Antwerp 2610, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp 2610, Belgium.,Department of Neurology, University Hospital Antwerp, Antwerp 2650, Belgium
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Sarah Weckhuysen
- Applied and Translational Neurogenomics Group, VIB Centre for Molecular Neurology, VIB, Antwerp 2610, Belgium.,Department of Neurology, University Hospital Antwerp, Antwerp 2650, Belgium.,Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp 2650, Belgium.,µNEURO Research Centre of Excellence, University of Antwerp, Antwerp 2610, Belgium
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.,Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA
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3
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Marcogliese PC, Deal SL, Andrews J, Harnish JM, Bhavana VH, Graves HK, Jangam S, Luo X, Liu N, Bei D, Chao YH, Hull B, Lee PT, Pan H, Bhadane P, Huang MC, Longley CM, Chao HT, Chung HL, Haelterman NA, Kanca O, Manivannan SN, Rossetti LZ, German RJ, Gerard A, Schwaibold EMC, Fehr S, Guerrini R, Vetro A, England E, Murali CN, Barakat TS, van Dooren MF, Wilke M, van Slegtenhorst M, Lesca G, Sabatier I, Chatron N, Brownstein CA, Madden JA, Agrawal PB, Keren B, Courtin T, Perrin L, Brugger M, Roser T, Leiz S, Mau-Them FT, Delanne J, Sukarova-Angelovska E, Trajkova S, Rosenhahn E, Strehlow V, Platzer K, Keller R, Pavinato L, Brusco A, Rosenfeld JA, Marom R, Wangler MF, Yamamoto S. Drosophila functional screening of de novo variants in autism uncovers damaging variants and facilitates discovery of rare neurodevelopmental diseases. Cell Rep 2022; 38:110517. [PMID: 35294868 PMCID: PMC8983390 DOI: 10.1016/j.celrep.2022.110517] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 09/23/2021] [Accepted: 02/18/2022] [Indexed: 12/30/2022] Open
Abstract
Individuals with autism spectrum disorder (ASD) exhibit an increased burden of de novo mutations (DNMs) in a broadening range of genes. While these studies have implicated hundreds of genes in ASD pathogenesis, which DNMs cause functional consequences in vivo remains unclear. We functionally test the effects of ASD missense DNMs using Drosophila through "humanization" rescue and overexpression-based strategies. We examine 79 ASD variants in 74 genes identified in the Simons Simplex Collection and find 38% of them to cause functional alterations. Moreover, we identify GLRA2 as the cause of a spectrum of neurodevelopmental phenotypes beyond ASD in 13 previously undiagnosed subjects. Functional characterization of variants in ASD candidate genes points to conserved neurobiological mechanisms and facilitates gene discovery for rare neurodevelopmental diseases.
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Affiliation(s)
- Paul C Marcogliese
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Samantha L Deal
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Program in Developmental Biology, BCM, Houston, TX 77030, USA
| | - Jonathan Andrews
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - J Michael Harnish
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - V Hemanjani Bhavana
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Hillary K Graves
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Sharayu Jangam
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Xi Luo
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Department of Pediatrics, Division of Hematology/Oncology, BCM, Houston, TX 77030, USA
| | - Ning Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Baylor Genetics Laboratories, Houston, TX 77021, USA
| | - Danqing Bei
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Yu-Hsin Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Brooke Hull
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Pei-Tseng Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Hongling Pan
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Pradnya Bhadane
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Mei-Chu Huang
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Colleen M Longley
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Program in Developmental Biology, BCM, Houston, TX 77030, USA
| | - Hsiao-Tuan Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Department of Pediatrics, Division of Neurology and Developmental Neuroscience, BCM, Houston, TX 77030, USA; Department of Neuroscience, BCM, Houston, TX 77030, USA; McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX 77030, USA; TCH, Houston, TX 77030, USA; Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX 77030, USA
| | - Hyung-Lok Chung
