1
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Shanley HT, Taki AC, Nguyen N, Wang T, Byrne JJ, Ang CS, Leeming MG, Williamson N, Chang BCH, Jabbar A, Sleebs BE, Gasser RB. Comparative structure activity and target exploration of 1,2-diphenylethynes in Haemonchus contortus and Caenorhabditis elegans. Int J Parasitol Drugs Drug Resist 2024; 25:100534. [PMID: 38554597 PMCID: PMC10992699 DOI: 10.1016/j.ijpddr.2024.100534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/14/2024] [Accepted: 03/17/2024] [Indexed: 04/01/2024]
Abstract
Infections and diseases caused by parasitic nematodes have a major adverse impact on the health and productivity of animals and humans worldwide. The control of these parasites often relies heavily on the treatment with commercially available chemical compounds (anthelmintics). However, the excessive or uncontrolled use of these compounds in livestock animals has led to major challenges linked to drug resistance in nematodes. Therefore, there is a need to develop new anthelmintics with novel mechanism(s) of action. Recently, we identified a small molecule, designated UMW-9729, with nematocidal activity against the free-living model organism Caenorhabditis elegans. Here, we evaluated UMW-9729's potential as an anthelmintic in a structure-activity relationship (SAR) study in C. elegans and the highly pathogenic, blood-feeding Haemonchus contortus (barber's pole worm), and explored the compound-target relationship using thermal proteome profiling (TPP). First, we synthesised and tested 25 analogues of UMW-9729 for their nematocidal activity in both H. contortus (larvae and adults) and C. elegans (young adults), establishing a preliminary nematocidal pharmacophore for both species. We identified several compounds with marked activity against either H. contortus or C. elegans which had greater efficacy than UMW-9729, and found a significant divergence in compound bioactivity between these two nematode species. We also identified a UMW-9729 analogue, designated 25, that moderately inhibited the motility of adult female H. contortus in vitro. Subsequently, we inferred three H. contortus proteins (HCON_00134350, HCON_00021470 and HCON_00099760) and five C. elegans proteins (F30A10.9, F15B9.8, B0361.6, DNC-4 and UNC-11) that interacted directly with UMW-9729; however, no conserved protein target was shared between the two nematode species. Future work aims to extend the SAR investigation in these and other parasitic nematode species, and validate individual proteins identified here as possible targets of UMW-9729. Overall, the present study evaluates this anthelmintic candidate and highlights some challenges associated with early anthelmintic investigation.
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Affiliation(s)
- Harrison T Shanley
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia; Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
| | - Aya C Taki
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Nghi Nguyen
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
| | - Tao Wang
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Joseph J Byrne
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Ching-Seng Ang
- Melbourne Mass Spectrometry and Proteomics Facility, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Michael G Leeming
- Melbourne Mass Spectrometry and Proteomics Facility, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Nicholas Williamson
- Melbourne Mass Spectrometry and Proteomics Facility, The Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Bill C H Chang
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Abdul Jabbar
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Brad E Sleebs
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia; Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia.
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Science, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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2
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Kapoor S, Adhikary K, Kotak S. PP2A-B55 SUR-6 promotes nuclear envelope breakdown in C. elegans embryos. Cell Rep 2023; 42:113495. [PMID: 37995185 DOI: 10.1016/j.celrep.2023.113495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/25/2023] [Accepted: 11/09/2023] [Indexed: 11/25/2023] Open
Abstract
Nuclear envelope (NE) disassembly during mitosis is critical to ensure faithful segregation of the genetic material. NE disassembly is a phosphorylation-dependent process wherein mitotic kinases hyper-phosphorylate lamina and nucleoporins to initiate nuclear envelope breakdown (NEBD). In this study, we uncover an unexpected role of the PP2A phosphatase B55SUR-6 in NEBD during the first embryonic division of Caenorhabditis elegans embryo. B55SUR-6 depletion delays NE permeabilization and stabilizes lamina and nucleoporins. As a result, the merging of parental genomes and chromosome segregation is impaired. NEBD defect upon B55SUR-6 depletion is not due to delayed mitotic onset or mislocalization of mitotic kinases. Importantly, we demonstrate that microtubule-dependent mechanical forces synergize with B55SUR-6 for efficient NEBD. Finally, our data suggest that the lamin LMN-1 is likely a bona fide target of PP2A-B55SUR-6. These findings establish a model highlighting biochemical crosstalk between kinases, PP2A-B55SUR-6 phosphatase, and microtubule-generated mechanical forces in timely NE dissolution.
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Affiliation(s)
- Sukriti Kapoor
- Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), Bangalore 560012, India
| | - Kuheli Adhikary
- Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), Bangalore 560012, India
| | - Sachin Kotak
- Department of Microbiology and Cell Biology (MCB), Indian Institute of Science (IISc), Bangalore 560012, India.
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3
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Pierron M, Woglar A, Busso C, Jha K, Mikeladze‐Dvali T, Croisier M, Gönczy P. Centriole elimination during Caenorhabditis elegans oogenesis initiates with loss of the central tube protein SAS-1. EMBO J 2023; 42:e115076. [PMID: 37987153 PMCID: PMC10711648 DOI: 10.15252/embj.2023115076] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023] Open
Abstract
In most metazoans, centrioles are lost during oogenesis, ensuring that the zygote is endowed with the correct number of two centrioles, which are paternally contributed. How centriole architecture is dismantled during oogenesis is not understood. Here, we analyze with unprecedent detail the ultrastructural and molecular changes during oogenesis centriole elimination in Caenorhabditis elegans. Centriole elimination begins with loss of the so-called central tube and organelle widening, followed by microtubule disassembly. The resulting cluster of centriolar proteins then disappears gradually, usually moving in a microtubule- and dynein-dependent manner to the plasma membrane. Our analysis indicates that neither Polo-like kinases nor the PCM, which modulate oogenesis centriole elimination in Drosophila, do so in C. elegans. Furthermore, we demonstrate that the central tube protein SAS-1 normally departs initially from the organelle, which loses integrity earlier in sas-1 mutants. Overall, our work provides novel mechanistic insights regarding the fundamental process of oogenesis centriole elimination.
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Affiliation(s)
- Marie Pierron
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life SciencesSwiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Alexander Woglar
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life SciencesSwiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Coralie Busso
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life SciencesSwiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Keshav Jha
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life SciencesSwiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | | | - Marie Croisier
- BIO‐EM platform, School of Life SciencesSwiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Pierre Gönczy
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life SciencesSwiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
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4
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Maheshwari R, Rahman MM, Drey S, Onyundo M, Fabig G, Martinez MAQ, Matus DQ, Müller-Reichert T, Cohen-Fix O. A membrane reticulum, the centriculum, affects centrosome size and function in Caenorhabditis elegans. Curr Biol 2023; 33:791-806.e7. [PMID: 36693370 PMCID: PMC10023444 DOI: 10.1016/j.cub.2022.12.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/21/2022] [Accepted: 12/21/2022] [Indexed: 01/24/2023]
Abstract
Centrosomes are cellular structures that nucleate microtubules. At their core is a pair of centrioles that recruit pericentriolar material (PCM). Although centrosomes are considered membraneless organelles, in many cell types, including human cells, centrosomes are surrounded by endoplasmic reticulum (ER)-derived membranes of unknown structure and function. Using volume electron microscopy (vEM), we show that centrosomes in the Caenorhabditis elegans (C. elegans) early embryo are surrounded by a three-dimensional (3D), ER-derived membrane reticulum that we call the centriculum, for centrosome-associated membrane reticulum. The centriculum is adjacent to the nuclear envelope in interphase and early mitosis and fuses with the fenestrated nuclear membrane at metaphase. Centriculum formation is dependent on the presence of an underlying centrosome and on microtubules. Conversely, increasing centriculum size by genetic means led to the expansion of the PCM, increased microtubule nucleation capacity, and altered spindle width. The effect of the centriculum on centrosome function suggests that in the C. elegans early embryo, the centrosome is not membraneless. Rather, it is encased in a membrane meshwork that affects its properties. We provide evidence that the centriculum serves as a microtubule "filter," preventing the elongation of a subset of microtubules past the centriculum. Finally, we propose that the fusion between the centriculum and the nuclear membrane contributes to nuclear envelope breakdown by coupling spindle elongation to nuclear membrane fenestration.
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Affiliation(s)
- Richa Maheshwari
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mohammad M Rahman
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Seth Drey
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Megan Onyundo
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gunar Fabig
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Michael A Q Martinez
- Department of Biochemistry and Cell Biology, Stony Brook University, 450 Life Sciences Building, Stony Brook, NY 11794, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, 450 Life Sciences Building, Stony Brook, NY 11794, USA
| | - Thomas Müller-Reichert
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Orna Cohen-Fix
- The Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892, USA.
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5
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Medley JC, Song MH. kin-3 genetically suppresses sur-6 in centrosome assembly during Caenorhabditis elegans embryogenesis. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000791. [PMID: 36969515 PMCID: PMC10031309 DOI: 10.17912/micropub.biology.000791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/03/2023] [Accepted: 03/05/2023] [Indexed: 03/29/2023]
Abstract
Protein phosphorylation plays a critical role in cell cycle progression. In Caenorhabditis elegans , Casein Kinase II (CK2) negatively regulates centrosome assembly, and Protein Phosphatase 2A (PP2A) SUR-6 /B55 acts as a positive regulator of centrosome duplication, suggesting CK2 and PP2A SUR-6 /B55 play opposing roles in centrosome assembly. Here, we examined the genetic interaction between kin-3 , encoding the catalytic subunit of CK2, and sur-6 , encoding the PP2Aregulatory subunit SUR-6 /B55, in Caenorhabditis elegans embryos. Our results show that kin-3 (RNAi) partially restores normal centrosome duplication and embryonic viability to hypomorphic sur-6 mutants, suggesting that kin-3 genetically suppresses sur-6 in centrosome assembly during Caenorhabditis elegans embryogenesis.
