51
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Chen W, Zhang X, Fan Y, Li B, Ryabov E, Shi N, Zhao M, Yu Z, Qin C, Zheng Q, Zhang P, Wang H, Jackson S, Cheng Q, Liu Y, Gallusci P, Hong Y. A Genetic Network for Systemic RNA Silencing in Plants. PLANT PHYSIOLOGY 2018; 176:2700-2719. [PMID: 29439213 PMCID: PMC5884585 DOI: 10.1104/pp.17.01828] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 01/25/2018] [Indexed: 05/20/2023]
Abstract
Non-cell autonomous RNA silencing can spread from cell to cell and over long distances in animals and plants. However, the genetic requirements and signals involved in plant mobile gene silencing are poorly understood. Here, we identified a DICER-LIKE2 (DCL2)-dependent mechanism for systemic spread of posttranscriptional RNA silencing, also known as posttranscriptional gene silencing (PTGS), in Nicotiana benthamiana Using a suite of transgenic DCL RNAi lines coupled with a GFP reporter, we demonstrated that N. benthamiana DCL1, DCL2, DCL3, and DCL4 are required to produce microRNAs and 22, 24, and 21nt small interfering RNAs (siRNAs), respectively. All investigated siRNAs produced in local incipient cells were present at low levels in distal tissues. Inhibition of DCL2 expression reduced the spread of gene silencing, while suppression of DCL3 or DCL4 expression enhanced systemic PTGS. In contrast to DCL4 RNAi lines, DCL2-DCL4 double-RNAi lines developed systemic PTGS similar to that observed in DCL2 RNAi. We further showed that the 21 or 24 nt local siRNAs produced by DCL4 or DCL3 were not involved in long-distance gene silencing. Grafting experiments demonstrated that DCL2 was required in the scion to respond to the signal, but not in the rootstock to produce/send the signal. These results suggest a coordinated DCL genetic pathway in which DCL2 plays an essential role in systemic PTGS in N. benthamiana, while both DCL4 and DCL3 attenuate systemic PTGS. We discuss the potential role of 21, 22, and 24 nt siRNAs in systemic PTGS.
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Affiliation(s)
- Weiwei Chen
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Xian Zhang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yaya Fan
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Bin Li
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Eugene Ryabov
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick CV4 7AL, United Kingdom
| | - Nongnong Shi
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Mei Zhao
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Zhiming Yu
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Cheng Qin
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Qianqian Zheng
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Pengcheng Zhang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Huizhong Wang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Stephen Jackson
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick CV4 7AL, United Kingdom
| | - Qi Cheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yule Liu
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Philippe Gallusci
- UMR EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, 210 Chemin de Leysotte, CS 50008, 33882 Villenave d'Ornon, France
| | - Yiguo Hong
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick CV4 7AL, United Kingdom
- Worcester-Hangzhou Joint Molecular Plant Health Laboratory, Institute of Science and the Environment, University of Worcester, WR2 6AJ, United Kingdom
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52
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Steele EJ, Al-Mufti S, Augustyn KA, Chandrajith R, Coghlan JP, Coulson SG, Ghosh S, Gillman M, Gorczynski RM, Klyce B, Louis G, Mahanama K, Oliver KR, Padron J, Qu J, Schuster JA, Smith WE, Snyder DP, Steele JA, Stewart BJ, Temple R, Tokoro G, Tout CA, Unzicker A, Wainwright M, Wallis J, Wallis DH, Wallis MK, Wetherall J, Wickramasinghe DT, Wickramasinghe JT, Wickramasinghe NC, Liu Y. Cause of Cambrian Explosion - Terrestrial or Cosmic? PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 136:3-23. [PMID: 29544820 DOI: 10.1016/j.pbiomolbio.2018.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus. A third focus concerns the micro-organism fossil evidence contained within meteorites as well as the detection in the upper atmosphere of apparent incoming life-bearing particles from space. In our view the totality of the multifactorial data and critical analyses assembled by Fred Hoyle, Chandra Wickramasinghe and their many colleagues since the 1960s leads to a very plausible conclusion - life may have been seeded here on Earth by life-bearing comets as soon as conditions on Earth allowed it to flourish (about or just before 4.1 Billion years ago); and living organisms such as space-resistant and space-hardy bacteria, viruses, more complex eukaryotic cells, fertilised ova and seeds have been continuously delivered ever since to Earth so being one important driver of further terrestrial evolution which has resulted in considerable genetic diversity and which has led to the emergence of mankind.
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Affiliation(s)
- Edward J Steele
- CY O'Connor ERADE Village Foundation, Piara Waters, WA, Australia; Centre for Astrobiology, University of Ruhuna, Matara, Sri Lanka.
