1
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Cao W, Fan Q, Amparado G, Begic D, Godini R, Gopal S, Pocock R. A nucleic acid binding protein map of germline regulation in Caenorhabditis elegans. Nat Commun 2024; 15:6884. [PMID: 39128930 PMCID: PMC11317507 DOI: 10.1038/s41467-024-51212-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 08/01/2024] [Indexed: 08/13/2024] Open
Abstract
Fertility requires the faithful proliferation of germ cells and their differentiation into gametes. Controlling these cellular states demands precise timing and expression of gene networks. Nucleic acid binding proteins (NBPs) play critical roles in gene expression networks that influence germ cell development. There has, however, been no functional analysis of the entire NBP repertoire in controlling in vivo germ cell development. Here, we analyzed germ cell states and germline architecture to systematically investigate the function of 364 germline-expressed NBPs in the Caenorhabditis elegans germ line. Using germline-specific knockdown, automated germ cell counting, and high-content analysis of germ cell nuclei and plasma membrane organization, we identify 156 NBPs with discrete autonomous germline functions. By identifying NBPs that control the germ cell cycle, proliferation, differentiation, germline structure and fertility, we have created an atlas for mechanistic dissection of germ cell behavior and gamete production.
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Affiliation(s)
- Wei Cao
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia.
| | - Qi Fan
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Gemmarie Amparado
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Dean Begic
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Rasoul Godini
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia
| | - Sandeep Gopal
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia.
- Lund Stem Cell Center, Department of Experimental Medical Science, Lund University, Lund, Sweden.
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, 3800, Australia.
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2
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Rockman MV. Parental-effect gene-drive elements under partial selfing, or why do Caenorhabditis genomes have hyperdivergent regions? BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.23.604817. [PMID: 39091748 PMCID: PMC11291142 DOI: 10.1101/2024.07.23.604817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Self-fertile Caenorhabditis nematodes carry a surprising number of Medea elements, alleles that act in heterozygous mothers and cause death or developmental delay in offspring that don't inherit them. At some loci, both alleles in a cross operate as independent Medeas, affecting all the homozygous progeny of a selfing heterozygote. The genomic coincidence of Medea elements and ancient, deeply coalescing haplotypes, which pepper the otherwise homogeneous genomes of these animals, raises questions about how these apparent gene-drive elements persist for long periods of time. Here I investigate how mating system affects the evolution of Medeas, and their paternal-effect counterparts, peels. Despite an intuition that antagonistic alleles should induce balancing selection by killing homozygotes, models show that, under partial selfing, antagonistic elements experience positive frequency dependence: the common allele drives the rare one extinct, even if the rare one is more penetrant. Analytical results for the threshold frequency required for one allele to invade a population show that a very weakly penetrant allele, one whose effects would escape laboratory detection, could nevertheless prevent a much more penetrant allele from invading under high rates of selfing. Ubiquitous weak antagonistic Medeas and peels could then act as localized barriers to gene flow between populations, generating genomic islands of deep coalescence. Analysis of gene expression data, however, suggest that this cannot be the whole story. A complementary explanation is that ordinary ecological balancing selection generates ancient haplotypes on which Medeas can evolve, while high homozygosity in these selfers minimizes the role of gene drive in their evolution.
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Affiliation(s)
- Matthew V Rockman
- Department of Biology and Center for Genomics & Systems Biology, New York University, New York, NY 10003
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3
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Eliad B, Schneider N, Ben-Naim Zgayer O, Amichan Y, Glaser F, Erdmann EA, Rajendren S, Hundley HA, Lamm AT. ADBP-1 regulates ADR-2 nuclear localization to control editing substrate selection. Nucleic Acids Res 2024:gkae641. [PMID: 39036970 DOI: 10.1093/nar/gkae641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/05/2024] [Accepted: 07/09/2024] [Indexed: 07/23/2024] Open
Abstract
Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a prevalent and conserved RNA modification. While A-to-I RNA editing is essential in mammals, in Caenorhabditis elegans, it is not, making them invaluable for RNA editing research. In C. elegans, ADR-2 is the sole catalytic A-to-I editing enzyme, and ADR-1 is an RNA editing regulator. ADAR localization is well-studied in humans but not well-established in C. elegans. In this study, we examine the cellular and tissue-specific localization of ADR-2. We show that while ADR-2 is present in most cells in the embryo, at later developmental stages, its expression is both tissue- and cell-type-specific. Additionally, both ADARs are mainly in the nucleus. ADR-2 is adjacent to the chromosomes during the cell cycle. We show that the nuclear localization of endogenous ADR-2 depends on ADBP-1, not ADR-1. In adbp-1 mutant worms, ADR-2 is mislocalized, while ADR-1 is not, leading to decreased editing levels and de-novo editing, mostly in exons, suggesting that ADR-2 is also functional in the cytoplasm. Besides, mutated ADBP-1 affects gene expression. Furthermore, we show that ADR-2 targets adenosines with different surrounding nucleotides in exons and introns. Our findings indicate that ADR-2 cellular localization is highly regulated and affects its function.
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Affiliation(s)
- Berta Eliad
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Noa Schneider
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Orna Ben-Naim Zgayer
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Yarden Amichan
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Fabian Glaser
- Technion Center for Structural Biology, Technion Human Health Initiative, Technion, Haifa 32000, Israel
| | - Emily A Erdmann
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Suba Rajendren
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Heather A Hundley
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Ayelet T Lamm
- Faculty of Biology, Technion- Israel Institute of Technology, Technion City, Haifa 3200003, Israel
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4
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Eliad B, Schneider N, Zgayer OBN, Amichan Y, Glaser F, Erdmann EA, Rajendren S, Hundley HA, Lamm AT. ADBP-1 regulates ADR-2 nuclear localization to control editing substrate selection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.14.540679. [PMID: 38895382 PMCID: PMC11185548 DOI: 10.1101/2023.05.14.540679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is a prevalent and conserved RNA modification. While A-to-I RNA editing is essential in mammals, in Caenorhabditis elegans , it is not, making them invaluable for RNA editing research. In C. elegans , ADR-2 is the sole catalytic A-to-I editing enzyme, and ADR-1 is an RNA editing regulator. ADAR localization is well-studied in humans but not well-established in C. elegans . In this study, we examine the cellular and tissue-specific localization of ADR-2. We show that while ADR-2 is present in most cells in the embryo, at later developmental stages, its expression is both tissue- and cell-type-specific. Additionally, both ADARs are mainly in the nucleus. ADR-2 is adjacent to the chromosomes during the cell cycle. We show that the nuclear localization of endogenous ADR-2 depends on ADBP-1, not ADR-1. In adbp-1 mutant worms, ADR-2 is mislocalized, while ADR-1 is not, leading to decreased editing levels and de-novo editing, mostly in exons, suggesting that ADR-2 is also functional in the cytoplasm. Besides, mutated ADBP-1 affects gene expression. Furthermore, we show that ADR-2 targets adenosines with different surrounding nucleotides in exons and introns. Our findings indicate that ADR-2 cellular localization is highly regulated and affects its function.
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5
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Su Y, Shea J, DeStephanis D, Su Z. Transcriptomic Analysis of the Spatiotemporal Axis of Oogenesis and Fertilization in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.03.597235. [PMID: 38895354 PMCID: PMC11185608 DOI: 10.1101/2024.06.03.597235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
The oocyte germline of the C. elegans hermaphrodite presents a unique model to study the formation of oocytes. However, the size of the model animal and difficulties in retrieval of specific stages of the germline have obviated closer systematic studies of this process throughout the years. Here, we present a transcriptomic level analysis into the oogenesis of C. elegans hermaphrodites. We dissected a hermaphrodite gonad into seven sections corresponding to the mitotic distal region, the pachytene, the diplotene, the early diakinesis region and the 3 most proximal oocytes, and deeply sequenced the transcriptome of each of them along with that of the fertilized egg using a single-cell RNA-seq protocol. We identified specific gene expression events as well as gene splicing events in finer detail along the oocyte germline and provided novel insights into underlying mechanisms of the oogenesis process. Furthermore, through careful review of relevant research literature coupled with patterns observed in our analysis, we attempt to delineate transcripts that may serve functions in the interaction between the germline and cells of the somatic gonad. These results expand our knowledge of the transcriptomic space of the C. elegans germline and lay a foundation on which future studies of the germline can be based upon.