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Affiliation(s)
- Jeffrey C. Medley
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States
| | - Mi Hye Song
- Department of Biological Sciences, Oakland University, Rochester, Michigan, United States
- Correspondence to: Mi Hye Song (
)
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6
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Harvey AM, Chuang CH, Sumiyoshi E, Bowerman B. C. elegans XMAP215/ZYG-9 and TACC/TAC-1 act at multiple times during oocyte meiotic spindle assembly and promote both spindle pole coalescence and stability. PLoS Genet 2023; 19:e1010363. [PMID: 36608115 PMCID: PMC9851561 DOI: 10.1371/journal.pgen.1010363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/19/2023] [Accepted: 12/13/2022] [Indexed: 01/09/2023] Open
Abstract
The conserved two-component XMAP215/TACC modulator of microtubule stability is required in multiple animal phyla for acentrosomal spindle assembly during oocyte meiotic cell division. In C. elegans, XMAP215/zyg-9 and TACC/tac-1 mutant oocytes exhibit multiple and indistinguishable oocyte spindle assembly defects beginning early in meiosis I. To determine if these defects represent one or more early requirements with additional later and indirect consequences, or multiple temporally distinct and more direct requirements, we have used live cell imaging and fast-acting temperature-sensitive zyg-9 and tac-1 alleles to dissect their requirements at high temporal resolution. Temperature upshift and downshift experiments indicate that the ZYG-9/TAC-1 complex has multiple temporally distinct and separable requirements throughout oocyte meiotic cell division. First, we show that during prometaphase ZYG-9 and TAC-1 promote the coalescence of early pole foci into a bipolar structure, stabilizing pole foci as they grow and limiting their growth rate, with these requirements being independent of an earlier defect in microtubule organization that occurs upon nuclear envelope breakdown. Second, during metaphase, ZYG-9 and TAC-1 maintain spindle bipolarity by suppressing ectopic pole formation. Third, we show that ZYG-9 and TAC-1 also are required for spindle assembly during meiosis II, independently of their meiosis I requirements. The metaphase pole stability requirement appears to be important for maintaining chromosome congression, and we discuss how negative regulation of microtubule stability by ZYG-9/TAC-1 during oocyte meiotic cell division might account for the observed defects in spindle pole coalescence and stability.
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Affiliation(s)
- Austin M. Harvey
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Chien-Hui Chuang
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Eisuke Sumiyoshi
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
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7
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Nishida K, Tsuchiya K, Obinata H, Onodera S, Honda Y, Lai YC, Haruta N, Sugimoto A. Expression Patterns and Levels of All Tubulin Isotypes Analyzed in GFP Knock-In C. elegans Strains. Cell Struct Funct 2021; 46:51-64. [PMID: 33967119 PMCID: PMC10511039 DOI: 10.1247/csf.21022] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 04/28/2021] [Indexed: 11/11/2022] Open
Abstract
Most organisms have multiple α- and β-tubulin isotypes that likely contribute to the diversity of microtubule (MT) functions. To understand the functional differences of tubulin isotypes in Caenorhabditis elegans, which has nine α-tubulin isotypes and six β-tubulin isotypes, we systematically constructed null mutants and GFP-fusion strains for all tubulin isotypes with the CRISPR/Cas9 system and analyzed their expression patterns and levels in adult hermaphrodites. Four isotypes-α-tubulins TBA-1 and TBA-2 and β-tubulins TBB-1 and TBB-2-were expressed in virtually all tissues, with a distinct tissue-specific spectrum. Other isotypes were expressed in specific tissues or cell types at significantly lower levels than the broadly expressed isotypes. Four isotypes (TBA-5, TBA-6, TBA-9, and TBB-4) were expressed in different subsets of ciliated sensory neurons, and TBB-4 was inefficiently incorporated into mitotic spindle MTs. Taken together, we propose that MTs in C. elegans are mainly composed of four broadly expressed tubulin isotypes and that incorporation of a small amount of tissue-specific isotypes may contribute to tissue-specific MT properties. These newly constructed strains will be useful for further elucidating the distinct roles of tubulin isotypes.Key words: tubulin isotypes, microtubules, C. elegans.
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Affiliation(s)
- Kei Nishida
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Kenta Tsuchiya
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Hiroyuki Obinata
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Shizuka Onodera
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Yu Honda
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Yen-Cheng Lai
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Nami Haruta
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Asako Sugimoto
- Laboratory of Developmental Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
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8
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Benton D, Jaeger EC, Kilner A, Kimble A, Lowry J, Schleicher EM, Power KM, Uibel D, Eisele C, Bowerman B, Lyczak R. Interactions between the WEE-1.3 kinase and the PAM-1 aminopeptidase in oocyte maturation and the early C. elegans embryo. G3-GENES GENOMES GENETICS 2021; 11:6157833. [PMID: 33681968 PMCID: PMC8049411 DOI: 10.1093/g3journal/jkab063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/23/2021] [Indexed: 11/25/2022]
Abstract
Puromycin-sensitive aminopeptidases are found across phyla and are known to regulate the cell-cycle and play a protective role in neurodegenerative disease. PAM-1 is a puromycin-sensitive aminopeptidase important for meiotic exit and polarity establishment in the one-cell Caenorhabditis elegans embryo. Despite conservation of this aminopeptidase, little is known about its targets during development. In order to identify novel interactors, we conducted a suppressor screen and isolated four suppressing mutations in three genes that partially rescued the maternal-effect lethality of pam-1 mutants. Suppressed strains show improved embryonic viability and polarization of the anterior–posterior axis. We identified a missense mutation in wee-1.3 in one of these suppressed strains. WEE-1.3 is an inhibitory kinase that regulates maturation promoting factor. Although the missense mutation suppressed polarity phenotypes in pam-1, it does so without restoring centrosome–cortical contact or altering the cortical actomyosin cytoskeleton. To see if PAM-1 and WEE-1.3 interact in other processes, we examined oocyte maturation. Although depletion of wee-1.3 causes sterility due to precocious oocyte maturation, this effect was lessened in pam-1 worms, suggesting that PAM-1 and WEE-1.3 interact in this process. Levels of WEE-1.3 were comparable between wild-type and pam-1 strains, suggesting that WEE-1.3 is not a direct target of the aminopeptidase. Thus, we have established an interaction between PAM-1 and WEE-1.3 in multiple developmental processes and have identified suppressors that are likely to further our understanding of the role of puromycin-sensitive aminopeptidases during development.
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Affiliation(s)
- Dorothy Benton
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Eva C Jaeger
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Arielle Kilner
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA.,Biomedical Studies Department, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, 2900 W. Queen Lane Philadelphia, PA 19129, US A
| | - Ashley Kimble
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Josh Lowry
- Institute of Molecular Biology, 1229 University of Oregon, 1318 Franklin Blvd., Eugene, OR 97403, USA
| | - Emily M Schleicher
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Kaiden M Power
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Danielle Uibel
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Caprice Eisele
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, 1229 University of Oregon, 1318 Franklin Blvd., Eugene, OR 97403, USA
| | - Rebecca Lyczak
- Biology Department, Ursinus College, 601 E Main Street, Collegeville, PA 19426, USA
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9
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Jud MC, Lowry J, Padilla T, Clifford E, Yang Y, Fennell F, Miller AK, Hamill D, Harvey AM, Avila-Zavala M, Shao H, Nguyen Tran N, Bao Z, Bowerman B. A genetic screen for temperature-sensitive morphogenesis-defective Caenorhabditis elegans mutants. G3-GENES GENOMES GENETICS 2021; 11:6169531. [PMID: 33713117 PMCID: PMC8133775 DOI: 10.1093/g3journal/jkab026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/18/2021] [Indexed: 11/21/2022]
Abstract
Morphogenesis involves coordinated cell migrations and cell shape changes that generate tissues and organs, and organize the body plan. Cell adhesion and the cytoskeleton are important for executing morphogenesis, but their regulation remains poorly understood. As genes required for embryonic morphogenesis may have earlier roles in development, temperature-sensitive embryonic-lethal mutations are useful tools for investigating this process. From a collection of ∼200 such Caenorhabditis elegans mutants, we have identified 17 that have highly penetrant embryonic morphogenesis defects after upshifts from the permissive to the restrictive temperature, just prior to the cell shape changes that mediate elongation of the ovoid embryo into a vermiform larva. Using whole genome sequencing, we identified the causal mutations in seven affected genes. These include three genes that have roles in producing the extracellular matrix, which is known to affect the morphogenesis of epithelial tissues in multicellular organisms: the rib-1 and rib-2 genes encode glycosyltransferases, and the emb-9 gene encodes a collagen subunit. We also used live imaging to characterize epidermal cell shape dynamics in one mutant, or1219ts, and observed cell elongation defects during dorsal intercalation and ventral enclosure that may be responsible for the body elongation defects. These results indicate that our screen has identified factors that influence morphogenesis and provides a platform for advancing our understanding of this fundamental biological process.
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Affiliation(s)
- Molly C Jud
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Josh Lowry
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Thalia Padilla
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Erin Clifford
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Yuqi Yang
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Francesca Fennell
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Alexander K Miller
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Danielle Hamill
- Department of Zoology, Ohio Wesleyan University, Delaware, OH, 43015, USA
| | - Austin M Harvey
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Martha Avila-Zavala
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
| | - Hong Shao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Nhan Nguyen Tran
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Zhirong Bao
- Developmental Biology Program, Sloan Kettering Institute, New York, NY, 10065, USA
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97402, USA
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10
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Magescas J, Eskinazi S, Tran MV, Feldman JL. Centriole-less pericentriolar material serves as a microtubule organizing center at the base of C. elegans sensory cilia. Curr Biol 2021; 31:2410-2417.e6. [PMID: 33798428 DOI: 10.1016/j.cub.2021.03.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/18/2021] [Accepted: 03/05/2021] [Indexed: 01/20/2023]
Abstract
During mitosis in animal cells, the centrosome acts as a microtubule organizing center (MTOC) to assemble the mitotic spindle. MTOC function at the centrosome is driven by proteins within the pericentriolar material (PCM), however the molecular complexity of the PCM makes it difficult to differentiate the proteins required for MTOC activity from other centrosomal functions. We used the natural spatial separation of PCM proteins during mitotic exit to identify a minimal module of proteins required for centrosomal MTOC function in C. elegans. Using tissue-specific degradation, we show that SPD-5, the functional homolog of CDK5RAP2, is essential for embryonic mitosis, while SPD-2/CEP192 and PCMD-1, which are essential in the one-cell embryo, are dispensable. Surprisingly, although the centriole is known to be degraded in the ciliated sensory neurons in C. elegans,1-3 we find evidence for "centriole-less PCM" at the base of cilia and use this structure as a minimal testbed to dissect centrosomal MTOC function. Super-resolution imaging revealed that this PCM inserts inside the lumen of the ciliary axoneme and directly nucleates the assembly of dendritic microtubules toward the cell body. Tissue-specific degradation in ciliated sensory neurons revealed a role for SPD-5 and the conserved microtubule nucleator γ-TuRC, but not SPD-2 or PCMD-1, in MTOC function at centriole-less PCM. This MTOC function was in the absence of regulation by mitotic kinases, highlighting the intrinsic ability of these proteins to drive microtubule growth and organization and further supporting a model that SPD-5 is the primary driver of MTOC function at the PCM.
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Affiliation(s)
- Jérémy Magescas
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA.
| | - Sani Eskinazi
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA
| | - Michael V Tran
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA
| | - Jessica L Feldman
- Department of Biology, Stanford University, 371 Serra Mall, Stanford, 94305, CA, USA.
