1
|
Liu J, Murray JI. Mechanisms of lineage specification in Caenorhabditis elegans. Genetics 2023; 225:iyad174. [PMID: 37847877 DOI: 10.1093/genetics/iyad174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 09/18/2023] [Indexed: 10/19/2023] Open
Abstract
The studies of cell fate and lineage specification are fundamental to our understanding of the development of multicellular organisms. Caenorhabditis elegans has been one of the premiere systems for studying cell fate specification mechanisms at single cell resolution, due to its transparent nature, the invariant cell lineage, and fixed number of somatic cells. We discuss the general themes and regulatory mechanisms that have emerged from these studies, with a focus on somatic lineages and cell fates. We next review the key factors and pathways that regulate the specification of discrete cells and lineages during embryogenesis and postembryonic development; we focus on transcription factors and include numerous lineage diagrams that depict the expression of key factors that specify embryonic founder cells and postembryonic blast cells, and the diverse somatic cell fates they generate. We end by discussing some future perspectives in cell and lineage specification.
Collapse
Affiliation(s)
- Jun Liu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - John Isaac Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
2
|
Ferdous AS, Lynch TR, Costa Dos Santos SJ, Kapadia DH, Crittenden SL, Kimble J. LST-1 is a bifunctional regulator that feeds back on Notch-dependent transcription to regulate C. elegans germline stem cells. Proc Natl Acad Sci U S A 2023; 120:e2309964120. [PMID: 37729202 PMCID: PMC10523584 DOI: 10.1073/pnas.2309964120] [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: 06/13/2023] [Accepted: 08/15/2023] [Indexed: 09/22/2023] Open
Abstract
Notch signaling regulates stem cells across animal phylogeny. C. elegans Notch signaling activates transcription of two genes, lst-1 and sygl-1, that encode potent regulators of germline stem cells. The LST-1 protein regulates stem cells in two distinct ways: It promotes self-renewal posttranscriptionally and also restricts self-renewal by a poorly understood mechanism. Its self-renewal promoting activity resides in its N-terminal region, while its self-renewal restricting activity resides in its C-terminal region and requires the Zn finger. Here, we report that LST-1 limits self-renewal by down-regulating Notch-dependent transcription. We detect LST-1 in the nucleus, in addition to its previously known cytoplasmic localization. LST-1 lowers nascent transcript levels at both lst-1 and sygl-1 loci but not at let-858, a Notch-independent locus. LST-1 also lowers levels of two key components of the Notch activation complex, the LAG-1 DNA binding protein and Notch intracellular domain (NICD). Genetically, an LST-1 Zn finger mutant increases Notch signaling strength in both gain- and loss-of-function GLP-1/Notch receptor mutants. Biochemically, LST-1 co-immunoprecipitates with LAG-1 from nematode extracts, suggesting a direct effect. LST-1 is thus a bifunctional regulator that coordinates posttranscriptional and transcriptional mechanisms in a single protein. This LST-1 bifunctionality relies on its bipartite protein architecture and is bolstered by generation of two LST-1 isoforms, one specialized for Notch downregulation. A conserved theme from worms to human is the coupling of PUF-mediated RNA repression together with Notch feedback in the same protein.
Collapse
Affiliation(s)
- Ahlan S. Ferdous
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI53706
- Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Tina R. Lynch
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI53706
- Integrated Program in Biochemistry, University of Wisconsin-Madison, Madison, WI53706
| | | | - Deep H. Kapadia
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Sarah L. Crittenden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI53706
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI53706
| |
Collapse
|
3
|
Fan Q, Li XM, Zhai C, Li B, Li ST, Dong MQ. Somatic nuclear blebbing in Caenorhabditis elegans is not a feature of organismal aging but a potential indicator of germline proliferation in early adulthood. G3 (BETHESDA, MD.) 2023; 13:jkad029. [PMID: 36735812 PMCID: PMC10085788 DOI: 10.1093/g3journal/jkad029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/26/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
Abnormal nuclear morphology is suggested to be a hallmark of aging and one such abnormality is nuclear blebbing. However, little is known about whether and how nuclear blebbing participates in animal aging, and what regulates it. In this study, we show that the frequency of nuclear blebbing in the hypodermis increases during aging in wild-type C. elegans. These nuclear blebs are enveloped by the nuclear lamina, the inner and the outer nuclear membrane, and 42% of them contain chromatin. Although nuclear blebbing could lead to DNA loss if chromatin-containing blebs detach and fuse with lysosomes, we find by time-lapse imaging that nuclear blebs rarely detach, and the estimated lifetime of a nuclear bleb is 772 h or 32 days. The amount of DNA lost through nuclear blebbing is estimated to be about 0.1% of the total DNA loss by adult Day 11. Furthermore, the frequency of nuclear blebbing does not correlate with the rate of aging in C. elegans. Old age does not necessarily induce nuclear blebbing, neither does starvation, heat stress, or oxidative stress. Intriguingly, we find that proliferation of germ cells promotes nuclear blebbing.
Collapse
Affiliation(s)
- Qiang Fan
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Xue-Mei Li
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Chao Zhai
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Bin Li
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Shang-Tong Li
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Meng-Qiu Dong
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| |
Collapse
|
4
|
Yamakawa T, Yuslimatin Mujizah E, Matsuno K. Notch Signalling Under Maternal-to-Zygotic Transition. Fly (Austin) 2022; 16:347-359. [PMID: 36346359 PMCID: PMC9645253 DOI: 10.1080/19336934.2022.2139981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The development of all animal embryos is initially directed by the gene products supplied by their mothers. With the progression of embryogenesis, the embryo's genome is activated to command subsequent developments. This transition, which has been studied in many model animals, is referred to as the Maternal-to-Zygotic Transition (MZT). In many organisms, including flies, nematodes, and sea urchins, genes involved in Notch signaling are extensively influenced by the MZT. This signaling pathway is highly conserved across metazoans; moreover, it regulates various developmental processes. Notch signaling defects are commonly associated with various human diseases. The maternal contribution of its factors was first discovered in flies. Subsequently, several genes were identified from mutant embryos with a phenotype similar to Notch mutants only upon the removal of the maternal contributions. Studies on these maternal genes have revealed various novel steps in the cascade of Notch signal transduction. Among these genes, pecanex and almondex have been functionally characterized in recent studies. Therefore, in this review, we will focus on the roles of these two maternal genes in Notch signaling and discuss future research directions on its maternal function.
Collapse
Affiliation(s)
- Tomoko Yamakawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan,CONTACT Tomoko Yamakawa Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan
| | | | - Kenji Matsuno
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan
| |
Collapse
|
5
|
Booth LN, Shi C, Tantilert C, Yeo RW, Miklas JW, Hebestreit K, Hollenhorst CN, Maures TJ, Buckley MT, Murphy CT, Brunet A. Males induce premature demise of the opposite sex by multifaceted strategies. NATURE AGING 2022; 2:809-823. [PMID: 37118502 PMCID: PMC10154206 DOI: 10.1038/s43587-022-00276-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 08/03/2022] [Indexed: 04/30/2023]
Abstract
Interactions between the sexes negatively impact health in many species. In Caenorhabditis, males shorten the lifespan of the opposite sex-hermaphrodites or females. Here we use transcriptomic profiling and targeted screens to systematically uncover conserved genes involved in male-induced demise in C. elegans. Some genes (for example, delm-2, acbp-3), when knocked down, are specifically protective against male-induced demise. Others (for example, sri-40), when knocked down, extend lifespan with and without males, suggesting general mechanisms of protection. In contrast, many classical long-lived mutants are impacted more negatively than wild type by the presence of males, highlighting the importance of sexual environment for longevity. Interestingly, genes induced by males are triggered by specific male components (seminal fluid, sperm and pheromone), and manipulating these genes in combination in hermaphrodites induces stronger protection. One of these genes, the conserved ion channel delm-2, acts in the nervous system and intestine to regulate lipid metabolism. Our analysis reveals striking differences in longevity in single sex versus mixed sex environments and uncovers elaborate strategies elicited by sexual interactions that could extend to other species.
Collapse
Affiliation(s)
- Lauren N Booth
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Calico Life Sciences, South San Francisco, CA, USA
| | - Cheng Shi
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- LSI Genomics, Princeton University, Princeton, NJ, USA
| | - Cindy Tantilert
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Robin W Yeo
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jason W Miklas
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Katja Hebestreit
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Travis J Maures
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Matthew T Buckley
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Coleen T Murphy
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
- LSI Genomics, Princeton University, Princeton, NJ, USA.
| | - Anne Brunet
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
- Glenn Laboratories for the Biology of Aging and Stanford University, Stanford, CA, USA.
| |
Collapse
|
6
|
Shaffer JM, Greenwald I. SALSA, a genetically encoded biosensor for spatiotemporal quantification of Notch signal transduction in vivo. Dev Cell 2022; 57:930-944.e6. [PMID: 35413239 PMCID: PMC9473748 DOI: 10.1016/j.devcel.2022.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/14/2022] [Accepted: 03/14/2022] [Indexed: 12/26/2022]
Abstract
Notch-mediated lateral specification is a fundamental mechanism to resolve stochastic cell fate choices by amplifying initial differences between equivalent cells. To study how stochastic events impact Notch activity, we developed a biosensor, SALSA (sensor able to detect lateral signaling activity), consisting of an amplifying "switch"-Notch tagged with TEV protease-and a "reporter"-GFP fused to a nuclearly localized red fluorescent protein, separated by a TEVp cut site. When ligand activates Notch, TEVp enters the nucleus and releases GFP from its nuclear tether, allowing Notch activation to be quantified based on the changes in GFP subcellular localization. We show that SALSA accurately reports Notch activity in different signaling paradigms in Caenorhabditis elegans and use time-lapse imaging to test hypotheses about how stochastic elements ensure a reproducible and robust outcome in a canonical lin-12/Notch-mediated lateral signaling paradigm. SALSA should be generalizable to other experimental systems and be adaptable to increase options for bespoke "SynNotch" applications.
