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Ewe CK, Rechavi O. Inheritance: Leaving sticky notes for the children. Curr Biol 2024; 34:R1180-R1182. [PMID: 39626630 DOI: 10.1016/j.cub.2024.09.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2024]
Abstract
It is currently unknown to what degree parents' life history can affect the next generation and how such information might be transmitted. A new study finds that nematodes transmit amyloid proteins to their progeny, which influence developmental processes.
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Affiliation(s)
- Chee Kiang Ewe
- School of Neurobiology, Biochemistry and Biophysics, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
| | - Oded Rechavi
- School of Neurobiology, Biochemistry and Biophysics, Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
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2
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Galindo-Torres P, Rosas C, Ramos-Rodríguez S, Galindo-Sánchez CE. Chronic thermal stress on Octopus maya embryos down-regulates epigenome-related genes and those involved in the nervous system development and morphogenesis. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2024; 52:101332. [PMID: 39366120 DOI: 10.1016/j.cbd.2024.101332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 09/20/2024] [Accepted: 09/22/2024] [Indexed: 10/06/2024]
Abstract
Red Octopus maya is strongly influenced by temperature. Recent studies have reported negative reproduction effects on males and females when exposed to temperatures higher than 27 °C. Embryos under thermal stress show morphological and physiological alterations; similar phenotypes have been reported in embryos from stressed females, evidencing transgenerational consequences. Transcriptomic profiles were characterized along embryo development during normal-under thermal stress and epigenetic alterations through DNA methylation and damage quantification. Total RNA in organogenesis, activation, and growth stages in control and thermal stress were sequenced with Illumina RNA-Seq. Similarly, total DNA was used for DNA methylation and damage quantification between temperatures and embryo stages. Differential gene expression analyses showed that embryos express genes associated with oxygen transport, morphogenesis, nervous system, neuroendocrine cell differentiation, spermatogenesis, and male sex differentiation. Conversely, embryos turn off genes involved mainly in nervous system development, morphogenesis, and gene expression regulation when exposed to thermal stress - consistent with O. maya embryo phenotypes showing abnormal arms, eyes, and body development. No significant differences were observed in quantifying DNA methylation between temperatures but they were for DNA damage quantification. Epigenetic alterations are hypothesized to occur since several genes found downregulated belong to the epigenetic machinery but at histone tail level.
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Affiliation(s)
- Pavel Galindo-Torres
- Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), Carretera Tijuana-Ensenada No. 3918, Zona Playitas, Ensenada, Baja California CP 22860, Mexico.
| | - Carlos Rosas
- Unidad Multidisciplinaria de Docencia e Investigacion (UMDI), Facultad de Ciencias, Universidad Nacional Autonoma de Mexico (UNAM), Puerto DE Abrigo s/n, Sisal, Hunucma, Yucatan CP97355, Mexico.
| | - Sadot Ramos-Rodríguez
- Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), Carretera Tijuana-Ensenada No. 3918, Zona Playitas, Ensenada, Baja California CP 22860, Mexico.
| | - Clara E Galindo-Sánchez
- Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE), Carretera Tijuana-Ensenada No. 3918, Zona Playitas, Ensenada, Baja California CP 22860, Mexico.
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3
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Kulikova DA, Bespalova AV, Zelentsova ES, Evgen'ev MB, Funikov SY. Epigenetic Phenomenon of Paramutation in Plants and Animals. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1429-1450. [PMID: 39245454 DOI: 10.1134/s0006297924080054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 06/17/2024] [Accepted: 06/27/2024] [Indexed: 09/10/2024]
Abstract
The phenomenon of paramutation describes the interaction between two alleles, in which one allele initiates inherited epigenetic conversion of another allele without affecting the DNA sequence. Epigenetic transformations due to paramutation are accompanied by the change in DNA and/or histone methylation patterns, affecting gene expression. Studies of paramutation in plants and animals have identified small non-coding RNAs as the main effector molecules required for the initiation of epigenetic changes in gene loci. Due to the fact that small non-coding RNAs can be transmitted across generations, the paramutation effect can be inherited and maintained in a population. In this review, we will systematically analyze examples of paramutation in different living systems described so far, highlighting common and different molecular and genetic aspects of paramutation between organisms, and considering the role of this phenomenon in evolution.
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Affiliation(s)
- Dina A Kulikova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Alina V Bespalova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Elena S Zelentsova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Mikhail B Evgen'ev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - Sergei Yu Funikov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
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Shen Y, Lin SY, Harbin J, Amin R, Vassalotti A, Romanowski J, Schmidt E, Tierney A, Ellis RE. Rewiring the Sex-Determination Pathway During the Evolution of Self-Fertility. Mol Biol Evol 2024; 41:msae101. [PMID: 38880992 PMCID: PMC11180601 DOI: 10.1093/molbev/msae101] [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: 03/08/2024] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 06/18/2024] Open
Abstract
Although evolution is driven by changes in how regulatory pathways control development, we know little about the molecular details underlying these transitions. The TRA-2 domain that mediates contact with TRA-1 is conserved in Caenorhabditis. By comparing the interaction of these proteins in two species, we identified a striking change in how sexual development is controlled. Identical mutations in this domain promote oogenesis in Caenorhabditis elegans but promote spermatogenesis in Caenorhabditis briggsae. Furthermore, the effects of these mutations involve the male-promoting gene fem-3 in C. elegans but are independent of fem-3 in C. briggsae. Finally, reciprocal mutations in these genes show that C. briggsae TRA-2 binds TRA-1 to prevent expression of spermatogenesis regulators. By contrast, in C. elegans TRA-1 sequesters TRA-2 in the germ line, allowing FEM-3 to initiate spermatogenesis. Thus, we propose that the flow of information within the sex determination pathway has switched directions during evolution. This result has important implications for how evolutionary change can occur.
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Affiliation(s)
- Yongquan Shen
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Shin-Yi Lin
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Jonathan Harbin
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Richa Amin
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Allison Vassalotti
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Joseph Romanowski
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Emily Schmidt
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Alexis Tierney
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
| | - Ronald E Ellis
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Science, Rowan-Virtua School of Osteopathic Medicine, Stratford, NJ 08084, USA
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5
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Pliota P, Marvanova H, Koreshova A, Kaufman Y, Tikanova P, Krogull D, Hagmüller A, Widen SA, Handler D, Gokcezade J, Duchek P, Brennecke J, Ben-David E, Burga A. Selfish conflict underlies RNA-mediated parent-of-origin effects. Nature 2024; 628:122-129. [PMID: 38448590 PMCID: PMC10990930 DOI: 10.1038/s41586-024-07155-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/02/2024] [Indexed: 03/08/2024]
Abstract
Genomic imprinting-the non-equivalence of maternal and paternal genomes-is a critical process that has evolved independently in many plant and mammalian species1,2. According to kinship theory, imprinting is the inevitable consequence of conflictive selective forces acting on differentially expressed parental alleles3,4. Yet, how these epigenetic differences evolve in the first place is poorly understood3,5,6. Here we report the identification and molecular dissection of a parent-of-origin effect on gene expression that might help to clarify this fundamental question. Toxin-antidote elements (TAs) are selfish elements that spread in populations by poisoning non-carrier individuals7-9. In reciprocal crosses between two Caenorhabditis tropicalis wild isolates, we found that the slow-1/grow-1 TA is specifically inactive when paternally inherited. This parent-of-origin effect stems from transcriptional repression of the slow-1 toxin by the PIWI-interacting RNA (piRNA) host defence pathway. The repression requires PIWI Argonaute and SET-32 histone methyltransferase activities and is transgenerationally inherited via small RNAs. Remarkably, when slow-1/grow-1 is maternally inherited, slow-1 repression is halted by a translation-independent role of its maternal mRNA. That is, slow-1 transcripts loaded into eggs-but not SLOW-1 protein-are necessary and sufficient to counteract piRNA-mediated repression. Our findings show that parent-of-origin effects can evolve by co-option of the piRNA pathway and hinder the spread of selfish genes that require sex for their propagation.
