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Crook M, Carvajal T, Davis P, Ferdush J, Page RB, Tennyson E. Modelling the Caenorhabditis elegans gonad over developmental time using the Distal Tip Cell marker lag-2p::gfp. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000629. [PMID: 36060032 PMCID: PMC9434325 DOI: 10.17912/micropub.biology.000629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 11/11/2022]
Abstract
Development is a process that occurs over time, but defects are often scored at the end point of the process being studied. We are interested in understanding the molecular basis of gonad development in Caenorhabditis elegans and have used the Distal Tip Cell marker lag-2p::gfp to develop a larval size model of gonad growth. We found that gonad length demonstrates two distinct phases relative to larval length, with a breakpoint in mid-L3 stage. We hope that this model will help determine at what point in gonad development our genes of interest act.
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Affiliation(s)
- Matt Crook
- Texas A&M University-San Antonio
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Correspondence to: Matt Crook (
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Gu N, Chen C, Kabeya Y, Hasebe M, Tamada Y. Topoisomerase 1α is required for synchronous spermatogenesis in Physcomitrium patens. THE NEW PHYTOLOGIST 2022; 234:137-148. [PMID: 35067949 DOI: 10.1111/nph.17983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
DNA topoisomerase 1 (TOP1) plays general roles in DNA replication and transcription by regulating DNA topology in land plants and metazoans. TOP1 is also involved in specific developmental events; however, whether TOP1 plays a conserved developmental role among multicellular organisms is unknown. Here, we investigated the developmental roles of TOP1 in the moss Physcomitrium (Physcomitrella) patens with gene targeting, microscopy, 3D image segmentation and crossing experiments. We discovered that the disruption of TOP1α, but not its paralogue TOP1β, leads to a defect in fertilisation and subsequent sporophyte formation in P. patens. In the top1α mutant, the egg cell was functional for fertilisation, while sperm cells were fewer and infertile with disordered structures. We observed that the nuclei volume of wild-type sperm cells synchronously decreases during antheridium development, indicating chromatin condensation towards the compact sperm head. By contrast, the top1α mutant exhibited attenuated cell divisions and asynchronous and defective contraction of the nuclei of sperm cells throughout spermatogenesis. These results indicate that TOP1α is involved in cell division and chromatin condensation during spermatogenesis in P. patens. Our results suggest that the regulation of DNA topology by TOP1 plays a key role in spermatogenesis in both land plants and metazoans.
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Affiliation(s)
- Nan Gu
- Robotics, Engineering and Agriculture-technology Laboratory (REAL), Utsunomiya University, Utsunomiya, 321-8585, Japan
- School of Engineering, Utsunomiya University, Utsunomiya, 321-8585, Japan
- Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Chunli Chen
- Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Institute of Agro-Bioengineering, College of Life Science, Guizhou University, Guiyang, 550025, China
| | - Yukiko Kabeya
- Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
| | - Mitsuyasu Hasebe
- Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
- School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, 444-8585, Japan
| | - Yosuke Tamada
- Robotics, Engineering and Agriculture-technology Laboratory (REAL), Utsunomiya University, Utsunomiya, 321-8585, Japan
- School of Engineering, Utsunomiya University, Utsunomiya, 321-8585, Japan
- Division of Evolutionary Biology, National Institute for Basic Biology, Okazaki, 444-8585, Japan
- School of Life Science, The Graduate University for Advanced Studies, SOKENDAI, Okazaki, 444-8585, Japan
- Center for Optical Research & Education (CORE), Utsunomiya University, Utsunomiya, 321-8585, Japan
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Huang W, Liu Z, Rong YS. Dynamic localization of DNA topoisomerase I and its functional relevance during Drosophila development. G3-GENES GENOMES GENETICS 2021; 11:6298592. [PMID: 34544118 PMCID: PMC8661406 DOI: 10.1093/g3journal/jkab202] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 06/09/2021] [Indexed: 11/23/2022]
Abstract
DNA topoisomerase I (Top1) maintains chromatin conformation during transcription. While Top1 is not essential in simple eukaryotic organisms such as yeast, it is required for the development of multicellular organisms. In fact, tissue and cell-type-specific functions of Top1 have been suggested in the fruit fly Drosophila. A better understanding of Top1’s function in the context of development is important as Top1 inhibitors are among the most widely used anticancer drugs. As a step toward such a better understanding, we studied its localization in live cells of Drosophila. Consistent with prior results, Top1 is highly enriched at the nucleolus in transcriptionally active polyploid cells, and this enrichment responds to perturbation of transcription. In diploid cells, we uncovered evidence for Top1 foci formation at genomic regions not limited to the active rDNA locus, suggestive of novel regulation of Top1 recruitment. In the male germline, Top1 is highly enriched at the paired rDNA loci on sex chromosomes suggesting that it might participate in regulating their segregation during meiosis. Results from RNAi-mediated Top1 knockdown lend support to this hypothesis. Our study has provided one of the most comprehensive descriptions of Top1 localization during animal development.