Collapse
Affiliation(s)
- Justin M Shaffer
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Iva Greenwald
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
| |
Collapse
|
7
|
The great small organisms of developmental genetics: Caenorhabditis elegans and Drosophila melanogaster. Dev Biol 2022; 485:93-122. [PMID: 35247454 PMCID: PMC9092520 DOI: 10.1016/j.ydbio.2022.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/25/2022] [Accepted: 02/27/2022] [Indexed: 12/30/2022]
Abstract
Experimental embryologists working at the turn of the 19th century suggested fundamental mechanisms of development, such as localized cytoplasmic determinants and tissue induction. However, the molecular basis underlying these processes proved intractable for a long time, despite concerted efforts in many developmental systems to isolate factors with a biological role. That road block was overcome by combining developmental biology with genetics. This powerful approach used unbiased genome-wide screens to isolate mutants with developmental defects and to thereby identify genes encoding key determinants and regulatory pathways that govern development. Two small invertebrates were the pioneers: the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans. Their modes of development differ in many ways, but the two together led the way to unraveling the molecular mechanisms of many fundamental developmental processes. The discovery of the grand homologies between key players in development throughout the animal kingdom underscored the usefulness of studying these small invertebrate models for animal development and even human disease. We describe developmental genetics in Drosophila and C. elegans up to the rise of genomics at the beginning of the 21st Century. Finally, we discuss themes that emerge from the histories of such distinct organisms and prospects of this approach for the future.
Collapse
|
8
|
Li CL, Pu M, Wang W, Chaturbedi A, Emerson FJ, Lee SS. Region-specific H3K9me3 gain in aged somatic tissues in Caenorhabditis elegans. PLoS Genet 2021; 17:e1009432. [PMID: 34506495 PMCID: PMC8457455 DOI: 10.1371/journal.pgen.1009432] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 09/22/2021] [Accepted: 08/17/2021] [Indexed: 12/13/2022] Open
Abstract
Epigenetic alterations occur as organisms age, and lead to chromatin deterioration, loss of transcriptional silencing and genomic instability. Dysregulation of the epigenome has been associated with increased susceptibility to age-related disorders. In this study, we aimed to characterize the age-dependent changes of the epigenome and, in turn, to understand epigenetic processes that drive aging phenotypes. We focused on the aging-associated changes in the repressive histone marks H3K9me3 and H3K27me3 in C. elegans. We observed region-specific gain and loss of both histone marks, but the changes are more evident for H3K9me3. We further found alteration of heterochromatic boundaries in aged somatic tissues. Interestingly, we discovered that the most statistically significant changes reflected H3K9me3-marked regions that are formed during aging, and are absent in developing worms, which we termed "aging-specific repressive regions" (ASRRs). These ASRRs preferentially occur in genic regions that are marked by high levels of H3K9me2 and H3K36me2 in larval stages. Maintenance of high H3K9me2 levels in these regions have been shown to correlate with a longer lifespan. Next, we examined whether the changes in repressive histone marks lead to de-silencing of repetitive DNA elements, as reported for several other organisms. We observed increased expression of active repetitive DNA elements but not global re-activation of silent repeats in old worms, likely due to the distributed nature of repetitive elements in the C. elegans genome. Intriguingly, CELE45, a putative short interspersed nuclear element (SINE), was greatly overexpressed at old age and upon heat stress. SINEs have been suggested to regulate transcription in response to various cellular stresses in mammals. It is likely that CELE45 RNAs also play roles in stress response and aging in C. elegans. Taken together, our study revealed significant and specific age-dependent changes in repressive histone modifications and repetitive elements, providing important insights into aging biology.
Collapse
Affiliation(s)
- Cheng-Lin Li
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Mintie Pu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan, China
| | - Wenke Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Amaresh Chaturbedi
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Felicity J Emerson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Siu Sylvia Lee
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| |
Collapse
|
9
|
Mayya VK, Flamand MN, Lambert AM, Jafarnejad SM, Wohlschlegel JA, Sonenberg N, Duchaine TF. microRNA-mediated translation repression through GYF-1 and IFE-4 in C. elegans development. Nucleic Acids Res 2021; 49:4803-4815. [PMID: 33758928 PMCID: PMC8136787 DOI: 10.1093/nar/gkab162] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/24/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
microRNA (miRNA)-mediated gene silencing is enacted through the recruitment of effector proteins that direct translational repression or degradation of mRNA targets, but the relative importance of their activities for animal development remains unknown. Our concerted proteomic surveys identified the uncharacterized GYF-domain encoding protein GYF-1 and its direct interaction with IFE-4, the ortholog of the mammalian translation repressor 4EHP, as key miRNA effector proteins in Caenorhabditis elegans. Recruitment of GYF-1 protein to mRNA reporters in vitro or in vivo leads to potent translation repression without affecting the poly(A) tail or impinging on mRNA stability. Loss of gyf-1 is synthetic lethal with hypomorphic alleles of embryonic miR-35-42 and larval (L4) let-7 miRNAs, which is phenocopied through engineered mutations in gyf-1 that abolish interaction with IFE-4. GYF-1/4EHP function is cascade-specific, as loss of gyf-1 had no noticeable impact on the functions of other miRNAs, including lin-4 and lsy-6. Overall, our findings reveal the first direct effector of miRNA-mediated translational repression in C. elegans and its physiological importance for the function of several, but likely not all miRNAs.
Collapse
Affiliation(s)
- Vinay K Mayya
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Mathieu N Flamand
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Alice M Lambert
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast BT9 7AE UK
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Nahum Sonenberg
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Thomas F Duchaine
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| |
Collapse
|
10
|
Senchuk MM, Van Raamsdonk JM, Moore DJ. Multiple genetic pathways regulating lifespan extension are neuroprotective in a G2019S LRRK2 nematode model of Parkinson's disease. Neurobiol Dis 2021; 151:105267. [PMID: 33450392 PMCID: PMC7925424 DOI: 10.1016/j.nbd.2021.105267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/17/2020] [Accepted: 01/10/2021] [Indexed: 01/02/2023] Open
Abstract
Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most frequent cause of late-onset, familial Parkinson's disease (PD), and LRRK2 variants are associated with increased risk for sporadic PD. While advanced age represents the strongest risk factor for disease development, it remains unclear how different age-related pathways interact to regulate LRRK2-driven late-onset PD. In this study, we employ a C. elegans model expressing PD-linked G2019S LRRK2 to examine the interplay between age-related pathways and LRRK2-induced dopaminergic neurodegeneration. We find that multiple genetic pathways that regulate lifespan extension can provide robust neuroprotection against mutant LRRK2. However, the level of neuroprotection does not strictly correlate with the magnitude of lifespan extension, suggesting that lifespan can be experimentally dissociated from neuroprotection. Using tissue-specific RNAi, we demonstrate that lifespan-regulating pathways, including insulin/insulin-like growth factor-1 (IGF-1) signaling, target of rapamycin (TOR), and mitochondrial respiration, can be directly manipulated in neurons to mediate neuroprotection. We extend this finding for AGE-1/PI3K, where pan-neuronal versus dopaminergic neuronal restoration of AGE-1 reveals both cell-autonomous and non-cell-autonomous neuroprotective mechanisms downstream of insulin signaling. Our data demonstrate the importance of distinct lifespan-regulating pathways in the pathogenesis of LRRK2-linked PD, and suggest that extended longevity is broadly neuroprotective via the actions of these pathways at least in part within neurons. This study further highlights the complex interplay that occurs between cells and tissues during organismal aging and disease manifestation.