| | - Shirwan Al-Mufti
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - Kenneth A Augustyn
- Center for the Physics of Living Organisms, Department of Physics, Michigan Technological University, Michigan, United States
| | | | - John P Coghlan
- University of Melbourne, Office of the Dean, Faculty Medicine, Dentistry and Health Sciences, 3rd Level, Alan Gilbert Building, Australia
| | - S G Coulson
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - Sudipto Ghosh
- Metallurgical & Materials Engineering IIT, Kanpur, India
| | - Mark Gillman
- South African Brain Research Institute, 6 Campbell Street, Waverly, Johannesburg, South Africa
| | - Reginald M Gorczynski
- University Toronto Health Network, Toronto General Hospital, University of Toronto, Canada
| | - Brig Klyce
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - Godfrey Louis
- Department of Physics, Cochin University of Science and Technology Cochin, India
| | | | - Keith R Oliver
- School of Veterinary and Life Sciences Murdoch University, Perth, WA, Australia
| | - Julio Padron
- Studio Eutropi, Clinical Pathology and Nutrition, Via Pompei 46, Ardea, 00040, Rome, Italy
| | - Jiangwen Qu
- Department of Infectious Disease Control, Tianjin Center for Disease Control and Prevention, China
| | - John A Schuster
- School of History and Philosophy of Science, Faculty of Science, University of Sydney, Sydney, Australia
| | - W E Smith
- Institute for the Study of Panspermia and Astrobiology, Gifu, Japan
| | - Duane P Snyder
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - Julian A Steele
- Centre for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200F, 3001, Leuven, Belgium
| | - Brent J Stewart
- CY O'Connor ERADE Village Foundation, Piara Waters, WA, Australia
| | - Robert Temple
- The History of Chinese Culture Foundation, Conway Hall, London, UK
| | - Gensuke Tokoro
- Institute for the Study of Panspermia and Astrobiology, Gifu, Japan
| | - Christopher A Tout
- Institute of Astronomy, The Observatories, Madingley Road, Cambridge, CB3 0HA, UK
| | | | - Milton Wainwright
- Buckingham Centre for Astrobiology, University of Buckingham, UK; Centre for Astrobiology, University of Ruhuna, Matara, Sri Lanka
| | - Jamie Wallis
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - Daryl H Wallis
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - Max K Wallis
- Buckingham Centre for Astrobiology, University of Buckingham, UK
| | - John Wetherall
- School of Biomedical Sciences, Perth, Curtin University, WA, Australia
| | - D T Wickramasinghe
- College of Physical and Mathematical Sciences, Australian National University, Canberra, Australia
| | | | - N Chandra Wickramasinghe
- Buckingham Centre for Astrobiology, University of Buckingham, UK; Centre for Astrobiology, University of Ruhuna, Matara, Sri Lanka; Institute for the Study of Panspermia and Astrobiology, Gifu, Japan
| | - Yongsheng Liu
- Henan Collaborative Innovation Center of Modern Biological Breeding, Henan Institute of Science and Technology, Xinxiang, 453003, China; Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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53
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Ow MC, Borziak K, Nichitean AM, Dorus S, Hall SE. Early experiences mediate distinct adult gene expression and reproductive programs in Caenorhabditis elegans. PLoS Genet 2018; 14:e1007219. [PMID: 29447162 PMCID: PMC5831748 DOI: 10.1371/journal.pgen.1007219] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 02/28/2018] [Accepted: 01/24/2018] [Indexed: 01/16/2023] Open
Abstract
Environmental stress during early development in animals can have profound effects on adult phenotypes via programmed changes in gene expression. Using the nematode C. elegans, we demonstrated previously that adults retain a cellular memory of their developmental experience that is manifested by differences in gene expression and life history traits; however, the sophistication of this system in response to different environmental stresses, and how it dictates phenotypic plasticity in adults that contribute to increased fitness in response to distinct environmental challenges, was unknown. Using transcriptional profiling, we show here that C. elegans adults indeed retain distinct cellular memories of different environmental conditions. We identified approximately 500 genes in adults that entered dauer due to starvation that exhibit significant opposite (“seesaw”) transcriptional phenotypes compared to adults that entered dauer due to crowding, and are distinct from animals that bypassed dauer. Moreover, we show that two-thirds of the genes in the genome experience a 2-fold or greater seesaw trend in gene expression, and based upon the direction of change, are enriched in large, tightly linked regions on different chromosomes. Importantly, these transcriptional programs correspond to significant changes in brood size depending on the experienced stress. In addition, we demonstrate that while the observed seesaw gene expression changes occur in both somatic and germline tissue, only starvation-induced changes require a functional GLP-4 protein necessary for germline development, and both programs require the Argonaute CSR-1. Thus, our results suggest that signaling between the soma and the germ line can generate phenotypic plasticity as a result of early environmental experience, and likely contribute to increased fitness in adverse conditions and the evolution of the C. elegans genome. Environmental stress during early development in animals can have profound effects on adult behavior and physiology due to programmed changes in gene expression. However, whether different stresses result in distinct changes in traits that allow stressed animals to better survive and reproduce in future adverse conditions is largely unknown. Using the animal model system, C. elegans, we show that adults that experienced starvation exhibit opposite (“seesaw”) genome-wide gene expression changes compared to adults that experienced crowding, and are distinct from animals that experienced favorable conditions. Genes that are similarly up- or downregulated due to either starvation or crowding are located in clusters on the same chromosomes. Importantly, these gene expression changes of differently-stressed animals result in corresponding changes in progeny number, a life history trait of evolutionary significance. These distinct gene expression programs require different signaling pathways that communicate across somatic and germline tissue types. Thus, different environmental stresses experienced early in development induce distinct signaling mechanisms to result in changes in gene expression and reproduction in adults, and likely contribute to increased survival in future adverse conditions.