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Affiliation(s)
- Yangqi Su
- Department of Bioinformatics and Genomics, the University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Jonathan Shea
- Department of Bioinformatics and Genomics, the University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Darla DeStephanis
- Department of Bioinformatics and Genomics, the University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Zhengchang Su
- Department of Bioinformatics and Genomics, the University of North Carolina at Charlotte, Charlotte, NC 28223, USA
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6
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Amran A, Pigatto L, Farley J, Godini R, Pocock R, Gopal S. The matrisome landscape controlling in vivo germ cell fates. Nat Commun 2024; 15:4200. [PMID: 38760342 PMCID: PMC11101451 DOI: 10.1038/s41467-024-48283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 04/26/2024] [Indexed: 05/19/2024] Open
Abstract
The developmental fate of cells is regulated by intrinsic factors and the extracellular environment. The extracellular matrix (matrisome) delivers chemical and mechanical cues that can modify cellular development. However, comprehensive understanding of how matrisome factors control cells in vivo is lacking. Here we show that specific matrisome factors act individually and collectively to control germ cell development. Surveying development of undifferentiated germline stem cells through to mature oocytes in the Caenorhabditis elegans germ line enabled holistic functional analysis of 443 conserved matrisome-coding genes. Using high-content imaging, 3D reconstruction, and cell behavior analysis, we identify 321 matrisome genes that impact germ cell development, the majority of which (>80%) are undescribed. Our analysis identifies key matrisome networks acting autonomously and non-autonomously to coordinate germ cell behavior. Further, our results demonstrate that germ cell development requires continual remodeling of the matrisome landscape. Together, this study provides a comprehensive platform for deciphering how extracellular signaling controls cellular development and anticipate this will establish new opportunities for manipulating cell fates.
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Affiliation(s)
- Aqilah Amran
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Lund Stem Cell Center, Lund University, Lund, Sweden
- Lund Cancer Center, Lund University, Lund, Sweden
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute. Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Lara Pigatto
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Lund Stem Cell Center, Lund University, Lund, Sweden
- Lund Cancer Center, Lund University, Lund, Sweden
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute. Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Johanna Farley
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Lund Stem Cell Center, Lund University, Lund, Sweden
- Lund Cancer Center, Lund University, Lund, Sweden
| | - Rasoul Godini
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute. Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute. Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia.
| | - Sandeep Gopal
- Department of Experimental Medical Science, Lund University, Lund, Sweden.
- Lund Stem Cell Center, Lund University, Lund, Sweden.
- Lund Cancer Center, Lund University, Lund, Sweden.
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute. Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC, Australia.
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7
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Robert VJ, Caron M, Gely L, Adrait A, Pakulska V, Couté Y, Chevalier M, Riedel CG, Bedet C, Palladino F. SIN-3 acts in distinct complexes to regulate the germline transcriptional program in Caenorhabditis elegans. Development 2023; 150:dev201755. [PMID: 38771303 PMCID: PMC10617626 DOI: 10.1242/dev.201755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 09/18/2023] [Indexed: 10/12/2023]
Abstract
The transcriptional co-regulator SIN3 influences gene expression through multiple interactions that include histone deacetylases. Haploinsufficiency and mutations in SIN3 are the underlying cause of Witteveen-Kolk syndrome and related intellectual disability and autism syndromes, emphasizing its key role in development. However, little is known about the diversity of its interactions and functions in developmental processes. Here, we show that loss of SIN-3, the single SIN3 homolog in Caenorhabditis elegans, results in maternal-effect sterility associated with de-regulation of the germline transcriptome, including de-silencing of X-linked genes. We identify at least two distinct SIN3 complexes containing specific histone deacetylases and show that they differentially contribute to fertility. Single-cell, single-molecule fluorescence in situ hybridization reveals that in sin-3 mutants the X chromosome becomes re-expressed prematurely and in a stochastic manner in individual germ cells, suggesting a role for SIN-3 in its silencing. Furthermore, we identify histone residues whose acetylation increases in the absence of SIN-3. Together, this work provides a powerful framework for the in vivo study of SIN3 and associated proteins.
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Affiliation(s)
- Valerie J. Robert
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Matthieu Caron
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Loic Gely
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Annie Adrait
- Grenoble Alpes, CEA, Inserm, UA13 BGE, CNRS, CEA, FR2048, 38000 Grenoble, France
| | - Victoria Pakulska
- Grenoble Alpes, CEA, Inserm, UA13 BGE, CNRS, CEA, FR2048, 38000 Grenoble, France
| | - Yohann Couté
- Grenoble Alpes, CEA, Inserm, UA13 BGE, CNRS, CEA, FR2048, 38000 Grenoble, France
| | - Manon Chevalier
- Department of Biosciences and Nutrition, Karolinska Institutet, Blickagången 16, 14157 Huddinge, Sweden
| | - Christian G. Riedel
- Department of Biosciences and Nutrition, Karolinska Institutet, Blickagången 16, 14157 Huddinge, Sweden
| | - Cecile Bedet
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Francesca Palladino
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
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8
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Lu L, Abbott AL. Male gonad-enriched microRNAs function to control sperm production in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.10.561762. [PMID: 37873419 PMCID: PMC10592766 DOI: 10.1101/2023.10.10.561762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Germ cell development and gamete production in animals require small RNA pathways. While studies indicate that microRNAs (miRNAs) are necessary for normal sperm production and function, the specific roles for individual miRNAs are largely unknown. Here, we use small RNA sequencing of dissected gonads and functional analysis of new loss of function alleles to identify functions for miRNAs in the control of fecundity and sperm production in Caenorhabditis elegans males and hermaphrodites. We describe a set of 29 male gonad-enriched miRNAs and identify a set of 3 individual miRNAs (mir-58.1, mir-83, and mir-235) and a miRNA cluster (mir-4807-4810.1) that are required for optimal sperm production at 20°C and 5 additional miRNAs (mir-49, mir-57, mir-261, and mir-357/358) that are required for sperm production at 25°C. We observed defects in meiotic progression in mir-58.1, mir-83, mir-235, and mir-4807-4810.1 mutants that may contribute to the reduced number of sperm. Further, analysis of multiple mutants of these miRNAs suggested complex genetic interactions between these miRNAs for sperm production. This study provides insights on the regulatory roles of miRNAs that promote optimal sperm production and fecundity in males and hermaphrodites.
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Affiliation(s)
- Lu Lu
- Department of Biological Sciences, Marquette University, Milwaukee, WI, 53201 USA
| | - Allison L. Abbott
- Department of Biological Sciences, Marquette University, Milwaukee, WI, 53201 USA
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9
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Poorna R, Chen WW, Qiu P, Cicerone MT. Toward Gene-Correlated Spatially Resolved Metabolomics with Fingerprint Coherent Raman Imaging. J Phys Chem B 2023; 127:5576-5587. [PMID: 37311254 PMCID: PMC10316396 DOI: 10.1021/acs.jpcb.3c01446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/30/2023] [Indexed: 06/15/2023]
Abstract
Raman spectroscopy has long been known to provide sufficient information to discriminate distinct cell phenotypes. Underlying this discriminating capability is that Raman spectra provide an overall readout of the metabolic profiles that change with transcriptomic activity. Robustly associating Raman spectral changes with the regulation of specific signaling pathways may be possible, but the spectral signals of interest may be weak and vary somewhat among individuals. Establishing a Raman-to-transcriptome mapping will thus require tightly controlled and easily manipulated biological systems and high-throughput spectral acquisition. We attempt to meet these requirements using broadband coherent anti-Stokes Raman scattering (BCARS) microscopy to spatio-spectrally map the C. elegans hermaphrodite gonad in vivo at subcellular resolution. The C. elegans hermaphrodite gonad is an ideal model system with a sequential, continuous process of highly regulated spatiotemporal cellular events. We demonstrate that the BCARS spatio-spectral signatures correlate with gene expression profiles in the gonad, evincing that BCARS has potential as a spatially resolved omics surrogate.
