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Zuo Y, Mei X, Singson A. CRISPR/Cas9 Mediated Fluorescent Tagging of Caenorhabditis elegans SPE-38 Reveals a Complete Localization Pattern in Live Spermatozoa. Biomolecules 2023; 13:biom13040623. [PMID: 37189371 DOI: 10.3390/biom13040623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 04/01/2023] Open
Abstract
The Caenorhabditis elegans spe-38 gene encodes a four-pass transmembrane molecule that is required in sperm for fertilization. In previous work, the localization of the SPE-38 protein was examined using polyclonal antibodies on spermatids and mature amoeboid spermatozoa. SPE-38 is localized to unfused membranous organelles (MOs) in nonmotile spermatids. Different fixation conditions revealed that SPE-38 either localized to fused MOs and the cell body plasma membrane or the pseudopod plasma membrane of mature sperm. To address this localization paradox in mature sperm, CRISPR/Cas9 genome editing was used to tag endogenous SPE-38 with fluorescent wrmScarlet-I. Homozygous male and hermaphrodite worms encoding SPE-38::wrmScarlet-I were fertile indicating the fluorescent tag does not interfere with SPE-38 function during sperm activation or fertilization. We found that SPE-38::wrmScarlet-I localized to MOs in spermatids consistent with previous antibody localization. In mature and motile spermatozoa we found SPE-38::wrmScarlet-I in fused MOs, the cell body plasma membrane, and the pseudopod plasma membrane. We conclude that the localization pattern observed with SPE-38::wrmScarlet-I represents the complete distribution of SPE-38 in mature spermatozoa and this localization pattern is consistent with a hypothesized role of SPE-38 directly in sperm-egg binding and/or fusion.
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Crittenden SL, Seidel HS, Kimble J. Analysis of the C. elegans Germline Stem Cell Pool. Methods Mol Biol 2023; 2677:1-36. [PMID: 37464233 DOI: 10.1007/978-1-0716-3259-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
The Caenorhabditis elegans germline is an excellent model for studying the genetic and molecular regulation of stem cell self-renewal and progression of cells from a stem cell state to a differentiated state. The germline tissue is organized in an assembly line with the germline stem cell (GSC) pool at one end and differentiated gametes at the other. A simple mesenchymal niche caps the GSC pool and maintains GSCs in an undifferentiated state by signaling through the conserved Notch pathway. Notch signaling activates transcription of the key GSC regulators lst-1 and sygl-1 proteins in a gradient through the GSC pool. LST-1 and SYGL-1 proteins work with PUF RNA regulators in a self-renewal hub to maintain the GSC pool. In this chapter, we present methods for characterizing the C. elegans GSC pool and early stages of germ cell differentiation. The methods include examination of germlines in living and fixed worms, cell cycle analysis, and analysis of markers. We also discuss assays to separate mutant phenotypes that affect the stem cell vs. differentiation decision from those that affect germ cell processes more generally.
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Affiliation(s)
- Sarah L Crittenden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Hannah S Seidel
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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Li T, Wang X, Feng Z, Zou Y. Live imaging of postembryonic developmental processes in C. elegans. STAR Protoc 2022; 3:101336. [PMID: 35496803 PMCID: PMC9043753 DOI: 10.1016/j.xpro.2022.101336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Live imaging is an important tool to track dynamic processes such as neuronal patterning events. Here, we describe a protocol for time-lapse microscopy analysis using neuronal migration and dendritic growth as examples. This protocol can provide detailed information for understanding cellular dynamics during postembryonic development in Caenorhabditis elegans (C. elegans). For complete details on the use and execution of this protocol, please refer to Feng et al. (2020), Li et al. (2021), and Wang et al. (2021).
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Affiliation(s)
- Tingting Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinjian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhigang Feng
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yan Zou
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Han Z, Lo WS, Lightfoot JW, Witte H, Sun S, Sommer RJ. Improving Transgenesis Efficiency and CRISPR-Associated Tools Through Codon Optimization and Native Intron Addition in Pristionchus Nematodes. Genetics 2020; 216:947-956. [PMID: 33060138 PMCID: PMC7768246 DOI: 10.1534/genetics.120.303785] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/14/2020] [Indexed: 12/12/2022] Open
Abstract
A lack of appropriate molecular tools is one obstacle that prevents in-depth mechanistic studies in many organisms. Transgenesis, clustered regularly interspaced short palindromic repeats (CRISPR)-associated engineering, and related tools are fundamental in the modern life sciences, but their applications are still limited to a few model organisms. In the phylum Nematoda, transgenesis can only be performed in a handful of species other than Caenorhabditis elegans, and additionally, other species suffer from significantly lower transgenesis efficiencies. We hypothesized that this may in part be due to incompatibilities of transgenes in the recipient organisms. Therefore, we investigated the genomic features of 10 nematode species from three of the major clades representing all different lifestyles. We found that these species show drastically different codon usage bias and intron composition. With these findings, we used the species Pristionchus pacificus as a proof of concept for codon optimization and native intron addition. Indeed, we were able to significantly improve transgenesis efficiency, a principle that may be usable in other nematode species. In addition, with the improved transgenes, we developed a fluorescent co-injection marker in P. pacificus for the detection of CRISPR-edited individuals, which helps considerably to reduce associated time and costs.