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Affiliation(s)
- Pinelopi Pliota
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Hana Marvanova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Alevtina Koreshova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Yotam Kaufman
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Polina Tikanova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Daniel Krogull
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Andreas Hagmüller
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Sonya A Widen
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Dominik Handler
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Joseph Gokcezade
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Peter Duchek
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Julius Brennecke
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Eyal Ben-David
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
- Illumina Artificial Intelligence Laboratory, Illumina, San Diego, CA, USA
| | - Alejandro Burga
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.
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6
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Wilson R, Le Bourgeois M, Perez M, Sarkies P. Fluctuations in chromatin state at regulatory loci occur spontaneously under relaxed selection and are associated with epigenetically inherited variation in C. elegans gene expression. PLoS Genet 2023; 19:e1010647. [PMID: 36862744 PMCID: PMC10013927 DOI: 10.1371/journal.pgen.1010647] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 03/14/2023] [Accepted: 02/01/2023] [Indexed: 03/03/2023] Open
Abstract
Some epigenetic information can be transmitted between generations without changes in the underlying DNA sequence. Changes in epigenetic regulators, termed epimutations, can occur spontaneously and be propagated in populations in a manner reminiscent of DNA mutations. Small RNA-based epimutations occur in C. elegans and persist for around 3-5 generations on average. Here, we explored whether chromatin states also undergo spontaneous change and whether this could be a potential alternative mechanism for transgenerational inheritance of gene expression changes. We compared the chromatin and gene expression profiles at matched time points from three independent lineages of C. elegans propagated at minimal population size. Spontaneous changes in chromatin occurred in around 1% of regulatory regions each generation. Some were heritable epimutations and were significantly enriched for heritable changes in expression of nearby protein-coding genes. Most chromatin-based epimutations were short-lived but a subset had longer duration. Genes subject to long-lived epimutations were enriched for multiple components of xenobiotic response pathways. This points to a possible role for epimutations in adaptation to environmental stressors.
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Affiliation(s)
- Rachel Wilson
- MRC London Institute of Medical Sciences, London, United Kingdom.,Institute of Clinical Sciences, Imperial College London, London, United Kingdom.,Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | | | - Marcos Perez
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Peter Sarkies
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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Gajic Z, Kaur D, Ni J, Zhu Z, Zhebrun A, Gajic M, Kim M, Hong J, Priyadarshini M, Frøkjær-Jensen C, Gu S. Target-dependent suppression of siRNA production modulates the levels of endogenous siRNAs in the Caenorhabditis elegans germline. Development 2022; 149:dev200692. [PMID: 35876680 PMCID: PMC9481970 DOI: 10.1242/dev.200692] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/14/2022] [Indexed: 08/24/2023]
Abstract
Despite the prominent role of endo-siRNAs in transposon silencing, their expression is not limited to these 'nonself' DNA elements. Transcripts of protein-coding genes ('self' DNA) in some cases also produce endo-siRNAs in yeast, plants and animals. How cells distinguish these two populations of siRNAs to prevent unwanted silencing of active genes in animals is not well understood. To address this question, we inserted various self-gene or gfp fragments into an LTR retrotransposon that produces abundant siRNAs and examined the propensity of these gene fragments to produce ectopic siRNAs in the Caenorhabditis elegans germline. We found that fragments of germline genes are generally protected from production of ectopic siRNAs. This phenomenon, which we termed 'target-directed suppression of siRNA production' (or siRNA suppression), is dependent on the germline expression of target mRNA and requires germline P-granule components. We found that siRNA suppression can also occur in naturally produced endo-siRNAs. We suggest that siRNA suppression plays an important role in regulating siRNA expression and preventing self-genes from aberrant epigenetic silencing. This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Zoran Gajic
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Diljeet Kaur
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Julie Ni
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Zhaorong Zhu
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Anna Zhebrun
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Maria Gajic
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Matthew Kim
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Julia Hong
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Monika Priyadarshini
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955–6900, Kingdom of Saudi Arabia
| | - Christian Frøkjær-Jensen
- Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955–6900, Kingdom of Saudi Arabia
| | - Sam Gu
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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Devanapally S, Raman P, Chey M, Allgood S, Ettefa F, Diop M, Lin Y, Cho YE, Jose AM. Mating can initiate stable RNA silencing that overcomes epigenetic recovery. Nat Commun 2021; 12:4239. [PMID: 34244495 PMCID: PMC8270896 DOI: 10.1038/s41467-021-24053-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 05/29/2021] [Indexed: 01/09/2023] Open
Abstract
Stable epigenetic changes appear uncommon, suggesting that changes typically dissipate or are repaired. Changes that stably alter gene expression across generations presumably require particular conditions that are currently unknown. Here we report that a minimal combination of cis-regulatory sequences can support permanent RNA silencing of a single-copy transgene and its derivatives in C. elegans simply upon mating. Mating disrupts competing RNA-based mechanisms to initiate silencing that can last for >300 generations. This stable silencing requires components of the small RNA pathway and can silence homologous sequences in trans. While animals do not recover from mating-induced silencing, they often recover from and become resistant to trans silencing. Recovery is also observed in most cases when double-stranded RNA is used to silence the same coding sequence in different regulatory contexts that drive germline expression. Therefore, we propose that regulatory features can evolve to oppose permanent and potentially maladaptive responses to transient change.