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Affiliation(s)
- Rajas Poorna
- Department
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Wei-Wen Chen
- Department
of Chemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Peng Qiu
- Department
of Biomedical Engineering, Georgia Institute
of Technology, Atlanta, Georgia 30332, United States
| | - Marcus T. Cicerone
- Department
of Chemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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10
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Trimmer KA, Zhao P, Seemann J, Chen SY, Mondal S, Ben-Yakar A, Arur S. Spatial single-cell sequencing of meiosis I arrested oocytes indicates acquisition of maternal transcripts from the soma. Cell Rep 2023; 42:112544. [PMID: 37227820 PMCID: PMC10592488 DOI: 10.1016/j.celrep.2023.112544] [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: 08/26/2022] [Revised: 03/08/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023] Open
Abstract
Maternal RNAs are stored from minutes to decades in oocytes throughout meiosis I arrest in a transcriptionally quiescent state. Recent reports, however, propose a role for nascent transcription in arrested oocytes. Whether arrested oocytes launch nascent transcription in response to environmental or hormonal signals while maintaining the meiosis I arrest remains undetermined. We test this by integrating single-cell RNA sequencing, RNA velocity, and RNA fluorescence in situ hybridization on C. elegans meiosis I arrested oocytes. We identify transcripts that increase as the arrested meiosis I oocyte ages, but rule out extracellular signaling through ERK MAPK and nascent transcription as a mechanism for this increase. We report transcript acquisition from neighboring somatic cells as a mechanism of transcript increase during meiosis I arrest. These analyses provide a deeper view at single-cell resolution of the RNA landscape of a meiosis I arrested oocyte and as it prepares for oocyte maturation and fertilization.
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Affiliation(s)
- Kenneth A Trimmer
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Peisen Zhao
- Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Jacob Seemann
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Shin-Yu Chen
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sudip Mondal
- Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Adela Ben-Yakar
- Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX 78712, USA; Department of Mechanical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Swathi Arur
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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11
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Seroussi U, Lugowski A, Wadi L, Lao RX, Willis AR, Zhao W, Sundby AE, Charlesworth AG, Reinke AW, Claycomb JM. A comprehensive survey of C. elegans argonaute proteins reveals organism-wide gene regulatory networks and functions. eLife 2023; 12:e83853. [PMID: 36790166 PMCID: PMC10101689 DOI: 10.7554/elife.83853] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 02/14/2023] [Indexed: 02/16/2023] Open
Abstract
Argonaute (AGO) proteins associate with small RNAs to direct their effector function on complementary transcripts. The nematode Caenorhabditis elegans contains an expanded family of 19 functional AGO proteins, many of which have not been fully characterized. In this work, we systematically analyzed every C. elegans AGO using CRISPR-Cas9 genome editing to introduce GFP::3xFLAG tags. We have characterized the expression patterns of each AGO throughout development, identified small RNA binding complements, and determined the effects of ago loss on small RNA populations and developmental phenotypes. Our analysis indicates stratification of subsets of AGOs into distinct regulatory modules, and integration of our data led us to uncover novel stress-induced fertility and pathogen response phenotypes due to ago loss.
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Affiliation(s)
- Uri Seroussi
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Andrew Lugowski
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Lina Wadi
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Robert X Lao
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | | | - Winnie Zhao
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Adam E Sundby
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | | | - Aaron W Reinke
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Julie M Claycomb
- Department of Molecular Genetics, University of TorontoTorontoCanada
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12
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Martinez-Garcia M, Naharro PR, Skinner MW, Baran KA, Lascarez-Lagunas LI, Nadarajan S, Shin N, Silva-García CG, Saito TT, Beese-Sims S, Diaz-Pacheco BN, Berson E, Castañer AB, Pacheco S, Martinez-Perez E, Jordan PW, Colaiácovo MP. GRAS-1 is a novel regulator of early meiotic chromosome dynamics in C. elegans. PLoS Genet 2023; 19:e1010666. [PMID: 36809245 PMCID: PMC9983901 DOI: 10.1371/journal.pgen.1010666] [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: 10/27/2022] [Revised: 03/03/2023] [Accepted: 02/13/2023] [Indexed: 02/23/2023] Open
Abstract
Chromosome movements and licensing of synapsis must be tightly regulated during early meiosis to ensure accurate chromosome segregation and avoid aneuploidy, although how these steps are coordinated is not fully understood. Here we show that GRAS-1, the worm homolog of mammalian GRASP/Tamalin and CYTIP, coordinates early meiotic events with cytoskeletal forces outside the nucleus. GRAS-1 localizes close to the nuclear envelope (NE) in early prophase I and interacts with NE and cytoskeleton proteins. Delayed homologous chromosome pairing, synaptonemal complex (SC) assembly, and DNA double-strand break repair progression are partially rescued by the expression of human CYTIP in gras-1 mutants, supporting functional conservation. However, Tamalin, Cytip double knockout mice do not exhibit obvious fertility or meiotic defects, suggesting evolutionary differences between mammals. gras-1 mutants show accelerated chromosome movement during early prophase I, implicating GRAS-1 in regulating chromosome dynamics. GRAS-1-mediated regulation of chromosome movement is DHC-1-dependent, placing it acting within the LINC-controlled pathway, and depends on GRAS-1 phosphorylation at a C-terminal S/T cluster. We propose that GRAS-1 coordinates the early steps of homology search and licensing of SC assembly by regulating the pace of chromosome movement in early prophase I.
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Affiliation(s)
- Marina Martinez-Garcia
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pedro Robles Naharro
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marnie W Skinner
- Biochemistry and Molecular Biology Department, John Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Kerstin A Baran
- Biochemistry and Molecular Biology Department, John Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Laura I Lascarez-Lagunas
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Saravanapriah Nadarajan
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Nara Shin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Carlos G Silva-García
- Department of Molecular Metabolism, Harvard T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts, United States of America
| | - Takamune T Saito
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sara Beese-Sims
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brianna N Diaz-Pacheco
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Elizaveta Berson
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ana B Castañer
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sarai Pacheco
- MRC London Institute of Medical Sciences, London, United Kingdom
| | | | - Philip W Jordan
- Biochemistry and Molecular Biology Department, John Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Monica P Colaiácovo
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
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13
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Shabtai R, Tzur YB. Male-specific roles of lincRNA in C. elegans fertility. Front Cell Dev Biol 2023; 11:1115605. [PMID: 37035238 PMCID: PMC10076526 DOI: 10.3389/fcell.2023.1115605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
The testis is the mammalian tissue with the highest expression levels of long intergenic non-coding RNAs (lincRNAs). However, most in vivo models have not found significant reductions in male fertility when highly expressed lincRNA genes were removed. This suggests that certain lincRNAs may act redundantly or lack functional roles. In the genome of the nematode Caenorhabditis elegans, there is an order of magnitude fewer lincRNA genes than in mammals. This characteristic lowers the potential for redundancy, making it an ideal model to test these possibilities. We identified five highly and dynamically expressed lincRNAs in male C. elegans gonads and quantified the fertility of worm strains in which these genes were removed. In contrast to the hermaphrodites of deletion strains, which exhibited no significant reductions in broods, smaller brood sizes were observed in the progeny of males of three of the lincRNA deleted strains. This demonstrates reduced male fertility in worms with those genes removed. Interestingly, reduced brood size was statistically significant only in the last days of egg laying in two of these strains. This suggests the effect is due to early deterioration and aging of the transferred sperm. We detected a mild increase in embryonic lethality in only one of the strains, supporting the possibility that these lincRNAs do not affect fertility through critical roles in essential meiotic processes. Together our results indicate a sexually dimorphic outcome on fertility when lincRNA are removed and show that, unlike mammals, individual lincRNAs in C. elegans do play significant roles in male fertility.