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11
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Lantzsch I, Yu CH, Chen YZ, Zimyanin V, Yazdkhasti H, Lindow N, Szentgyoergyi E, Pani AM, Prohaska S, Srayko M, Fürthauer S, Redemann S. Microtubule reorganization during female meiosis in C. elegans. eLife 2021; 10:58903. [PMID: 34114562 PMCID: PMC8225387 DOI: 10.7554/elife.58903] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 05/24/2021] [Indexed: 02/01/2023] Open
Abstract
Most female meiotic spindles undergo striking morphological changes while transitioning from metaphase to anaphase. The ultra-structure of meiotic spindles, and how changes to this structure correlate with such dramatic spindle rearrangements remains largely unknown. To address this, we applied light microscopy, large-scale electron tomography and mathematical modeling of female meiotic Caenorhabditis elegans spindles. Combining these approaches, we find that meiotic spindles are dynamic arrays of short microtubules that turn over within seconds. The results show that the metaphase to anaphase transition correlates with an increase in microtubule numbers and a decrease in their average length. Detailed analysis of the tomographic data revealed that the microtubule length changes significantly during the metaphase-to-anaphase transition. This effect is most pronounced for microtubules located within 150 nm of the chromosome surface. To understand the mechanisms that drive this transition, we developed a mathematical model for the microtubule length distribution that considers microtubule growth, catastrophe, and severing. Using Bayesian inference to compare model predictions and data, we find that microtubule turn-over is the major driver of the spindle reorganizations. Our data suggest that in metaphase only a minor fraction of microtubules, those closest to the chromosomes, are severed. The large majority of microtubules, which are not in close contact with chromosomes, do not undergo severing. Instead, their length distribution is fully explained by growth and catastrophe. This suggests that the most prominent drivers of spindle rearrangements are changes in nucleation and catastrophe rate. In addition, we provide evidence that microtubule severing is dependent on katanin.
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Affiliation(s)
- Ina Lantzsch
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität DresdenDresdenGermany
| | - Che-Hang Yu
- Department of Electrical and Computer Engineering, University of California, Santa BarbaraSanta BarbaraUnited States
| | - Yu-Zen Chen
- Center for Membrane and Cell Physiology, University of Virginia School of MedicineCharlottesvilleUnited States,Department of Molecular Physiology and Biological Physics, University of Virginia, School of MedicineCharlottesvilleUnited States
| | - Vitaly Zimyanin
- Center for Membrane and Cell Physiology, University of Virginia School of MedicineCharlottesvilleUnited States,Department of Molecular Physiology and Biological Physics, University of Virginia, School of MedicineCharlottesvilleUnited States
| | - Hossein Yazdkhasti
- Center for Membrane and Cell Physiology, University of Virginia School of MedicineCharlottesvilleUnited States,Department of Molecular Physiology and Biological Physics, University of Virginia, School of MedicineCharlottesvilleUnited States
| | | | - Erik Szentgyoergyi
- Experimental Center, Faculty of Medicine Carl Gustav Carus, Technische Universität DresdenDresdenGermany
| | - Ariel M Pani
- Department of Biology, University of VirginiaCharlottesvilleUnited States,Department of Cell Biology, University of Virginia School of MedicineCharlottesvilleUnited States
| | | | - Martin Srayko
- Department of Biological Sciences, University of AlbertaEdmontonCanada
| | | | - Stefanie Redemann
- Center for Membrane and Cell Physiology, University of Virginia School of MedicineCharlottesvilleUnited States,Department of Molecular Physiology and Biological Physics, University of Virginia, School of MedicineCharlottesvilleUnited States,Department of Cell Biology, University of Virginia School of MedicineCharlottesvilleUnited States
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12
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Kovács IA, Barabási DL, Barabási AL. Uncovering the genetic blueprint of the C. elegans nervous system. Proc Natl Acad Sci U S A 2020; 117:33570-33577. [PMID: 33318182 PMCID: PMC7777131 DOI: 10.1073/pnas.2009093117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Despite rapid advances in connectome mapping and neuronal genetics, we lack theoretical and computational tools to unveil, in an experimentally testable fashion, the genetic mechanisms that govern neuronal wiring. Here we introduce a computational framework to link the adjacency matrix of a connectome to the expression patterns of its neurons, helping us uncover a set of genetic rules that govern the interactions between neurons in contact. The method incorporates the biological realities of the system, accounting for noise from data collection limitations, as well as spatial restrictions. The resulting methodology allows us to infer a network of 19 innexin interactions that govern the formation of gap junctions in Caenorhabditis elegans, five of which are already supported by experimental data. As advances in single-cell gene expression profiling increase the accuracy and the coverage of the data, the developed framework will allow researchers to systematically infer experimentally testable connection rules, offering mechanistic predictions for synapse and gap junction formation.
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Affiliation(s)
- István A Kovács
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
- Department of Data and Network Science, Central European University, Budapest 1051, Hungary
- Network Science Institute, Northeastern University, Boston, MA 02115
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, Budapest 1121, Hungary
| | | | - Albert-László Barabási
- Department of Data and Network Science, Central European University, Budapest 1051, Hungary;
- Network Science Institute, Northeastern University, Boston, MA 02115
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
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13
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Mei X, Singson AW. The molecular underpinnings of fertility: Genetic approaches in Caenorhabditis elegans. ADVANCED GENETICS (HOBOKEN, N.J.) 2020; 2:e10034. [PMID: 34322672 PMCID: PMC8315475 DOI: 10.1002/ggn2.10034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The study of mutations that impact fertility has a catch-22. Fertility mutants are often lost since they cannot simply be propagated and maintained. This has hindered progress in understanding the genetics of fertility. In mice, several molecules are found to be required for the interactions between the sperm and egg, with JUNO and IZUMO1 being the only known receptor pair on the egg and sperm surface, respectively. In Caenorhabditis elegans, a total of 12 proteins on the sperm or oocyte have been identified to mediate gamete interactions. Majority of these genes were identified through mutants isolated from genetic screens. In this review, we summarize the several key screening strategies that led to the identification of fertility mutants in C. elegans and provide a perspective about future research using genetic approaches. Recently, advancements in new technologies such as high-throughput sequencing and Crispr-based genome editing tools have accelerated the molecular, cell biological, and mechanistic analysis of fertility genes. We review how these valuable tools advance our understanding of the molecular underpinnings of fertilization. We draw parallels of the molecular mechanisms of fertilization between worms and mammals and argue that our work in C. elegans complements fertility research in humans and other species.
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Affiliation(s)
- Xue Mei
- Department of GeneticsWaksman Institute, Rutgers, The State University of New JerseyPiscatawayNew JerseyUSA
| | - Andrew W. Singson
- Department of GeneticsWaksman Institute, Rutgers, The State University of New JerseyPiscatawayNew JerseyUSA
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14
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Défachelles L, Russo AE, Nelson CR, Bhalla N. The conserved AAA-ATPase PCH-2 TRIP13 regulates spindle checkpoint strength. Mol Biol Cell 2020; 31:2219-2233. [PMID: 32697629 PMCID: PMC7550697 DOI: 10.1091/mbc.e20-05-0310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Spindle checkpoint strength is dictated by the number of unattached kinetochores, cell volume, and cell fate. We show that the conserved AAA-ATPase PCH-2/TRIP13, which remodels the checkpoint effector Mad2 from an active conformation to an inactive one, controls checkpoint strength in Caenorhabditis elegans. Having previously established that this function is required for spindle checkpoint activation, we demonstrate that in cells genetically manipulated to decrease in cell volume, PCH-2 is no longer required for the spindle checkpoint or recruitment of Mad2 at unattached kinetochores. This role is not limited to large cells: the stronger checkpoint in germline precursor cells also depends on PCH-2. PCH-2 is enriched in germline precursor cells, and this enrichment relies on conserved factors that induce asymmetry in the early embryo. Finally, the stronger checkpoint in germline precursor cells is regulated by CMT-1, the ortholog of p31comet, which is required for both PCH-2′s localization to unattached kinetochores and its enrichment in germline precursor cells. Thus, PCH-2, likely by regulating the availability of inactive Mad2 at and near unattached kinetochores, governs checkpoint strength. This requirement may be particularly relevant in oocytes and early embryos enlarged for developmental competence, cells that divide in syncytial tissues, and immortal germline cells.
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Affiliation(s)
- Lénaïg Défachelles
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Anna E Russo
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Christian R Nelson
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Needhi Bhalla
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
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15
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Testa ND, Kaul S, Le KN, Zhan M, Lu H, Paaby AB. A portable, low-cost device for precise control of specimen temperature under stereomicroscopes. PLoS One 2020; 15:e0230241. [PMID: 32160236 PMCID: PMC7065815 DOI: 10.1371/journal.pone.0230241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/25/2020] [Indexed: 11/27/2022] Open
Abstract
To facilitate precise and convenient control of biological sample temperature, we developed a low-cost device that can be used independently or with any stereomicroscope. The purpose of the device is to control the thermal environment during experimental intervals in which a specimen must be manipulated outside of an incubator, e.g. for dissection or slide-mounting in preparation for imaging. Sample temperatures can be both cooled to below and heated to above room temperatures, and stably maintained at a precision of +/- 0.1˚C. To demonstrate the utility of this device, we report improved characterization of the penetrance of a short-acting temperature-sensitive allele in C. elegans embryos, and identification of the upper temperature threshold for embryonic viability for six Caenorhabditis species. By controlling the temperature environment even as a specimen is manipulated, this device offers consistency and flexibility, reduces environmental noise, and enables precision timing in experiments requiring temperature shifts.
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Affiliation(s)
- Nicholas D. Testa
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Samiksha Kaul
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Kim N. Le
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Mei Zhan
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Annalise B. Paaby
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States of America
- * E-mail:
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16
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Differential Requirements for Centrioles in Mitotic Centrosome Growth and Maintenance. Dev Cell 2019; 50:355-366.e6. [DOI: 10.1016/j.devcel.2019.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/29/2019] [Accepted: 06/10/2019] [Indexed: 10/26/2022]
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17
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A behavior-based drug screening system using a Caenorhabditis elegans model of motor neuron disease. Sci Rep 2019; 9:10104. [PMID: 31300701 PMCID: PMC6626054 DOI: 10.1038/s41598-019-46642-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 07/01/2019] [Indexed: 11/24/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons, for which there is no effective treatment. Previously, we generated a Caenorhabditis elegans model of ALS, in which the expression of dnc-1, the homologous gene of human dynactin-1, is knocked down (KD) specifically in motor neurons. This dnc-1 KD model showed progressive motor defects together with axonal and neuronal degeneration, as observed in ALS patients. In the present study, we established a behavior-based, automated, and quantitative drug screening system using this dnc-1 KD model together with Multi-Worm Tracker (MWT), and tested whether 38 candidate neuroprotective compounds could improve the mobility of the dnc-1 KD animals. We found that 12 compounds, including riluzole, which is an approved medication for ALS patients, ameliorated the phenotype of the dnc-1 KD animals. Nifedipine, a calcium channel blocker, most robustly ameliorated the motor deficits as well as axonal degeneration of dnc-1 KD animals. Nifedipine also ameliorated the motor defects of other motor neuronal degeneration models of C. elegans, including dnc-1 mutants and human TAR DNA-binding protein of 43 kDa overexpressing worms. Our results indicate that dnc-1 KD in C. elegans is a useful model for the screening of drugs against motor neuron degeneration, and that MWT is a powerful tool for the behavior-based screening of drugs.