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Affiliation(s)
- Maria C. Ow
- Department of Biology, Syracuse University, Syracuse, NY, United States of America
| | - Kirill Borziak
- Department of Biology, Syracuse University, Syracuse, NY, United States of America
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY, United States of America
| | | | - Steve Dorus
- Department of Biology, Syracuse University, Syracuse, NY, United States of America
- Center for Reproductive Evolution, Department of Biology, Syracuse University, Syracuse, NY, United States of America
| | - Sarah E. Hall
- Department of Biology, Syracuse University, Syracuse, NY, United States of America
- * E-mail:
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54
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Shiu PK, Hunter CP. Early Developmental Exposure to dsRNA Is Critical for Initiating Efficient Nuclear RNAi in C. elegans. Cell Rep 2017; 18:2969-2978. [PMID: 28329688 DOI: 10.1016/j.celrep.2017.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 12/21/2016] [Accepted: 02/28/2017] [Indexed: 11/17/2022] Open
Abstract
RNAi has enabled researchers to study the function of many genes. However, it is not understood why some RNAi experiments succeed while others do not. Here, we show in C. elegans that pharyngeal muscle is resistant to RNAi when initially exposed to double-stranded RNA (dsRNA) by feeding but sensitive to RNAi in the next generation. Investigating this observation, we find that pharyngeal muscle cells as well as vulval muscle cells require nuclear rather than cytoplasmic RNAi. Further, we find in these cell types that nuclear RNAi silencing is most efficiently triggered during early development, defining a critical period for initiating nuclear RNAi. Finally, using heat-shock-induced dsRNA expression, we show that synMuv B class mutants act in part to extend this critical window. The synMuv-B-dependent early-development-associated critical period for initiating nuclear RNAi suggests that mechanisms that restrict developmental plasticity may also restrict the initiation of nuclear RNAi.
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Affiliation(s)
- Philip K Shiu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Craig P Hunter
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
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55
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Abstract
In recent years, a Lamarckian theme has found its way back into academic discourse on evolution and inheritance. Especially the emerging field of transgenerational small RNAs has provided at least a proof of concept for the inheritance of acquired traits. Yet it remains unclear whether the Lamarckian concept of inheritance will in fact have its rennaisance or whether it will remain the rallying cry for the outlaws, heretics and enfants terribles of molecular biology. As unclear as the future of Lamarckian theory is its content and reference. Since the formulation of the Philosophie Zoologique, Lamarckian thought has been de- and reconfiguring in and out of the scientific literature and become an umbrella-term for all kinds of unconventional modes of inheritance. This essay will argue that heritable small RNAs might in fact provide a case of genuine Lamarckian inheritance. Moreover, it will be claimed that not only the very broad concept of “inheritance of acquired traits“ applies, but also that Lamarck's mechanistic insight into a use/disuse relation might help to explain a specific mode of transgenerational inheritance.
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56
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Abstract
Early - intrauterine - environmental factors are linked to the development of cardiovascular disease in later life. Traditionally, these factors are considered to be maternal factors such as maternal under and overnutrition, exposure to toxins, lack of micronutrients, and stress during pregnancy. However, in the recent years, it became obvious that also paternal environmental factors before conception and during sperm development determine the health of the offspring in later life. We will first describe clinical observational studies providing evidence for paternal programming of adulthood diseases in progeny. Next, we describe key animal studies proving this relationship, followed by a detailed analysis of our current understanding of the underlying molecular mechanisms of paternal programming. Alterations of noncoding sperm micro-RNAs, histone acetylation, and targeted as well as global DNA methylation seem to be in particular involved in paternal programming of offspring's diseases in later life.
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57
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Rompala GR, Finegersh A, Slater M, Homanics GE. Paternal preconception alcohol exposure imparts intergenerational alcohol-related behaviors to male offspring on a pure C57BL/6J background. Alcohol 2017; 60:169-177. [PMID: 27876231 DOI: 10.1016/j.alcohol.2016.11.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 12/14/2022]
Abstract
While alcohol use disorder (AUD) is a highly heritable condition, the basis of AUD in families with a history of alcoholism is difficult to explain by genetic variation alone. Emerging evidence suggests that parental experience prior to conception can affect inheritance of complex behaviors in offspring via non-genomic (epigenetic) mechanisms. For instance, male C57BL/6J (B6) mice exposed to chronic intermittent vapor ethanol (CIE) prior to mating with Strain 129S1/SvImJ ethanol-naïve females produce male offspring with reduced ethanol-drinking preference, increased ethanol sensitivity, and increased brain-derived neurotrophic factor (BDNF) expression in the ventral tegmental area (VTA). In the present study, we tested the hypothesis that these intergenerational effects of paternal CIE are reproducible in male offspring on an inbred B6 background. To this end, B6 males were exposed to 6 weeks of CIE (or room air as a control) before mating with ethanol-naïve B6 females to produce ethanol (E)-sired and control (C)-sired male and female offspring. We observed a sex-specific effect, as E-sired males exhibited decreased two-bottle free-choice ethanol-drinking preference, increased sensitivity to the anxiolytic effects of ethanol, and increased VTA BDNF expression; no differences were observed in female offspring. These findings confirm and extend our previous results by demonstrating that the effects of paternal preconception ethanol are reproducible using genetically identical, inbred B6 animals.