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Howard Hughes Medical Institute, Houston, TX 77030, USA
| | - Nele A Haelterman
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Sathiya N Manivannan
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Linda Z Rossetti
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA
| | - Ryan J German
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA
| | - Amanda Gerard
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; TCH, Houston, TX 77030, USA
| | | | - Sarah Fehr
- Praxis für Humangenetik Tübingen, Tübingen, Germany
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Meyer-University of Florence, Florence, Italy
| | - Annalisa Vetro
- Neuroscience Department, Children's Hospital Meyer-University of Florence, Florence, Italy
| | - Eleina England
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Chaya N Murali
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; TCH, Houston, TX 77030, USA
| | - Tahsin Stefan Barakat
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Marieke F van Dooren
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Martina Wilke
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Marjon van Slegtenhorst
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Gaetan Lesca
- Department of Medical Genetics, Lyon University Hospital, Université Claude Bernard Lyon 1, Lyon, France; Institut NeuroMyoGène, CNRS UMR 5310 - INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | - Isabelle Sabatier
- Department of Pediatric Neurology, Lyon University Hospitals, Lyon, France
| | - Nicolas Chatron
- Department of Medical Genetics, Lyon University Hospital, Université Claude Bernard Lyon 1, Lyon, France; Institut NeuroMyoGène, CNRS UMR 5310 - INSERM U1217, Université Claude Bernard Lyon 1, Lyon, France
| | - Catherine A Brownstein
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA
| | - Jill A Madden
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Pankaj B Agrawal
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Division of Newborn Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Boris Keren
- Genetic Department, Pitié-Salpêtrière Hospital, APHP.Sorbonne Université, Paris 75013, France
| | - Thomas Courtin
- Genetic Department, Pitié-Salpêtrière Hospital, APHP.Sorbonne Université, Paris 75013, France
| | - Laurence Perrin
- Genetic Department, Robert Debré Hospital, APHP.Nord-Université de Paris, Paris 75019, France
| | - Melanie Brugger
- Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Timo Roser
- Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Department of Pediatrics, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, Lindwurmstraße 4, 80337 Munich, Germany
| | - Steffen Leiz
- Department of Pediatrics and Adolescent Medicine, Hospital Dritter Orden, Munich, Germany
| | - Frederic Tran Mau-Them
- INSERM U1231, LNC UMR1231 GAD, Burgundy University, 21000 Dijon, France; Laboratoire de Génétique, Innovation en Diagnostic Génomique des Maladies Rares UF6254, Plateau Technique de Biologie, CHU Dijon, 14 Rue Paul Gaffarel, BP 77908, 21079 Dijon, France
| | - Julian Delanne
- INSERM U1231, LNC UMR1231 GAD, Burgundy University, 21000 Dijon, France
| | - Elena Sukarova-Angelovska
- Department of Endocrinology and Genetics, University Clinic for Children's Diseases, Medical Faculty, University Sv. Kiril i Metodij, Skopje, Republic of Macedonia
| | - Slavica Trajkova
- Department of Medical Sciences, University of Torino, Turin, Italy
| | - Erik Rosenhahn
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Vincent Strehlow
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Roberto Keller
- Adult Autism Center, Mental Health Department, Health Unit ASL Città di Torino, Turin, Italy
| | - Lisa Pavinato
- Department of Medical Sciences, University of Torino, Turin, Italy; Institute of Human Genetics and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, Turin, Italy; Medical Genetics Unit, Città della Salute e della Scienza, University Hospital, Turin, Italy
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Baylor Genetics Laboratories, Houston, TX 77021, USA
| | - Ronit Marom
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; TCH, Houston, TX 77030, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; TCH, Houston, TX 77030, USA; Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX 77030, USA.
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital (TCH), Houston, TX 77030, USA; Program in Developmental Biology, BCM, Houston, TX 77030, USA; Department of Neuroscience, BCM, Houston, TX 77030, USA; Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX 77030, USA.