Collapse
Affiliation(s)
- Megan M Senchuk
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI 49503, USA
| | - Jeremy M Van Raamsdonk
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H4A 3J1, Canada; Metabolic Disorders and Complications Program, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada; Department of Genetics, Harvard Medical School, Cambridge, MA 02115, USA.
| | - Darren J Moore
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI 49503, USA.
| |
Collapse
|
11
|
Liu YJ, McIntyre RL, Janssens GE, Williams EG, Lan J, van Weeghel M, Schomakers B, van der Veen H, van der Wel NN, Yao P, Mair WB, Aebersold R, MacInnes AW, Houtkooper RH. Mitochondrial translation and dynamics synergistically extend lifespan in C. elegans through HLH-30. J Cell Biol 2021; 219:151623. [PMID: 32259199 PMCID: PMC7265311 DOI: 10.1083/jcb.201907067] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 01/22/2020] [Accepted: 03/05/2020] [Indexed: 01/18/2023] Open
Abstract
Mitochondrial form and function are closely interlinked in homeostasis and aging. Inhibiting mitochondrial translation is known to increase lifespan in C. elegans, and is accompanied by a fragmented mitochondrial network. However, whether this link between mitochondrial translation and morphology is causal in longevity remains uncharacterized. Here, we show in C. elegans that disrupting mitochondrial network homeostasis by blocking fission or fusion synergizes with reduced mitochondrial translation to prolong lifespan and stimulate stress response such as the mitochondrial unfolded protein response, UPRMT. Conversely, immobilizing the mitochondrial network through a simultaneous disruption of fission and fusion abrogates the lifespan increase induced by mitochondrial translation inhibition. Furthermore, we find that the synergistic effect of inhibiting both mitochondrial translation and dynamics on lifespan, despite stimulating UPRMT, does not require it. Instead, this lifespan-extending synergy is exclusively dependent on the lysosome biogenesis and autophagy transcription factor HLH-30/TFEB. Altogether, our study reveals the mechanistic crosstalk between mitochondrial translation, mitochondrial dynamics, and lysosomal signaling in regulating longevity.
Collapse
Affiliation(s)
- Yasmine J Liu
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Rebecca L McIntyre
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Georges E Janssens
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Evan G Williams
- Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology in Zurich, Zurich, Switzerland
| | - Jiayi Lan
- Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology in Zurich, Zurich, Switzerland
| | - Michel van Weeghel
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands.,Core Facility Metabolomics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Bauke Schomakers
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands.,Core Facility Metabolomics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Henk van der Veen
- Electron Microscopy Center Amsterdam, Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Nicole N van der Wel
- Electron Microscopy Center Amsterdam, Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Pallas Yao
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA
| | - William B Mair
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology in Zurich, Zurich, Switzerland.,Faculty of Science, University of Zurich, Zurich, Switzerland
| | - Alyson W MacInnes
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Riekelt H Houtkooper
- Laboratory Genetic Metabolic Diseases, Amsterdam Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
12
|
Deonarine A, Walker MWG, Westerheide SD. HSF-1 displays nuclear stress body formation in multiple tissues in Caenorhabditis elegans upon stress and following the transition to adulthood. Cell Stress Chaperones 2021; 26:417-431. [PMID: 33392968 PMCID: PMC7925714 DOI: 10.1007/s12192-020-01188-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 01/09/2023] Open
Abstract
The transcription factor heat shock factor-1 (HSF-1) regulates the heat shock response (HSR), a cytoprotective response induced by proteotoxic stresses. Data from model organisms has shown that HSF-1 also has non-stress biological roles, including roles in the regulation of development and longevity. To better study HSF-1 function, we created a C. elegans strain containing HSF-1 tagged with GFP at its endogenous locus utilizing CRISPR/Cas9-guided transgenesis. We show that the HSF-1::GFP CRISPR worm strain behaves similarly to wildtype worms in response to heat and other stresses, and in other physiological processes. HSF-1 was expressed in all tissues assayed. Immediately following the initiation of reproduction, HSF-1 formed nuclear stress bodies, a hallmark of activation, throughout the germline. Upon the transition to adulthood, of HSF-1 nuclear stress bodies appeared in most somatic cells. Genetic loss of the germline suppressed nuclear stress body formation with age, suggesting that the germline influences HSF-1 activity. Interestingly, we found that various neurons did not form nuclear stress bodies after transitioning to adulthood. Therefore, the formation of HSF-1 nuclear stress bodies upon the transition to adulthood does not occur in a synchronous manner in all cell types. In sum, these studies enhance our knowledge of the expression and activity of the aging and proteostasis factor HSF-1 in a tissue-specific manner with age.
Collapse
Affiliation(s)
- Andrew Deonarine
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620 USA
| | - Matt W. G. Walker
- Department of Biological Sciences, Columbia University, New York, NY 10027 USA
| | - Sandy D. Westerheide
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620 USA
| |
Collapse
|
13
|
Dalfó D, Ding Y, Liang Q, Fong A, Cipriani PG, Piano F, Zheng JC, Qin Z, Hubbard EJA. A Genome-Wide RNAi Screen for Enhancers of a Germline Tumor Phenotype Caused by Elevated GLP-1/Notch Signaling in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2020; 10:4323-4334. [PMID: 33077477 PMCID: PMC7718737 DOI: 10.1534/g3.120.401632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/08/2020] [Indexed: 11/18/2022]
Abstract
Stem cells are tightly controlled in vivo Both the balance between self-renewal and differentiation and the rate of proliferation are often regulated by multiple factors. The Caenorhabditis elegans hermaphrodite germ line provides a simple and accessible system for studying stem cells in vivo In this system, GLP-1/Notch activity prevents the differentiation of distal germ cells in response to ligand production from the nearby distal tip cell, thereby supporting a stem cell pool. However, a delay in germline development relative to somatic gonad development can cause a pool of undifferentiated germ cells to persist in response to alternate Notch ligands expressed in the proximal somatic gonad. This pool of undifferentiated germ cells forms a proximal tumor that, in adulthood, blocks the oviduct. This type of "latent niche"-driven proximal tumor is highly penetrant in worms bearing the temperature-sensitive weak gain-of-function mutation glp-1(ar202) at the restrictive temperature. At the permissive temperature, few worms develop tumors. Nevertheless, several interventions elevate the penetrance of proximal tumor formation at the permissive temperature, including reduced insulin signaling or the ablation of distal-most sheath cells. To systematically identify genetic perturbations that enhance proximal tumor formation, we sought genes that, upon RNAi depletion, elevate the percentage of worms bearing proximal germline tumors in glp-1(ar202) at the permissive temperature. We identified 43 genes representing a variety of functional classes, the most enriched of which is "translation". Some of these genes also influence the distal germ line, and some are conserved genes for which genetic interactions with Notch were not previously known in this system.
Collapse
Affiliation(s)
- Diana Dalfó
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, NYU Grossman School of Medicine
| | | | | | - Alex Fong
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, NYU Grossman School of Medicine
| | - Patricia Giselle Cipriani
- Center for Genomics and Systems Biology, Department of Biology, New York University and Center for Genomics and Systems Biology, New York University Abu Dhabi
| | - Fabio Piano
- Center for Genomics and Systems Biology, Department of Biology, New York University and Center for Genomics and Systems Biology, New York University Abu Dhabi
| | | | - Zhao Qin
- School of Medicine, Tongji University
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopedic Department of Tongji Hospital, School of Medicine, Tongji University
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, NYU Grossman School of Medicine
| |
Collapse
|
14
|
Mei X, Singson AW. The molecular underpinnings of fertility: Genetic approaches in Caenorhabditis elegans. ADVANCED GENETICS (HOBOKEN, N.J.) 2020; 2:e10034. [PMID: 34322672 PMCID: PMC8315475 DOI: 10.1002/ggn2.10034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The study of mutations that impact fertility has a catch-22. Fertility mutants are often lost since they cannot simply be propagated and maintained. This has hindered progress in understanding the genetics of fertility. In mice, several molecules are found to be required for the interactions between the sperm and egg, with JUNO and IZUMO1 being the only known receptor pair on the egg and sperm surface, respectively. In Caenorhabditis elegans, a total of 12 proteins on the sperm or oocyte have been identified to mediate gamete interactions. Majority of these genes were identified through mutants isolated from genetic screens. In this review, we summarize the several key screening strategies that led to the identification of fertility mutants in C. elegans and provide a perspective about future research using genetic approaches. Recently, advancements in new technologies such as high-throughput sequencing and Crispr-based genome editing tools have accelerated the molecular, cell biological, and mechanistic analysis of fertility genes. We review how these valuable tools advance our understanding of the molecular underpinnings of fertilization. We draw parallels of the molecular mechanisms of fertilization between worms and mammals and argue that our work in C. elegans complements fertility research in humans and other species.
Collapse
Affiliation(s)
- Xue Mei
- Department of GeneticsWaksman Institute, Rutgers, The State University of New JerseyPiscatawayNew JerseyUSA
| | - Andrew W. Singson
- Department of GeneticsWaksman Institute, Rutgers, The State University of New JerseyPiscatawayNew JerseyUSA
| |
Collapse
|
15
|
Harnessing the power of genetics: fast forward genetics in Caenorhabditis elegans. Mol Genet Genomics 2020; 296:1-20. [PMID: 32888055 DOI: 10.1007/s00438-020-01721-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 08/27/2020] [Indexed: 12/23/2022]
Abstract
Forward genetics is a powerful tool to unravel molecular mechanisms of diverse biological processes. The success of genetic screens primarily relies on the ease of genetic manipulation of an organism and the availability of a plethora of genetic tools. The roundworm Caenorhabditis elegans has been one of the favorite models for genetic studies due to its hermaphroditic lifestyle, ease of maintenance, and availability of various genetic manipulation tools. The strength of C. elegans genetics is highlighted by the leading role of this organism in the discovery of several conserved biological processes. In this review, the principles and strategies for forward genetics in C. elegans are discussed. Further, the recent advancements that have drastically accelerated the otherwise time-consuming process of mutation identification, making forward genetic screens a method of choice for understanding biological functions, are discussed. The emphasis of the review has been on providing practical and conceptual pointers for designing genetic screens that will identify mutations, specifically disrupting the biological processes of interest.