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14
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Lascarez-Lagunas LI, Martinez-Garcia M, Nadarajan S, Diaz-Pacheco BN, Berson E, Colaiácovo MP. Chromatin landscape, DSB levels, and cKU-70/80 contribute to patterning of meiotic DSB processing along chromosomes in C. elegans. PLoS Genet 2023; 19:e1010627. [PMID: 36706157 PMCID: PMC9907818 DOI: 10.1371/journal.pgen.1010627] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 02/08/2023] [Accepted: 01/20/2023] [Indexed: 01/28/2023] Open
Abstract
Programmed DNA double-strand break (DSB) formation is essential for achieving accurate chromosome segregation during meiosis. DSB repair timing and template choice are tightly regulated. However, little is known about how DSB distribution and the choice of repair pathway are regulated along the length of chromosomes, which has direct effects on the recombination landscape and chromosome remodeling at late prophase I. Here, we use the spatiotemporal resolution of meiosis in the Caenorhabditis elegans germline along with genetic approaches to study distribution of DSB processing and its regulation. High-resolution imaging of computationally straightened chromosomes immunostained for the RAD-51 recombinase marking DSB repair sites reveals that the pattern of RAD-51 foci throughout pachytene resembles crossover distribution in wild type. Specifically, RAD-51 foci occur primarily along the gene-poor distal thirds of the chromosomes in both early and late pachytene, and on both the X and the autosomes. However, this biased off-center distribution can be abrogated by the formation of excess DSBs. Reduced condensin function, but not an increase in total physical axial length, results in a homogeneous distribution of RAD-51 foci, whereas regulation of H3K9 methylation is required for the enrichment of RAD-51 at off-center positions. Finally, the DSB recognition heterodimer cKU-70/80, but not the non-homologous end-joining canonical ligase LIG-4, contributes to the enriched off-center distribution of RAD-51 foci. Taken together, our data supports a model by which regulation of the chromatin landscape, DSB levels, and DSB detection by cKU-70/80 collaborate to promote DSB processing by homologous recombination at off-center regions of the chromosomes in C. elegans.
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Affiliation(s)
- Laura I. Lascarez-Lagunas
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Marina Martinez-Garcia
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Saravanapriah Nadarajan
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brianna N. Diaz-Pacheco
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Elizaveta Berson
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mónica P. Colaiácovo
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
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15
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Tzur YB. lncRNAs in fertility: redefining the gene expression paradigm? Trends Genet 2022; 38:1170-1179. [PMID: 35728988 DOI: 10.1016/j.tig.2022.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/02/2022] [Accepted: 05/26/2022] [Indexed: 01/24/2023]
Abstract
Comparative transcriptome approaches assume that highly or dynamically expressed genes are important. This has led to the identification of many genes critical for cellular activity and organism development. However, while testes express the highest levels of long noncoding RNAs (lncRNAs), there is scarcely any evidence for lncRNAs with significant roles in fertility. This was explained by changes in chromatin structure during spermatogenesis that lead to 'promiscuous transcription' with no functional roles for the transcripts. Recent discoveries offer novel and surprising alternatives. Here, I review the current knowledge regarding the involvement of lncRNAs in fertility, why I find gametogenesis different from other developmental processes, offer models to explain why the experimental evidence did not meet theoretical predictions, and suggest possible approaches to test the models.
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Affiliation(s)
- Yonatan B Tzur
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
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16
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Sperm-inherited H3K27me3 epialleles are transmitted transgenerationally in cis. Proc Natl Acad Sci U S A 2022; 119:e2209471119. [PMID: 36161922 PMCID: PMC9546627 DOI: 10.1073/pnas.2209471119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transmission of chromatin states from parent cells to daughter cells preserves cell-specific transcriptional states and thus cell identity through cell division. The mechanism that underpins this process is not fully understood. The role that chromatin states serve in transmitting gene expression information across generations via sperm and oocytes is even less understood. Here, we utilized a model in which Caenorhabditis elegans sperm and oocyte alleles were inherited in different states of the repressive mark H3K27me3. This resulted in the alleles achieving different transcriptional states within the nuclei of offspring. Using this model, we showed that sperm alleles inherited without H3K27me3 were sensitive to up-regulation in offspring somatic and germline tissues, and tissue context determined which genes were up-regulated. We found that the subset of sperm alleles that were up-regulated in offspring germlines retained the H3K27me3(-) state and were transmitted to grandoffspring as H3K27me3(-) and up-regulated epialleles, demonstrating that H3K27me3 can serve as a transgenerational epigenetic carrier in C. elegans.
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17
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Cockrum CS, Strome S. Maternal H3K36 and H3K27 HMTs protect germline development via regulation of the transcription factor LIN-15B. eLife 2022; 11:77951. [PMID: 35920536 PMCID: PMC9348848 DOI: 10.7554/elife.77951] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/18/2022] [Indexed: 12/05/2022] Open
Abstract
Maternally synthesized products play critical roles in the development of offspring. A premier example is the Caenorhabditis elegans H3K36 methyltransferase MES-4, which is essential for germline survival and development in offspring. How maternal MES-4 protects the germline is not well understood, but its role in H3K36 methylation hinted that it may regulate gene expression in primordial germ cells (PGCs). We tested this hypothesis by profiling transcripts from nascent germlines (PGCs and their descendants) dissected from wild-type and mes-4 mutant (lacking maternal and zygotic MES-4) larvae. mes-4 nascent germlines displayed downregulation of some germline genes, upregulation of some somatic genes, and dramatic upregulation of hundreds of genes on the X chromosome. We demonstrated that upregulation of one or more genes on the X is the cause of germline death by generating and analyzing mes-4 mutants that inherited different endowments of X chromosome(s). Intriguingly, removal of the THAP transcription factor LIN-15B from mes-4 mutants reduced X misexpression and prevented germline death. lin-15B is X-linked and misexpressed in mes-4 PGCs, identifying it as a critical target for MES-4 repression. The above findings extend to the H3K27 methyltransferase MES-2/3/6, the C. elegans version of polycomb repressive complex 2. We propose that maternal MES-4 and PRC2 cooperate to protect germline survival by preventing synthesis of germline-toxic products encoded by genes on the X chromosome, including the key transcription factor LIN-15B.
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Affiliation(s)
- Chad Steven Cockrum
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
| | - Susan Strome
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
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18
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Carro MDLM, Grimson A, Cohen PE. Small RNAs and their protein partners in animal meiosis. Curr Top Dev Biol 2022; 151:245-279. [PMID: 36681472 DOI: 10.1016/bs.ctdb.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Meiosis is characterized by highly regulated transitions in gene expression that require diverse mechanisms of gene regulation. For example, in male mammals, transcription undergoes a global shut-down in early prophase I of meiosis, followed by increasing transcriptional activity into pachynema. Later, as spermiogenesis proceeds, the histones bound to DNA are replaced with transition proteins, which are themselves replaced with protamines, resulting in a highly condensed nucleus with repressed transcriptional activity. In addition, two specialized gene silencing events take place during prophase I: meiotic silencing of unsynapsed chromatin (MSUC), and the sex chromatin specific mechanism, meiotic sex chromosome inactivation (MSCI). Notably, conserved roles for the RNA binding protein (RBP) machinery that functions with small non-coding RNAs have been described as participating in these meiosis-specific mechanisms, suggesting that RNA-mediated gene regulation is critical for fertility in many species. Here, we review roles of small RNAs and their associated RBPs in meiosis-related processes such as centromere function, silencing of unpaired chromatin and meiotic recombination. We will discuss the emerging evidence of non-canonical functions of these components in meiosis.