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4
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Manivannan SN, Darouich S, Masmoudi A, Gordon D, Zender G, Han Z, Fitzgerald-Butt S, White P, McBride KL, Kharrat M, Garg V. Novel frameshift variant in MYL2 reveals molecular differences between dominant and recessive forms of hypertrophic cardiomyopathy. PLoS Genet 2020; 16:e1008639. [PMID: 32453731 PMCID: PMC7274480 DOI: 10.1371/journal.pgen.1008639] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 06/05/2020] [Accepted: 01/29/2020] [Indexed: 12/18/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is characterized by thickening of the ventricular muscle without dilation and is often associated with dominant pathogenic variants in cardiac sarcomeric protein genes. Here, we report a family with two infants diagnosed with infantile-onset HCM and mitral valve dysplasia that led to death before one year of age. Using exome sequencing, we discovered that one of the affected children had a homozygous frameshift variant in Myosin light chain 2 (MYL2:NM_000432.3:c.431_432delCT: p.Pro144Argfs*57;MYL2-fs), which alters the last 20 amino acids of the protein and is predicted to impact the most C-terminal of the three EF-hand domains in MYL2. The parents are unaffected heterozygous carriers of the variant and the variant is absent in control cohorts from gnomAD. The absence of the phenotype in carriers and the infantile presentation of severe HCM is in contrast to HCM associated with dominant MYL2 variants. Immunohistochemical analysis of the ventricular muscle of the deceased patient with the MYL2-fs variant showed a marked reduction of MYL2 expression compared to an unaffected control. In vitro overexpression studies further indicate that the MYL2-fs variant is actively degraded. In contrast, an HCM-associated missense variant (MYL2:p.Gly162Arg) and three other MYL2 stop-gain variants (p.E22*, p.K62*, p.E97*) that result in loss of the EF domains are stably expressed but show impaired localization. The degradation of the MYL2-fs can be rescued by inhibiting the cell’s proteasome function supporting a post-translational effect of the variant. In vivo rescue experiments with a Drosophila MYL2-homolog (Mlc2) knockdown model indicate that neither the MYL2-fs nor the MYL2:p.Gly162Arg variant supports normal cardiac function. The tools that we have generated provide a rapid screening platform for functional assessment of variants of unknown significance in MYL2. Our study supports an autosomal recessive model of inheritance for MYL2 loss-of-function variants in infantile HCM and highlights the variant-specific molecular differences found in MYL2-associated cardiomyopathy. We report a novel frameshift variant in MYL2 that is associated with a severe form of infantile-onset hypertrophic cardiomyopathy. The impact of the variant is only observed in the recessive form of the disease found in the proband and not in the parents who are carriers of the variant. This contrasts with other dominant variants in MYL2 that are associated with cardiomyopathies. We compared the stability of this variant to that of other cardiomyopathy associated MYL2 variants and found molecular differences that correlated with disease pathology. We also show different protein domain requirements for stability and localization of MYL2 in cardiomyocytes. Furthermore, we used a fly model to demonstrate functional deficits due to the variant in the developing heart. Overall, our study shows a molecular mechanism by which loss-of-function variants in MYL2 are recessive while missense variants are dominant. We highlight the use of exome sequencing and functional testing to assist in the diagnosis of rare forms of disease where pathogenicity of the variant is not obvious. The new tools we developed for in vitro functional study and the fly fluorescent reporter analysis will permit rapid analysis of MYL2 variants of unknown significance.
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Affiliation(s)
- Sathiya N. Manivannan
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Sihem Darouich
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Laboratory of Human Genetics, Tunis, Tunisia
- * E-mail: (SD); (VG)
| | - Aida Masmoudi
- University of Tunis El Manar, Faculty of Medicine of Tunis, Department of Embryo-Fetopathology, Maternity and Neonatology Center, Tunis, Tunisia
| | - David Gordon
- Institute for Genomic Medicine at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Gloria Zender
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Zhe Han
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sara Fitzgerald-Butt
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Peter White
- Institute for Genomic Medicine at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Kim L. McBride
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
| | - Maher Kharrat
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES10 Laboratory of Human Genetics, Tunis, Tunisia
| | - Vidu Garg
- Center for Cardiovascular Research, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Heart Center, Nationwide Children’s Hospital, Columbus, Ohio, United States of America
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (SD); (VG)
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5
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Abstract
Mosaic analysis in Drosophila, an important tool to assess cellular phenotypes of mutants in an otherwise heterozygous background, relies on mitosis. Hence, it cannot be used to inactivate gene function in mitotically inactive, terminally differentiated cells such as neurons. To address this issue, we developed "Flip-flop", a novel, Flippase-dependent in vivo cassette-inversion method that functions independent of mitosis, and therefore can be used for gene inactivation in both mitotic as well as postmitotic cells. This method allows tagging protein-coding genes with EGFP and generates mutant cells that are marked with mCherry upon cassette inversion. Here, we describe protocols for generation and validation of fly lines that can be used for conditional gene inactivation in mitotic as well as post-mitotic cells. We provide typical examples of Flip-flop mediated mosaic analysis in SNF4Aγ and Trim9. Use of Flip-flop mediated functional analysis will permit a detailed investigation of the role of genes previously recalcitrant to mosaic analysis.