Collapse
|
16
|
Zárate-Potes A, Yang W, Pees B, Schalkowski R, Segler P, Andresen B, Haase D, Nakad R, Rosenstiel P, Tetreau G, Colletier JP, Schulenburg H, Dierking K. The C. elegans GATA transcription factor elt-2 mediates distinct transcriptional responses and opposite infection outcomes towards different Bacillus thuringiensis strains. PLoS Pathog 2020; 16:e1008826. [PMID: 32970778 PMCID: PMC7513999 DOI: 10.1371/journal.ppat.1008826] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/21/2020] [Indexed: 12/20/2022] Open
Abstract
The nematode Caenorhabditis elegans has been extensively used as a model for the study of innate immune responses against bacterial pathogens. While it is well established that the worm mounts distinct transcriptional responses to different bacterial species, it is still unclear in how far it can fine-tune its response to different strains of a single pathogen species, especially if the strains vary in virulence and infection dynamics. To rectify this knowledge gap, we systematically analyzed the C. elegans response to two strains of Bacillus thuringiensis (Bt), MYBt18247 (Bt247) and MYBt18679 (Bt679), which produce different pore forming toxins (PFTs) and vary in infection dynamics. We combined host transcriptomics with cytopathological characterizations and identified both a common and also a differentiated response to the two strains, the latter comprising almost 10% of the infection responsive genes. Functional genetic analyses revealed that the AP-1 component gene jun-1 mediates the common response to both Bt strains. In contrast, the strain-specific response is mediated by the C. elegans GATA transcription factor ELT-2, a homolog of Drosophila SERPENT and vertebrate GATA4-6, and a known master regulator of intestinal responses in the nematode. elt-2 RNAi knockdown decreased resistance to Bt679, but remarkably, increased survival on Bt247. The elt-2 silencing-mediated increase in survival was characterized by reduced intestinal tissue damage despite a high pathogen burden and might thus involve increased tolerance. Additional functional genetic analyses confirmed the involvement of distinct signaling pathways in the C. elegans defense response: the p38-MAPK pathway acts either directly with or in parallel to elt-2 in mediating resistance to Bt679 infection but is not required for protection against Bt247. Our results further suggest that the elt-2 silencing-mediated increase in survival on Bt247 is multifactorial, influenced by the nuclear hormone receptors NHR-99 and NHR-193, and may further involve lipid metabolism and detoxification. Our study highlights that the nematode C. elegans with its comparatively simple immune defense system is capable of generating a differentiated response to distinct strains of the same pathogen species. Importantly, our study provides a molecular insight into the diversity of biological processes that are influenced by a single master regulator and jointly determine host survival after pathogen infection.
Collapse
Affiliation(s)
- Alejandra Zárate-Potes
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Wentao Yang
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Barbara Pees
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Rebecca Schalkowski
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Philipp Segler
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Bentje Andresen
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Daniela Haase
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Rania Nakad
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Philip Rosenstiel
- Institute for Clinical Molecular Biology (IKMB), Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Guillaume Tetreau
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, Grenoble, France
| | | | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
- Max Planck Institute for Evolutionary Biology, Ploen, Germany
| | - Katja Dierking
- Department of Evolutionary Ecology and Genetics, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| |
Collapse
|
17
|
Secoisolariciresinol Diglucoside Delays the Progression of Aging-Related Diseases and Extends the Lifespan of Caenorhabditis elegans via DAF-16 and HSF-1. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:1293935. [PMID: 32733632 PMCID: PMC7378611 DOI: 10.1155/2020/1293935] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 12/12/2022]
Abstract
Secoisolariciresinol diglucoside (SDG) is a phytoestrogen and rich in food flaxseed, sunflower seeds, and sesame seeds. Among the beneficial pharmacological activities of SDG on health, many are age related, such as anticancer, antidiabetes, antioxidant, and neuroprotective effects. Thus, we investigated if SDG had an effect on antiaging in Caenorhabditis elegans (C. elegans). Our results showed that SDG could extend the lifespan of C. elegans by up to 22.0%, delay age-related decline of body movement, reduce the lethality of heat and oxidative stress, alleviate dopamine neurodegeneration induced by 6-hydroxydopamine (6-OHDA), and decrease the toxicity of Aβ protein in C. elegans. SDG could increase the expression of the downstream genes of DAF-16, DAF-12, NHR-80, and HSF-1 at mRNA level. SDG could not extend the lifespan of mutants from genes daf-16, hsf-1, nhr-80, daf-12, glp-1, eat-2, and aak-2. The above results suggested that SDG might enhance the stress resistance, delay the progression of aging-related diseases, and extend the lifespan of C. elegans via DAF-16 and HSF-1.
Collapse
|
18
|
Cohen-Berkman M, Dudkevich R, Ben-Hamo S, Fishman A, Salzberg Y, Waldman Ben-Asher H, Lamm AT, Henis-Korenblit S. Endogenous siRNAs promote proteostasis and longevity in germline-less Caenorhabditis elegans. eLife 2020; 9:e50896. [PMID: 32213289 PMCID: PMC7136021 DOI: 10.7554/elife.50896] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 03/26/2020] [Indexed: 12/19/2022] Open
Abstract
How lifespan and the rate of aging are set is a key problem in biology. Small RNAs are conserved molecules that impact diverse biological processes through the control of gene expression. However, in contrast to miRNAs, the role of endo-siRNAs in aging remains unexplored. Here, by combining deep sequencing and genomic and genetic approaches in Caenorhabditis elegans, we reveal an unprecedented role for endo-siRNA molecules in the maintenance of proteostasis and lifespan extension in germline-less animals. Furthermore, we identify an endo-siRNA-regulated tyrosine phosphatase, which limits the longevity of germline-less animals by restricting the activity of the heat shock transcription factor HSF-1. Altogether, our findings point to endo-siRNAs as a link between germline removal and the HSF-1 proteostasis and longevity-promoting somatic pathway. This establishes a role for endo siRNAs in the aging process and identifies downstream genes and physiological processes that are regulated by the endo siRNAs to affect longevity.
Collapse
Affiliation(s)
- Moran Cohen-Berkman
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan UniversityRamat-GanIsrael
| | - Reut Dudkevich
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan UniversityRamat-GanIsrael
| | - Shani Ben-Hamo
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan UniversityRamat-GanIsrael
| | - Alla Fishman
- Faculty of Biology, Technion-Israel Institute of Technology, Technion CityHaifaIsrael
| | - Yehuda Salzberg
- Department of Neurobiology, Weizmann Institute of ScienceRehovotIsrael
| | | | - Ayelet T Lamm
- Faculty of Biology, Technion-Israel Institute of Technology, Technion CityHaifaIsrael
| | - Sivan Henis-Korenblit
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan UniversityRamat-GanIsrael
| |
Collapse
|
19
|
Chen J, Mohammad A, Pazdernik N, Huang H, Bowman B, Tycksen E, Schedl T. GLP-1 Notch-LAG-1 CSL control of the germline stem cell fate is mediated by transcriptional targets lst-1 and sygl-1. PLoS Genet 2020; 16:e1008650. [PMID: 32196486 PMCID: PMC7153901 DOI: 10.1371/journal.pgen.1008650] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 04/13/2020] [Accepted: 02/04/2020] [Indexed: 12/16/2022] Open
Abstract
Stem cell systems are essential for the development and maintenance of polarized tissues. Intercellular signaling pathways control stem cell systems, where niche cells signal stem cells to maintain the stem cell fate/self-renewal and inhibit differentiation. In the C. elegans germline, GLP-1 Notch signaling specifies the stem cell fate, employing the sequence-specific DNA binding protein LAG-1 to implement the transcriptional response. We undertook a comprehensive genome-wide approach to identify transcriptional targets of GLP-1 signaling. We expected primary response target genes to be evident at the intersection of genes identified as directly bound by LAG-1, from ChIP-seq experiments, with genes identified as requiring GLP-1 signaling for RNA accumulation, from RNA-seq analysis. Furthermore, we performed a time-course transcriptomics analysis following auxin inducible degradation of LAG-1 to distinguish between genes whose RNA level was a primary or secondary response of GLP-1 signaling. Surprisingly, only lst-1 and sygl-1, the two known target genes of GLP-1 in the germline, fulfilled these criteria, indicating that these two genes are the primary response targets of GLP-1 Notch and may be the sole germline GLP-1 signaling protein-coding transcriptional targets for mediating the stem cell fate. In addition, three secondary response genes were identified based on their timing following loss of LAG-1, their lack of a LAG-1 ChIP-seq peak and that their glp-1 dependent mRNA accumulation could be explained by a requirement for lst-1 and sygl-1 activity. Moreover, our analysis also suggests that the function of the primary response genes lst-1 and sygl-1 can account for the glp-1 dependent peak protein accumulation of FBF-2, which promotes the stem cell fate and, in part, for the spatial restriction of elevated LAG-1 accumulation to the stem cell region. Stem cell systems are central to tissue development, homeostasis and regeneration, where niche to stem cell signaling pathways promote the stem cell fate/self-renewal and inhibit differentiation. The evolutionarily conserved GLP-1 Notch signaling pathway in the C. elegans germline is an experimentally tractable system, allowing dissection of control of the stem cell fate and inhibition of meiotic development. However, as in many systems, the primary molecular targets of the signaling pathway in stem cells is incompletely known, as are secondary molecular targets, and this knowledge is essential for a deep understanding of stem cell systems. Here we focus on the identification of the primary transcriptional targets of the GLP-1 signaling pathway that promotes the stem cell fate, employing unbiased multilevel genomic approaches. We identify only lst-1 and sygl-1, two of a number of previously reported targets, as likely the sole primary mRNA transcriptional targets of GLP-1 signaling that promote the germline stem cell fate. We also identify secondary GLP-1 signaling RNA and protein targets, whose expression shows dependence on lst-1 and sygl-1, where the protein targets reinforce the importance of posttranscriptional regulation in control of the stem cell fate.