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Affiliation(s)
- María de Las Mercedes Carro
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States; Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, United States
| | - Andrew Grimson
- Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, United States; Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY, United States.
| | - Paula E Cohen
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States; Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, United States.
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19
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Hicks T, Koury E, McCabe C, Williams C, Crahan C, Smolikove S. R-loop-induced irreparable DNA damage evades checkpoint detection in the C. elegans germline. Nucleic Acids Res 2022; 50:8041-8059. [PMID: 35871299 PMCID: PMC9371901 DOI: 10.1093/nar/gkac621] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 06/28/2022] [Accepted: 07/18/2022] [Indexed: 11/24/2022] Open
Abstract
Accumulation of DNA–RNA hybrids in the form of R-loops can result in replication–transcription conflict that leads to the formation of DNA double strand breaks (DSBs). Using null mutants for the two Caenorhabditis elegans genes encoding for RNaseH1 and RNaseH2, we identify novel effects of R-loop accumulation in the germline. R-loop accumulation leads, as expected, to replication stress, followed by the formation of DSBs. A subset of these DSBs are irreparable. However, unlike irreparable DSBs generated in other systems, which trigger permanent cell cycle arrest, germline irreparable DSBs are propagated to oocytes. Despite DNA damage checkpoint activation in the stem cell niche, the signaling cannot be sustained and nuclei with irreparable DNA damage progress into meiosis. Moreover, unlike other forms of DNA damage that increase germline apoptosis, R-loop-generated DSBs remain undetected by the apoptotic checkpoint. This coincides with attenuation of ATM/ATR signaling in mid-to-late meiotic prophase I. These data altogether indicate that in the germline, DSBs that are generated by R-loops can lead to irreparable DSBs that evade cellular machineries designed for damage recognition. These studies implicate germline R-loops as an especially dangerous driver of germline mutagenesis.
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Affiliation(s)
- Tara Hicks
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Emily Koury
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Caleb McCabe
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Cameron Williams
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Caroline Crahan
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
| | - Sarit Smolikove
- Department of Biology, The University of Iowa , IA City, IA 52242, USA
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20
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Ellis RE. Sex Determination in Nematode Germ Cells. Sex Dev 2022:1-18. [PMID: 35172320 PMCID: PMC9378769 DOI: 10.1159/000520872] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/02/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Animal germ cells differentiate as sperm or as oocytes. These sexual fates are controlled by complex regulatory pathways to ensure that the proper gametes are made at the appropriate times. SUMMARY Nematodes like Caenorhabditis elegans and its close relatives are ideal models for studying how this regulation works, because the XX animals are self-fertile hermaphrodites that produce both sperm and oocytes. In these worms, germ cells use the same signal transduction pathway that functions in somatic cells. This pathway determines the activity of the transcription factor TRA-1, a Gli protein that can repress male genes. However, the pathway is extensively modified in germ cells, largely by the action of translational regulators like the PUF proteins. Many of these modifications play critical roles in allowing the XX hermaphrodites to make sperm in an otherwise female body. Finally, TRA-1 cooperates with chromatin regulators in the germ line to control the activity of fog-1 and fog-3, which are essential for spermatogenesis. FOG-1 and FOG-3 work together to determine germ cell fates by blocking the translation of oogenic transcripts. Key Messages: Although there is great diversity in how germ cell fates are controlled in other animals, many of the key nematode genes are conserved, and the critical role of translational regulators may be universal.
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Affiliation(s)
- Ronald E Ellis
- Department of Molecular Biology, Rowan University SOM, Stratford, New Jersey, USA
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21
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Rappaport Y, Falk R, Achache H, Tzur YB. linc-20 and linc-9 do not have compensatory fertility roles in C. elegans. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000524. [PMID: 35169683 PMCID: PMC8837906 DOI: 10.17912/micropub.biology.000524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 11/15/2022]
Abstract
Long intergenic non-coding RNAs (lincRNAs) are transcripts longer than 200 nucleotides which are transcribed from regions that do not overlap with protein coding sequences. Reproductive organs express high levels of lincRNAs, yet removal of many lincRNA genes with high and dynamic germline expression did not lead to fertility defects. It was previously suggested this stems from redundant roles of different lincRNA genes. We previously reported engineering C. elegans strains in which we deleted lincRNA genes with high and dynamic expression in the gonad. The individual mutations did not lead to major effects on fertility. Two of those lincRNA genes, linc-9 and linc-20, are highly homologous, suggesting they could perform redundant roles. Here we report that in the double mutant linc-9; linc-20 the brood size and embryonic lethality do not significantly differ from wild-type worms. This could be explained by either lack of fertility roles, or redundancy with other lincRNA genes.
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Affiliation(s)
- Yisrael Rappaport
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Roni Falk
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Hanna Achache
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yonatan B. Tzur
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel,
Correspondence to: Yonatan B. Tzur ()
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22
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Zagoskin MV, Wang J, Neff AT, Veronezi GMB, Davis RE. Small RNA pathways in the nematode Ascaris in the absence of piRNAs. Nat Commun 2022; 13:837. [PMID: 35149688 PMCID: PMC8837657 DOI: 10.1038/s41467-022-28482-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/13/2022] [Indexed: 02/07/2023] Open
Abstract
Small RNA pathways play key and diverse regulatory roles in C. elegans, but our understanding of their conservation and contributions in other nematodes is limited. We analyzed small RNA pathways in the divergent parasitic nematode Ascaris. Ascaris has ten Argonautes with five worm-specific Argonautes (WAGOs) that associate with secondary 5’-triphosphate 22-24G-RNAs. These small RNAs target repetitive sequences or mature mRNAs and are similar to the C. elegans mutator, nuclear, and CSR-1 small RNA pathways. Even in the absence of a piRNA pathway, Ascaris CSR-1 may still function to “license” as well as fine-tune or repress gene expression. Ascaris ALG-4 and its associated 26G-RNAs target and likely repress specific mRNAs during testis meiosis. Ascaris WAGO small RNAs demonstrate target plasticity changing their targets between repeats and mRNAs during development. We provide a unique and comprehensive view of mRNA and small RNA expression throughout spermatogenesis. Overall, our study illustrates the conservation, divergence, dynamics, and flexibility of small RNA pathways in nematodes. The parasitic nematode Ascaris lacks piRNAs. Here the authors compare Argonaute proteins and small RNAs from C. elegans and Ascaris, expanding our understanding of the conservation, divergence, and flexibility of Argonautes and small RNA pathways in nematodes.
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Affiliation(s)
- Maxim V Zagoskin
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA.,RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, USA.,Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA
| | - Jianbin Wang
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA. .,RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, USA. .,Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, USA. .,UT-ORNL Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, USA.
| | - Ashley T Neff
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Giovana M B Veronezi
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Richard E Davis
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA. .,RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, USA.