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58
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Bharadwaj PS, Hall SE. Endogenous RNAi Pathways Are Required in Neurons for Dauer Formation in Caenorhabditis elegans. Genetics 2017; 205:1503-1516. [PMID: 28122825 PMCID: PMC5378109 DOI: 10.1534/genetics.116.195438] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/21/2017] [Indexed: 12/16/2022] Open
Abstract
Animals can adapt to unfavorable environments through changes in physiology or behavior. In the nematode, Caenorhabditis elegans, environmental conditions perceived early in development determine whether the animal enters either the reproductive cycle, or enters into an alternative diapause stage named dauer. Here, we show that endogenous RNAi pathways play a role in dauer formation in crowding (high pheromone), starvation, and high temperature conditions. Disruption of the Mutator proteins or the nuclear Argonaute CSR-1 result in differential dauer-deficient phenotypes that are dependent upon the experienced environmental stress. We provide evidence that the RNAi pathways function in chemosensory neurons for dauer formation, upstream of the TGF-β and insulin signaling pathways. In addition, we show that Mutator MUT-16 expression in a subset of individual pheromone-sensing neurons is sufficient for dauer formation in high pheromone conditions, but not in starvation or high temperature conditions. Furthermore, we also show that MUT-16 and CSR-1 are required for expression of a subset of G proteins with functions in the detection of pheromone components. Together, our data suggest a model where Mutator-amplified siRNAs that associate with the CSR-1 pathway promote expression of genes required for the detection and signaling of environmental conditions to regulate development and behavior in C. elegans This study highlights a mechanism whereby RNAi pathways mediate the link between environmental stress and adaptive phenotypic plasticity in animals.
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Affiliation(s)
| | - Sarah E Hall
- Department of Biology, Syracuse University, New York 13244
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59
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Abstract
Exposure of mother worms to mild osmotic stress induces gene expression changes in offspring that protect them from strong osmotic stress. Inheritance of protection is now shown to depend on altered insulin-like signalling in the maternal germline, which confers protection through increased expression of zygotic gpdh-2, a rate-limiting enzyme in glycerol biosynthesis.
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Affiliation(s)
- Kiyomi R Kaneshiro
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Susan Strome
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
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60
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Post RM, Altshuler LL, Kupka R, McElroy SL, Frye MA, Rowe M, Grunze H, Suppes T, Keck PE, Leverich GS, Nolen WA. More childhood onset bipolar disorder in the United States than Canada or Europe: Implications for treatment and prevention. Neurosci Biobehav Rev 2017; 74:204-213. [PMID: 28119069 DOI: 10.1016/j.neubiorev.2017.01.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 01/18/2017] [Indexed: 02/05/2023]
Abstract
Evidence of a high or increasing incidence of childhood onset bipolar disorder in the United States (US) has been viewed skeptically. Here we review evidence that childhood onsets of bipolar disorder are more common in the US than in Europe, treatment delays are longer, and illness course is more adverse and difficult. Epidemiological data and studies of offspring at high risk also support these findings. In our cohort of outpatients with bipolar disorder, two of the major vulnerability factors for early onset - genetics and environmental adversity in childhood - were also greater in the US than in Europe. An increased familial loading for multiple psychiatric disorders was apparent in 4 generations of the family members of the patients from the US, and that familial burden was linked to early onset bipolar disorder. Since both early onset and treatment delay are risk factors for a poor outcome in adulthood, new clinical, research, and public health initiatives are needed to begin to address and ameliorate this ongoing and potentially devastating clinical situation.
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Affiliation(s)
- Robert M Post
- Bipolar Collaborative Network, Bethesda, MD, USA; Department of Psychiatry and Behavioral Sciences, George Washington University, Washington, D.C., USA.
| | - Lori L Altshuler
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Department of Psychiatry, VA Greater Los Angeles Healthcare System, West Los Angeles Healthcare Center, Los Angeles, CA, USA
| | - Ralph Kupka
- Department of Psychiatry & Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Susan L McElroy
- Lindner Center of HOPE, Mason, OH, USA; Biological Psychiatry Program, University of Cincinnati Medical College, Cincinnati, OH, USA
| | - Mark A Frye
- Department of Psychiatry, Mayo Clinic, Rochester, MI, USA
| | - Michael Rowe
- Bipolar Collaborative Network, Bethesda, MD, USA
| | - Heinz Grunze
- Paracelsius Medical University, Salzburg, Austria
| | - Trisha Suppes
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, USA; V.A. Palo Alto Health Care System, Palo Alto, CA, USA
| | - Paul E Keck
- Department of Psychiatry & Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Lindner Center of HOPE, Mason, OH, USA
| | | | - Willem A Nolen
- University Medical Center, University of Groningen, Groningen, The Netherlands
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61
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Abstract
Health is a continuum of an optimized state of a biologic system, an outcome of positive relationships with the self and others. A healthy system follows the principles of systems science derived from observations of nature, highlighting the character of relationships as the key determinant. Relationships evolve from our decisions, which are consequential to the function of our own biologic system on all levels, including the genome, where epigenetics impact our morphology. In healthy systems, decisions emanate from the reciprocal collaboration of hippocampal memory and the executive prefrontal cortex. We can decide to change relationships through choices. What is selected, however, only represents the cognitive interpretation of our limited sensory perception; it strongly reflects inherent biases toward either optimizing state, making a biologic system healthy, or not. Health or its absence is then the outcome; there is no inconsequential choice. Public health effort should not focus on punitive steps (e.g. taxation of unhealthy products or behaviors) in order to achieve a higher level of public’s health. It should teach people the process of making healthy decisions; otherwise, people will just migrate/shift from one unhealthy product/behavior to another, and well-intended punitive steps will not make much difference. Physical activity, accompanied by nutrition and stress management, have the greatest impact on fashioning health and simultaneously are the most cost-effective measures. Moderate-to-vigorous exercise not only improves aerobic fitness but also positively influences cognition, including memory and senses. Collective, rational societal decisions can then be anticipated. Health care is a business system principally governed by self-maximizing decisions of its components; uneven and contradictory outcomes are the consequences within such a non-optimized system. Health is not health care. We are biologic systems subject to the laws of biology in spite of our incongruous decisions that are detrimental to health. A biologic system/a human body originates from structural, deterministic genes as well as shared epigenetic memory of our ancestors affecting our bodily function and structure. The political governing systems’ vertical hierarchy has control over money and laws, neither of which materially affect individual lifestyle/behavioral choices toward health. Improved health comes from focusing on enhancing the biologic age and not the chronologic one, which simply represents a linear time from a birth certificate to a death certificate and is applicable only in its extremes. “Age-related diseases” are simply reflections of a given culture. Biologic age, reflecting the actual state of health, could be used in all health-related assessments including health-life insurance premiums, licensing of job categories, etc., all with a broader and healthy societal impact.