Collapse
Affiliation(s)
- Jian Chen
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Ariz Mohammad
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Nanette Pazdernik
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Current address, Integrated DNA Technologies, Coralville, Iowa, United States of America
| | - Huiyan Huang
- Department of Pediatrics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Beth Bowman
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
- Current address, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Eric Tycksen
- Genome Technology Access Center, McDonnell Genome Institute, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Tim Schedl
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
| |
Collapse
|
20
|
Insulin-dependent Non-canonical Activation of Notch in Drosophila: A Story of Notch-Induced Muscle Stem Cell Proliferation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1227:131-144. [PMID: 32072503 DOI: 10.1007/978-3-030-36422-9_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Notch plays multiple roles both in development and in adult tissue homeostasis. Notch was first identified in Drosophila in which it has then been extensively studied. Among the flag-ship Notch functions we could mention its capacity to keep precursor and stem cells in a nondifferentiated state but also its ability to activate cell proliferation that in some contexts could led to cancer. In general, both these functions involve, canonical, ligand-dependent Notch activation. However, a ligand-independent Notch activation has also been described in a few cellular contexts. Here, we focus on one of such contexts, Drosophila muscle stem cells, called AMPs, and discuss how insulin-dependent noncanonical activation of Notch pushes quiescent AMPs to proliferation.
Collapse
|
21
|
Lee HJ, Noormohammadi A, Koyuncu S, Calculli G, Simic MS, Herholz M, Trifunovic A, Vilchez D. Prostaglandin signals from adult germ stem cells delay somatic aging of Caenorhabditis elegans. Nat Metab 2019; 1:790-810. [PMID: 31485561 PMCID: PMC6726479 DOI: 10.1038/s42255-019-0097-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A moderate reduction of body temperature can induce a remarkable lifespan extension. Here we examine the link between cold temperature, germ line fitness and organismal longevity. We show that low temperature reduces age-associated exhaustion of germ stem cells (GSCs) in Caenorhabditis elegans, a process modulated by thermosensory neurons. Notably, robust self-renewal of adult GSCs delays reproductive aging and is required for extended lifespan at cold temperatures. These cells release prostaglandin E2 (PGE2) to induce cbs-1 expression in the intestine, increasing somatic production of hydrogen sulfide (H2S), a gaseous signaling molecule that prolongs lifespan. Whereas loss of adult GSCs reduces intestinal cbs-1 expression and cold-induced longevity, application of exogenous PGE2 rescues these phenotypes. Importantly, tissue-specific intestinal overexpression of cbs-1 mimics cold-temperature conditions and extends longevity even at warm temperatures. Thus, our results indicate that GSCs communicate with somatic tissues to coordinate extended reproductive capacity with longevity.
Collapse
Affiliation(s)
- Hyun Ju Lee
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Alireza Noormohammadi
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Seda Koyuncu
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Giuseppe Calculli
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Milos S Simic
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Marija Herholz
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Aleksandra Trifunovic
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
| |
Collapse
|
22
|
Booth LN, Maures TJ, Yeo RW, Tantilert C, Brunet A. Self-sperm induce resistance to the detrimental effects of sexual encounters with males in hermaphroditic nematodes. eLife 2019; 8:46418. [PMID: 31282863 PMCID: PMC6697445 DOI: 10.7554/elife.46418] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 07/02/2019] [Indexed: 12/19/2022] Open
Abstract
Sexual interactions have a potent influence on health in several species, including mammals. Previous work in C. elegans identified strategies used by males to accelerate the demise of the opposite sex (hermaphrodites). But whether hermaphrodites evolved counter-strategies against males remains unknown. Here we discover that young C. elegans hermaphrodites are remarkably resistant to brief sexual encounters with males, whereas older hermaphrodites succumb prematurely. Surprisingly, it is not their youthfulness that protects young hermaphrodites, but the fact that they have self-sperm. The beneficial effect of self-sperm is mediated by a sperm-sensing pathway acting on the soma rather than by fertilization. Activation of this pathway in females triggers protection from the negative impact of males. Interestingly, the role of self-sperm in protecting against the detrimental effects of males evolved independently in hermaphroditic nematodes. Endogenous strategies to delay the negative effect of mating may represent a key evolutionary innovation to maximize reproductive success. A nematode worm known as Caenorhabditis elegans is often used in the laboratory to study how animals grow and develop. There are two types of C. elegans worm: hermaphrodite individuals produce both female sex cells (eggs) and male sex cells (sperm), while male individuals only produce sperm. The hermaphrodite worms are able to reproduce without mating with another worm, allowing populations of C. elegans to grow rapidly when they are living in favorable conditions. However, when the hermaphrodites do mate with males they tend to produce more offspring. These offspring are also usually healthier because they receive a mixture of genetic material from two different parents. Although mating is beneficial for the survival of a species it can also harm an individual animal. Previous studies have shown that mating with male worms can accelerate aging of hermaphrodite worms and cause premature death. However, it remained unclear whether hermaphrodite worms have evolved any mechanisms to protect themselves after mating with a male. To address this question, Booth et al. used genetic techniques to study the lifespans of hermaphrodite worms. The experiments found that the hermaphrodites’ own sperm (known as self-sperm) regulated a sperm-sensing signaling pathway that protected them from the negative impact of mating with males. Hermaphrodites with self-sperm that mated with males lived for a similar length of time as hermaphrodites that did not mate. On the other hand, hermaphrodites that did not have self-sperm (because they were older or had a genetic mutation) had shorter lifespans after mating than worms that did not mate. Modulating the sperm-sensing signaling pathway in worms that lacked self-sperm was sufficient to protect them from the negative effects of mating with males. Further experiments found that the hermaphrodites of another nematode worm called C. briggsae – which evolved self-sperm independently of C. elegans – also protected themselves from the negative effects of mating with males in a similar way. This suggests that other animals may also have evolved similar mechanisms to protect themselves from harm when mating. A separate study by Shi et al. has found that the beneficial effects of self-sperm are mediated by a pathway linked to longevity that also exists in mammals. The results of both investigations combined suggest possible avenues for future research into the complex relationship between health, longevity, and reproduction.
Collapse
Affiliation(s)
- Lauren N Booth
- Department of Genetics, Stanford University, Stanford, United States
| | - Travis J Maures
- Department of Genetics, Stanford University, Stanford, United States
| | - Robin W Yeo
- Department of Genetics, Stanford University, Stanford, United States
| | - Cindy Tantilert
- Department of Genetics, Stanford University, Stanford, United States
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, United States.,Glenn Laboratories for the Biology of Aging at Stanford University, Stanford, United States
| |
Collapse
|
23
|
Suo S, Harada K, Matsuda S, Kyo K, Wang M, Maruyama K, Awaji T, Tsuboi T. Sexually Dimorphic Regulation of Behavioral States by Dopamine in Caenorhabditis elegans. J Neurosci 2019; 39:4668-4683. [PMID: 30988167 PMCID: PMC6561698 DOI: 10.1523/jneurosci.2985-18.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 11/21/2022] Open
Abstract
Sex differences in behavior allow animals to effectively mate and reproduce. However, the mechanism by which biological sex regulates behavioral states, which underlie the regulation of sex-shared behaviors, such as locomotion, is largely unknown. In this study, we studied sex differences in the behavioral states of Caenorhabditis elegans and found that males spend less time in a low locomotor activity state than hermaphrodites and that dopamine generates this sex difference. In males, dopamine reduces the low activity state by acting in the same pathway as polycystic kidney disease-related genes that function in male-specific neurons. In hermaphrodites, dopamine increases the low activity state by suppression of octopamine signaling in the sex-shared SIA neurons, which have reduced responsiveness to octopamine in males. Furthermore, dopamine promotes exploration both inside and outside of bacterial lawn (the food source) in males and suppresses it in hermaphrodites. These results demonstrate that sexually dimorphic signaling allows the same neuromodulator to promote adaptive behavior for each sex.SIGNIFICANCE STATEMENT The mechanisms that generate sex differences in sex-shared behaviors, including locomotion, are not well understood. We show that there are sex differences in the regulation of behavioral states in the model animal Caenorhabditis elegans Dopamine promotes the high locomotor activity state in males, which must search for mates to reproduce, and suppresses it in self-fertilizing hermaphrodites through distinct molecular mechanisms. This study demonstrates that sex-specific signaling generates sex differences in the regulation of behavioral states, which in turn modulates the locomotor activity to suit reproduction for each sex.