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Affiliation(s)
- Wuqiang Huang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province, 510275, China.,Hengyang College of Medicine, University of South China, Hengyang 421001, China
| | - Zhiping Liu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province, 510275, China
| | - Yikang S Rong
- Hengyang College of Medicine, University of South China, Hengyang 421001, China
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Li Z, Yu Z, Cui C, Ai F, Yin D. Multi-generational obesogenic effects of sulfomethoxazole on Caenorhabditis elegans through epigenetic regulation. JOURNAL OF HAZARDOUS MATERIALS 2020; 382:121061. [PMID: 31470303 DOI: 10.1016/j.jhazmat.2019.121061] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/17/2019] [Accepted: 08/20/2019] [Indexed: 06/10/2023]
Abstract
Increasing concerns are earned on the multigenerational hazards of antibiotics due to the connection between their mother-children transfer via cord blood and breast milk and obesity in the children. Currently, Caenorhabditis elegans was exposed to sulfamethoxazole (SMX) over 11 generations (F0-F10). Indicators of obesogenic effects and gene expressions were measured in each generation and also in T11 to T13 that were the offspring of F10. Biochemical analysis results showed that SMX stimulated fatty acids in most generations including T13. The stimulation was resulted from the balance between enzymes for fatty acid synthesis (e.g., fatty acid synthetase) and those for its consumption (e.g., fatty acid transport protein). Gene expression analysis demonstrated that the obesogenic effects of SMX involved peroxisome proliferator activated receptors (PPARs, e.g., nhr-49) and insulin/insulin-like signaling (IIS) pathways (e.g., ins-1, daf-2 and daf-16). Further epigenetic analysis demonstrated that SMX caused 3-fold more H3K4me3 binding genes than the control in F10 and T13. In F10, the most significantly activated genes were in metabolic and biosynthetic processes of various lipids, nervous system and development. The different gene expressions in T13 from those in F10 involved development, growth, reproduction and responses to chemicals in addition to metabolic processes.