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Affiliation(s)
| | | | - Mary Chey
- University of Maryland, College Park, MD, USA
| | | | | | | | - Yixin Lin
- University of Maryland, College Park, MD, USA
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9
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Galindo-Torres P, Ventura-López C, Llera-Herrera R, Ibarra AM. A natural antisense transcript of the fem-1 gene was found expressed in female gonads during the characterization, expression profile, and cellular localization of the fem-1 gene in Pacific white shrimp Penaeus vannamei. Gene 2019; 706:19-31. [PMID: 31028869 DOI: 10.1016/j.gene.2019.04.066] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 03/29/2019] [Accepted: 04/23/2019] [Indexed: 12/19/2022]
Abstract
The fem-1 gene in Caenorhabditis elegans is involved in sex differentiation; it is specifically required for all aspects of male development. In this study, the full-length cDNA of the fem-1 (Pvfem-1) gene was isolated from the Pacific whiteleg shrimp Penaeus vannamei. The Pvfem-1 transcript is 3778 nt long and encodes a putative protein (PvFEM-1) of 638 amino acids that presented eight ankyrin repeats. The translated protein showed a significant (P < 0.05) structural similitude by superposition with C. elegans FEM-1 protein. Pvfem-1 expression was evaluated by qPCR and in situ hybridization (ISH) during embryogenesis, larval development, and gonads of both genders in subadult and adult life stages. Pvfem-1 was found expressed in brain, intestine, hepatopancreas, and in the gonads of both genders in subadults and adults when quantified by RT-qPCR. A significant finding was the discovery of a natural antisense transcript (NAT) of Pvfem-1 by ISH. It was present in the oocyte nucleus of subadult female shrimp gonads but was not seen within oocytes from adult females, although it was detected in follicular cells, suggesting a possible post-transcriptional regulation of Pvfem-1 in female gonad. Conversely, in males, no NAT was observed, and Pvfem-1 was found expressed in spermatogonia of both, subadult and adult shrimps indicating a function in male sexual differentiation and gametes generation. This study represents the first step for future functional analysis that is expected to contribute to clarifying the role of Pvfem-1 in sex differentiation and determination.
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Affiliation(s)
- Pavel Galindo-Torres
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Aquaculture Genetics and Breeding Laboratory, Ave. Instituto Politécnico Nacional No. 195, Col. Playa Palo de Santa Rita, 23096 La Paz, Baja California Sur, Mexico.
| | - Claudia Ventura-López
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Aquaculture Genetics and Breeding Laboratory, Ave. Instituto Politécnico Nacional No. 195, Col. Playa Palo de Santa Rita, 23096 La Paz, Baja California Sur, Mexico
| | - Raúl Llera-Herrera
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Aquaculture Genetics and Breeding Laboratory, Ave. Instituto Politécnico Nacional No. 195, Col. Playa Palo de Santa Rita, 23096 La Paz, Baja California Sur, Mexico
| | - Ana M Ibarra
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Aquaculture Genetics and Breeding Laboratory, Ave. Instituto Politécnico Nacional No. 195, Col. Playa Palo de Santa Rita, 23096 La Paz, Baja California Sur, Mexico.
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10
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Frézal L, Demoinet E, Braendle C, Miska E, Félix MA. Natural Genetic Variation in a Multigenerational Phenotype in C. elegans. Curr Biol 2018; 28:2588-2596.e8. [PMID: 30078564 PMCID: PMC6984962 DOI: 10.1016/j.cub.2018.05.091] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/16/2018] [Accepted: 05/31/2018] [Indexed: 10/28/2022]
Abstract
Although heredity mostly relies on the transmission of DNA sequence, additional molecular and cellular features are heritable across several generations. In the nematode Caenorhabditis elegans, insights into such unconventional inheritance result from two lines of work. First, the mortal germline (Mrt) phenotype was defined as a multigenerational phenotype whereby a selfing lineage becomes sterile after several generations, implying multigenerational memory [1, 2]. Second, certain RNAi effects are heritable over several generations in the absence of the initial trigger [3-5]. Both lines of work converged when the subset of Mrt mutants that are heat sensitive were found to closely correspond to mutants defective in the RNAi-inheritance machinery, including histone modifiers [6-9]. Here, we report the surprising finding that several C. elegans wild isolates display a heat-sensitive mortal germline phenotype in laboratory conditions: upon chronic exposure to higher temperatures, such as 25°C, lines reproducibly become sterile after several generations. This phenomenon is reversible, as it can be suppressed by temperature alternations at each generation, suggesting a non-genetic basis for the sterility. We tested whether natural variation in the temperature-induced Mrt phenotype was of genetic nature by building recombinant inbred lines between the isolates MY10 (Mrt) and JU1395 (non-Mrt). Using bulk segregant analysis, we detected two quantitative trait loci. After further recombinant mapping and genome editing, we identified the major causal locus as a polymorphism in the set-24 gene, encoding a SET- and SPK-domain protein. We conclude that C. elegans natural populations may harbor natural genetic variation in epigenetic inheritance phenomena.
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Affiliation(s)
- Lise Frézal
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, INSERM, École Normale Supérieure, Paris Sciences et Lettres, Paris, France; Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK; Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | | | | | - Eric Miska
- Wellcome Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK; Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK; Wellcome Sanger Institute, Wellcome Trust Genome Campus, Cambridge CB10 1SA, UK.
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique, INSERM, École Normale Supérieure, Paris Sciences et Lettres, Paris, France.
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11
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Alptekin B, Langridge P, Budak H. Abiotic stress miRNomes in the Triticeae. Funct Integr Genomics 2017; 17:145-170. [PMID: 27665284 PMCID: PMC5383695 DOI: 10.1007/s10142-016-0525-9] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 09/02/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022]
Abstract
The continued growth in world population necessitates increases in both the quantity and quality of agricultural production. Triticeae members, particularly wheat and barley, make an important contribution to world food reserves by providing rich sources of carbohydrate and protein. These crops are grown over diverse production environments that are characterized by a range of environmental or abiotic stresses. Abiotic stresses such as drought, heat, salinity, or nutrient deficiencies and toxicities cause large yield losses resulting in economic and environmental damage. The negative effects of abiotic stresses have increased at an alarming rate in recent years and are predicted to further deteriorate due to climate change, land degradation, and declining water supply. New technologies have provided an important tool with great potential for improving crop tolerance to the abiotic stresses: microRNAs (miRNAs). miRNAs are small regulators of gene expression that act on many different molecular and biochemical processes such as development, environmental adaptation, and stress tolerance. miRNAs can act at both the transcriptional and post-transcriptional levels, although post-transcriptional regulation is the most common in plants where miRNAs can inhibit the translation of their mRNA targets via complementary binding and cleavage. To date, expression of several miRNA families such as miR156, miR159, and miR398 has been detected as responsive to environmental conditions to regulate stress-associated molecular mechanisms individually and/or together with their various miRNA partners. Manipulation of these miRNAs and their targets may pave the way to improve crop performance under several abiotic stresses. Here, we summarize the current status of our knowledge on abiotic stress-associated miRNAs in members of the Triticeae tribe, specifically in wheat and barley, and the miRNA-based regulatory mechanisms triggered by stress conditions. Exploration of further miRNA families together with their functions under stress will improve our knowledge and provide opportunities to enhance plant performance to help us meet global food demand.
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Affiliation(s)
- Burcu Alptekin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA
| | - Peter Langridge
- School of Agriculture, Food and Wine, University of Adelaide, Adelaide, Australia
| | - Hikmet Budak
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA.