Collapse
Affiliation(s)
- Satoshi Suo
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan,
| | - Kazuki Harada
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 153-8902, Japan
| | - Shogo Matsuda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033, Japan, and
| | - Koki Kyo
- Department of Human Sciences, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, 080-8555, Japan
| | - Min Wang
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Kei Maruyama
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Takeo Awaji
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, 350-0495, Japan
| | - Takashi Tsuboi
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, 153-8902, Japan
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, 113-0033, Japan, and
| |
Collapse
|
24
|
Marsac R, Pinson B, Saint-Marc C, Olmedo M, Artal-Sanz M, Daignan-Fornier B, Gomes JE. Purine Homeostasis Is Necessary for Developmental Timing, Germline Maintenance and Muscle Integrity in Caenorhabditis elegans. Genetics 2019; 211:1297-1313. [PMID: 30700528 PMCID: PMC6456310 DOI: 10.1534/genetics.118.301062] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 01/24/2019] [Indexed: 12/12/2022] Open
Abstract
Purine homeostasis is ensured through a metabolic network widely conserved from prokaryotes to humans. Purines can either be synthesized de novo, reused, or produced by interconversion of extant metabolites using the so-called recycling pathway. Although thoroughly characterized in microorganisms, such as yeast or bacteria, little is known about regulation of the purine biosynthesis network in metazoans. In humans, several diseases are linked to purine metabolism through as yet poorly understood etiologies. Particularly, the deficiency in adenylosuccinate lyase (ADSL)-an enzyme involved both in the purine de novo and recycling pathways-causes severe muscular and neuronal symptoms. In order to address the mechanisms underlying this deficiency, we established Caenorhabditis elegans as a metazoan model organism to study purine metabolism, while focusing on ADSL. We show that the purine biosynthesis network is functionally conserved in C. elegans Moreover, adsl-1 (the gene encoding ADSL in C. elegans) is required for developmental timing, germline stem cell maintenance and muscle integrity. Importantly, these traits are not affected when solely the de novo pathway is abolished, and we present evidence that germline maintenance is linked specifically to ADSL activity in the recycling pathway. Hence, our results allow developmental and tissue specific phenotypes to be ascribed to separable steps of the purine metabolic network in an animal model.
Collapse
Affiliation(s)
- Roxane Marsac
- Institut de Biochimie et Génétique Cellulaires, Université de Bordeaux and CNRS UMR5095, 33077 Bordeaux cedex, France
| | - Benoît Pinson
- Institut de Biochimie et Génétique Cellulaires, Université de Bordeaux and CNRS UMR5095, 33077 Bordeaux cedex, France
| | - Christelle Saint-Marc
- Institut de Biochimie et Génétique Cellulaires, Université de Bordeaux and CNRS UMR5095, 33077 Bordeaux cedex, France
| | - María Olmedo
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Department of Molecular Biology and Biochemical Engineering, 41013 Seville, Spain
| | - Marta Artal-Sanz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Department of Molecular Biology and Biochemical Engineering, 41013 Seville, Spain
| | - Bertrand Daignan-Fornier
- Institut de Biochimie et Génétique Cellulaires, Université de Bordeaux and CNRS UMR5095, 33077 Bordeaux cedex, France
| | - José-Eduardo Gomes
- Institut de Biochimie et Génétique Cellulaires, Université de Bordeaux and CNRS UMR5095, 33077 Bordeaux cedex, France
| |
Collapse
|
25
|
Memar N, Schiemann S, Hennig C, Findeis D, Conradt B, Schnabel R. Twenty million years of evolution: The embryogenesis of four Caenorhabditis species are indistinguishable despite extensive genome divergence. Dev Biol 2019; 447:182-199. [DOI: 10.1016/j.ydbio.2018.12.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022]
|
26
|
Roy D, Kahler DJ, Yun C, Hubbard EJA. Functional Interactions Between rsks-1/S6K, glp-1/Notch, and Regulators of Caenorhabditis elegans Fertility and Germline Stem Cell Maintenance. G3 (BETHESDA, MD.) 2018; 8:3293-3309. [PMID: 30126834 PMCID: PMC6169383 DOI: 10.1534/g3.118.200511] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/06/2018] [Indexed: 12/17/2022]
Abstract
The proper accumulation and maintenance of stem cells is critical for organ development and homeostasis. The Notch signaling pathway maintains stem cells in diverse organisms and organ systems. In Caenorhabditis elegans, GLP-1/Notch activity prevents germline stem cell (GSC) differentiation. Other signaling mechanisms also influence the maintenance of GSCs, including the highly-conserved TOR substrate ribosomal protein S6 kinase (S6K). Although C. elegans bearing either a null mutation in rsks-1/S6K or a reduction-of-function (rf) mutation in glp-1/Notch produce half the normal number of adult germline progenitors, virtually all these single mutant animals are fertile. However, glp-1(rf) rsks-1(null) double mutant animals are all sterile, and in about half of their gonads, all GSCs differentiate, a distinctive phenotype associated with a significant reduction or loss of GLP-1 signaling. How rsks-1/S6K promotes GSC fate is unknown. Here, we determine that rsks-1/S6K acts germline-autonomously to maintain GSCs, and that it does not act through Cyclin-E or MAP kinase in this role. We found that interfering with translation also enhances glp-1(rf), but that regulation through rsks-1 cannot fully account for this effect. In a genome-scale RNAi screen for genes that act similarly to rsks-1/S6K, we identified 56 RNAi enhancers of glp-1(rf) sterility, many of which were previously not known to interact functionally with Notch. Further investigation revealed at least six candidates that, by genetic criteria, act linearly with rsks-1/S6K. These include genes encoding translation-related proteins, cacn-1/Cactin, an RNA exosome component, and a Hedgehog-related ligand. We found that additional Hedgehog-related ligands may share functional relationships with glp-1/Notch and rsks-1/S6K in maintaining germline progenitors.
Collapse
Affiliation(s)
- Debasmita Roy
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016
| | - David J Kahler
- NYU High Throughput Biology Laboratory, NYU Langone Health, New York, NY 10016
| | - Chi Yun
- NYU High Throughput Biology Laboratory, NYU Langone Health, New York, NY 10016
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016
| |
Collapse
|
27
|
Gutnik S, Thomas Y, Guo Y, Stoecklin J, Neagu A, Pintard L, Merlet J, Ciosk R. PRP-19, a conserved pre-mRNA processing factor and E3 ubiquitin ligase, inhibits the nuclear accumulation of GLP-1/Notch intracellular domain. Biol Open 2018; 7:bio034066. [PMID: 30012553 PMCID: PMC6078339 DOI: 10.1242/bio.034066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/15/2018] [Indexed: 01/13/2023] Open
Abstract
The Notch signalling pathway is a conserved and widespread signalling paradigm, and its misregulation has been implicated in numerous disorders, including cancer. The output of Notch signalling depends on the nuclear accumulation of the Notch receptor intracellular domain (ICD). Using the Caenorhabditis elegans germline, where GLP-1/Notch-mediated signalling is essential for maintaining stem cells, we monitored GLP-1 in vivo We found that the nuclear enrichment of GLP-1 ICD is dynamic: while the ICD is enriched in germ cell nuclei during larval development, it is depleted from the nuclei in adult germlines. We found that this pattern depends on the ubiquitin proteolytic system and the splicing machinery and, identified the splicing factor PRP-19 as a candidate E3 ubiquitin ligase required for the nuclear depletion of GLP-1 ICD.
Collapse
Affiliation(s)
- Silvia Gutnik
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Yann Thomas
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Yanwu Guo
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Janosch Stoecklin
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Anca Neagu
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Lionel Pintard
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Jorge Merlet
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, UMR 7622, F-75005 Paris, France
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| |
Collapse
|
28
|
Favarolo MB, López SL. Notch signaling in the division of germ layers in bilaterian embryos. Mech Dev 2018; 154:122-144. [PMID: 29940277 DOI: 10.1016/j.mod.2018.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/08/2018] [Accepted: 06/18/2018] [Indexed: 01/09/2023]
Abstract
Bilaterian embryos are triploblastic organisms which develop three complete germ layers (ectoderm, mesoderm, and endoderm). While the ectoderm develops mainly from the animal hemisphere, there is diversity in the location from where the endoderm and the mesoderm arise in relation to the animal-vegetal axis, ranging from endoderm being specified between the ectoderm and mesoderm in echinoderms, and the mesoderm being specified between the ectoderm and the endoderm in vertebrates. A common feature is that part of the mesoderm segregates from an ancient bipotential endomesodermal domain. The process of segregation is noisy during the initial steps but it is gradually refined. In this review, we discuss the role of the Notch pathway in the establishment and refinement of boundaries between germ layers in bilaterians, with special focus on its interaction with the Wnt/β-catenin pathway.