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Affiliation(s)
- Ivo Janecka
- Research and Education, Foundation for Systems
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62
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Sharma A. Transgenerational epigenetics: Integrating soma to germline communication with gametic inheritance. Mech Ageing Dev 2017; 163:15-22. [PMID: 28093237 DOI: 10.1016/j.mad.2016.12.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/07/2016] [Accepted: 12/13/2016] [Indexed: 12/28/2022]
Abstract
Evidence supporting germline mediated epigenetic inheritance of environmentally induced traits has increasingly emerged over the past several years. Although the mechanisms underlying this inheritance remain unclear, recent findings suggest that parental gamete-borne epigenetic factors, particularly RNAs, affect post-fertilization and developmental gene regulation, ultimately leading to phenotypic appearance in the offspring. Complex processes involving gene expression and epigenetic regulation are considered to perpetuate across generations. In addition to transfer of germline factors, epigenetic inheritance via gametes also requires a mechanism whereby the information pertaining to the induced traits is communicated from soma to germline. Despite violating a century-old view in biology, this communication seems to play a role in transmission of environmental effects across generations. Circulating RNAs, especially those associated with extracellular vesicles like exosomes, are emerging as promising candidates that can transmit gene regulatory information in this direction. Cumulatively, these new observations provide a basis to integrate epigenetic inheritance. With significant implications in health, disease and ageing, the latter appears poised to revolutionize biology.
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Affiliation(s)
- Abhay Sharma
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Sukhdev Vihar, Mathura Road, New Delhi, 110025, India.
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63
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Lim MYT, Okamura K. Switches in Dicer Activity During Oogenesis and Early Development. Results Probl Cell Differ 2017; 63:325-351. [PMID: 28779324 DOI: 10.1007/978-3-319-60855-6_14] [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: 06/07/2023]
Abstract
Dicer is a versatile protein regulating diverse biological processes via the production of multiple classes of small regulatory RNAs, including microRNAs (miRNAs) and small interfering RNAs (siRNAs). In this chapter, we will discuss roles for Dicer in driving temporal changes in activity of individual small RNA classes to support oogenesis and early embryogenesis. Genetic strategies that perturb particular functions of Dicer family proteins, such as ablation of individual Dicer paralogs or their binding partners as well as introduction of point mutations to individual domains, allowed the dissection of Dicer functions in diverse small RNA pathways. Evolutionary conservation and divergence of the mechanisms highlight the importance of Dicer versatility in supporting rapid changes in gene expression during oogenesis and early development. Furthermore, we will discuss potential roles of Dicer in transgenerational inheritance of small RNA-mediated gene regulation.
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Affiliation(s)
- Mandy Yu Theng Lim
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore, 117604, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 639798, Singapore
| | - Katsutomo Okamura
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore, 117604, Singapore.
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 639798, Singapore.
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64
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Chen Q, Yan W, Duan E. Epigenetic inheritance of acquired traits through sperm RNAs and sperm RNA modifications. Nat Rev Genet 2016; 17:733-743. [PMID: 27694809 PMCID: PMC5441558 DOI: 10.1038/nrg.2016.106] [Citation(s) in RCA: 306] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Once deemed heretical, emerging evidence now supports the notion that the inheritance of acquired characteristics can occur through ancestral exposures or experiences and that certain paternally acquired traits can be 'memorized' in the sperm as epigenetic information. The search for epigenetic factors in mammalian sperm that transmit acquired phenotypes has recently focused on RNAs and, more recently, RNA modifications. Here, we review insights that have been gained from studying sperm RNAs and RNA modifications, and their roles in influencing offspring phenotypes. We discuss the possible mechanisms by which sperm become acquisitive following environmental-somatic-germline interactions, and how they transmit paternally acquired phenotypes by shaping early embryonic development.
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Affiliation(s)
- Qi Chen
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada 89512, USA
| | - Wei Yan
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada 89512, USA
| | - Enkui Duan
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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65
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Extracellular RNA is transported from one generation to the next in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2016; 113:12496-12501. [PMID: 27791108 DOI: 10.1073/pnas.1608959113] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Experiences during the lifetime of an animal have been proposed to have consequences for subsequent generations. Although it is unclear how such intergenerational transfer of information occurs, RNAs found extracellularly in animals are candidate molecules that can transfer gene-specific regulatory information from one generation to the next because they can enter cells and regulate gene expression. In support of this idea, when double-stranded RNA (dsRNA) is introduced into some animals, the dsRNA can silence genes of matching sequence and the silencing can persist in progeny. Such persistent gene silencing is thought to result from sequence-specific interaction of the RNA within parents to generate chromatin modifications, DNA methylation, and/or secondary RNAs, which are then inherited by progeny. Here, we show that dsRNA can be directly transferred between generations in the worm Caenorhabditis elegans Intergenerational transfer of dsRNA occurs even in animals that lack any DNA of matching sequence, and dsRNA that reaches progeny can spread between cells to cause gene silencing. Surprisingly, extracellular dsRNA can also reach progeny without entry into the cytosol, presumably within intracellular vesicles. Fluorescently labeled dsRNA is imported from extracellular space into oocytes along with yolk and accumulates in punctate structures within embryos. Subsequent entry into the cytosol of early embryos causes gene silencing in progeny. These results demonstrate the transport of extracellular RNA from one generation to the next to regulate gene expression in an animal and thus suggest a mechanism for the transmission of experience-dependent effects between generations.