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23
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Dohn R, Xie B, Back R, Selewa A, Eckart H, Rao RP, Basu A. mDrop-Seq: Massively Parallel Single-Cell RNA-Seq of Saccharomyces cerevisiae and Candida albicans. Vaccines (Basel) 2021; 10:vaccines10010030. [PMID: 35062691 PMCID: PMC8779198 DOI: 10.3390/vaccines10010030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/18/2021] [Accepted: 12/22/2021] [Indexed: 11/16/2022] Open
Abstract
Advances in high-throughput single-cell RNA sequencing (scRNA-seq) have been limited by technical challenges such as tough cell walls and low RNA quantity that prevent transcriptomic profiling of microbial species at throughput. We present microbial Drop-seq or mDrop-seq, a high-throughput scRNA-seq technique that is demonstrated on two yeast species, Saccharomyces cerevisiae, a popular model organism, and Candida albicans, a common opportunistic pathogen. We benchmarked mDrop-seq for sensitivity and specificity and used it to profile 35,109 S. cerevisiae cells to detect variation in mRNA levels between them. As a proof of concept, we quantified expression differences in heat shock S. cerevisiae using mDrop-seq. We detected differential activation of stress response genes within a seemingly homogenous population of S. cerevisiae under heat shock. We also applied mDrop-seq to C. albicans cells, a polymorphic and clinically relevant species of yeast with a thicker cell wall compared to S. cerevisiae. Single-cell transcriptomes in 39,705 C. albicans cells were characterized using mDrop-seq under different conditions, including exposure to fluconazole, a common anti-fungal drug. We noted differential regulation in stress response and drug target pathways between C. albicans cells, changes in cell cycle patterns and marked increases in histone activity when treated with fluconazole. We demonstrate mDrop-seq to be an affordable and scalable technique that can quantify the variability in gene expression in different yeast species. We hope that mDrop-seq will lead to a better understanding of genetic variation in pathogens in response to stimuli and find immediate applications in investigating drug resistance, infection outcome and developing new drugs and treatment strategies.
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Affiliation(s)
- Ryan Dohn
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (B.X.); (R.B.); (A.S.); (H.E.); (A.B.)
- Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA
- Correspondence:
| | - Bingqing Xie
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (B.X.); (R.B.); (A.S.); (H.E.); (A.B.)
| | - Rebecca Back
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (B.X.); (R.B.); (A.S.); (H.E.); (A.B.)
| | - Alan Selewa
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (B.X.); (R.B.); (A.S.); (H.E.); (A.B.)
- Biophysical Sciences Graduate Program, University of Chicago, Chicago, IL 60637, USA
| | - Heather Eckart
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (B.X.); (R.B.); (A.S.); (H.E.); (A.B.)
| | - Reeta Prusty Rao
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA 01609, USA;
| | - Anindita Basu
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA; (B.X.); (R.B.); (A.S.); (H.E.); (A.B.)
- Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA
- Biophysical Sciences Graduate Program, University of Chicago, Chicago, IL 60637, USA
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24
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Gopal S, Amran A, Elton A, Ng L, Pocock R. A somatic proteoglycan controls Notch-directed germ cell fate. Nat Commun 2021; 12:6708. [PMID: 34795288 PMCID: PMC8602670 DOI: 10.1038/s41467-021-27039-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/02/2021] [Indexed: 11/24/2022] Open
Abstract
Communication between the soma and germline optimizes germ cell fate programs. Notch receptors are key determinants of germ cell fate but how somatic signals direct Notch-dependent germ cell behavior is undefined. Here we demonstrate that SDN-1 (syndecan-1), a somatic transmembrane proteoglycan, controls expression of the GLP-1 (germline proliferation-1) Notch receptor in the Caenorhabditis elegans germline. We find that SDN-1 control of a somatic TRP calcium channel governs calcium-dependent binding of an AP-2 transcription factor (APTF-2) to the glp-1 promoter. Hence, SDN-1 signaling promotes GLP-1 expression and mitotic germ cell fate. Together, these data reveal SDN-1 as a putative communication nexus between the germline and its somatic environment to control germ cell fate decisions.
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Affiliation(s)
- Sandeep Gopal
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, 3800, Australia.
| | - Aqilah Amran
- grid.1002.30000 0004 1936 7857Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800 Australia
| | - Andre Elton
- grid.1002.30000 0004 1936 7857Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800 Australia
| | - Leelee Ng
- grid.1002.30000 0004 1936 7857Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800 Australia
| | - Roger Pocock
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, 3800, Australia.
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25
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Rappaport Y, Achache H, Falk R, Murik O, Ram O, Tzur YB. Bisection of the X chromosome disrupts the initiation of chromosome silencing during meiosis in Caenorhabditis elegans. Nat Commun 2021; 12:4802. [PMID: 34376665 PMCID: PMC8355143 DOI: 10.1038/s41467-021-24815-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/01/2021] [Indexed: 01/04/2023] Open
Abstract
During meiosis, gene expression is silenced in aberrantly unsynapsed chromatin and in heterogametic sex chromosomes. Initiation of sex chromosome silencing is disrupted in meiocytes with sex chromosome-autosome translocations. To determine whether this is due to aberrant synapsis or loss of continuity of sex chromosomes, we engineered Caenorhabditis elegans nematodes with non-translocated, bisected X chromosomes. In early meiocytes of mutant males and hermaphrodites, X segments are enriched with euchromatin assembly markers and active RNA polymerase II staining, indicating active transcription. Analysis of RNA-seq data showed that genes from the X chromosome are upregulated in gonads of mutant worms. Contrary to previous models, which predicted that any unsynapsed chromatin is silenced during meiosis, our data indicate that unsynapsed X segments are transcribed. Therefore, our results suggest that sex chromosome chromatin has a unique character that facilitates its meiotic expression when its continuity is lost, regardless of whether or not it is synapsed.
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Affiliation(s)
- Yisrael Rappaport
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hanna Achache
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Roni Falk
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Omer Murik
- Medical Genetics Institute, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Oren Ram
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yonatan B Tzur
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
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26
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Nadarajan S, Altendorfer E, Saito TT, Martinez-Garcia M, Colaiácovo MP. HIM-17 regulates the position of recombination events and GSP-1/2 localization to establish short arm identity on bivalents in meiosis. Proc Natl Acad Sci U S A 2021; 118:e2016363118. [PMID: 33883277 PMCID: PMC8092412 DOI: 10.1073/pnas.2016363118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The position of recombination events established along chromosomes in early prophase I and the chromosome remodeling that takes place in late prophase I are intrinsically linked steps of meiosis that need to be tightly regulated to ensure accurate chromosome segregation and haploid gamete formation. Here, we show that RAD-51 foci, which form at the sites of programmed meiotic DNA double-strand breaks (DSBs), exhibit a biased distribution toward off-centered positions along the chromosomes in wild-type Caenorhabditis elegans, and we identify two meiotic roles for chromatin-associated protein HIM-17 that ensure normal chromosome remodeling in late prophase I. During early prophase I, HIM-17 regulates the distribution of DSB-dependent RAD-51 foci and crossovers on chromosomes, which is critical for the formation of distinct chromosome subdomains (short and long arms of the bivalents) later during chromosome remodeling. During late prophase I, HIM-17 promotes the normal expression and localization of protein phosphatases GSP-1/2 to the surface of the bivalent chromosomes and may promote GSP-1 phosphorylation, thereby antagonizing Aurora B kinase AIR-2 loading on the long arms and preventing premature loss of sister chromatid cohesion. We propose that HIM-17 plays distinct roles at different stages during meiotic progression that converge to promote normal chromosome remodeling and accurate chromosome segregation.
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Affiliation(s)
| | - Elisabeth Altendorfer
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | - Takamune T Saito
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
| | | | - Monica P Colaiácovo
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115
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27
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Maniates KA, Olson BS, Abbott AL. Sperm fate is promoted by the mir-44 microRNA family in the Caenorhabditis elegans hermaphrodite germline. Genetics 2021; 217:1-14. [PMID: 33683352 PMCID: PMC8045739 DOI: 10.1093/genetics/iyaa006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 11/12/2020] [Indexed: 11/12/2022] Open
Abstract
Posttranscriptional regulation of gene expression, typically effected by RNA-binding proteins, microRNAs (miRNAs), and translation initiation factors, is essential for normal germ cell function. Numerous miRNAs have been detected in the germline; however, the functions of specific miRNAs remain largely unknown. Functions of miRNAs have been difficult to determine as miRNAs often modestly repress target mRNAs and are suggested to sculpt or fine tune gene expression to allow for the robust expression of cell fates. In Caenorhabditis elegans hermaphrodites, cell fate decisions are made for germline sex determination during larval development when sperm are generated in a short window before the switch to oocyte production. Here, analysis of newly generated mir-44 family mutants has identified a family of miRNAs that modulate the germline sex determination pathway in C. elegans. Mutants with the loss of mir-44 and mir-45 produce fewer sperm, showing both a delay in the specification and formation of sperm as well as an early termination of sperm specification accompanied by a premature switch to oocyte production. mir-44 and mir-45 are necessary for the normal period of fog-1 expression in larval development. Through genetic analysis, we find that mir-44 and mir-45 may act upstream of fbf-1 and fem-3 to promote sperm specification. Our research indicates that the mir-44 family promotes sperm cell fate specification during larval development and identifies an additional posttranscriptional regulator of the germline sex determination pathway.