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Tay MLI, Pek JW. Maternally Inherited Stable Intronic Sequence RNA Triggers a Self-Reinforcing Feedback Loop during Development. Curr Biol 2017; 27:1062-1067. [DOI: 10.1016/j.cub.2017.02.040] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/15/2017] [Accepted: 02/16/2017] [Indexed: 12/01/2022]
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13
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Frøkjær-Jensen C, Jain N, Hansen L, Davis MW, Li Y, Zhao D, Rebora K, Millet JRM, Liu X, Kim SK, Dupuy D, Jorgensen EM, Fire AZ. An Abundant Class of Non-coding DNA Can Prevent Stochastic Gene Silencing in the C. elegans Germline. Cell 2016; 166:343-357. [PMID: 27374334 PMCID: PMC4947018 DOI: 10.1016/j.cell.2016.05.072] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 03/31/2016] [Accepted: 05/18/2016] [Indexed: 11/30/2022]
Abstract
Cells benefit from silencing foreign genetic elements but must simultaneously avoid inactivating endogenous genes. Although chromatin modifications and RNAs contribute to maintenance of silenced states, the establishment of silenced regions will inevitably reflect underlying DNA sequence and/or structure. Here we demonstrate that a pervasive non-coding DNA feature in Caenorhabditis elegans, characterized by 10-basepair periodic An/Tn-clusters (PATCs), can license transgenes for germline expression within repressive chromatin domains. Transgenes containing natural or synthetic PATCs are resistant to position effect variegation and stochastic silencing in the germline. Among endogenous genes, intron length and PATC-character undergo dramatic changes as orthologs move from active to repressive chromatin over evolutionary time, indicating a dynamic character to the An/Tn periodicity. We propose that PATCs form the basis of a cellular immune system, identifying certain endogenous genes in heterochromatic contexts as privileged while foreign DNA can be suppressed with no requirement for a cellular memory of prior exposure.
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Affiliation(s)
- Christian Frøkjær-Jensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT 84112, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Sciences and Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Nimit Jain
- Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Loren Hansen
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - M Wayne Davis
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Yongbin Li
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Di Zhao
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Karine Rebora
- IECB, University of Bordeaux, Laboratoire ARNA-INSERM, U869, 33600 Pessac, France
| | - Jonathan R M Millet
- IECB, University of Bordeaux, Laboratoire ARNA-INSERM, U869, 33600 Pessac, France
| | - Xiao Liu
- Department of Developmental Biology, Stanford University Medical Center, Stanford, CA 94305, USA; School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Stuart K Kim
- Department of Developmental Biology, Stanford University Medical Center, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Denis Dupuy
- IECB, University of Bordeaux, Laboratoire ARNA-INSERM, U869, 33600 Pessac, France
| | - Erik M Jorgensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT 84112, USA.
| | - Andrew Z Fire
- Department of Pathology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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14
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Ni JZ, Kalinava N, Chen E, Huang A, Trinh T, Gu SG. A transgenerational role of the germline nuclear RNAi pathway in repressing heat stress-induced transcriptional activation in C. elegans. Epigenetics Chromatin 2016; 9:3. [PMID: 26779286 PMCID: PMC4714518 DOI: 10.1186/s13072-016-0052-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/05/2016] [Indexed: 02/07/2023] Open
Abstract
Background Environmental stress-induced transgenerational epigenetic effects have been observed in various model organisms and human. The capacity and mechanism of such phenomena are poorly understood. In C. elegans, siRNA mediates transgenerational gene
silencing through the germline nuclear RNAi pathway. This pathway is also required to maintain the germline immortality when C. elegans is under heat stress. However, the underlying molecular mechanism is unknown. In this study, we investigated the impact of heat stress on chromatin, transcription, and siRNAs at the whole-genome level, and whether any of the heat-induced effects is transgenerationally heritable in either the wild-type or the germline nuclear RNAi mutant animals. Results We performed 12-generation temperature-shift experiments using the wild-type C. elegans and a mutant strain that lacks the germline-specific nuclear Argonaute protein HRDE-1/WAGO-9. By examining the mRNA, small RNA, RNA polymerase II, and H3K9 trimethylation profiles at the whole-genome level, we revealed an epigenetic role of HRDE-1 in repressing heat stress-induced transcriptional activation of over 280 genes. Many of these genes are in or near LTR (long-terminal repeat) retrotransposons. Strikingly, for some of these genes, the heat stress-induced transcriptional activation in the hrde-1 mutant intensifies in the late generations under the heat stress and is heritable for at least two generations after the mutant animals are shifted back to lower temperature. hrde-1 mutation also leads to siRNA expression changes of many genes. This effect on siRNA is dependent on both the temperature and generation. Conclusions Our study demonstrated that a large number of the endogenous targets of the germline nuclear RNAi pathway in C. elegans are sensitive to heat-induced transcriptional activation. This effect at certain genomic loci including LTR retrotransposons is transgenerational. Germline nuclear RNAi antagonizes this temperature effect at the transcriptional level and therefore may play a key role in heat stress response in C. elegans. Electronic supplementary material The online version of this article (doi:10.1186/s13072-016-0052-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julie Zhouli Ni
- Department of Molecular Biology and Biochemistry, Rutgers the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Natallia Kalinava
- Department of Molecular Biology and Biochemistry, Rutgers the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Esteban Chen
- Department of Molecular Biology and Biochemistry, Rutgers the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Alex Huang
- Department of Molecular Biology and Biochemistry, Rutgers the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Thi Trinh
- Department of Molecular Biology and Biochemistry, Rutgers the State University of New Jersey, Piscataway, NJ 08854 USA
| | - Sam Guoping Gu
- Department of Molecular Biology and Biochemistry, Rutgers the State University of New Jersey, Piscataway, NJ 08854 USA ; Nelson Labs A125, 604 Allison Road, Piscataway, NJ 08854 USA
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15
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Gibson JD, Arechavaleta-Velasco ME, Tsuruda JM, Hunt GJ. Biased Allele Expression and Aggression in Hybrid Honeybees may be Influenced by Inappropriate Nuclear-Cytoplasmic Signaling. Front Genet 2015; 6:343. [PMID: 26648977 PMCID: PMC4664729 DOI: 10.3389/fgene.2015.00343] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/20/2015] [Indexed: 11/15/2022] Open
Abstract
Hybrid effects are often exhibited asymmetrically between reciprocal families. One way this could happen is if silencing of one parent’s allele occurs in one lineage but not the other, which could affect the phenotypes of the hybrids asymmetrically by silencing that allele in only one of the hybrid families. We have previously tested for allele-specific expression biases in hybrids of European and Africanized honeybees and we found that there was an asymmetric overabundance of genes showing a maternal bias in the family with a European mother. Here, we further analyze allelic bias in these hybrids to ascertain whether they may underlie previously described asymmetries in metabolism and aggression in similar hybrid families and we speculate on what mechanisms may produce this biased allele usage. We find that there are over 500 genes that have some form of biased allele usage and over 200 of these are biased toward the maternal allele but only in the family with European maternity, mirroring the pattern observed for aggression and metabolic rate. This asymmetrically biased set is enriched for genes in loci associated with aggressive behavior and also for mitochondrial-localizing proteins. It contains many genes that play important roles in metabolic regulation. Moreover we find genes relating to the piwi-interacting RNA (piRNA) pathway, which is involved in chromatin modifications and epigenetic regulation and may help explain the mechanism underlying this asymmetric allele use. Based on these findings and previous work investigating aggression and metabolism in bees, we propose a novel hypothesis; that the asymmetric pattern of biased allele usage in these hybrids is a result of inappropriate use of piRNA-mediated nuclear-cytoplasmic signaling that is normally used to modulate aggression in honeybees. This is the first report of widespread asymmetric effects on allelic expression in hybrids and may represent a novel mechanism for gene regulation.