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66
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You are what your parents ate: A Darwinian perspective on the inheritance of food effects. Trends Food Sci Technol 2016. [DOI: 10.1016/j.tifs.2016.05.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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67
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Le HH, Looney M, Strauss B, Bloodgood M, Jose AM. Tissue homogeneity requires inhibition of unequal gene silencing during development. J Cell Biol 2016; 214:319-31. [PMID: 27458132 PMCID: PMC4970325 DOI: 10.1083/jcb.201601050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 06/29/2016] [Indexed: 11/22/2022] Open
Abstract
Multicellular organisms can generate and maintain homogenous populations of cells that make up individual tissues. However, cellular processes that can disrupt homogeneity and how organisms overcome such disruption are unknown. We found that ∼100-fold differences in expression from a repetitive DNA transgene can occur between intestinal cells in Caenorhabditis elegans These differences are caused by gene silencing in some cells and are actively suppressed by parental and zygotic factors such as the conserved exonuclease ERI-1. If unsuppressed, silencing can spread between some cells in embryos but can be repeat specific and independent of other homologous loci within each cell. Silencing can persist through DNA replication and nuclear divisions, disrupting uniform gene expression in developed animals. Analysis at single-cell resolution suggests that differences between cells arise during early cell divisions upon unequal segregation of an initiator of silencing. Our results suggest that organisms with high repetitive DNA content, which include humans, could use similar developmental mechanisms to achieve and maintain tissue homogeneity.
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Affiliation(s)
- Hai H Le
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Monika Looney
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Benjamin Strauss
- Center for Advanced Study of Language, University of Maryland, College Park, MD 20742
| | - Michael Bloodgood
- Center for Advanced Study of Language, University of Maryland, College Park, MD 20742
| | - Antony M Jose
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
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68
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Sims JR, Ow MC, Nishiguchi MA, Kim K, Sengupta P, Hall SE. Developmental programming modulates olfactory behavior in C. elegans via endogenous RNAi pathways. eLife 2016; 5. [PMID: 27351255 PMCID: PMC4924998 DOI: 10.7554/elife.11642] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 05/09/2016] [Indexed: 02/01/2023] Open
Abstract
Environmental stress during early development can impact adult phenotypes via programmed changes in gene expression. C. elegans larvae respond to environmental stress by entering the stress-resistant dauer diapause pathway and resume development once conditions improve (postdauers). Here we show that the osm-9 TRPV channel gene is a target of developmental programming and is down-regulated specifically in the ADL chemosensory neurons of postdauer adults, resulting in a corresponding altered olfactory behavior that is mediated by ADL in an OSM-9-dependent manner. We identify a cis-acting motif bound by the DAF-3 SMAD and ZFP-1 (AF10) proteins that is necessary for the differential regulation of osm-9, and demonstrate that both chromatin remodeling and endo-siRNA pathways are major contributors to the transcriptional silencing of the osm-9 locus. This work describes an elegant mechanism by which developmental experience influences adult phenotypes by establishing and maintaining transcriptional changes via RNAi and chromatin remodeling pathways. DOI:http://dx.doi.org/10.7554/eLife.11642.001 Increasing evidence suggests that experiencing stressful environments early on in life can have profound effects on the health and behavior of adults. For example, stressful conditions in the womb have been linked to adult depression and metabolic disorders. These effects are thought to be the result of changes in the way that genes in specific tissues are regulated in the individuals that have experienced the stress. However, it is not clear how a particular stress can cause long-term changes in gene activity in specific tissues. A microscopic worm called Caenorhabditis elegans is often used as a simple animal model to study how animals develop and behave. Previous studies have shown that adult worms that experienced stress early in life show differences in behavior and gene activity compared to genetically identical worms that did not experience the stress. Here, Sims, Ow et al. asked what signals are required for these changes to happen. The experiments show that a gene called osm-9 – which plays a role in the nervous system – is less active in sensory nerve cells in worms that experienced stress early on in life. This loss of activity resulted in the worms being unable to respond to a particular odor. Two proteins called DAF-3 and ZFP-1 are able to bind to a section of DNA in the osm-9 gene to decrease its activity in response to stress. These proteins are similar to human proteins that are important for development and are associated with some types of leukemia. Further experiments show that small molecules of ribonucleic acid in the “RNA interference” pathway also help to decrease the activity of osm-9 after stress. Together, Sims, Ow et al.’s findings suggest that environmental conditions in early life regulate the osm-9 gene through the coordinated effort of DAF-3, ZFP-1 and the RNA interference pathway. The next steps are to investigate how these molecules are able to target osm-9 and to identify other proteins that regulate gene activity in response to stress in early life. DOI:http://dx.doi.org/10.7554/eLife.11642.002
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Affiliation(s)
- Jennie R Sims
- Department of Biology, Syracuse University, Syracuse, United States
| | - Maria C Ow
- Department of Biology, Syracuse University, Syracuse, United States
| | | | - Kyuhyung Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - Piali Sengupta
- National Center for Behavioral Genomics, Department of Biology, Brandeis University, Waltham, United States
| | - Sarah E Hall
- Department of Biology, Syracuse University, Syracuse, United States
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69
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Rey O, Danchin E, Mirouze M, Loot C, Blanchet S. Adaptation to Global Change: A Transposable Element-Epigenetics Perspective. Trends Ecol Evol 2016; 31:514-526. [PMID: 27080578 DOI: 10.1016/j.tree.2016.03.013] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 12/21/2022]
Abstract
Understanding how organisms cope with global change is a major scientific challenge. The molecular pathways underlying rapid adaptive phenotypic responses to global change remain poorly understood. Here, we highlight the relevance of two environment-sensitive molecular elements: transposable elements (TEs) and epigenetic components (ECs). We first outline the sensitivity of these elements to global change stressors and review how they interact with each other. We then propose an integrative molecular engine coupling TEs and ECs and allowing organisms to fine-tune phenotypes in a real-time fashion, adjust the production of phenotypic and genetic variation, and produce heritable phenotypes with different levels of transmission fidelity. We finally discuss the implications of this molecular engine in the context of global change.