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18
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Kinetochore Recruitment of the Spindle and Kinetochore-Associated (Ska) Complex Is Regulated by Centrosomal PP2A in Caenorhabditis elegans. Genetics 2019; 212:509-522. [PMID: 31018924 DOI: 10.1534/genetics.119.302105] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 04/07/2019] [Indexed: 12/31/2022] Open
Abstract
During mitosis, kinetochore-microtubule interactions ensure that chromosomes are accurately segregated to daughter cells. RSA-1 (regulator of spindle assembly-1) is a regulatory B″ subunit of protein phosphatase 2A that was previously proposed to modulate microtubule dynamics during spindle assembly. We have identified a genetic interaction between the centrosomal protein, RSA-1, and the spindle- and kinetochore-associated (Ska) complex in Caenorhabditis elegans In a forward genetic screen for suppressors of rsa-1(or598) embryonic lethality, we identified mutations in ska-1 and ska-3 Loss of SKA-1 and SKA-3, as well as components of the KMN (KNL-1/MIS-12/NDC-80) complex and the microtubule end-binding protein EBP-2, all suppressed the embryonic lethality of rsa-1(or598) These suppressors also disrupted the intracellular localization of the Ska complex, revealing a network of proteins that influence Ska function during mitosis. In rsa-1(or598) embryos, SKA-1 is excessively and prematurely recruited to kinetochores during spindle assembly, but SKA-1 levels return to normal just prior to anaphase onset. Loss of the TPX2 homolog, TPXL-1, also resulted in overrecruitment of SKA-1 to the kinetochores and this correlated with the loss of Aurora A kinase on the spindle microtubules. We propose that rsa-1 regulates the kinetochore localization of the Ska complex, with spindle-associated Aurora A acting as a potential mediator. These data reveal a novel mechanism of protein phosphatase 2A function during mitosis involving a centrosome-based regulatory mechanism for Ska complex recruitment to the kinetochore.
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19
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Boudreau V, Chen R, Edwards A, Sulaimain M, Maddox PS. PP2A-B55/SUR-6 collaborates with the nuclear lamina for centrosome separation during mitotic entry. Mol Biol Cell 2019; 30:876-886. [PMID: 30840554 PMCID: PMC6589783 DOI: 10.1091/mbc.e18-10-0631] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Across most sexually reproducing animals, centrosomes are provided to the oocyte through fertilization and must be positioned properly to establish the zygotic mitotic spindle. How centrosomes are positioned in space and time through the concerted action of key mitotic entry biochemical regulators, including protein phosphatase 2A (PP2A-B55/SUR-6), biophysical regulators, including dynein, and the nuclear lamina is unclear. Here, we uncover a role for PP2A-B55/SUR-6 in regulating centrosome separation. Mechanistically, PP2A-B55/SUR-6 regulates nuclear size before mitotic entry, in turn affecting nuclear envelope–based dynein density and motor capacity. Computational simulations predicted the requirement of PP2A-B55/SUR-6 regulation of nuclear size and nuclear-envelope dynein density for proper centrosome separation. Conversely, compromising nuclear lamina integrity led to centrosome detachment from the nuclear envelope and migration defects. Removal of PP2A-B55/SUR-6 and the nuclear lamina simultaneously further disrupted centrosome separation, leading to unseparated centrosome pairs dissociated from the nuclear envelope. Taking these combined results into consideration, we propose a model in which centrosomes migrate and are positioned through the concerted action of PP2A-B55/SUR-6–regulated nuclear envelope–based dynein pulling forces and centrosome–nuclear envelope tethering. Our results add critical precision to models of centrosome separation relative to the nucleus during spindle formation in cell division.
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Affiliation(s)
- Vincent Boudreau
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514
| | - Richard Chen
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514
| | - Alan Edwards
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514
| | - Muhammad Sulaimain
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514
| | - Paul S Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514
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20
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Klinkert K, Levernier N, Gross P, Gentili C, von Tobel L, Pierron M, Busso C, Herrman S, Grill SW, Kruse K, Gönczy P. Aurora A depletion reveals centrosome-independent polarization mechanism in Caenorhabditis elegans. eLife 2019; 8:e44552. [PMID: 30801250 PMCID: PMC6417861 DOI: 10.7554/elife.44552] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/24/2019] [Indexed: 12/14/2022] Open
Abstract
How living systems break symmetry in an organized manner is a fundamental question in biology. In wild-type Caenorhabditis elegans zygotes, symmetry breaking during anterior-posterior axis specification is guided by centrosomes, resulting in anterior-directed cortical flows and a single posterior PAR-2 domain. We uncover that C. elegans zygotes depleted of the Aurora A kinase AIR-1 or lacking centrosomes entirely usually establish two posterior PAR-2 domains, one at each pole. We demonstrate that AIR-1 prevents symmetry breaking early in the cell cycle, whereas centrosomal AIR-1 instructs polarity initiation thereafter. Using triangular microfabricated chambers, we establish that bipolarity of air-1(RNAi) embryos occurs effectively in a cell-shape and curvature-dependent manner. Furthermore, we develop an integrated physical description of symmetry breaking, wherein local PAR-2-dependent weakening of the actin cortex, together with mutual inhibition of anterior and posterior PAR proteins, provides a mechanism for spontaneous symmetry breaking without centrosomes.
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Affiliation(s)
- Kerstin Klinkert
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Nicolas Levernier
- Department of BiochemistryUniversity of GenevaGenevaSwitzerland
- Department of Theoretical PhysicsUniversity of GenevaGenevaSwitzerland
| | | | - Christian Gentili
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Lukas von Tobel
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Marie Pierron
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Coralie Busso
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Sarah Herrman
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
| | - Stephan W Grill
- BIOTECTU DresdenDresdenGermany
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Cluster of Excellence Physics of LifeTU DresdenDresdenGermany
| | - Karsten Kruse
- Department of BiochemistryUniversity of GenevaGenevaSwitzerland
- Department of Theoretical PhysicsUniversity of GenevaGenevaSwitzerland
- National Center of Competence in Research Chemical Biology, University of GenevaGenevaSwitzerland
| | - Pierre Gönczy
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL)LausanneSwitzerland
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21
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Pintard L, Bowerman B. Mitotic Cell Division in Caenorhabditis elegans. Genetics 2019; 211:35-73. [PMID: 30626640 PMCID: PMC6325691 DOI: 10.1534/genetics.118.301367] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/24/2018] [Indexed: 11/18/2022] Open
Abstract
Mitotic cell divisions increase cell number while faithfully distributing the replicated genome at each division. The Caenorhabditis elegans embryo is a powerful model for eukaryotic cell division. Nearly all of the genes that regulate cell division in C. elegans are conserved across metazoan species, including humans. The C. elegans pathways tend to be streamlined, facilitating dissection of the more redundant human pathways. Here, we summarize the virtues of C. elegans as a model system and review our current understanding of centriole duplication, the acquisition of pericentriolar material by centrioles to form centrosomes, the assembly of kinetochores and the mitotic spindle, chromosome segregation, and cytokinesis.
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Affiliation(s)
- Lionel Pintard
- Equipe labellisée Ligue contre le Cancer, Institut Jacques Monod, Team Cell Cycle and Development UMR7592, Centre National de la Recherche Scientifique - Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
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22
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Capovilla G, Delhomme N, Collani S, Shutava I, Bezrukov I, Symeonidi E, de Francisco Amorim M, Laubinger S, Schmid M. PORCUPINE regulates development in response to temperature through alternative splicing. NATURE PLANTS 2018; 4:534-539. [PMID: 29988152 DOI: 10.1038/s41477-018-0176-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/14/2018] [Indexed: 05/20/2023]
Abstract
Recent findings suggest that alternative splicing has a critical role in controlling the responses of plants to temperature variations. However, alternative splicing factors in plants are largely uncharacterized. Here we establish the putative splice regulator, PORCUPINE (PCP), as temperature-specific regulator of development in Arabidopsis thaliana. Our findings point to the misregulation of WUSCHEL and CLAVATA3 as the possible cause for the meristem defects affecting the pcp-1 loss-of-function mutants at low temperatures.
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Affiliation(s)
- Giovanna Capovilla
- Max Planck Institute for Developmental Biology, Department of Molecular Biology, Tübingen, Germany
| | - Nicolas Delhomme
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University for Agricultural Sciences, Umeå, Sweden
| | - Silvio Collani
- Max Planck Institute for Developmental Biology, Department of Molecular Biology, Tübingen, Germany
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Iryna Shutava
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Ilja Bezrukov
- Max Planck Institute for Developmental Biology, Department of Molecular Biology, Tübingen, Germany
| | - Efthymia Symeonidi
- Max Planck Institute for Developmental Biology, Department of Molecular Biology, Tübingen, Germany
| | | | - Sascha Laubinger
- Centre for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
- Institute for Biology and Environmental Sciences (IBU), University of Oldenburg, Oldenburg, Germany
| | - Markus Schmid
- Max Planck Institute for Developmental Biology, Department of Molecular Biology, Tübingen, Germany.
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
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23
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Hattersley N, Lara-Gonzalez P, Cheerambathur D, Gomez-Cavazos JS, Kim T, Prevo B, Khaliullin R, Lee KY, Ohta M, Green R, Oegema K, Desai A. Employing the one-cell C. elegans embryo to study cell division processes. Methods Cell Biol 2018; 144:185-231. [PMID: 29804670 DOI: 10.1016/bs.mcb.2018.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The one-cell Caenorhabditis elegans embryo offers many advantages for mechanistic analysis of cell division processes. Conservation of key genes and pathways involved in cell division makes findings in C. elegans broadly relevant. A key technical advantage of this system is the ability to penetrantly deplete essential gene products by RNA interference (RNAi) and replace them with wild-type or mutant versions expressed at endogenous levels from single copy RNAi-resistant transgene insertions. This ability to precisely perturb essential genes is complemented by the inherently highly reproducible nature of the zygotic division that facilitates development of quantitative imaging assays. Here, we detail approaches to generate targeted single copy transgene insertions that are RNAi-resistant, to engineer variants of individual genes employing transgene insertions as well as at the endogenous locus, and to in situ tag genes with fluorophores/purification tags. We also describe imaging assays and common image analysis tools employed to quantitatively monitor phenotypic effects of specific perturbations on meiotic and mitotic chromosome segregation, centrosome assembly/function, and cortical dynamics/cytokinesis.
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Affiliation(s)
- Neil Hattersley
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Pablo Lara-Gonzalez
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Dhanya Cheerambathur
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - J Sebastian Gomez-Cavazos
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Taekyung Kim
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Bram Prevo
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Renat Khaliullin
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Kian-Yong Lee
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Midori Ohta
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Rebecca Green
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Karen Oegema
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States
| | - Arshad Desai
- Ludwig Institute for Cancer Research, La Jolla, CA, United States; Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, United States.