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Affiliation(s)
- Ziduan Han
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Wen-Sui Lo
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - James W Lightfoot
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Hanh Witte
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Shuai Sun
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
| | - Ralf J Sommer
- Max Planck Institute for Developmental Biology, Tuebingen 72076, Germany
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The C. elegans intestine: organogenesis, digestion, and physiology. Cell Tissue Res 2019; 377:383-396. [DOI: 10.1007/s00441-019-03036-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 04/12/2019] [Indexed: 12/16/2022]
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Thomas BJ, Wight IE, Chou WYY, Moreno M, Dawson Z, Homayouni A, Huang H, Kim H, Jia H, Buland JR, Wambach JA, Cole FS, Pak SC, Silverman GA, Luke CJ. CemOrange2 fusions facilitate multifluorophore subcellular imaging in C. elegans. PLoS One 2019; 14:e0214257. [PMID: 30913273 PMCID: PMC6435234 DOI: 10.1371/journal.pone.0214257] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/08/2019] [Indexed: 11/18/2022] Open
Abstract
Due to its ease of genetic manipulation and transparency, Caenorhabditis elegans (C. elegans) has become a preferred model system to study gene function by microscopy. The use of Aequorea victoria green fluorescent protein (GFP) fused to proteins or targeting sequences of interest, further expanded upon the utility of C. elegans by labeling subcellular structures, which enables following their disposition during development or in the presence of genetic mutations. Fluorescent proteins with excitation and emission spectra different from that of GFP accelerated the use of multifluorophore imaging in real time. We have expanded the repertoire of fluorescent proteins for use in C. elegans by developing a codon-optimized version of Orange2 (CemOrange2). Proteins or targeting motifs fused to CemOrange2 were distinguishable from the more common fluorophores used in the nematode; such as GFP, YFP, and mKate2. We generated a panel of CemOrange2 fusion constructs, and confirmed they were targeted to their correct subcellular addresses by colocalization with independent markers. To demonstrate the potential usefulness of this new panel of fluorescent protein markers, we showed that CemOrange2 fusion proteins could be used to: 1) monitor biological pathways, 2) multiplex with other fluorescent proteins to determine colocalization and 3) gain phenotypic knowledge of a human ABCA3 orthologue, ABT-4, trafficking variant in the C. elegans model organism.
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Affiliation(s)
- Brian J. Thomas
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Ira E. Wight
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Wendy Y. Y. Chou
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Marco Moreno
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Zachary Dawson
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Arielle Homayouni
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, MO, United States of America
| | - Huiyan Huang
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Hyori Kim
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Hanna Jia
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Justin R. Buland
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Jennifer A. Wambach
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - F. Sessions Cole
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Stephen C. Pak
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
| | - Gary A. Silverman
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Cliff J. Luke
- Department of Pediatrics, Washington University School of Medicine and St. Louis Children’s Hospital, St. Louis, MO, United States of America
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Abstract
C. elegans has been widely used as a model organism for basic biological research and is particularly amenable for molecular genetic studies using a broad repertoire of techniques. Biochemical approaches, including Western blot analysis, have emerged as a powerful tool in C. elegans biology for understanding molecular mechanisms that link genotypes to phenotypes. Here, we provide a protocol for Western blot analysis using protein extracts obtained from C. elegans samples.
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Affiliation(s)
- Dae-Eun Jeong
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Yujin Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Seung-Jae V Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea.
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea.
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Abstract
The Caenorhabditis elegans germline is an excellent model for studying the regulation of a pool of stem cells and progression of cells from a stem cell state to a differentiated state. At the tissue level, the germline is organized in an assembly line with the germline stem cell (GSC) pool at one end and differentiated cells at the other. A simple mesenchymal niche caps the GSC region of the germline and maintains GSCs in an undifferentiated state by signaling through the conserved Notch pathway. Downstream of Notch signaling, key regulators include novel LST-1 and SYGL-1 proteins and a network of RNA regulatory proteins. In this chapter we present methods for characterizing the C. elegans GSC pool and early germ cell differentiation. The methods include examination of the germline in living and fixed worms, cell cycle analysis, and analysis of markers. We also discuss assays to separate mutants that affect the stem cell vs. differentiation decision from those that affect germ cell processes more generally.