Collapse
Affiliation(s)
- María Belén Favarolo
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Facultad de Medicina, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina
| | - Silvia L López
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Facultad de Medicina, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina.
| |
Collapse
|
29
|
Pu M, Wang M, Wang W, Velayudhan SS, Lee SS. Unique patterns of trimethylation of histone H3 lysine 4 are prone to changes during aging in Caenorhabditis elegans somatic cells. PLoS Genet 2018; 14:e1007466. [PMID: 29912876 PMCID: PMC6023244 DOI: 10.1371/journal.pgen.1007466] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 06/28/2018] [Accepted: 06/02/2018] [Indexed: 11/18/2022] Open
Abstract
Tri-methylation on histone H3 lysine 4 (H3K4me3) is associated with active gene expression but its regulatory role in transcriptional activation is unclear. Here we used Caenorhabditis elegans to investigate the connection between H3K4me3 and gene expression regulation during aging. We uncovered around 30% of H3K4me3 enriched regions to show significant and reproducible changes with age. We further showed that these age-dynamic H3K4me3 regions largely mark gene-bodies and are acquired during adult stages. We found that these adult-specific age-dynamic H3K4me3 regions are correlated with gene expression changes with age. In contrast, H3K4me3 marking established during developmental stages remained largely stable with age, even when the H3K4me3 associated genes exhibited RNA expression changes during aging. Importantly, the genes associated with changes in H3K4me3 and RNA levels with age are enriched for functional groups commonly implicated in aging biology. Therefore, our findings suggested divergent roles of H3K4me3 in gene expression regulation during aging, with important implications on aging-dependent pathophysiologies. Histone modifications, the specific chemical modifications on histone proteins, are key for regulating the packing of DNA, and thus have important influence on diverse biological processes. An intensely studied function of histone modifications is their contribution to regulating gene expression. Recent studies in diverse model organisms demonstrated that the global alterations of particular histone modifications, for instance H3K4me3, extend the lifespan of the organism. However, the underlying molecular mechanisms remain largely unclear. In this study, we monitored whether and how the genome-wide pattern of the histone modification H3K4me3 changes during aging in the somatic cells of the model organism C. elegans. We identified interesting and non-conventional patterns of H3K4me3, which span gene-bodies and are acquired during adulthood, that are particularly prone to changes with aging. This is contrasted to the well-studied H3K4me3 patterns that span transcriptional start sites and 5’ promoter regions and are established early during development, which remain stable with age. Consistent with the close association between H3K4me3 marking and active transcription, we observed that the age-dynamic H3K4me3 markings are highly correlated with corresponding RNA expression changes. Importantly, the genes that are associated with both H3K4me3 and RNA expression changes with age are over-represented for functional groups commonly implicated in aging biology. In summary, our findings revealed a lesser known pattern of H3K4me3 modification that can have important biological roles in aging.
Collapse
Affiliation(s)
- Mintie Pu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
- * E-mail: (MP); (SSL)
| | - Minghui Wang
- Computational Biology Service Unit, Cornell University, Ithaca, New York City, United States of America
| | - Wenke Wang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
| | - Satheeja Santhi Velayudhan
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
| | - Siu Sylvia Lee
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York City, United States of America
- * E-mail: (MP); (SSL)
| |
Collapse
|
30
|
Host-mediated RNAi of a Notch-like receptor gene in Meloidogyne incognita induces nematode resistance. Parasitology 2018; 145:1896-1906. [PMID: 29692277 DOI: 10.1017/s0031182018000641] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
GLP-1 (abnormal germline proliferation) is a Notch-like receptor protein that plays an essential role in pharyngeal development. In this study, an orthologue of Caenorhabditis elegans glp-1 was identified in Meloidogyne incognita. A computational analysis revealed that the orthologue contained almost all the domains present in the C. elegans gene: specifically, the LIN-12/Notch repeat, the ankyrin repeat, a transmembrane domain and different ligand-binding motifs were present in orthologue, but the epidermal growth factor-like motif was not observed. An expression analysis showed differential expression of glp-1 throughout the life cycle of M. incognita, with relatively higher expression in the egg stage. To evaluate the silencing efficacy of Mi-glp-1, transgenic Arabidopsis plants carrying double-stranded RNA constructs of glp-1 were generated, and infection of these plants with M. incognita resulted in a 47-50% reduction in the numbers of galls, females and egg masses. Females obtained from the transgenic RNAi lines exhibited 40-60% reductions in the transcript levels of the targeted glp-1 gene compared with females isolated from the control plants. Second-generation juveniles (J2s), which were descendants of the infected females from the transgenic lines, showed aberrant phenotypes. These J2s exhibited a significant decrease in the overall distance from the stylet to the metacorpus region, and this effect was accompanied by disruption around the metacorporeal bulb of the pharynx. The present study suggests a role for this gene in organ (pharynx) development during embryogenesis in M. incognita and its potential use as a target in the management of nematode infestations in plants.
Collapse
|
31
|
Webster CM, Pino EC, Carr CE, Wu L, Zhou B, Cedillo L, Kacergis MC, Curran SP, Soukas AA. Genome-wide RNAi Screen for Fat Regulatory Genes in C. elegans Identifies a Proteostasis-AMPK Axis Critical for Starvation Survival. Cell Rep 2018; 20:627-640. [PMID: 28723566 DOI: 10.1016/j.celrep.2017.06.068] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 05/11/2017] [Accepted: 06/22/2017] [Indexed: 12/26/2022] Open
Abstract
Organisms must execute metabolic defenses to survive nutrient deprivation. We performed a genome-wide RNAi screen in Caenorhabditis elegans to identify fat regulatory genes indispensable for starvation resistance. Here, we show that opposing proteostasis pathways are principal determinants of starvation survival. Reduced function of cytoplasmic aminoacyl tRNA synthetases (ARS genes) increases fat mass and extends starvation survival, whereas reduced proteasomal function reduces fat and starvation survival. These opposing pathways converge on AMP-activated protein kinase (AMPK) as the critical effector of starvation defenses. Extended starvation survival in ARS deficiency is dependent upon increased proteasome-mediated activation of AMPK. When the proteasome is inhibited, neither starvation nor ARS deficiency can fully activate AMPK, leading to greatly diminished starvation survival. Thus, activity of the proteasome and AMPK are mechanistically linked and highly correlated with starvation resistance. Conversely, aberrant activation of the proteostasis-AMPK axis during nutritional excess may have implications for obesity and cardiometabolic diseases.
Collapse
Affiliation(s)
- Christopher M Webster
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Elizabeth C Pino
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Christopher E Carr
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Lianfeng Wu
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Ben Zhou
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Lucydalila Cedillo
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Graduate Program in Biomedical and Biological Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Michael C Kacergis
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Sean P Curran
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Alexander A Soukas
- Department of Medicine, Center for Genomic Medicine and Diabetes Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| |
Collapse
|
32
|
Gengnianchun Extends the Lifespan of Caenorhabditis elegans via the Insulin/IGF-1 Signalling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:4740739. [PMID: 29670680 PMCID: PMC5835280 DOI: 10.1155/2018/4740739] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/18/2017] [Indexed: 12/29/2022]
Abstract
Gengnianchun (GNC), a traditional Chinese medicine (TCM), is believed to have beneficial effects on ageing-related diseases, such as antioxidant properties and effects against Aβ-induced toxicity. We previously found that GNC extended the lifespan of Caenorhabditis elegans. However, the mechanism underlying this effect was unclear. In this study, we further explored the mechanisms of GNC using a C. elegans model. GNC significantly increased the lifespan of C. elegans and enhanced oxidative and thermal stress resistance. Moreover, chemotaxis increased after GNC treatment. RNA-seq analysis showed that GNC regulated genes associated with longevity. We also conducted lifespan assays with a series of worm mutants. The results showed that GNC significantly extended the lifespan of several mutant strains, including eat-2 (ad465), rsks-1 (ok1255), and glp-1 (e2144), suggesting that the prolongevity effect of GNC is independent of the function of these genes. However, GNC failed to extend the lifespan of daf-2 (e1370), age-1 (hx546), and daf-16 (mu86) mutant strains. Our findings suggest that GNC extends the lifespan of C. elegans via the insulin/IGF-1 signalling pathway and may be a potential antiageing agent.
Collapse
|
33
|
Spickard EA, Joshi PM, Rothman JH. The multipotency-to-commitment transition in Caenorhabditis elegans-implications for reprogramming from cells to organs. FEBS Lett 2018; 592:838-851. [PMID: 29334121 DOI: 10.1002/1873-3468.12977] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/22/2017] [Accepted: 01/11/2018] [Indexed: 12/13/2022]
Abstract
In animal embryos, cells transition from a multipotential state, with the capacity to adopt multiple fates, into an irreversible, committed state of differentiation. This multipotency-to-commitment transition (MCT) is evident from experiments in which cell fate is reprogrammed by transcription factors for cell type-specific differentiation, as has been observed extensively in Caenorhabditis elegans. Although factors that direct differentiation into each of the three germ layer types cannot generally reprogram cells after the MCT in this animal, transcription factors for endoderm development are able to do so in multiple differentiated cell types. In one case, these factors can redirect the development of an entire organ in the process of "transorganogenesis". Natural transdifferentiation also occurs in a small number of differentiated cells during normal C. elegans development. We review these reprogramming and transdifferentiation events, highlighting the cellular and developmental contexts in which they occur, and discuss common themes underlying direct cell lineage reprogramming. Although certain aspects may be unique to the model system, growing evidence suggests that some mechanisms are evolutionarily conserved and may shed light on cellular plasticity and disease in humans.