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Affiliation(s)
- Zhuo Li
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Zhenyang Yu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Changzheng Cui
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China; State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Fangting Ai
- Jiaxing Tongji Institute for Environment, Jiaxing, Zhejiang Province, 3014051 PR China
| | - Daqiang Yin
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
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Wani S, Kuroyanagi H. An emerging model organism Caenorhabditis elegans for alternative pre-mRNA processing in vivo. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28703462 DOI: 10.1002/wrna.1428] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 05/02/2017] [Accepted: 05/02/2017] [Indexed: 12/13/2022]
Abstract
A nematode Caenorhabditis elegans is an intron-rich organism and up to 25% of its pre-mRNAs are estimated to be alternatively processed. Its compact genomic organization enables construction of fluorescence splicing reporters with intact genomic sequences and visualization of alternative processing patterns of interest in the transparent living animals with single-cell resolution. Genetic analysis with the reporter worms facilitated identification of trans-acting factors and cis-acting elements, which are highly conserved in mammals. Analysis of unspliced and partially spliced pre-mRNAs in vivo raised models for alternative splicing regulation relying on specific order of intron excision. RNA-seq analysis of splicing factor mutants and CLIP-seq analysis of the factors allow global search for target genes in the whole animal. An mRNA surveillance system is not essential for its viability or fertility, allowing analysis of unproductively spliced noncoding mRNAs. These features offer C. elegans as an ideal model organism for elucidating alternative pre-mRNA processing mechanisms in vivo. Examples of isoform-specific functions of alternatively processed genes are summarized. WIREs RNA 2017, 8:e1428. doi: 10.1002/wrna.1428 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Shotaro Wani
- Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Hidehito Kuroyanagi
- Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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Ragle JM, Katzman S, Akers TF, Barberan-Soler S, Zahler AM. Coordinated tissue-specific regulation of adjacent alternative 3' splice sites in C. elegans. Genome Res 2015; 25:982-94. [PMID: 25922281 PMCID: PMC4484395 DOI: 10.1101/gr.186783.114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 04/27/2015] [Indexed: 12/30/2022]
Abstract
Adjacent alternative 3′ splice sites, those separated by ≤18 nucleotides, provide a unique problem in the study of alternative splicing regulation; there is overlap of the cis-elements that define the adjacent sites. Identification of the intron's 3′ end depends upon sequence elements that define the branchpoint, polypyrimidine tract, and terminal AG dinucleotide. Starting with RNA-seq data from germline-enriched and somatic cell-enriched Caenorhabditis elegans samples, we identify hundreds of introns with adjacent alternative 3′ splice sites. We identify 203 events that undergo tissue-specific alternative splicing. For these, the regulation is monodirectional, with somatic cells preferring to splice at the distal 3′ splice site (furthest from the 5′ end of the intron) and germline cells showing a distinct shift toward usage of the adjacent proximal 3′ splice site (closer to the 5′ end of the intron). Splicing patterns in somatic cells follow C. elegans consensus rules of 3′ splice site definition; a short stretch of pyrimidines preceding an AG dinucleotide. Splicing in germline cells occurs at proximal 3′ splice sites that lack a preceding polypyrimidine tract, and in three instances the germline-specific site lacks the AG dinucleotide. We provide evidence that use of germline-specific proximal 3′ splice sites is conserved across Caenorhabditis species. We propose that there are differences between germline and somatic cells in the way that the basal splicing machinery functions to determine the intron terminus.
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Affiliation(s)
- James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology and The Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Sol Katzman
- Center for Biomolecular Science and Engineering, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Taylor F Akers
- Department of Molecular, Cell, and Developmental Biology and The Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Sergio Barberan-Soler
- Gene Regulation, Stem Cells, and Cancer Program, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain
| | - Alan M Zahler
- Department of Molecular, Cell, and Developmental Biology and The Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
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Alternative Splicing Regulation of Cancer-Related Pathways in Caenorhabditis elegans: An In Vivo Model System with a Powerful Reverse Genetics Toolbox. Int J Cell Biol 2013; 2013:636050. [PMID: 24069034 PMCID: PMC3771449 DOI: 10.1155/2013/636050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 07/29/2013] [Indexed: 11/18/2022] Open
Abstract
Alternative splicing allows for the generation of protein diversity and fine-tunes gene expression. Several model systems have been used for the in vivo study of alternative splicing. Here we review the use of the nematode Caenorhabditis elegans to study splicing regulation in vivo. Recent studies have shown that close to 25% of genes in the worm genome undergo alternative splicing. A big proportion of these events are functional, conserved, and under strict regulation either across development or other conditions. Several techniques like genome-wide RNAi screens and bichromatic reporters are available for the study of alternative splicing in worms. In this review, we focus, first, on the main studies that have been performed to dissect alternative splicing in this system and later on examples from genes that have human homologs that are implicated in cancer. The significant advancement towards understanding the regulation of alternative splicing and cancer that the C. elegans system has offered is discussed.
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