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Affiliation(s)
- Katherine A Maniates
- Department of Biological Sciences, Marquette University, 1428 W. Clybourn Ave, PO Box 1881, Milwaukee, WI 53233, USA
| | - Benjamin S Olson
- Department of Biological Sciences, Marquette University, 1428 W. Clybourn Ave, PO Box 1881, Milwaukee, WI 53233, USA
| | - Allison L Abbott
- Department of Biological Sciences, Marquette University, 1428 W. Clybourn Ave, PO Box 1881, Milwaukee, WI 53233, USA
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28
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Zhang Z, Xie S, Wang R, Guo S, Zhao Q, Nie H, Liu Y, Zhang F, Chen M, Liu L, Meng X, Liu M, Zhao L, Colaiácovo MP, Zhou J, Gao J. Multivalent weak interactions between assembly units drive synaptonemal complex formation. J Cell Biol 2021; 219:151585. [PMID: 32211900 PMCID: PMC7199860 DOI: 10.1083/jcb.201910086] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/22/2020] [Accepted: 02/26/2020] [Indexed: 12/28/2022] Open
Abstract
The synaptonemal complex (SC) is an ordered but highly dynamic structure assembled between homologous chromosomes to control interhomologous crossover formation, ensuring accurate meiotic chromosome segregation. However, the mechanisms regulating SC assembly and dynamics remain unclear. Here, we identified two new SC components, SYP-5 and SYP-6, in Caenorhabditis elegans that have distinct expression patterns and form distinct SC assembly units with other SYPs through stable interactions. SYP-5 and SYP-6 exhibit diverse in vivo SC regulatory functions and distinct phase separation properties in cells. Charge-interacting elements (CIEs) are enriched in SC intrinsically disordered regions (IDRs), and IDR deletion or CIE removal confirmed a requirement for these elements in SC regulation. Our data support the theory that multivalent weak interactions between the SC units drive SC formation and that CIEs confer multivalency to the assembly units.
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Affiliation(s)
- Zhenguo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Songbo Xie
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Ruoxi Wang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Shuqun Guo
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Qiuchen Zhao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Hui Nie
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Yuanyuan Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Fengguo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Miao Chen
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Libo Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Xiaoqian Meng
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Min Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Li Zhao
- Department of Pathology, Harvard Medical School, Dana-Farber/Harvard Cancer Center, Boston, MA.,Department of Laboratory Medicine, Children's Hospital Boston, Boston, MA
| | | | - Jun Zhou
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China.,State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jinmin Gao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
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29
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Vicencio J, Cerón J. A Living Organism in your CRISPR Toolbox: Caenorhabditis elegans Is a Rapid and Efficient Model for Developing CRISPR-Cas Technologies. CRISPR J 2021; 4:32-42. [PMID: 33538637 DOI: 10.1089/crispr.2020.0103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The Cas9 nuclease from Streptococcus pyogenes (SpCas9) is the most popular enzyme for CRISPR technologies. However, considering the wide diversity of microorganisms (discovered and still unknown), a massive number of CRISPR effectors are being and will be identified and characterized in the search of optimal Cas variants for each of the many applications of CRISPR. In this context, a versatile and efficient multicellular system for CRISPR editing such as Caenorhabditis elegans would be of great help in the development of these effectors. Here, we highlight the benefits of using C. elegans for the rapid evaluation of new CRISPR effectors, and for optimizing CRISPR efficiency in animals in several ways such as by modulating the balance between repair pathways, modifying chromatin accessibility, or controlling the expression and activity of nucleases and guide RNAs.
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Affiliation(s)
- Jeremy Vicencio
- Modeling human diseases in C. elegans Group, Genes, Disease and Therapy Program, Bellvitge Biomedical Research Institute-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Julián Cerón
- Modeling human diseases in C. elegans Group, Genes, Disease and Therapy Program, Bellvitge Biomedical Research Institute-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain
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30
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Rödelsperger C, Ebbing A, Sharma DR, Okumura M, Sommer RJ, Korswagen HC. Spatial Transcriptomics of Nematodes Identifies Sperm Cells as a Source of Genomic Novelty and Rapid Evolution. Mol Biol Evol 2021; 38:229-243. [PMID: 32785688 PMCID: PMC8480184 DOI: 10.1093/molbev/msaa207] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Divergence of gene function and expression during development can give rise to phenotypic differences at the level of cells, tissues, organs, and ultimately whole organisms. To gain insights into the evolution of gene expression and novel genes at spatial resolution, we compared the spatially resolved transcriptomes of two distantly related nematodes, Caenorhabditis elegans and Pristionchus pacificus, that diverged 60-90 Ma. The spatial transcriptomes of adult worms show little evidence for strong conservation at the level of single genes. Instead, regional expression is largely driven by recent duplication and emergence of novel genes. Estimation of gene ages across anatomical structures revealed an enrichment of novel genes in sperm-related regions. This provides first evidence in nematodes for the "out of testis" hypothesis that has been previously postulated based on studies in Drosophila and mammals. "Out of testis" genes represent a mix of products of pervasive transcription as well as fast evolving members of ancient gene families. Strikingly, numerous novel genes have known functions during meiosis in Caenorhabditis elegans indicating that even universal processes such as meiosis may be targets of rapid evolution. Our study highlights the importance of novel genes in generating phenotypic diversity and explicitly characterizes gene origination in sperm-related regions. Furthermore, it proposes new functions for previously uncharacterized genes and establishes the spatial transcriptome of Pristionchus pacificus as a catalog for future studies on the evolution of gene expression and function.
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Affiliation(s)
- Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Annabel Ebbing
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht,
The Netherlands
| | - Devansh Raj Sharma
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Misako Okumura
- Program of Biomedical Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Hendrik C Korswagen
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences and University Medical Center Utrecht, Utrecht,
The Netherlands
- Developmental Biology, Department of Biology, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht,
The Netherlands
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31
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Ragle JM, Aita AL, Morrison KN, Martinez-Mendez R, Saeger HN, Ashley GA, Johnson LC, Schubert KA, Shakes DC, Ward JD. The conserved molting/circadian rhythm regulator NHR-23/NR1F1 serves as an essential co-regulator of C. elegans spermatogenesis. Development 2020; 147:dev193862. [PMID: 33060131 PMCID: PMC7710015 DOI: 10.1242/dev.193862] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/12/2020] [Indexed: 12/21/2022]
Abstract
In sexually reproducing metazoans, spermatogenesis is the process by which uncommitted germ cells give rise to haploid sperm. Work in model systems has revealed mechanisms controlling commitment to the sperm fate, but how this fate is subsequently executed remains less clear. While studying the well-established role of the conserved nuclear hormone receptor transcription factor, NHR-23/NR1F1, in regulating C. elegans molting, we discovered that NHR-23/NR1F1 is also constitutively expressed in developing primary spermatocytes and is a critical regulator of spermatogenesis. In this novel role, NHR-23/NR1F1 functions downstream of the canonical sex-determination pathway. Degron-mediated depletion of NHR-23/NR1F1 within hermaphrodite or male germlines causes sterility due to an absence of functional sperm, as depleted animals produce arrested primary spermatocytes rather than haploid sperm. These spermatocytes arrest in prometaphase I and fail to either progress to anaphase or attempt spermatid-residual body partitioning. They make sperm-specific membranous organelles but fail to assemble their major sperm protein into fibrous bodies. NHR-23/NR1F1 appears to function independently of the known SPE-44 gene regulatory network, revealing the existence of an NHR-23/NR1F1-mediated module that regulates the spermatogenesis program.