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Affiliation(s)
- Joshua D Gibson
- Department of Entomology, Purdue University, West Lafayette IN, USA
| | - Miguel E Arechavaleta-Velasco
- CENID-Fisiología y Mejoramiento Animal, Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias México, Mexico
| | | | - Greg J Hunt
- Department of Entomology, Purdue University, West Lafayette IN, USA
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16
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Gabriel JM, Hollick JB. Paramutation in maize and related behaviors in metazoans. Semin Cell Dev Biol 2015; 44:11-21. [PMID: 26318741 DOI: 10.1016/j.semcdb.2015.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Accepted: 08/18/2015] [Indexed: 12/31/2022]
Abstract
Paramutation refers to both the process and results of trans-homolog interactions causing heritable changes in both gene regulation and silencing abilities. Originally described in plants, paramutation-like behaviors have now been reported in model metazoans. Here we detail our current understanding of the paramutation mechanism as defined in Zea mays and compare this paradigm to these metazoan examples. Experimental results implicate functional roles of small RNAs in all these model organisms that highlight a diversity of mechanisms by which these molecules specify meiotically heritable regulatory information in the eukarya.
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Affiliation(s)
- Janelle M Gabriel
- Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Jay B Hollick
- Department of Molecular Genetics, Center for RNA Biology, The Ohio State University, Columbus, OH, USA.
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17
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Molecular characterization and expression profile of three Fem-1 genes in Eriocheir sinensis provide a new insight into crab sex-determining mechanism. Comp Biochem Physiol B Biochem Mol Biol 2015; 189:6-14. [PMID: 26188322 DOI: 10.1016/j.cbpb.2015.07.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 06/25/2015] [Accepted: 07/07/2015] [Indexed: 02/02/2023]
Abstract
The FEM-1 protein of Caenorhabditis elegans plays a crucial role in the nematode sex-determination pathway. Here, we reported the characterization of three members of Fem-1 gene family in Eriocheir sinensis (designated EsFem-1a, EsFem-1b, and EsFem-1c), which were homologs of the nematode FEM-1 protein. The amino acid sequences of EsFem-1a, EsFem-1b, and EsFem-1c contained eight, nine, and eight ankyrin repeats, respectively. None of the ankyrin repeats had its own specific signature, and the evolution of ankyrin repeat was not completely independent. The predicted three-dimensional structure of EsFem-1 proteins exhibited highly similar superhelical conformation, especially the N-terminal six contiguous ankyrin repeats, which provided a binding surface for the protein-protein interaction. Phylogenetic tree based on the amino acid sequences revealed that EsFem-1a, EsFem-1b, and EsFem-1c were divided into three obvious separated clades. EsFem-1 genes were highly expressed in fertilized egg, 2-4 cell and blastula stage comparing with larval stage (P<0.01), which suggested they might be maternal genes. They also showed a certain degree of sexually dimorphic expression in some tissues. Notably, the highest expression of EsFem-1a was in the hepatopancreas, with EsFem-1b in testes and EsFem-1c in muscle (P<0.05), which indicated their potential role in a broad array of tissues. In addition, the genes initially involved in sex differentiation were not limited to those specifically expressed in the developing gonad. Taken together, these results suggested that EsFem-1 might function in crab early sex determination and late gonad development. The identification of Fem-1 gene family in E. sinensis provides a new insight into crab sex-determination mechanism.
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18
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Anava S, Posner R, Rechavi O. The soft genome. WORM 2015; 3:e989798. [PMID: 26430554 DOI: 10.4161/21624054.2014.989798] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 11/14/2014] [Indexed: 11/19/2022]
Abstract
Caenorhabditis elegans (C. elegans) nematodes transmit small RNAs across generations, a process that enables transgenerational regulation of genes. In contrast to changes to the DNA sequence, transgenerational transmission of small RNA-mediated responses is reversible, and thus enables "soft" or "flexible" inheritance of acquired characteristics. Until very recently only introduction of foreign genetic material (viruses, transposons, transgenes) was shown to directly lead to inheritance of small RNAs. New discoveries however, demonstrate that starvation also triggers inheritance of endogenous small RNAs in C.elegans. Multiple generations of worms inherit starvation-responsive endogenous small RNAs, and starvation also results in heritable extension of the progeny's lifespan. In this Commentary paper we explore the intriguing possibility that large parts of the genome and many additional traits are similarly subjected to heritable small RNA-mediated regulation, and focus on the potential influence of transgenerational RNAi on the worm's physiology. While the universal relevance of this mechanism remains to be discovered, we will examine how the discoveries made in worms already challenge long held dogmas in genetics and evolution.
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Affiliation(s)
- Sarit Anava
- Department of Neurobiology; Wise Faculty of Life Sciences & Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv, Israel
| | - Rachel Posner
- Department of Neurobiology; Wise Faculty of Life Sciences & Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv, Israel
| | - Oded Rechavi
- Department of Neurobiology; Wise Faculty of Life Sciences & Sagol School of Neuroscience; Tel Aviv University ; Tel Aviv, Israel
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19
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Technologies to probe functions and mechanisms of long noncoding RNAs. Nat Struct Mol Biol 2015; 22:29-35. [DOI: 10.1038/nsmb.2921] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 10/22/2014] [Indexed: 12/20/2022]
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20
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Youngman EM, Claycomb JM. From early lessons to new frontiers: the worm as a treasure trove of small RNA biology. Front Genet 2014; 5:416. [PMID: 25505902 PMCID: PMC4245922 DOI: 10.3389/fgene.2014.00416] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 11/07/2014] [Indexed: 02/02/2023] Open
Abstract
In the past 20 years, the tiny soil nematode Caenorhabditis elegans has provided critical insights into our understanding of the breadth of small RNA-mediated gene regulatory activities. The first microRNA was identified in C. elegans in 1993, and the understanding that dsRNA was the driving force behind RNA-mediated gene silencing came from experiments performed in C. elegans in 1998. Likewise, early genetic screens in C. elegans for factors involved in RNA interference pointed to conserved mechanisms for small RNA-mediated gene silencing pathways, placing the worm squarely among the founding fathers of a now extensive field of molecular biology. Today, the worm continues to be at the forefront of ground-breaking insight into small RNA-mediated biology. Recent studies have revealed with increasing mechanistic clarity that C. elegans possesses an extensive nuclear small RNA regulatory network that encompasses not only gene silencing but also gene activating roles. Further, a portrait is emerging whereby small RNA pathways play key roles in integrating responses to environmental stimuli and transmitting epigenetic information about such responses from one generation to the next. Here we discuss endogenous small RNA pathways in C. elegans and the insight worm biology has provided into the mechanisms employed by these pathways. We touch on the increasingly spectacular diversity of small RNA biogenesis and function, and discuss the relevance of lessons learned in the worm for human biology.