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6
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Nagarkar-Jaiswal S, Manivannan SN, Zuo Z, Bellen HJ. A cell cycle-independent, conditional gene inactivation strategy for differentially tagging wild-type and mutant cells. eLife 2017; 6. [PMID: 28561736 PMCID: PMC5493436 DOI: 10.7554/elife.26420] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/25/2017] [Indexed: 12/14/2022] Open
Abstract
Here, we describe a novel method based on intronic MiMIC insertions described in Nagarkar-Jaiswal et al. (2015) to perform conditional gene inactivation in Drosophila. Mosaic analysis in Drosophila cannot be easily performed in post-mitotic cells. We therefore, therefore, developed Flip-Flop, a flippase-dependent in vivo cassette-inversion method that marks wild-type cells with the endogenous EGFP-tagged protein, whereas mutant cells are marked with mCherry upon inversion. We document the ease and usefulness of this strategy in differential tagging of wild-type and mutant cells in mosaics. We use this approach to phenotypically characterize the loss of SNF4Aγ, encoding the γ subunit of the AMP Kinase complex. The Flip-Flop method is efficient and reliable, and permits conditional gene inactivation based on both spatial and temporal cues, in a cell cycle-, and developmental stage-independent fashion, creating a platform for systematic screens of gene function in developing and adult flies with unprecedented detail. DOI:http://dx.doi.org/10.7554/eLife.26420.001 The instructions needed to build and maintain cells in an organism are encoded in their DNA. There are many different cell types, and each type only needs a small portion of the information found in the DNA to do its job. Hence, only some of the instructions, in the form of genes, need to be active or ‘expressed’ in any given cell type. To understand how a gene works, it is necessary to know in which cell the gene is expressed and where in the cell the gene product – normally a protein – is located. Researchers may study a gene by deleting it, which prevents the protein from being made, or by attaching a new instruction into the gene, which generates a fluorescent tag on the protein to determine where and when it is expressed. Until now, it was not possible to selectively inactivate a gene and simultaneously mark both normal cells containing the protein and mutant cells lacking the protein. Based on an existing tagging approach, Nagarkar-Jaiswal et al. have now developed a method in which normal and mutant cells of fruit flies are marked differently. A gene of interest is tagged with a fluorescent marker called green fluorescent protein (or GFP). The same gene is then inactivated in some of the cells, which are tagged with a red marker called mCherry. Nagarkar-Jaiswal et al. compared normal and mutant cells, and were able to determine how long it takes before the mutant cells become abnormal. With this new method, the role of numerous genes in any tissue of adult flies can be reassessed. This will allow to investigate what happens when a protein is removed in specific cells in adult flies. A future goal will be to apply this method to other animals that are more closely related to humans, such as mice, to gain a clearer picture of the role of genes in different cell types and how faulty genes may cause disease. DOI:http://dx.doi.org/10.7554/eLife.26420.002
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Affiliation(s)
| | - Sathiya N Manivannan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Hugo J Bellen
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States
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7
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Abstract
A long-standing problem with analyzing transgene expression in tissue-culture cells is the variation caused by random integration of different copy numbers of transfected transgenes. In mammalian cells, single transgenes can be inserted by homologous recombination but this process is inefficient in Drosophila cells. To tackle this problem, our group, and the Cherbas group, used recombination-mediated cassette exchange (RMCE) to introduce single-copy transgenes into specific locations in the Drosophila genome. In both cases, ϕC31 was used to catalyze recombination between its target sequences attP in the genome, and attB flanking the donor sequence. We generated cell lines de novo with a single attP-flanked cassette for recombination, whereas, Cherbas et al. introduced a single attP-flanked cassette into existing cell lines. In both approaches, a 2-drug selection scheme was used to select for cells with a single copy of the donor sequence inserted by RMCE and against cells with random integration of multiple copies. Here we describe the general advantages of using RMCE to introduce genes into fly cells, the different attributes of the 2 methods, and how future work could make use of other recombinases and CRISPR/Cas9 genome editing to further enable genetic manipulation of Drosophila cells in vitro.