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24
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Gerhold AR, Poupart V, Labbé JC, Maddox PS. Spindle assembly checkpoint strength is linked to cell fate in the Caenorhabditis elegans embryo. Mol Biol Cell 2018; 29:1435-1448. [PMID: 29688794 PMCID: PMC6014101 DOI: 10.1091/mbc.e18-04-0215] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The spindle assembly checkpoint (SAC) is a conserved mitotic regulator that preserves genome stability by monitoring kinetochore-microtubule attachments and blocking anaphase onset until chromosome biorientation is achieved. Despite its central role in maintaining mitotic fidelity, the ability of the SAC to delay mitotic exit in the presence of kinetochore-microtubule attachment defects (SAC "strength") appears to vary widely. How different cellular aspects drive this variation remains largely unknown. Here we show that SAC strength is correlated with cell fate during development of Caenorhabditis elegans embryos, with germline-fated cells experiencing longer mitotic delays upon spindle perturbation than somatic cells. These differences are entirely dependent on an intact checkpoint and only partially attributable to differences in cell size. In two-cell embryos, cell size accounts for half of the difference in SAC strength between the larger somatic AB and the smaller germline P1 blastomeres. The remaining difference requires asymmetric cytoplasmic partitioning downstream of PAR polarity proteins, suggesting that checkpoint-regulating factors are distributed asymmetrically during early germ cell divisions. Our results indicate that SAC activity is linked to cell fate and reveal a hitherto unknown interaction between asymmetric cell division and the SAC.
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Affiliation(s)
- Abigail R Gerhold
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Vincent Poupart
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Jean-Claude Labbé
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada.,Department of Pathology and Cell Biology, Université de Montréal, Succ. Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Paul S Maddox
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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25
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Hernando-Rodríguez B, Erinjeri AP, Rodríguez-Palero MJ, Millar V, González-Hernández S, Olmedo M, Schulze B, Baumeister R, Muñoz MJ, Askjaer P, Artal-Sanz M. Combined flow cytometry and high-throughput image analysis for the study of essential genes in Caenorhabditis elegans. BMC Biol 2018; 16:36. [PMID: 29598825 PMCID: PMC5875015 DOI: 10.1186/s12915-018-0496-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/06/2018] [Indexed: 12/28/2022] Open
Abstract
Background Advances in automated image-based microscopy platforms coupled with high-throughput liquid workflows have facilitated the design of large-scale screens utilising multicellular model organisms such as Caenorhabditis elegans to identify genetic interactions, therapeutic drugs or disease modifiers. However, the analysis of essential genes has lagged behind because lethal or sterile mutations pose a bottleneck for high-throughput approaches, and a systematic way to analyse genetic interactions of essential genes in multicellular organisms has been lacking. Results In C. elegans, non-conditional lethal mutations can be maintained in heterozygosity using chromosome balancers, commonly expressing green fluorescent protein (GFP) in the pharynx. However, gene expression or function is typically monitored by the use of fluorescent reporters marked with the same fluorophore, presenting a challenge to sort worm populations of interest, particularly at early larval stages. Here, we develop a sorting strategy capable of selecting homozygous mutants carrying a GFP stress reporter from GFP-balanced animals at the second larval stage. Because sorting is not completely error-free, we develop an automated high-throughput image analysis protocol that identifies and discards animals carrying the chromosome balancer. We demonstrate the experimental usefulness of combining sorting of homozygous lethal mutants and automated image analysis in a functional genomic RNA interference (RNAi) screen for genes that genetically interact with mitochondrial prohibitin (PHB). Lack of PHB results in embryonic lethality, while homozygous PHB deletion mutants develop into sterile adults due to maternal contribution and strongly induce the mitochondrial unfolded protein response (UPRmt). In a chromosome-wide RNAi screen for C. elegans genes having human orthologues, we uncover both known and new PHB genetic interactors affecting the UPRmt and growth. Conclusions The method presented here allows the study of balanced lethal mutations in a high-throughput manner. It can be easily adapted depending on the user’s requirements and should serve as a useful resource for the C. elegans community for probing new biological aspects of essential nematode genes as well as the generation of more comprehensive genetic networks. Electronic supplementary material The online version of this article (10.1186/s12915-018-0496-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Blanca Hernando-Rodríguez
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain.,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain
| | - Annmary Paul Erinjeri
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain.,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain
| | - María Jesús Rodríguez-Palero
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain.,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain
| | - Val Millar
- GE Healthcare Life Sciences, Maynard Centre, Forest Farm, Whitchurch, Cardiff, UK.,Present address: Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sara González-Hernández
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain.,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain.,Present address: Cell and Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - María Olmedo
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain.,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain.,Present address: Department of Genetics, University of Seville, Seville, Spain
| | - Bettina Schulze
- Centre for Biological Signalling Studies (BIOSS), Laboratory for Bioinformatics and Molecular Genetics, Faculty of Biology, and ZBMZ Center for Biochemistry and Molecular Cell Biology (Faculty of Medicine), Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Ralf Baumeister
- Centre for Biological Signalling Studies (BIOSS), Laboratory for Bioinformatics and Molecular Genetics, Faculty of Biology, and ZBMZ Center for Biochemistry and Molecular Cell Biology (Faculty of Medicine), Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| | - Manuel J Muñoz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain.,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain
| | - Peter Askjaer
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain
| | - Marta Artal-Sanz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Seville, Spain. .,Department of Molecular Biology and Biochemical Engineering, Universidad Pablo de Olavide, Seville, Spain.
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26
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Martino L, Morchoisne-Bolhy S, Cheerambathur DK, Van Hove L, Dumont J, Joly N, Desai A, Doye V, Pintard L. Channel Nucleoporins Recruit PLK-1 to Nuclear Pore Complexes to Direct Nuclear Envelope Breakdown in C. elegans. Dev Cell 2017; 43:157-171.e7. [PMID: 29065307 PMCID: PMC8184135 DOI: 10.1016/j.devcel.2017.09.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 08/02/2017] [Accepted: 09/22/2017] [Indexed: 01/24/2023]
Abstract
In animal cells, nuclear envelope breakdown (NEBD) is required for proper chromosome segregation. Whereas mitotic kinases have been implicated in NEBD, how they coordinate their activity to trigger this event is unclear. Here, we show that both in human cells and Caenorhabditis elegans, the Polo-like kinase 1 (PLK-1) is recruited to the nuclear pore complexes, just prior to NEBD, through its Polo-box domain (PBD). We provide evidence that PLK-1 localization to the nuclear envelope (NE) is required for efficient NEBD. We identify the central channel nucleoporins NPP-1/Nup58, NPP-4/Nup54, and NPP-11/Nup62 as the critical factors anchoring PLK-1 to the NE in C. elegans. In particular, NPP-1, NPP-4, and NPP-11 primed at multiple Polo-docking sites by Cdk1 and PLK-1 itself physically interact with the PLK-1 PBD. We conclude that nucleoporins play an unanticipated regulatory role in NEBD, by recruiting PLK-1 to the NE thereby facilitating phosphorylation of critical downstream targets.
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Affiliation(s)
- Lisa Martino
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Stéphanie Morchoisne-Bolhy
- Non-conventional Functions of Nuclear Pore, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Dhanya K Cheerambathur
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Lucie Van Hove
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Julien Dumont
- Cell Division and Reproduction, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Nicolas Joly
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Arshad Desai
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Valérie Doye
- Non-conventional Functions of Nuclear Pore, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Lionel Pintard
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
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27
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MIP-MAP: High-Throughput Mapping of Caenorhabditis elegans Temperature-Sensitive Mutants via Molecular Inversion Probes. Genetics 2017; 207:447-463. [PMID: 28827289 PMCID: PMC5629315 DOI: 10.1534/genetics.117.300179] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 07/30/2017] [Indexed: 11/18/2022] Open
Abstract
Mutants remain a powerful means for dissecting gene function in model organisms such as Caenorhabditis elegans. Massively parallel sequencing has simplified the detection of variants after mutagenesis but determining precisely which change is responsible for phenotypic perturbation remains a key step. Genetic mapping paradigms in C. elegans rely on bulk segregant populations produced by crosses with the problematic Hawaiian wild isolate and an excess of redundant information from whole-genome sequencing (WGS). To increase the repertoire of available mutants and to simplify identification of the causal change, we performed WGS on 173 temperature-sensitive (TS) lethal mutants and devised a novel mapping method. The mapping method uses molecular inversion probes (MIP-MAP) in a targeted sequencing approach to genetic mapping, and replaces the Hawaiian strain with a Million Mutation Project strain with high genomic and phenotypic similarity to the laboratory wild-type strain N2. We validated MIP-MAP on a subset of the TS mutants using a competitive selection approach to produce TS candidate mapping intervals with a mean size < 3 Mb. MIP-MAP successfully uses a non-Hawaiian mapping strain and multiplexed libraries are sequenced at a fraction of the cost of WGS mapping approaches. Our mapping results suggest that the collection of TS mutants contains a diverse library of TS alleles for genes essential to development and reproduction. MIP-MAP is a robust method to genetically map mutations in both viable and essential genes and should be adaptable to other organisms. It may also simplify tracking of individual genotypes within population mixtures.
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28
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Wang SC, Low TYF, Nishimura Y, Gole L, Yu W, Motegi F. Cortical forces and CDC-42 control clustering of PAR proteins for Caenorhabditis elegans embryonic polarization. Nat Cell Biol 2017; 19:988-995. [DOI: 10.1038/ncb3577] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 06/20/2017] [Indexed: 12/12/2022]
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29
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Differential regulation of polarized synaptic vesicle trafficking and synapse stability in neural circuit rewiring in Caenorhabditis elegans. PLoS Genet 2017. [PMID: 28636662 PMCID: PMC5500376 DOI: 10.1371/journal.pgen.1006844] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Neural circuits are dynamic, with activity-dependent changes in synapse density and connectivity peaking during different phases of animal development. In C. elegans, young larvae form mature motor circuits through a dramatic switch in GABAergic neuron connectivity, by concomitant elimination of existing synapses and formation of new synapses that are maintained throughout adulthood. We have previously shown that an increase in microtubule dynamics during motor circuit rewiring facilitates new synapse formation. Here, we further investigate cellular control of circuit rewiring through the analysis of mutants obtained in a forward genetic screen. Using live imaging, we characterize novel mutations that alter cargo binding in the dynein motor complex and enhance anterograde synaptic vesicle movement during remodeling, providing in vivo evidence for the tug-of-war between kinesin and dynein in fast axonal transport. We also find that a casein kinase homolog, TTBK-3, inhibits stabilization of nascent synapses in their new locations, a previously unexplored facet of structural plasticity of synapses. Our study delineates temporally distinct signaling pathways that are required for effective neural circuit refinement. In this study, we identify pathways that regulate the formation and maintenance of synapses, the functional connections between neurons, in the nervous system of the nematode C. elegans. Our work characterizes the interaction between molecular motors kinesin and dynein, which carry cargo and move towards opposite ends of microtubules during synapse formation. We also address the role of a protein kinase gene TTBK-3 in maintaining synapse structure once synaptic components have reached the sites of new synapses. Our findings shed mechanistic insight into the coordination of molecular motors and the cytoskeleton in neural circuit function.