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Affiliation(s)
| | - Julie M Claycomb
- Department of Molecular Genetics, University of Toronto Toronto, ON, Canada
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21
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Dey A, Jin Q, Chen YC, Cutter AD. Gonad morphogenesis defects drive hybrid male sterility in asymmetric hybrid breakdown of Caenorhabditis nematodes. Evol Dev 2014; 16:362-72. [PMID: 25196892 DOI: 10.1111/ede.12097] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Determining the causes and evolution of reproductive barriers to gene flow between populations, speciation, is the key to understanding the origin of diversity in nature. Many species manifest hybrid breakdown when they intercross, characterized by increasingly exacerbated problems in later generations of hybrids. Recently, Caenorhabditis nematodes have emerged as a genetic model for studying speciation, and here we investigate the nature and causes of hybrid breakdown between Caenorhabditis remanei and C. latens. We quantify partial F1 hybrid inviability and extensive F2 hybrid inviability; the ~75% F2 embryonic arrest occurs primarily during gastrulation or embryonic elongation. Moreover, F1 hybrid males exhibit Haldane's rule asymmetrically for both sterility and inviability, being strongest when C. remanei serves as maternal parent. We show that the mechanism by which sterile hybrid males are incapable of transferring sperm or a copulatory plug involves defective gonad morphogenesis, which we hypothesize results from linker cell defects in migration and/or cell death during development. This first documented case of partial hybrid male sterility in Caenorhabditis follows expectations of Darwin's corollary to Haldane's rule for asymmetric male fitness, providing a powerful foundation for molecular dissection of intrinsic reproductive barriers and divergence of genetic pathways controlling organ morphogenesis.
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Affiliation(s)
- Alivia Dey
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, Canada, M5S 3B2
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22
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Robinson NA, Gopikrishna G, Baranski M, Katneni VK, Shekhar MS, Shanmugakarthik J, Jothivel S, Gopal C, Ravichandran P, Gitterle T, Ponniah AG. QTL for white spot syndrome virus resistance and the sex-determining locus in the Indian black tiger shrimp (Penaeus monodon). BMC Genomics 2014; 15:731. [PMID: 25164406 PMCID: PMC4158065 DOI: 10.1186/1471-2164-15-731] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 08/20/2014] [Indexed: 11/10/2022] Open
Abstract
Background Shrimp culture is a fast growing aquaculture sector, but in recent years there has been a shift away from tiger shrimp Penaeus monodon to other species. This is largely due to the susceptibility of P. monodon to white spot syndrome virus disease (Whispovirus sp.) which has impacted production around the world. As female penaeid shrimp grow more rapidly than males, mono-sex production would be advantageous, however little is known about genes controlling or markers associated with sex determination in shrimp. In this study, a mapped set of 3959 transcribed single nucleotide polymorphisms were used to scan the P. monodon genome for loci associated with resistance to white-spot syndrome virus and sex in seven full-sibling tiger shrimp families challenged with white spot syndrome virus. Results Linkage groups 2, 3, 5, 6, 17, 18, 19, 22, 27 and 43 were found to contain quantitative trait loci significantly associated with hours of survival after white spot syndrome virus infection (P < 0.05 after Bonferroni correction). Nine QTL were significantly associated with hours of survival. Of the SNPs mapping to these and other regions with suggestive associations, many were found to occur in transcripts showing homology to genes with putative immune functions of interest, including genes affecting the action of the ubiquitin-proteasome pathway, lymphocyte-cell function, heat shock proteins, the TOLL pathway, protein kinase signal transduction pathways, mRNA binding proteins, lectins and genes affecting the development and differentiation of the immune system (eg. RUNT protein 1A). Several SNPs significantly associated with sex were mapped to linkage group 30, the strongest associations (P < 0.001 after Bonferroni correction) for 3 SNPs located in a 0.8 cM stretch between positions 43.5 and 44.3 cM where the feminisation gene (FEM-1, affecting sexual differentiation in Caenorhabditis elegans) mapped. Conclusions The markers for disease resistance and sexual differentiation identified by this study could be useful for marker assisted selection to improve resistance to WSSV and for identifying homogametic female individuals for mono-sex (all female) production. The genes with putative functions affecting immunity and sexual differentiation that were found to closely map to these loci provide leads about the mechanisms affecting these important economic traits in shrimp. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-731) contains supplementary material, which is available to authorized users.
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Abstract
Cell identities can be stable over a long time due to a “cellular memory” of expression profiles achieved through epigenetic mechanisms. In this review, Stuwe et al. describe recent studies demonstrating that short noncoding RNAs can also provide molecular signals that define epigenetic states of cells, leading to transgenerational epigenetic inheritance. Cells in multicellular organisms have distinct identities characterized by their profiles of expressed genes. Cell identities can be stable over a long time and through multiple cellular divisions but are also responsive to extracellular signals. Since the DNA sequence is identical in all cells, a “cellular memory” of expression profiles is achieved by what are defined as epigenetic mechanisms. Two major molecular principles—networks of transcription factors and maintenance of cis-chromatin modifications—have been implicated in maintaining cellular memory. Here we describe recent studies demonstrating that short noncoding RNAs can also provide molecular signals that define epigenetic states of cells. Small RNAs can act independently or cooperate with chromatin modifications to achieve long-lasting effects necessary for cellular memory and transgenerational inheritance.
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Affiliation(s)
- Evelyn Stuwe
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA
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24
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Kelly WG. Transgenerational epigenetics in the germline cycle of Caenorhabditis elegans. Epigenetics Chromatin 2014; 7:6. [PMID: 24678826 PMCID: PMC3973826 DOI: 10.1186/1756-8935-7-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 03/18/2014] [Indexed: 12/11/2022] Open
Abstract
Epigenetic mechanisms create variably stable changes in gene expression through the establishment of heritable states of chromatin architecture. While many epigenetic phenomena are, by definition, heritably passed through cell division during animal and plant development, evidence suggests that 'epigenetic states' may also be inherited across multiple generations. Work in the nematode Caenorhabditis elegans has uncovered a number of mechanisms that participate in regulating the transgenerational passage of epigenetic states. These mechanisms include some that establish and maintain heritable epigenetic information in the form of histone modifications, as well as those that filter the epigenetic information that is stably transmitted. The information appears to influence and help guide or regulate gene activity and repression in subsequent generations. Genome surveillance mechanisms guided by small RNAs appear to be involved in identifying and directing heritable repression of genomic elements, and thus may participate in filtering information that is inappropriate for stable transmission. This review will attempt to summarize recent findings that illustrate this simple nematode to be a truly elegant resource for defining emerging biological paradigms.As the cell lineage that links generations, the germline is the carrier of both genetic and epigenetic information. Like genetic information, information in the epigenome can heritably affect gene regulation and phenotype; yet unlike genetic information, the epigenome of the germ lineage is highly modified within each generation. Despite such alterations, some epigenetic information is highly stable across generations, leading to transgenerationally stable phenotypes that are unlinked to genetic changes. Studies in the nematode C. elegans have uncovered mechanisms that contribute to transgenerational repression as well as to the expression of genes that rely on histone modifying machinery and/or non-coding RNA-based mechanisms. These studies indicate that epigenetic mechanisms operating within the germ cell cycle of this organism filter and maintain an epigenetic memory that is required for germ cell function and can also influence gene expression in somatic lineages.