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Affiliation(s)
- Sarah L Crittenden
- HHMI/Department of Biochemistry, Howard Hughes Medical Institute and University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706-1544, USA.
| | - Hannah S Seidel
- HHMI/Department of Biochemistry, Howard Hughes Medical Institute and University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706-1544, USA
| | - Judith Kimble
- HHMI/Department of Biochemistry, Howard Hughes Medical Institute and University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, 53706-1544, USA
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Shen XD, Hou F, Chen J, Jiang XY, Zou SM. Identification of nuclear localization signal within goldfish Tgf2 transposase. Gene 2016; 593:21-27. [PMID: 27468946 DOI: 10.1016/j.gene.2016.07.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/12/2016] [Accepted: 07/24/2016] [Indexed: 10/21/2022]
Abstract
The structure of goldfish (Carassius auratus) Tgf2 transposase is still poorly understood, although it can mediate efficient gene transfer in teleost fish. We hypothesized the existence of a nuclear localization signal (NLS) within Tgf2 transposase to assist transport into the nucleus. To explore this, 15 consecutive amino acid residues (656-670 aa) within the C-terminus of Tgf2 transposase were predicted in silico to be a NLS domain. The pEGFP-C1-Tgf2TP(△31C) plasmid encoding the NLS-domain-deleted Tgf2 transposase fused to EGFP was constructed, and transfected into 293T cells. After transfection with pEGFP-C1-Tgf2TP(△31C), EGFP was not detected in the nucleus alone, while 67.0% of cells expressed EGFP only in the cytoplasm. In contrast, after transfection with control plasmids containing C- or N-terminal truncated Tgf2 transposases with an intact NLS domain, EGFP was not detected in the cytoplasm alone, while approximately 40% of cells expressed EGFP only in the nucleus, and the remaining 60% expressed EGFP in both the nucleus and cytoplasm. Our results demonstrated that loss of the NLS domain results in expression in the cytoplasm but not in the nucleus. These findings suggest that 15 aa residues located from 656 to 670 aa within the C-terminus of Tgf2 transposase can function as a NLS to assist the transfer of the transposase into the nucleus where it mediates DNA transposition.
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Affiliation(s)
- Xiao-Dan Shen
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China
| | - Fei Hou
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China
| | - Jie Chen
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China
| | - Xia-Yun Jiang
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China.
| | - Shu-Ming Zou
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China.
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Jay Burr AH, Baldwin JG. The nematode stoma: Homology of cell architecture with improved understanding by confocal microscopy of labeled cell boundaries. J Morphol 2016; 277:1168-86. [DOI: 10.1002/jmor.20567] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/24/2016] [Accepted: 05/26/2016] [Indexed: 11/08/2022]
Affiliation(s)
- A. H. Jay Burr
- Department of Biological Sciences; Simon Fraser University; Burnaby British Columbia V5A 1S6 Canada
- Department of Nematology; University of California; Riverside California 92521
| | - James G. Baldwin
- Department of Nematology; University of California; Riverside California 92521
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Gasser RB, Schwarz EM, Korhonen PK, Young ND. Understanding Haemonchus contortus Better Through Genomics and Transcriptomics. ADVANCES IN PARASITOLOGY 2016; 93:519-67. [PMID: 27238012 DOI: 10.1016/bs.apar.2016.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Parasitic roundworms (nematodes) cause substantial mortality and morbidity in animals globally. The barber's pole worm, Haemonchus contortus, is one of the most economically significant parasitic nematodes of small ruminants worldwide. Although this and related nematodes can be controlled relatively well using anthelmintics, resistance against most drugs in common use has become a major problem. Until recently, almost nothing was known about the molecular biology of H. contortus on a global scale. This chapter gives a brief background on H. contortus and haemonchosis, immune responses, vaccine research, chemotherapeutics and current problems associated with drug resistance. It also describes progress in transcriptomics before the availability of H. contortus genomes and the challenges associated with such work. It then reviews major progress on the two draft genomes and developmental transcriptomes of H. contortus, and summarizes their implications for the molecular biology of this worm in both the free-living and the parasitic stages of its life cycle. The chapter concludes by considering how genomics and transcriptomics can accelerate research on Haemonchus and related parasites, and can enable the development of new interventions against haemonchosis.
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Affiliation(s)
- R B Gasser
- The University of Melbourne, Parkville, VIC, Australia
| | - E M Schwarz
- The University of Melbourne, Parkville, VIC, Australia; Cornell University, Ithaca, NY, United States
| | - P K Korhonen
- The University of Melbourne, Parkville, VIC, Australia
| | - N D Young
- The University of Melbourne, Parkville, VIC, Australia
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