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30
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Small LE, Dawes AT. PAR proteins regulate maintenance-phase myosin dynamics during Caenorhabditis elegans zygote polarization. Mol Biol Cell 2017; 28:2220-2231. [PMID: 28615321 PMCID: PMC5531737 DOI: 10.1091/mbc.e16-04-0263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 05/30/2017] [Accepted: 06/06/2017] [Indexed: 11/11/2022] Open
Abstract
Establishment of anterior-posterior polarity in the Caenorhabditis elegans zygote requires two different processes: mechanical activity of the actin-myosin cortex and biochemical activity of partitioning-defective (PAR) proteins. Here we analyze how PARs regulate the behavior of the cortical motor protein nonmuscle myosin (NMY-2) to complement recent efforts that investigate how PARs regulate the Rho GTPase CDC-42, which in turn regulates the actin-myosin cortex. We find that PAR-3 and PAR-6 concentrate CDC-42-dependent NMY-2 in the anterior cortex, whereas PAR-2 inhibits CDC-42-dependent NMY-2 in the posterior domain by inhibiting PAR-3 and PAR-6. In addition, we find that PAR-1 and PAR-3 are necessary for inhibiting movement of NMY-2 across the cortex. PAR-1 protects NMY-2 from being moved across the cortex by forces likely originating in the cytoplasm. Meanwhile, PAR-3 stabilizes NMY-2 against PAR-2 and PAR-6 dynamics on the cortex. We find that PAR signaling fulfills two roles: localizing NMY-2 to the anterior cortex and preventing displacement of the polarized cortical actin-myosin network.
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Affiliation(s)
- Lawrence E Small
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Adriana T Dawes
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 .,Department of Mathematics, The Ohio State University, Columbus, OH 43210
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31
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Davies T, Sundaramoorthy S, Jordan S, Shirasu-Hiza M, Dumont J, Canman J. Using fast-acting temperature-sensitive mutants to study cell division in Caenorhabditis elegans. Methods Cell Biol 2017; 137:283-306. [DOI: 10.1016/bs.mcb.2016.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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32
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Housden BE, Muhar M, Gemberling M, Gersbach CA, Stainier DYR, Seydoux G, Mohr SE, Zuber J, Perrimon N. Loss-of-function genetic tools for animal models: cross-species and cross-platform differences. Nat Rev Genet 2016; 18:24-40. [PMID: 27795562 DOI: 10.1038/nrg.2016.118] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Our understanding of the genetic mechanisms that underlie biological processes has relied extensively on loss-of-function (LOF) analyses. LOF methods target DNA, RNA or protein to reduce or to ablate gene function. By analysing the phenotypes that are caused by these perturbations the wild-type function of genes can be elucidated. Although all LOF methods reduce gene activity, the choice of approach (for example, mutagenesis, CRISPR-based gene editing, RNA interference, morpholinos or pharmacological inhibition) can have a major effect on phenotypic outcomes. Interpretation of the LOF phenotype must take into account the biological process that is targeted by each method. The practicality and efficiency of LOF methods also vary considerably between model systems. We describe parameters for choosing the optimal combination of method and system, and for interpreting phenotypes within the constraints of each method.
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Affiliation(s)
- Benjamin E Housden
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
| | - Matthias Muhar
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna 1030, Austria
| | - Matthew Gemberling
- Department of Biomedical Engineering and the Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA
| | - Charles A Gersbach
- Department of Biomedical Engineering and the Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708, USA
| | - Didier Y R Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 43 Ludwigstrasse, Bad Nauheim 61231, Germany
| | - Geraldine Seydoux
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21218, USA.,Howard Hughes Medical Institute, 725 North Wolfe Street, Baltimore, Maryland 21218, USA
| | - Stephanie E Mohr
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
| | - Johannes Zuber
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna 1030, Austria
| | - Norbert Perrimon
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA.,Howard Hughes Medical Institute, 77 Avenue Louis Pasteur, Boston, Massachusetts 02115, USA
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33
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Connolly AA, Sugioka K, Chuang CH, Lowry JB, Bowerman B. KLP-7 acts through the Ndc80 complex to limit pole number in C. elegans oocyte meiotic spindle assembly. J Cell Biol 2015; 210:917-32. [PMID: 26370499 PMCID: PMC4576866 DOI: 10.1083/jcb.201412010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
KLP-7/MCAK regulates kinetochore–microtubule attachment and spindle tension to promote the coalescence of early spindle pole foci, which produces a bipolar structure during the acentrosomal process of oocyte meiotic spindle assembly in C. elegans. During oocyte meiotic cell division in many animals, bipolar spindles assemble in the absence of centrosomes, but the mechanisms that restrict pole assembly to a bipolar state are unknown. We show that KLP-7, the single mitotic centromere–associated kinesin (MCAK)/kinesin-13 in Caenorhabditis elegans, is required for bipolar oocyte meiotic spindle assembly. In klp-7(−) mutants, extra microtubules accumulated, extra functional spindle poles assembled, and chromosomes frequently segregated as three distinct masses during meiosis I anaphase. Moreover, reducing KLP-7 function in monopolar klp-18(−) mutants often restored spindle bipolarity and chromosome segregation. MCAKs act at kinetochores to correct improper kinetochore–microtubule (k–MT) attachments, and depletion of the Ndc-80 kinetochore complex, which binds microtubules to mediate kinetochore attachment, restored bipolarity in klp-7(−) mutant oocytes. We propose a model in which KLP-7/MCAK regulates k–MT attachment and spindle tension to promote the coalescence of early spindle pole foci that produces a bipolar structure during the acentrosomal process of oocyte meiotic spindle assembly.
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Affiliation(s)
- Amy A Connolly
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Kenji Sugioka
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Chien-Hui Chuang
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Joshua B Lowry
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
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34
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Rahman MM, Munzig M, Kaneshiro K, Lee B, Strome S, Müller-Reichert T, Cohen-Fix O. Caenorhabditis elegans polo-like kinase PLK-1 is required for merging parental genomes into a single nucleus. Mol Biol Cell 2015; 26:4718-35. [PMID: 26490119 PMCID: PMC4678026 DOI: 10.1091/mbc.e15-04-0244] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 10/13/2015] [Indexed: 11/11/2022] Open
Abstract
Before the first zygotic division, the nuclear envelopes of the maternal and paternal pronuclei disassemble, allowing both sets of chromosomes to be incorporated into a single nucleus in daughter cells after mitosis. We found that in Caenorhabditis elegans, partial inactivation of the polo-like kinase PLK-1 causes the formation of two nuclei, containing either the maternal or paternal chromosomes, in each daughter cell. These two nuclei gave rise to paired nuclei in all subsequent cell divisions. The paired-nuclei phenotype was caused by a defect in forming a gap in the nuclear envelopes at the interface between the two pronuclei during the first mitotic division. This was accompanied by defects in chromosome congression and alignment of the maternal and paternal metaphase plates relative to each other. Perturbing chromosome congression by other means also resulted in failure to disassemble the nuclear envelope between the two pronuclei. Our data further show that PLK-1 is needed for nuclear envelope breakdown during early embryogenesis. We propose that during the first zygotic division, PLK-1-dependent chromosome congression and metaphase plate alignment are necessary for the disassembly of the nuclear envelope between the two pronuclei, ultimately allowing intermingling of the maternal and paternal chromosomes.
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Affiliation(s)
- Mohammad M Rahman
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Mandy Munzig
- Structural Cell Biology Group, Experimental Center, Medical Faculty Carl Gustav Carus, University of Technology Dresden, 01307 Dresden, Germany
| | - Kiyomi Kaneshiro
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Brandon Lee
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Susan Strome
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Thomas Müller-Reichert
- Structural Cell Biology Group, Experimental Center, Medical Faculty Carl Gustav Carus, University of Technology Dresden, 01307 Dresden, Germany
| | - Orna Cohen-Fix
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
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35
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Lowry J, Yochem J, Chuang CH, Sugioka K, Connolly AA, Bowerman B. High-Throughput Cloning of Temperature-Sensitive Caenorhabditis elegans Mutants with Adult Syncytial Germline Membrane Architecture Defects. G3 (BETHESDA, MD.) 2015; 5:2241-55. [PMID: 26311651 PMCID: PMC4632044 DOI: 10.1534/g3.115.021451] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022]
Abstract
The adult Caenorhabditis elegans hermaphrodite gonad consists of two mirror-symmetric U-shaped arms, with germline nuclei located peripherally in the distal regions of each arm. The nuclei are housed within membrane cubicles that are open to the center, forming a syncytium with a shared cytoplasmic core called the rachis. As the distal germline nuclei progress through meiotic prophase, they move proximally and eventually cellularize as their compartments grow in size. The development and maintenance of this complex and dynamic germline membrane architecture are relatively unexplored, and we have used a forward genetic screen to identify 20 temperature-sensitive mutations in 19 essential genes that cause defects in the germline membrane architecture. Using a combined genome-wide SNP mapping and whole genome sequencing strategy, we have identified the causal mutations in 10 of these mutants. Four of the genes we have identified are conserved, with orthologs known to be involved in membrane biology, and are required for proper development or maintenance of the adult germline membrane architecture. This work provides a starting point for further investigation of the mechanisms that control the dynamics of syncytial membrane architecture during adult oogenesis.
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Affiliation(s)
- Josh Lowry
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403
| | - John Yochem
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403
| | - Chien-Hui Chuang
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403
| | - Kenji Sugioka
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403
| | - Amy A Connolly
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403
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36
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Tavernier N, Noatynska A, Panbianco C, Martino L, Van Hove L, Schwager F, Léger T, Gotta M, Pintard L. Cdk1 phosphorylates SPAT-1/Bora to trigger PLK-1 activation and drive mitotic entry in C. elegans embryos. ACTA ACUST UNITED AC 2015; 208:661-9. [PMID: 25753036 PMCID: PMC4362466 DOI: 10.1083/jcb.201408064] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phosphorylation of SPAT-1/Bora by Cdk1 enhances Plk1 phosphorylation by Aurora A and promotes entry into mitosis in C. elegans. The molecular mechanisms governing mitotic entry during animal development are incompletely understood. Here, we show that the mitotic kinase CDK-1 phosphorylates Suppressor of Par-Two 1 (SPAT-1)/Bora to regulate its interaction with PLK-1 and to trigger mitotic entry in early Caenorhabditis elegans embryos. Embryos expressing a SPAT-1 version that is nonphosphorylatable by CDK-1 and that is defective in PLK-1 binding in vitro present delays in mitotic entry, mimicking embryos lacking SPAT-1 or PLK-1 functions. We further show that phospho–SPAT-1 activates PLK-1 by triggering phosphorylation on its activator T loop in vitro by Aurora A. Likewise, we show that phosphorylation of human Bora by Cdk1 promotes phosphorylation of human Plk1 by Aurora A, suggesting that this mechanism is conserved in humans. Our results suggest that CDK-1 activates PLK-1 via SPAT-1 phosphorylation to promote entry into mitosis. We propose the existence of a positive feedback loop that connects Cdk1 and Plk1 activation to ensure a robust control of mitotic entry and cell division timing.