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Affiliation(s)
- William G Kelly
- Biology Department, Emory University, Atlanta, GA 30322, USA.
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25
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Rechavi O. Guest list or black list: heritable small RNAs as immunogenic memories. Trends Cell Biol 2013; 24:212-20. [PMID: 24231398 DOI: 10.1016/j.tcb.2013.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 10/10/2013] [Accepted: 10/11/2013] [Indexed: 11/24/2022]
Abstract
Small RNA-mediated gene silencing plays a pivotal role in genome immunity by recognizing and eliminating viruses and transposons that may otherwise colonize the genome. However, individual genomic parasites are highly diverse and employ multiple immune-evasion techniques, making this silencing challenging. Here I review a new theory proposing that the integrity of the germline is maintained by transgenerationally transmitted RNA 'memories' that record ancestral gene expression patterns and delineate 'self' from 'foreign' sequences. To maintain such recollection, two tactics are employed in parallel: 'black listing' of invading nucleic acids and 'guest listing' of endogenous genes. Studies in several organisms have shown that this memorization is used by the next generation of small RNAs to act as 'inherited vaccines' that attack invading elements or as 'inherited licenses' that permit the transcription of autogenous sequences.
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Affiliation(s)
- Oded Rechavi
- Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel 69978; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel 69978.
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26
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Serobyan V, Ragsdale EJ, Müller MR, Sommer RJ. Feeding plasticity in the nematode Pristionchus pacificus is influenced by sex and social context and is linked to developmental speed. Evol Dev 2013; 15:161-70. [PMID: 23607300 DOI: 10.1111/ede.12030] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The increasing evidence for a role of developmental plasticity in evolution offers exciting prospects for testing interactions between ecological and developmental genetic processes. Recent advances with the model organism Pristionchus pacificus have provided inroads to a mechanistic understanding of a developmental plasticity. The developmental plasticity of P. pacificus comprises two discontinuous adult mouth-forms, a stenostomatous ("narrow mouthed") and a eurystomatous ("wide mouthed") form, the latter of which is structurally more complex and associated with predatory feeding. Both forms are consistently present in populations, but fundamental properties guiding fluctuations in their appearance have been poorly understood. Here, we provide a systematic characterization of the mouth plasticity in P. pacificus, quantifying a strong sexual dimorphism and revealing that, in an inbred genetic background, maternal phenotype is linked to that of male offspring. Furthermore, cues from conspecifics influenced the developmental decision in juvenile nematodes. Separating individuals from a population resulted in a lower eurystomatous frequency, which decreased incrementally with earlier isolation. Finally, the time to the reproductively mature stage was, in the presence of an abundant bacterial food supply, less for stenostomatous than for eurystomatous individuals, suggesting the potential for a fitness trade-off between developmental time and breadth of diet. This study provides a baseline understanding of the mouth dimorphism in P. pacificus as a necessary reference point for comparative analysis.
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Affiliation(s)
- Vahan Serobyan
- Department of Evolutionary Biology, Max Planck Institute for Developmental Biology, Spemannstraße 37, Tübingen, Germany
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27
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Kiani J, Grandjean V, Liebers R, Tuorto F, Ghanbarian H, Lyko F, Cuzin F, Rassoulzadegan M. RNA-mediated epigenetic heredity requires the cytosine methyltransferase Dnmt2. PLoS Genet 2013; 9:e1003498. [PMID: 23717211 PMCID: PMC3662642 DOI: 10.1371/journal.pgen.1003498] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 03/21/2013] [Indexed: 11/28/2022] Open
Abstract
RNA–mediated transmission of phenotypes is an important way to explain non-Mendelian heredity. We have previously shown that small non-coding RNAs can induce hereditary epigenetic variations in mice and act as the transgenerational signalling molecules. Two prominent examples for these paramutations include the epigenetic modulation of the Kit gene, resulting in altered fur coloration, and the modulation of the Sox9 gene, resulting in an overgrowth phenotype. We now report that expression of the Dnmt2 RNA methyltransferase is required for the establishment and hereditary maintenance of both paramutations. Our data show that the Kit paramutant phenotype was not transmitted to the progeny of Dnmt2−/− mice and that the Sox9 paramutation was also not established in Dnmt2−/− embryos. Similarly, RNA from Dnmt2-negative Kit heterozygotes did not induce the paramutant phenotype when microinjected into Dnmt2-deficient fertilized eggs and microinjection of the miR-124 microRNA failed to induce the characteristic giant phenotype. In agreement with an RNA–mediated mechanism of inheritance, no change was observed in the DNA methylation profiles of the Kit locus between the wild-type and paramutant mice. RNA bisulfite sequencing confirmed Dnmt2-dependent tRNA methylation in mouse sperm and also indicated Dnmt2-dependent cytosine methylation in Kit RNA in paramutant embryos. Together, these findings uncover a novel function of Dnmt2 in RNA–mediated epigenetic heredity. The possibility of a mode of inheritance distinct from the Mendelian model has been considered since the early days of genetics. Only recently, however, suitable experimental models were created. We now see the development of new experimental systems detecting non-Mendelian inheritance in a variety of organisms, from worms to mice. We have previously shown that RNA molecules act as transgenerational inducers of epigenetic variations in mice. We are currently using Mendelian genetics to dissect the factors involved in RNA–mediated transgenerational signalling. By showing an absolute requirement for Dnmt2 in this process, our study extends our knowledge of this still somewhat enigmatic protein. We confirmed that RNA rather than DNA methylation by the protein is involved in epigenetic heredity, and our genetic results indicate a requirement during an early step in the reproductive process, between parental gametogenesis and the preimplantation stage.