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Affiliation(s)
| | - Amanda Simcox
- Department of Molecular Genetics, The Ohio State University, Columbus, OH
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8
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Manivannan SN, Lai LB, Gopalan V, Simcox A. Transcriptional control of an essential ribozyme in Drosophila reveals an ancient evolutionary divide in animals. PLoS Genet 2015; 11:e1004893. [PMID: 25569672 PMCID: PMC4287351 DOI: 10.1371/journal.pgen.1004893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/13/2014] [Indexed: 11/19/2022] Open
Abstract
Ribonuclease P (RNase P) is an essential enzyme required for 5'-maturation of tRNA. While an RNA-free, protein-based form of RNase P exists in eukaryotes, the ribonucleoprotein (RNP) form is found in all domains of life. The catalytic component of the RNP is an RNA known as RNase P RNA (RPR). Eukaryotic RPR genes are typically transcribed by RNA polymerase III (pol III). Here we showed that the RPR gene in Drosophila, which is annotated in the intron of a pol II-transcribed protein-coding gene, lacks signals for transcription by pol III. Using reporter gene constructs that include the RPR-coding intron from Drosophila, we found that the intron contains all the sequences necessary for production of mature RPR but is dependent on the promoter of the recipient gene for expression. We also demonstrated that the intron-coded RPR copurifies with RNase P and is required for its activity. Analysis of RPR genes in various animal genomes revealed a striking divide in the animal kingdom that separates insects and crustaceans into a single group in which RPR genes lack signals for independent transcription and are embedded in different protein-coding genes. Our findings provide evidence for a genetic event that occurred approximately 500 million years ago in the arthropod lineage, which switched the control of the transcription of RPR from pol III to pol II.
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Affiliation(s)
- Sathiya N. Manivannan
- Molecular Cellular Developmental Biology Program, Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Lien B. Lai
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, United States of America
- Center for RNA Biology, Ohio State University, Columbus, Ohio, United States of America
| | - Venkat Gopalan
- Molecular Cellular Developmental Biology Program, Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, United States of America
- Center for RNA Biology, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (VG); (AS)
| | - Amanda Simcox
- Molecular Cellular Developmental Biology Program, Ohio State University, Columbus, Ohio, United States of America
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (VG); (AS)
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9
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Abstract
ErbB receptors, including the epidermal growth factor receptor (Egfr), are activated by EGF ligands to govern cell proliferation, survival, migration and differentiation. The different EGF-induced cell responses in development are regulated by deployment of multiple ligands. These inputs, however, engage only a limited number of intracellular pathways and are thought to elicit specific responses by regulating the amplitude or duration of the intracellular signal. The single Drosophila Egfr has four ligands: three of the TGF-α-type and a single neuregulin-like called vein (vn). Here, we used mutant combinations and gene replacement to determine the constraints of ligand specificity in development. Mutant analysis revealed extensive ligand redundancy in embryogenesis and wing development. Surprisingly, we found that the essential role of vn in development could be largely replaced by expression of any TGF-α ligand, including spitz (spi), in the endogenous vn pattern. vn mutants die as white undifferentiated pupae, but the rescued individuals showed global differentiation of adult body parts. Spi is more potent than Vn, and the best morphological rescue occurred when Spi expression was reduced to achieve an intracellular signaling level comparable to that produced by Vn. Our results show that the developmental repertoire of a strong ligand like Spi is flexible and at the appropriate level can emulate the activity of a weak ligand like Vn. These findings align with a model whereby cells respond similarly to an equivalent quantitative level of an intracellular signal generated by two distinct ligands regardless of ligand identity.