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Affiliation(s)
- Nicolas Tavernier
- Jacques Monod Institute, UMR7592; and Mass Spectrometry Facility, Jacques Monod Institute, UMR7592; Paris-Diderot University-Centre National de la Recherche Scientifique, 75013 Paris, France
| | - Anna Noatynska
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Costanza Panbianco
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Lisa Martino
- Jacques Monod Institute, UMR7592; and Mass Spectrometry Facility, Jacques Monod Institute, UMR7592; Paris-Diderot University-Centre National de la Recherche Scientifique, 75013 Paris, France
| | - Lucie Van Hove
- Jacques Monod Institute, UMR7592; and Mass Spectrometry Facility, Jacques Monod Institute, UMR7592; Paris-Diderot University-Centre National de la Recherche Scientifique, 75013 Paris, France
| | - Françoise Schwager
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Thibaut Léger
- Jacques Monod Institute, UMR7592; and Mass Spectrometry Facility, Jacques Monod Institute, UMR7592; Paris-Diderot University-Centre National de la Recherche Scientifique, 75013 Paris, France
| | - Monica Gotta
- Department of Cellular Physiology and Metabolism, Faculty of Medicine, University of Geneva, CH-1211 Geneva 4, Switzerland Swiss National Centre for Competence in Research Program Chemical Biology, 1211 Geneva, Switzerland
| | - Lionel Pintard
- Jacques Monod Institute, UMR7592; and Mass Spectrometry Facility, Jacques Monod Institute, UMR7592; Paris-Diderot University-Centre National de la Recherche Scientifique, 75013 Paris, France
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Shimanovskaya E, Viscardi V, Lesigang J, Lettman MM, Qiao R, Svergun DI, Round A, Oegema K, Dong G. Structure of the C. elegans ZYG-1 cryptic polo box suggests a conserved mechanism for centriolar docking of Plk4 kinases. Structure 2014; 22:1090-1104. [PMID: 24980795 PMCID: PMC4126857 DOI: 10.1016/j.str.2014.05.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/20/2014] [Accepted: 05/20/2014] [Indexed: 01/10/2023]
Abstract
Plk4 family kinases control centriole assembly. Plk4s target mother centrioles through an interaction between their cryptic polo box (CPB) and acidic regions in the centriolar receptors SPD-2/Cep192 and/or Asterless/Cep152. Here, we report a crystal structure for the CPB of C. elegans ZYG-1, which forms a Z-shaped dimer containing an intermolecular β sheet with an extended basic surface patch. Biochemical and in vivo analysis revealed that electrostatic interactions dock the ZYG-1 CPB basic patch onto the SPD-2-derived acidic region to promote ZYG-1 targeting and new centriole assembly. Analysis of a different crystal form of the Drosophila Plk4 (DmPlk4) CPB suggests that it also forms a Z-shaped dimer. Comparison of the ZYG-1 and DmPlk4 CPBs revealed structural changes in the ZYG-1 CPB that confer selectivity for binding SPD-2 over Asterless-derived acidic regions. Overall, our findings suggest a conserved mechanism for centriolar docking of Plk4 homologs that initiate daughter centriole assembly.
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Affiliation(s)
| | - Valeria Viscardi
- Department of Cellular and Molecular Medicine, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Johannes Lesigang
- Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Molly M Lettman
- Department of Cellular and Molecular Medicine, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Renping Qiao
- Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Hamburg Unit, EMBL c/o DESY, Notkestrasse 85, 22603 Hamburg, Germany
| | - Adam Round
- European Molecular Biology Laboratory, Grenoble Outstation, 6 rue Jules Horowitz, 38042 Grenoble, France; Unit for Virus Host-Cell Interactions, University Grenoble Alpes-EMBL-CNRS, 6 rue Jules Horowitz, 38042 Grenoble, France
| | - Karen Oegema
- Department of Cellular and Molecular Medicine, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Gang Dong
- Max F. Perutz Laboratories, Medical University of Vienna, 1030 Vienna, Austria.
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Connolly AA, Osterberg V, Christensen S, Price M, Lu C, Chicas-Cruz K, Lockery S, Mains PE, Bowerman B. Caenorhabditis elegans oocyte meiotic spindle pole assembly requires microtubule severing and the calponin homology domain protein ASPM-1. Mol Biol Cell 2014; 25:1298-311. [PMID: 24554763 PMCID: PMC3982995 DOI: 10.1091/mbc.e13-11-0687] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Oocyte meiotic spindles are bipolar but assemble without centrosomes. Three Caenorhabditis elegans genes that contribute are that for the calponin homology domain protein, aspm-1; the katanin mei-1; and the kinesin-12 family member klp-18. The results indicate that both microtubule severing and ASPM-1 promote pole assembly, whereas KLP-18 promotes bipolarity. In many animals, including vertebrates, oocyte meiotic spindles are bipolar but assemble in the absence of centrosomes. Although meiotic spindle positioning in oocytes has been investigated extensively, much less is known about their assembly. In Caenorhabditis elegans, three genes previously shown to contribute to oocyte meiotic spindle assembly are the calponin homology domain protein encoded by aspm-1, the katanin family member mei-1, and the kinesin-12 family member klp-18. We isolated temperature-sensitive alleles of all three and investigated their requirements using live-cell imaging to reveal previously undocumented requirements for aspm-1 and mei-1. Our results indicate that bipolar but abnormal oocyte meiotic spindles assemble in aspm-1(-) embryos, whereas klp-18(-) and mei-1(-) mutants assemble monopolar and apolar spindles, respectively. Furthermore, two MEI-1 functions—ASPM-1 recruitment to the spindle and microtubule severing—both contribute to monopolar spindle assembly in klp-18(-) mutants. We conclude that microtubule severing and ASPM-1 both promote meiotic spindle pole assembly in C. elegans oocytes, whereas the kinesin 12 family member KLP-18 promotes spindle bipolarity.
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Affiliation(s)
- Amy A Connolly
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403 Institute of Neuroscience, University of Oregon, Eugene, OR 97403 Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 4N1, Canada
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McNally K, Berg E, Cortes DB, Hernandez V, Mains PE, McNally FJ. Katanin maintains meiotic metaphase chromosome alignment and spindle structure in vivo and has multiple effects on microtubules in vitro. Mol Biol Cell 2014; 25:1037-49. [PMID: 24501424 PMCID: PMC3967969 DOI: 10.1091/mbc.e13-12-0764] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Caenorhabditis elegans bivalents are positioned between dense bundles of microtubules within female meiotic spindles. Rapid inactivation of katanin after meiotic spindle assembly causes loss of organized microtubule bundles and displacement of bivalents from the metaphase plate. Purified katanin can preferentially sever at intersections between microtubules. Assembly of Caenorhabditis elegans female meiotic spindles requires both MEI-1 and MEI-2 subunits of the microtubule-severing ATPase katanin. Strong loss-of-function mutants assemble apolar intersecting microtubule arrays, whereas weaker mutants assemble bipolar meiotic spindles that are longer than wild type. To determine whether katanin is also required for spindle maintenance, we monitored metaphase I spindles after a fast-acting mei-1(ts) mutant was shifted to a nonpermissive temperature. Within 4 min of temperature shift, bivalents moved off the metaphase plate, and microtubule bundles within the spindle lengthened and developed a high degree of curvature. Spindles eventually lost bipolar structure. Immunofluorescence of embryos fixed at increasing temperature indicated that MEI-1 was lost from spindle microtubules before loss of ASPM-1, indicating that MEI-1 and ASPM-1 act independently at spindle poles. We quantified the microtubule-severing activity of purified MEI-1/MEI-2 complexes corresponding to six different point mutations and found a linear relationship between microtubule disassembly rate and meiotic spindle length. Previous work showed that katanin is required for severing at points where two microtubules intersect in vivo. We show that purified MEI-1/MEI-2 complexes preferentially sever at intersections between two microtubules and directly bundle microtubules in vitro. These activities could promote parallel/antiparallel microtubule organization in meiotic spindles.
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Affiliation(s)
- Karen McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616 Genes and Development Research Group, Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 4N1, Canada
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Gomes JE, Tavernier N, Richaudeau B, Formstecher E, Boulin T, Mains PE, Dumont J, Pintard L. Microtubule severing by the katanin complex is activated by PPFR-1-dependent MEI-1 dephosphorylation. ACTA ACUST UNITED AC 2013; 202:431-9. [PMID: 23918937 PMCID: PMC3734088 DOI: 10.1083/jcb.201304174] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dephosphorylation of MEI-1 activates katanin during meiosis, whereas ubiquitin-mediated degradation of both MEI-1 and its activator PPFR-1 ensure efficient katanin inactivation during mitosis. Katanin is an evolutionarily conserved microtubule (MT)-severing complex implicated in multiple aspects of MT dynamics. In Caenorhabditis elegans, the katanin homologue MEI-1 is required for meiosis, but must be inactivated before mitosis. Here we show that PPFR-1, a regulatory subunit of a trimeric protein phosphatase 4 complex, enhanced katanin MT-severing activity during C. elegans meiosis. Loss of ppfr-1, similarly to the inactivation of MT severing, caused a specific defect in meiosis II spindle disassembly. We show that a fraction of PPFR-1 was degraded after meiosis, contributing to katanin inactivation. PPFR-1 interacted with MEL-26, the substrate recognition subunit of the CUL-3 RING E3 ligase (CRL3MEL-26), which also targeted MEI-1 for post-meiotic degradation. Reversible protein phosphorylation of MEI-1 may ensure temporal activation of the katanin complex during meiosis, whereas CRL3MEL-26-mediated degradation of both MEI-1 and its activator PPFR-1 ensure efficient katanin inactivation in the transition to mitosis.
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Affiliation(s)
- José-Eduardo Gomes
- Institut Jacques Monod, Centre National de la Recherche Scientifique, UMR 7592, University of Paris Diderot, F-75205 Paris, France
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41
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Cheng Z, Yi P, Wang X, Chai Y, Feng G, Yang Y, Liang X, Zhu Z, Li W, Ou G. Conditional targeted genome editing using somatically expressed TALENs in C. elegans. Nat Biotechnol 2013; 31:934-7. [PMID: 23955274 DOI: 10.1038/nbt.2674] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 07/22/2013] [Indexed: 11/08/2022]
Abstract
We have developed a method for the generation of conditional knockouts in Caenorhabditis elegans by expressing transcription activator-like effector nucleases (TALENs) in somatic cells. Using germline transformation with plasmids encoding TALENs under the control of an inducible or tissue-specific promoter, we observed effective gene modifications and resulting phenotypes in specific developmental stages and tissues. We further used this method to bypass the embryonic requirement of cor-1, which encodes the homolog of human severe combined immunodeficiency (SCID) protein coronin, and we determined its essential role in cell migration in larval Q-cell lineages. Our results show that TALENs expressed in the somatic cells of model organisms provide a versatile tool for functional genomics.