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Affiliation(s)
- Jafar Kiani
- University of Nice Sophia Antipolis, UFR Sciences, Nice, France
- Inserm UMR1091, CNRS UMR7277, Nice, France
| | - Valérie Grandjean
- University of Nice Sophia Antipolis, UFR Sciences, Nice, France
- Inserm UMR1091, CNRS UMR7277, Nice, France
| | - Reinhard Liebers
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Francesca Tuorto
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - Hossein Ghanbarian
- University of Nice Sophia Antipolis, UFR Sciences, Nice, France
- Inserm UMR1091, CNRS UMR7277, Nice, France
| | - Frank Lyko
- Division of Epigenetics, DKFZ-ZMBH Alliance, German Cancer Research Center, Heidelberg, Germany
| | - François Cuzin
- University of Nice Sophia Antipolis, UFR Sciences, Nice, France
- Inserm UMR1091, CNRS UMR7277, Nice, France
| | - Minoo Rassoulzadegan
- University of Nice Sophia Antipolis, UFR Sciences, Nice, France
- Inserm UMR1091, CNRS UMR7277, Nice, France
- * E-mail:
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28
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Van Wynsberghe PM, Maine EM. Epigenetic control of germline development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 757:373-403. [PMID: 22872484 DOI: 10.1007/978-1-4614-4015-4_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Dynamic regulation of histone modifications and small noncoding RNAs is observed throughout the development of the C. elegans germ line. Histone modifications are differentially regulated in the mitotic vs meiotic germ line, on X chromosomes vs autosomes and on paired chromosomes vs unpaired chromosomes. Small RNAs function in transposon silencing and developmental gene regulation. Histone modifications and small RNAs produced in the germ line can be inherited and impact embryonic development. Disruption of histone-modifying enzymes or small RNA machinery in the germ line can result in sterility due to degeneration of the germ line and/or an inability to produce functional gametes.
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29
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Zanetti S, Puoti A. Sex Determination in the Caenorhabditis elegans Germline. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 757:41-69. [DOI: 10.1007/978-1-4614-4015-4_3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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30
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Wang JT, Seydoux G. Germ cell specification. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 757:17-39. [PMID: 22872473 DOI: 10.1007/978-1-4614-4015-4_2] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The germline of Caenorhabditis elegans derives from a single founder cell, the germline blastomere P(4). P(4) is the product of four asymmetric cleavages that divide the zygote into distinct somatic and germline (P) lineages. P(4) inherits a specialized cytoplasm ("germ plasm") containing maternally encoded proteins and RNAs. The germ plasm has been hypothesized to specify germ cell fate, but the mechanisms involved remain unclear. Three processes stand out: (1) inhibition of mRNA transcription to prevent activation of somatic development, (2) translational regulation of the nanos homolog nos-2 and of other germ plasm mRNAs, and (3) establishment of a unique, partially repressive chromatin. Together, these processes ensure that the daughters of P(4), the primordial germ cells Z2 and Z3, gastrulate inside the embryo, associate with the somatic gonad, initiate the germline transcriptional program, and proliferate during larval development to generate ∼2,000 germ cells by adulthood.
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Affiliation(s)
- Jennifer T Wang
- Department of Molecular Biology and Genetics, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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31
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Nakaji P, Kalani MYS. Epigenetics and neurosurgery: editorial marks on the text of life. World Neurosurg 2012; 78:199-200. [PMID: 22771932 DOI: 10.1016/j.wneu.2012.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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32
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Ashe A, Sapetschnig A, Weick EM, Mitchell J, Bagijn MP, Cording AC, Doebley AL, Goldstein LD, Lehrbach NJ, Le Pen J, Pintacuda G, Sakaguchi A, Sarkies P, Ahmed S, Miska EA. piRNAs can trigger a multigenerational epigenetic memory in the germline of C. elegans. Cell 2012; 150:88-99. [PMID: 22738725 PMCID: PMC3464430 DOI: 10.1016/j.cell.2012.06.018] [Citation(s) in RCA: 530] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 06/18/2012] [Accepted: 06/18/2012] [Indexed: 11/23/2022]
Abstract
Transgenerational effects have wide-ranging implications for human health, biological adaptation, and evolution; however, their mechanisms and biology remain poorly understood. Here, we demonstrate that a germline nuclear small RNA/chromatin pathway can maintain stable inheritance for many generations when triggered by a piRNA-dependent foreign RNA response in C. elegans. Using forward genetic screens and candidate approaches, we find that a core set of nuclear RNAi and chromatin factors is required for multigenerational inheritance of environmental RNAi and piRNA silencing. These include a germline-specific nuclear Argonaute HRDE1/WAGO-9, a HP1 ortholog HPL-2, and two putative histone methyltransferases, SET-25 and SET-32. piRNAs can trigger highly stable long-term silencing lasting at least 20 generations. Once established, this long-term memory becomes independent of the piRNA trigger but remains dependent on the nuclear RNAi/chromatin pathway. Our data present a multigenerational epigenetic inheritance mechanism induced by piRNAs.
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Affiliation(s)
- Alyson Ashe
- Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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33
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Shirayama M, Seth M, Lee HC, Gu W, Ishidate T, Conte D, Mello CC. piRNAs initiate an epigenetic memory of nonself RNA in the C. elegans germline. Cell 2012; 150:65-77. [PMID: 22738726 PMCID: PMC3597741 DOI: 10.1016/j.cell.2012.06.015] [Citation(s) in RCA: 444] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 06/15/2012] [Accepted: 06/15/2012] [Indexed: 10/28/2022]
Abstract
Organisms employ a fascinating array of strategies to silence invasive nucleic acids such as transposons and viruses. Although evidence exists for several pathways that detect foreign sequences, including pathways that sense copy number, unpaired DNA, or aberrant RNA (e.g., dsRNA), in many cases, the mechanisms used to distinguish "self" from "nonself" nucleic acids remain mysterious. Here, we describe an RNA-induced epigenetic silencing pathway that permanently silences single-copy transgenes. We show that the Piwi Argonaute PRG-1 and its genomically encoded piRNA cofactors initiate permanent silencing, and maintenance depends on chromatin factors and the WAGO Argonaute pathway. Our findings support a model in which PRG-1 scans for foreign sequences and two other Argonaute pathways serve as epigenetic memories of "self" and "nonself" RNAs. These findings suggest how organisms can utilize RNAi-related mechanisms to detect foreign sequences not by any molecular signature, but by comparing the foreign sequence to a memory of previous gene expression.
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Affiliation(s)
- Masaki Shirayama
- Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA
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34
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Chang KC, Wang C, Wang H. Balancing self-renewal and differentiation by asymmetric division: insights from brain tumor suppressors in Drosophila neural stem cells. Bioessays 2012; 34:301-10. [PMID: 22287225 DOI: 10.1002/bies.201100090] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Balancing self-renewal and differentiation of stem cells is an important issue in stem cell and cancer biology. Recently, the Drosophila neuroblast (NB), neural stem cell has emerged as an excellent model for stem cell self-renewal and tumorigenesis. It is of great interest to understand how defects in the asymmetric division of neural stem cells lead to tumor formation. Here, we review recent advances in asymmetric division and the self-renewal control of Drosophila NBs. We summarize molecular mechanisms of asymmetric cell division and discuss how the defects in asymmetric division lead to tumor formation. Gain-of-function or loss-of-function of various proteins in the asymmetric machinery can drive NB overgrowth and tumor formation. These proteins control either the asymmetric protein localization or mitotic spindle orientation of NBs. We also discuss other mechanisms of brain tumor suppression that are beyond the control of asymmetric division.
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Affiliation(s)
- Kai Chen Chang
- Neuroscience & Behavioral Disorder Program, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
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