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Affiliation(s)
- James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Abigail L Aita
- Department of Biology, William & Mary, Williamsburg, VA 23187, USA
| | | | - Raquel Martinez-Mendez
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hannah N Saeger
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Guinevere A Ashley
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Londen C Johnson
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Katherine A Schubert
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Diane C Shakes
- Department of Biology, William & Mary, Williamsburg, VA 23187, USA
| | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
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32
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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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33
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Systematic analysis of long intergenic non-coding RNAs in C. elegans germline uncovers roles in somatic growth. RNA Biol 2020; 18:435-445. [PMID: 32892705 DOI: 10.1080/15476286.2020.1814549] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Long intergenic non-coding RNAs (lincRNAs) are transcripts longer than 200 nucleotides that are transcribed from non-coding loci yet undergo biosynthesis similar to coding mRNAs. The disproportional number of lincRNAs expressed in testes suggests that lincRNAs are important during gametogenesis, but experimental evidence has implicated very few lincRNAs in this process. We took advantage of the relatively limited number of lincRNAs in the genome of the nematode Caenorhabditis elegans to systematically analyse the functions of lincRNAs during meiosis. We deleted six lincRNA genes that are highly and dynamically expressed in the C. elegans gonad and tested the effects on central meiotic processes. Surprisingly, whereas the lincRNA deletions did not strongly impact fertility, germline apoptosis, crossovers, or synapsis, linc-4 was required for somatic growth. Slower growth was observed in linc-4-deletion mutants and in worms depleted of linc-4 using RNAi, indicating that linc-4 transcripts are required for this post-embryonic process. Unexpectedly, analysis of worms depleted of linc-4 in soma versus germline showed that the somatic role stems from linc-4 expression in germline cells. This unique feature suggests that some lincRNAs, like some small non-coding RNAs, are required for germ-soma interactions.
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34
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Identification of transcriptome differences in goat ovaries at the follicular phase and the luteal phase using an RNA-Seq method. Theriogenology 2020; 158:239-249. [PMID: 32987289 DOI: 10.1016/j.theriogenology.2020.06.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 06/23/2020] [Accepted: 06/29/2020] [Indexed: 01/01/2023]
Abstract
The ovaries, the main female reproductive organs, directly mediate ovulation and reproductive hormone secretion. These complex physiological processes are regulated by multiple genes and pathways. However, there is a lack of research on goat ovaries, and the molecular mechanisms underlying the signaling pathways remain unclear. In this study, Illumina HiSeq 4000 sequencing was used to sequence the transcriptomes of goat ovaries. The expression patterns of differentially expressed mRNAs in goat ovaries at both the follicular and luteal phases were determined by bioinformatics analysis. A total of 1,122, 014, 112 clean reads were obtained, and 3770 differentially expressed mRNAs were identified for further analysis. There were 1727 and 2043 upregulated mRNAs in the luteal phase and follicular phase, respectively. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, some mRNAs that were highly expressed in ovaries during the luteal phase, such as HSD17B7, 3BHSD, and SRD5A2, may be related to the synthesis of progesterone. In addition, some mRNAs that were highly expressed in ovaries during the follicular phase, such as RPL12, RPS13 and RPL10, are related to the growth and maturation of oocytes. Taken together, the findings of this study provide genome-wide mRNA expression profiles for goat ovaries at the follicular and luteal phases and identify mRNAs associated with goat hormone secretion and follicular development. In addition, this study provides a theoretical basis for further investigation of goat reproductive regulation.
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35
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Anderson EC, Frankino PA, Higuchi-Sanabria R, Yang Q, Bian Q, Podshivalova K, Shin A, Kenyon C, Dillin A, Meyer BJ. X Chromosome Domain Architecture Regulates Caenorhabditis elegans Lifespan but Not Dosage Compensation. Dev Cell 2019; 51:192-207.e6. [PMID: 31495695 DOI: 10.1016/j.devcel.2019.08.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/26/2019] [Accepted: 08/06/2019] [Indexed: 12/21/2022]
Abstract
Mechanisms establishing higher-order chromosome structures and their roles in gene regulation are elusive. We analyzed chromosome architecture during nematode X chromosome dosage compensation, which represses transcription via a dosage-compensation condensin complex (DCC) that binds hermaphrodite Xs and establishes megabase-sized topologically associating domains (TADs). We show that DCC binding at high-occupancy sites (rex sites) defines eight TAD boundaries. Single rex deletions disrupted boundaries, and single insertions created new boundaries, demonstrating that a rex site is necessary and sufficient to define DCC-dependent boundary locations. Deleting eight rex sites (8rexΔ) recapitulated TAD structure of DCC mutants, permitting analysis when chromosome-wide domain architecture was disrupted but most DCC binding remained. 8rexΔ animals exhibited no changes in X expression and lacked dosage-compensation mutant phenotypes. Hence, TAD boundaries are neither the cause nor the consequence of DCC-mediated gene repression. Abrogating TAD structure did, however, reduce thermotolerance, accelerate aging, and shorten lifespan, implicating chromosome architecture in stress responses and aging.
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Affiliation(s)
- Erika C Anderson
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Phillip A Frankino
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ryo Higuchi-Sanabria
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Qiming Yang
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Qian Bian
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Aram Shin
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Cynthia Kenyon
- Calico Life Sciences, South San Francisco, CA 94080, USA
| | - Andrew Dillin
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Barbara J Meyer
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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36
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Achache H, Laurent L, Hecker-Mimoun Y, Ishtayeh H, Rappaport Y, Kroizer E, Colaiácovo MP, Tzur YB. Progression of Meiosis Is Coordinated by the Level and Location of MAPK Activation Via OGR-2 in Caenorhabditis elegans. Genetics 2019; 212:213-229. [PMID: 30867196 PMCID: PMC6499523 DOI: 10.1534/genetics.119.302080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 03/07/2019] [Indexed: 02/07/2023] Open
Abstract
During meiosis, a series of evolutionarily conserved events allow for reductional chromosome division, which is required for sexual reproduction. Although individual meiotic processes have been extensively studied, we currently know far less about how meiosis is regulated and coordinated. In the Caenorhabditis elegans gonad, mitogen-activated protein kinase (MAPK) signaling drives oogenesis while undergoing spatial activation and deactivation waves. However, it is currently unclear how MAPK activation is governed and how it facilitates the progression of oogenesis. Here, we show that the oocyte and germline-related 2 (ogr-2) gene affects proper progression of oogenesis. Complete deletion of ogr-2 results in delayed meiotic entry and late spatial onset of double-strand break repair. Elevated levels of apoptosis are observed in this mutant, independent of the meiotic canonical checkpoints; however, they are dependent on the MAPK terminal member MPK-1/ERK. MPK-1 activation is elevated in diplotene in ogr-2 mutants and its aberrant spatial activation correlates with stages where meiotic progression defects are evident. Deletion of ogr-2 significantly reduces the expression of lip-1, a phosphatase reported to repress MPK-1, which is consistent with OGR-2 localization at chromatin in germ cells. We suggest that OGR-2 modulates the expression of lip-1 to promote the timely progression of meiosis through MPK-1 spatial deactivation.
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Affiliation(s)
- Hanna Achache
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Lévana Laurent
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Yaël Hecker-Mimoun
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Hasan Ishtayeh
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Yisrael Rappaport
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | - Eitan Kroizer
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
| | | | - Yonatan B Tzur
- Department of Genetics, Institute of Life Sciences, Hebrew University, Givat-Ram, Jerusalem 91904, Israel
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