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Affiliation(s)
- Olivier Rey
- CNRS, UPS, Station d'Écologie Théorique et Expérimentale, UMR 5321, 09200 Moulis, France; Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK.
| | - Etienne Danchin
- CNRS, UPS, ENFA, Évolution & Diversité Biologique (EDB) UMR 5174, 118 Route de Narbonne, 31062 Toulouse, Cedex 9, France; Université Paul Sabatier, Évolution & Diversité Biologique (EDB), 31062 Toulouse, Cedex 9, France
| | - Marie Mirouze
- Institut de Recherche pour le Développement, UMR232 DIADE Diversité Adaptation et Développement des Plantes, Laboratoire Génome et Développement des Plantes, 58 avenue Paul Alduy, 66860 Perpignan, France
| | - Céline Loot
- Institut Pasteur, Unité de Plasticité du Génome Bactérien, Paris, France; CNRS UMR3525, Paris, France
| | - Simon Blanchet
- CNRS, UPS, Station d'Écologie Théorique et Expérimentale, UMR 5321, 09200 Moulis, France; CNRS, UPS, ENFA, Évolution & Diversité Biologique (EDB) UMR 5174, 118 Route de Narbonne, 31062 Toulouse, Cedex 9, France.
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70
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Steele EJ. Commentary: Past, present, and future of epigenetics applied to livestock breeding - Hard versus Soft Lamarckian Inheritance Mechanisms. Front Genet 2016; 7:29. [PMID: 26941780 PMCID: PMC4763540 DOI: 10.3389/fgene.2016.00029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 02/13/2016] [Indexed: 12/24/2022] Open
Affiliation(s)
- Edward J Steele
- CY O'Connor ERADE Village Foundation Piara Waters, WA, Australia
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71
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Klosin A, Lehner B. Mechanisms, timescales and principles of trans-generational epigenetic inheritance in animals. Curr Opin Genet Dev 2016; 36:41-9. [DOI: 10.1016/j.gde.2016.04.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 12/20/2022]
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72
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Demura M, Saijoh K. The Role of DNA Methylation in Hypertension. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 956:583-598. [PMID: 27888489 DOI: 10.1007/5584_2016_80] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
DNA methylation is the covalent modification of DNA that affects its function, without altering DNA sequences. Three important roles of DNA methylation include intrauterine programming, acquired predisposition, and transgenerational inheritance. A wide variety of factors can affect DNA methylation. Intrauterine programming involves drastic changes in DNA methylation patterns during cellular development and differentiation, which have a long-lasting effect on the predisposition of offspring. Influences from the mother, including maternal nutritional status, modify intrauterine epigenetic programming. In contrast to the rapid and drastic changes in utero, postnatal factors in daily life can also continue to slowly and dynamically change DNA methylation patterns in both somatic and germ cells. Epigenetic changes occurring in germ cell DNA exert a transgenerational impact on the phenotype of future generations, thus providing a means for ancestral transmission of environmental experiences. Despite adaptive ability, mismatch effect of transgenerational inheritance could be potentially harmful to health if environment has changed, and the acquired acclimatization is no longer beneficial. Increasing evidence from both human and animal studies indicates that DNA methylation exerts a causal impact on the development of hypertension. Therefore, an adverse outcome of maternal malnutrition could be the development of hypertension in offspring, whereby nutritional factors or disease conditions could induce phenotypes susceptible to hypertension through alteration of DNA methylation patterns. These factors are likely to alter DNA methylation patterns in all tissues including germ cells, and despite no direct evidence of an association between transgenerational epigenetic inheritance and hypertension, it is likely to play a role.