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Affiliation(s)
- Ze Cheng
- 1] National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Chaoyang District, Beijing, China. [2] School of Life Sciences, Peking University, Beijing, China. [3]
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42
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Thompson O, Edgley M, Strasbourger P, Flibotte S, Ewing B, Adair R, Au V, Chaudhry I, Fernando L, Hutter H, Kieffer A, Lau J, Lee N, Miller A, Raymant G, Shen B, Shendure J, Taylor J, Turner EH, Hillier LW, Moerman DG, Waterston RH. The million mutation project: a new approach to genetics in Caenorhabditis elegans. Genome Res 2013; 23:1749-62. [PMID: 23800452 PMCID: PMC3787271 DOI: 10.1101/gr.157651.113] [Citation(s) in RCA: 298] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We have created a library of 2007 mutagenized Caenorhabditis elegans strains, each sequenced to a target depth of 15-fold coverage, to provide the research community with mutant alleles for each of the worm's more than 20,000 genes. The library contains over 800,000 unique single nucleotide variants (SNVs) with an average of eight nonsynonymous changes per gene and more than 16,000 insertion/deletion (indel) and copy number changes, providing an unprecedented genetic resource for this multicellular organism. To supplement this collection, we also sequenced 40 wild isolates, identifying more than 630,000 unique SNVs and 220,000 indels. Comparison of the two sets demonstrates that the mutant collection has a much richer array of both nonsense and missense mutations than the wild isolate set. We also find a wide range of rDNA and telomere repeat copy number in both sets. Scanning the mutant collection for molecular phenotypes reveals a nonsense suppressor as well as strains with higher levels of indels that harbor mutations in DNA repair genes and strains with abundant males associated with him mutations. All the strains are available through the Caenorhabditis Genetics Center and all the sequence changes have been deposited in WormBase and are available through an interactive website.
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Affiliation(s)
- Owen Thompson
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
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Lange KI, Heinrichs J, Cheung K, Srayko M. Suppressor mutations identify amino acids in PAA-1/PR65 that facilitate regulatory RSA-1/B″ subunit targeting of PP2A to centrosomes in C. elegans. Biol Open 2012; 2:88-94. [PMID: 23336080 PMCID: PMC3545272 DOI: 10.1242/bio.20122956] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 10/16/2012] [Indexed: 12/17/2022] Open
Abstract
Protein phosphorylation and dephosphorylation is a key mechanism for the spatial and temporal regulation of many essential developmental processes and is especially prominent during mitosis. The multi-subunit protein phosphatase 2A (PP2A) enzyme plays an important, yet poorly characterized role in dephosphorylating proteins during mitosis. PP2As are heterotrimeric complexes comprising a catalytic, structural, and regulatory subunit. Regulatory subunits are mutually exclusive and determine subcellular localization and substrate specificity of PP2A. At least 3 different classes of regulatory subunits exist (termed B, B′, B″) but there is no obvious similarity in primary sequence between these classes. Therefore, it is not known how these diverse regulatory subunits interact with the same holoenzyme to facilitate specific PP2A functions in vivo. The B″ family of regulatory subunits is the least understood because these proteins lack conserved structural domains. RSA-1 (regulator of spindle assembly) is a regulatory B″ subunit required for mitotic spindle assembly in Caenorhabditis elegans. In order to address how B″ subunits interact with the PP2A core enzyme, we focused on a conditional allele, rsa-1(or598ts), and determined that this mutation specifically disrupts the protein interaction between RSA-1 and the PP2A structural subunit, PAA-1. Through genetic screening, we identified a putative interface on the PAA-1 structural subunit that interacts with a defined region of RSA-1/B″. In the context of previously published results, these data propose a mechanism of how different PP2A B-regulatory subunit families can bind the same holoenzyme in a mutually exclusive manner, to perform specific tasks in vivo.
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Affiliation(s)
- Karen I Lange
- Department of Biological Sciences, University of Alberta , Edmonton, AB T6G 2E9 , Canada
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Reingle JM, Maldonado-Molina MM, Jennings WG, Komro KA. Racial/ethnic differences in trajectories of aggression in a longitudinal sample of high-risk, urban youth. J Adolesc Health 2012; 51:45-52. [PMID: 22727076 PMCID: PMC3383599 DOI: 10.1016/j.jadohealth.2011.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/07/2011] [Accepted: 11/08/2011] [Indexed: 11/24/2022]
Abstract
PURPOSE To estimate trajectories of aggression among African Americans and Hispanics using a longitudinal sample of urban adolescents, and test multiple domains of risk factors to differentiate profiles of aggression. METHODS Participants included 3,038 adolescents followed from sixth to eighth grade. Trajectories of aggression were estimated for African Americans and Hispanics separately, and multinomial regression procedures were used to evaluate the effect of multiple domains of risk and protective factors. Mediation analyses were conducted to evaluate the indirect effects of contextual variables on aggression. RESULTS Four profiles of aggression were identified. Among Hispanics, groups included: (1) low-aggression, (2) desistors, (3) escalators, and (4) consistent aggression; among African Americans: (1) low-aggression, (2) escalators, (3) moderate-consistent aggression, and (4) consistent aggression. Differences in the multiple domains of risk factors emerged between racial/ethnic groups. CONCLUSIONS Contextual variables (peer alcohol use, adult alcohol consumption, and access to alcohol at home) increased risk for aggression differentially by racial/ethnic group.
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Affiliation(s)
- Jennifer M. Reingle
- University of Florida, College of Public Health and Health Professions and College of Medicine, Department of Epidemiology, 101 S. Newell Dr., Gainesville, FL 32610-0177
| | - Mildred M. Maldonado-Molina
- University of Florida, College of Medicine, Department of Health Outcomes and Policy and Institute for Child Health Policy, 1329 SW 16th, Gainesville, FL 32610-0177
| | - Wesley G. Jennings
- University of South Florida, Department of Criminology, University of South Florida, 4202 E. Fowler Ave, Tampa, FL 33620
| | - Kelli A. Komro
- University of Florida, College of Medicine, Department of Health Outcomes and Policy and Institute for Child Health Policy, 1329 SW 16th, Gainesville, FL 32610-0177
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45
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Kinesin-1 prevents capture of the oocyte meiotic spindle by the sperm aster. Dev Cell 2012; 22:788-98. [PMID: 22465668 DOI: 10.1016/j.devcel.2012.01.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 12/03/2011] [Accepted: 01/12/2012] [Indexed: 11/20/2022]
Abstract
Centrioles are lost during oogenesis and inherited from the sperm at fertilization. In the zygote, the centrioles recruit pericentriolar proteins from the egg to form a mature centrosome that nucleates a sperm aster. The sperm aster then captures the female pronucleus to join the maternal and paternal genomes. Because fertilization occurs before completion of female meiosis, some mechanism must prevent capture of the meiotic spindle by the sperm aster. Here we show that in wild-type Caenorhabditis elegans zygotes, maternal pericentriolar proteins are not recruited to the sperm centrioles until after completion of meiosis. Depletion of kinesin-1 heavy chain or its binding partner resulted in premature centrosome maturation during meiosis and growth of a sperm aster that could capture the oocyte meiotic spindle. Kinesin prevents recruitment of pericentriolar proteins by coating the sperm DNA and centrioles and thus prevents triploidy by a nonmotor mechanism.
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46
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Bowerman B. The near demise and subsequent revival of classical genetics for investigating Caenorhabditis elegans embryogenesis: RNAi meets next-generation DNA sequencing. Mol Biol Cell 2012; 22:3556-8. [PMID: 21960050 PMCID: PMC3183011 DOI: 10.1091/mbc.e11-03-0185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Molecular genetic investigation of the early Caenorhabditis elegans embryo has contributed substantially to the discovery and general understanding of the genes, pathways, and mechanisms that regulate and execute developmental and cell biological processes. Initially, worm geneticists relied exclusively on a classical genetics approach, isolating mutants with interesting phenotypes after mutagenesis and then determining the identity of the affected genes. Subsequently, the discovery of RNA interference (RNAi) led to a much greater reliance on a reverse genetics approach: reducing the function of known genes with RNAi and then observing the phenotypic consequences. Now the advent of next-generation DNA sequencing technologies and the ensuing ease and affordability of whole-genome sequencing are reviving the use of classical genetics to investigate early C. elegans embryogenesis.
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Affiliation(s)
- Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
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47
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Gusnowski EM, Srayko M. Visualization of dynein-dependent microtubule gliding at the cell cortex: implications for spindle positioning. ACTA ACUST UNITED AC 2011; 194:377-86. [PMID: 21825072 PMCID: PMC3153651 DOI: 10.1083/jcb.201103128] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Distinct dynein–microtubule interactions are used for asymmetric spindle-positioning tasks in the C. elegans embryo. Dynein motors move along the microtubule (MT) lattice in a processive “walking” manner. In the one-cell Caenorhabditis elegans embryo, dynein is required for spindle-pulling forces during mitosis. Posteriorly directed spindle-pulling forces are higher than anteriorly directed forces, and this imbalance results in posterior spindle displacement during anaphase and an asymmetric division. To address how dynein could be asymmetrically activated to achieve posterior spindle displacement, we developed an assay to measure dynein’s activity on individual MTs at the embryo cortex. Our study reveals that cortical dynein motors maintain a basal level of activity that propels MTs along the cortex, even under experimental conditions that drastically reduce anaphase spindle forces. This suggests that dynein-based MT gliding is not sufficient for anaphase spindle-pulling force. Instead, we find that this form of dynein activity is most prominent during spindle centering in early prophase. We propose a model whereby different dynein–MT interactions are used for specific spindle-positioning tasks in the one-cell embryo.
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Affiliation(s)
- Eva M Gusnowski
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
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48
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Rapid mapping and identification of mutations in Caenorhabditis elegans by restriction site-associated DNA mapping and genomic interval pull-down sequencing. Genetics 2011; 189:767-78. [PMID: 21900274 DOI: 10.1534/genetics.111.134031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Forward genetic screens provide a powerful approach for inferring gene function on the basis of the phenotypes associated with mutated genes. However, determining the causal mutation by traditional mapping and candidate gene sequencing is often the rate-limiting step, especially when analyzing many mutants. We report two genomic approaches for more rapidly determining the identity of the affected genes in Caenorhabditis elegans mutants. First, we report our use of restriction site-associated DNA (RAD) polymorphism markers for rapidly mapping mutations after chemical mutagenesis and mutant isolation. Second, we describe our use of genomic interval pull-down sequencing (GIPS) to selectively capture and sequence megabase-sized portions of a mutant genome. Together, these two methods provide a rapid and cost-effective approach for positional cloning of C. elegans mutant loci, and are also applicable to other genetic model systems.
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