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Affiliation(s)
- Christina L Austin
- Department of Molecular Genetics, Ohio State University, Columbus, OH 43210, USA
| | - Sathiya N Manivannan
- Department of Molecular Genetics, Ohio State University, Columbus, OH 43210, USA
| | - Amanda Simcox
- Department of Molecular Genetics, Ohio State University, Columbus, OH 43210, USA
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10
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Butchar JP, Cain D, Manivannan SN, McCue AD, Bonanno L, Halula S, Truesdell S, Austin CL, Jacobsen TL, Simcox A. New negative feedback regulators of Egfr signaling in Drosophila. Genetics 2012; 191:1213-26. [PMID: 22595244 PMCID: PMC3416002 DOI: 10.1534/genetics.112.141093] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/07/2012] [Indexed: 12/18/2022] Open
Abstract
The highly conserved epidermal growth factor receptor (Egfr) pathway is required in all animals for normal development and homeostasis; consequently, aberrant Egfr signaling is implicated in a number of diseases. Genetic analysis of Drosophila melanogaster Egfr has contributed significantly to understanding this conserved pathway and led to the discovery of new components and targets. Here we used microarray analysis of third instar wing discs, in which Egfr signaling was perturbed, to identify new Egfr-responsive genes. Upregulated transcripts included five known targets, suggesting the approach was valid. We investigated the function of 29 previously uncharacterized genes, which had pronounced responses. The Egfr pathway is important for wing-vein patterning and using reverse genetic analysis we identified five genes that showed venation defects. Three of these genes are expressed in vein primordia and all showed transcriptional changes in response to altered Egfr activity consistent with being targets of the pathway. Genetic interactions with Egfr further linked two of the genes, Sulfated (Sulf1), an endosulfatase gene, and CG4096, an A Disintegrin And Metalloproteinase with ThromboSpondin motifs (ADAMTS) gene, to the pathway. Sulf1 showed a strong genetic interaction with the neuregulin-like ligand vein (vn) and may influence binding of Vn to heparan-sulfated proteoglycans (HSPGs). How Drosophila Egfr activity is modulated by CG4096 is unknown, but interestingly vertebrate EGF ligands are regulated by a related ADAMTS protein. We suggest Sulf1 and CG4096 are negative feedback regulators of Egfr signaling that function in the extracellular space to influence ligand activity.
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Affiliation(s)
- Jonathan P. Butchar
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Donna Cain
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | | | - Andrea D. McCue
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Liana Bonanno
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Sarah Halula
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Sharon Truesdell
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Christina L. Austin
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Thomas L. Jacobsen
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
| | - Amanda Simcox
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio 43210
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11
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Justiniano SE, Mathew A, Mitra S, Manivannan SN, Simcox A. Loss of the tumor suppressor Pten promotes proliferation of Drosophila melanogaster cells in vitro and gives rise to continuous cell lines. PLoS One 2012; 7:e31417. [PMID: 22363644 PMCID: PMC3283623 DOI: 10.1371/journal.pone.0031417] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 01/06/2012] [Indexed: 11/18/2022] Open
Abstract
In vivo analysis of Drosophila melanogaster has enhanced our understanding of many biological processes, notably the mechanisms of heredity and development. While in vivo analysis of mutants has been a strength of the field, analyzing fly cells in culture is valuable for cell biological, biochemical and whole genome approaches in which large numbers of homogeneous cells are required. An efficient genetic method to derive Drosophila cell lines using expression of an oncogenic form of Ras (Ras(V12)) has been developed. Mutations in tumor suppressors, which are known to cause cell hyperproliferation in vivo, could provide another method for generating Drosophila cell lines. Here we screened Drosophila tumor suppressor mutations to test if they promoted cell proliferation in vitro. We generated primary cultures and determined when patches of proliferating cells first emerged. These cells emerged on average at 37 days in wild-type cultures. Using this assay we found that a Pten mutation had a strong effect. Patches of proliferating cells appeared on average at 11 days and the cultures became confluent in about 3 weeks, which is similar to the timeframe for cultures expressing Ras(V12). Three Pten mutant cell lines were generated and these have now been cultured for between 250 and 630 cell doublings suggesting the life of the mutant cells is likely to be indefinite. We conclude that the use of Pten mutants is a powerful means to derive new Drosophila cell lines.
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Affiliation(s)
- Steven E. Justiniano
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Anne Mathew
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Sayan Mitra
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Sathiya N. Manivannan
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Amanda Simcox
- Department of Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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