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Affiliation(s)
- Masashi Demura
- Department of Hygiene, Graduate School of Medical Science, Kanazawa University, Kanazawa, 920-8640, Japan.
| | - Kiyofumi Saijoh
- Department of Hygiene, Graduate School of Medical Science, Kanazawa University, Kanazawa, 920-8640, Japan
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73
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Eaton SA, Jayasooriah N, Buckland ME, Martin DIK, Cropley JE, Suter CM. Roll over Weismann: extracellular vesicles in the transgenerational transmission of environmental effects. Epigenomics 2015; 7:1165-71. [DOI: 10.2217/epi.15.58] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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74
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Butler AA, Webb WM, Lubin FD. Regulatory RNAs and control of epigenetic mechanisms: expectations for cognition and cognitive dysfunction. Epigenomics 2015; 8:135-51. [PMID: 26366811 DOI: 10.2217/epi.15.79] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The diverse functions of noncoding RNAs (ncRNAs) can influence virtually every aspect of the transcriptional process including epigenetic regulation of genes. In the CNS, regulatory RNA networks and epigenetic mechanisms have broad relevance to gene transcription changes involved in long-term memory formation and cognition. Thus, it is becoming increasingly clear that multiple classes of ncRNAs impact neuronal development, neuroplasticity, and cognition. Currently, a large gap exists in our knowledge of how ncRNAs facilitate epigenetic processes, and how this phenomenon affects cognitive function. In this review, we discuss recent findings highlighting a provocative role for ncRNAs including lncRNAs and piRNAs in the control of epigenetic mechanisms involved in cognitive function. Furthermore, we discuss the putative roles for these ncRNAs in cognitive disorders such as schizophrenia and Alzheimer's disease.
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Affiliation(s)
- Anderson A Butler
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - William M Webb
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
| | - Farah D Lubin
- Department of Neurobiology, University of Alabama at Birmingham, 1825 University Boulevard, Birmingham, AL 35294, USA
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75
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Nagy C, Turecki G. Transgenerational epigenetic inheritance: an open discussion. Epigenomics 2015; 7:781-90. [DOI: 10.2217/epi.15.46] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Much controversy surrounds the idea of transgenerational epigenetics. Recent papers argue that epigenetic marks acquired through experience are passed to offspring, but as in much of the field of epigenetics, there is lack of precision in the definitions and perhaps too much eagerness to translate animal research to humans. Here, we review operational definitions of transgenerational inheritance and the processes of epigenetic programing during early development. Subsequently, based on this background, we critically examine some recent findings of studies investigating transgenerational inheritance. Finally, we discuss possible mechanisms that may explain transgenerational inheritance, including transmission of an epigenetic blueprint, which may predispose offspring to specific epigenetic patterning. Taken together, we conclude that presently, the evidence suggesting that acquired epigenetic marks are passed to the subsequent generation remains limited.
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Affiliation(s)
- Corina Nagy
- McGill Group for Suicide Studies, Douglas Hospital University Institute, 6875 Lasalle boul, Montreal, QC, Canada
| | - Gustavo Turecki
- McGill Group for Suicide Studies, Douglas Hospital University Institute, 6875 Lasalle boul, Montreal, QC, Canada
- Department of Psychiatry, McGill University, Montreal, QC, Canada
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76
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Jose AM. Movement of regulatory RNA between animal cells. Genesis 2015; 53:395-416. [PMID: 26138457 PMCID: PMC4915348 DOI: 10.1002/dvg.22871] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 06/28/2015] [Accepted: 06/29/2015] [Indexed: 12/12/2022]
Abstract
Recent studies suggest that RNA can move from one cell to another and regulate genes through specific base-pairing. Mechanisms that modify or select RNA for secretion from a cell are unclear. Secreted RNA can be stable enough to be detected in the extracellular environment and can enter the cytosol of distant cells to regulate genes. Mechanisms that import RNA into the cytosol of an animal cell can enable uptake of RNA from many sources including other organisms. This role of RNA is akin to that of steroid hormones, which cross cell membranes to regulate genes. The potential diagnostic use of RNA in human extracellular fluids has ignited interest in understanding mechanisms that enable the movement of RNA between animal cells. Genetic model systems will be essential to gain more confidence in proposed mechanisms of RNA transport and to connect an extracellular RNA with a specific biological function. Studies in the worm C. elegans and in other animals have begun to reveal parts of this novel mechanism of cell-to-cell communication. Here, I summarize the current state of this nascent field, highlight the many unknowns, and suggest future directions.
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Affiliation(s)
- Antony M Jose
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland
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77
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Abstract
It is not really helpful to consider modern environmental epigenetics as neo-Lamarckian; and there is no evidence that Lamarck considered the idea original to himself. We must all keep learning about inheritance, but attributing modern ideas to early researchers is not helpful, and can be misleading.
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Affiliation(s)
- David Penny
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
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78
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Zhi M, Liu Y. Darwin's sub-cellular theory of inheritance: unknown or ignored? Naturwissenschaften 2015; 102:24. [PMID: 25894590 DOI: 10.1007/s00114-015-1276-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/09/2015] [Indexed: 10/23/2022]
Affiliation(s)
- Mingxing Zhi
- Henan Institute of Science and Technology, Henan Collaborative Innovation Center of Modern Biological Breeding, Xinxiang, 453003, China
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79
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Sharma A. Transgenerational epigenetic inheritance requires a much deeper analysis. Trends Mol Med 2015; 21:269-70. [PMID: 25795540 DOI: 10.1016/j.molmed.2015.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 02/25/2015] [Indexed: 12/28/2022]
Abstract
In his article, Szyf [1] has addressed the key challenges in and the controversies surrounding nongenetic inheritance. However, crucial findings that are important to counter two major criticisms held against transgenerational inheritance, especially in mammals--namely epigenetic memory survival across generations, and soma-to-germline transfer of heritable information--need additional discussion. Given the far-reaching implications of nongenetic inheritance on the one hand, and the skepticisms about its existence on the other, it is important that the advances concerned are examined deeply. The following discussion fills the gap left by Szyf [1] and provides an integrated perspective.
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Affiliation(s)
- Abhay Sharma
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research, Sukhdev Vihar, Mathura Road, New Delhi 110025, India.
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