Collapse
Affiliation(s)
- Erik A Spickard
- Department of MCD Biology and Neuroscience Research Institute, University of California Santa Barbara, CA, USA
| | - Pradeep M Joshi
- Department of MCD Biology and Neuroscience Research Institute, University of California Santa Barbara, CA, USA
| | - Joel H Rothman
- Department of MCD Biology and Neuroscience Research Institute, University of California Santa Barbara, CA, USA
| |
Collapse
|
34
|
McGovern M, Castaneda PG, Pekar O, Vallier LG, Cram EJ, Hubbard EJA. The DSL ligand APX-1 is required for normal ovulation in C. elegans. Dev Biol 2018; 435:162-169. [PMID: 29371032 DOI: 10.1016/j.ydbio.2018.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/14/2017] [Accepted: 01/11/2018] [Indexed: 01/13/2023]
Abstract
DSL ligands activate the Notch receptor in many cellular contexts across metazoa to specify cell fate. In addition, Notch receptor activity is implicated in post-mitotic morphogenesis and neuronal function. In C. elegans, the DSL family ligand APX-1 is expressed in a subset of cells of the proximal gonad lineage, where it can act as a latent proliferation-promoting signal to maintain proximal germline tumors. Here we examine apx-1 in the proximal gonad and uncover a role in the maintenance of normal ovulation. Depletion of apx-1 causes an endomitotic oocyte (Emo) phenotype and ovulation defects. We find that lag-2 can substitute for apx-1 in this role, that the ovulation defect is partially suppressed by loss of ipp-5, and that lin-12 depletion causes a similar phenotype. In addition, we find that the ovulation defects are often accompanied by a delay of spermathecal distal neck closure after oocyte entry. Although calcium oscillations occur in the spermatheca, calcium signals are abnormal when the distal neck does not close completely. Moreover, oocytes sometimes cannot properly transit through the spermatheca, leading to fragmentation of oocytes once the neck closes. Finally, abnormal oocytes and neck closure defects are seen occasionally when apx-1 or lin-12 activity is reduced in adult animals, suggesting a possible post-developmental role for APX-1 and LIN-12 signaling in ovulation.
Collapse
Affiliation(s)
- Marie McGovern
- Department of Biological Sciences, Kingsborough Community College, City University of New York, 2001 Oriental Blvd, Brooklyn, NY 11235, United States; Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, United States
| | | | - Olga Pekar
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, United States
| | - Laura G Vallier
- Department of Biology, Hofstra University, Hempstead, NY 11549, United States
| | - Erin J Cram
- Department of Biology, Northeastern University, Boston, MA 02115, United States
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, United States.
| |
Collapse
|
35
|
Murray JI. Systems biology of embryonic development: Prospects for a complete understanding of the Caenorhabditis elegans embryo. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e314. [PMID: 29369536 DOI: 10.1002/wdev.314] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/01/2017] [Accepted: 12/12/2017] [Indexed: 01/07/2023]
Abstract
The convergence of developmental biology and modern genomics tools brings the potential for a comprehensive understanding of developmental systems. This is especially true for the Caenorhabditis elegans embryo because its small size, invariant developmental lineage, and powerful genetic and genomic tools provide the prospect of a cellular resolution understanding of messenger RNA (mRNA) expression and regulation across the organism. We describe here how a systems biology framework might allow large-scale determination of the embryonic regulatory relationships encoded in the C. elegans genome. This framework consists of two broad steps: (a) defining the "parts list"-all genes expressed in all cells at each time during development and (b) iterative steps of computational modeling and refinement of these models by experimental perturbation. Substantial progress has been made towards defining the parts list through imaging methods such as large-scale green fluorescent protein (GFP) reporter analysis. Imaging results are now being augmented by high-resolution transcriptome methods such as single-cell RNA sequencing, and it is likely the complete expression patterns of all genes across the embryo will be known within the next few years. In contrast, the modeling and perturbation experiments performed so far have focused largely on individual cell types or genes, and improved methods will be needed to expand them to the full genome and organism. This emerging comprehensive map of embryonic expression and regulatory function will provide a powerful resource for developmental biologists, and would also allow scientists to ask questions not accessible without a comprehensive picture. This article is categorized under: Invertebrate Organogenesis > Worms Technologies > Analysis of the Transcriptome Gene Expression and Transcriptional Hierarchies > Gene Networks and Genomics.
Collapse
Affiliation(s)
- John Isaac Murray
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| |
Collapse
|
36
|
Dottermusch M, Lakner T, Peyman T, Klein M, Walz G, Neumann-Haefelin E. Cell cycle controls stress response and longevity in C. elegans. Aging (Albany NY) 2017; 8:2100-2126. [PMID: 27668945 PMCID: PMC5076454 DOI: 10.18632/aging.101052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/09/2016] [Indexed: 12/30/2022]
Abstract
Recent studies have revealed a variety of genes and mechanisms that influence the rate of aging progression. In this study, we identified cell cycle factors as potent regulators of health and longevity in C. elegans. Focusing on the cyclin-dependent kinase 2 (cdk-2) and cyclin E (cye-1), we show that inhibition of cell cycle genes leads to tolerance towards environmental stress and longevity. The reproductive system is known as a key regulator of longevity in C. elegans. We uncovered the gonad as the central organ mediating the effects of cell cycle inhibition on lifespan. In particular, the proliferating germ cells were essential for conferring longevity. Steroid hormone signaling and the FOXO transcription factor DAF-16 were required for longevity associated with cell cycle inhibition. Furthermore, we discovered that SKN-1 (ortholog of mammalian Nrf proteins) activates protective gene expression and induces longevity when cell cycle genes are inactivated. We conclude that both, germline absence and inhibition through impairment of cell cycle machinery results in longevity through similar pathways. In addition, our studies suggest further roles of cell cycle genes beyond cell cycle progression and support the recently described connection of SKN-1/Nrf to signals deriving from the germline.
Collapse
Affiliation(s)
- Matthias Dottermusch
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Germany
| | - Theresa Lakner
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Germany
| | - Tobias Peyman
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Germany
| | - Marinella Klein
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Germany
| | - Gerd Walz
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Germany
| | - Elke Neumann-Haefelin
- Department of Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Germany
| |
Collapse
|
37
|
Flamand MN, Gan HH, Mayya VK, Gunsalus KC, Duchaine TF. A non-canonical site reveals the cooperative mechanisms of microRNA-mediated silencing. Nucleic Acids Res 2017; 45:7212-7225. [PMID: 28482037 PMCID: PMC5499589 DOI: 10.1093/nar/gkx340] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/18/2017] [Indexed: 01/08/2023] Open
Abstract
Although strong evidence supports the importance of their cooperative interactions, microRNA (miRNA)-binding sites are still largely investigated as functionally independent regulatory units. Here, a survey of alternative 3΄UTR isoforms implicates a non-canonical seedless site in cooperative miRNA-mediated silencing. While required for target mRNA deadenylation and silencing, this site is not sufficient on its own to physically recruit miRISC. Instead, it relies on facilitating interactions with a nearby canonical seed-pairing site to recruit the Argonaute complexes. We further show that cooperation between miRNA target sites is necessary for silencing in vivo in the C. elegans embryo, and for the recruitment of the Ccr4-Not effector complex. Using a structural model of cooperating miRISCs, we identified allosteric determinants of cooperative miRNA-mediated silencing that are required for both embryonic and larval miRNA functions. Our results delineate multiple cooperative mechanisms in miRNA-mediated silencing and further support the consideration of target site cooperation as a fundamental characteristic of miRNA function.
Collapse
Affiliation(s)
- Mathieu N Flamand
- Department of Biochemistry & Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3G 1Y6 Canada
| | - Hin Hark Gan
- Center for Genomics and Systems Biology, Department of Biology, New York University, 12 Waverly Place, New York, NY 10003, USA
| | - Vinay K Mayya
- Department of Biochemistry & Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3G 1Y6 Canada
| | - Kristin C Gunsalus
- Center for Genomics and Systems Biology, Department of Biology, New York University, 12 Waverly Place, New York, NY 10003, USA.,Division of Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Thomas F Duchaine
- Department of Biochemistry & Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3G 1Y6 Canada
| |
Collapse
|
38
|
Minkina O, Hunter CP. Stable Heritable Germline Silencing Directs Somatic Silencing at an Endogenous Locus. Mol Cell 2017; 65:659-670.e5. [PMID: 28212751 DOI: 10.1016/j.molcel.2017.01.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/27/2016] [Accepted: 01/09/2017] [Indexed: 12/19/2022]
Abstract
The importance of transgenerationally inherited epigenetic states to organismal fitness remains unknown as well-documented examples are often not amenable to mechanistic analysis or rely on artificial reporter loci. Here we describe an induced silenced state at an endogenous locus that persists, at 100% transmission without selection, for up to 13 generations. This unusually persistent silencing enables a detailed molecular genetic analysis of an inherited epigenetic state. We find that silencing is dependent on germline nuclear RNAi factors and post-transcriptional mechanisms. Consistent with these later observations, inheritance does not require the silenced locus, and we provide genetic evidence that small RNAs embody the inherited silencing signal. Notably, heritable germline silencing directs somatic epigenetic silencing. Somatic silencing does not require somatic nuclear RNAi but instead requires both maternal germline nuclear RNAi and chromatin-modifying activity. Coupling inherited germline silencing to somatic silencing may enable selection for physiologically important traits.
Collapse
Affiliation(s)
- Olga Minkina
- 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.
| |
Collapse
|
39
|
The anti-aging and anti-oxidation effects of tea water extract in Caenorhabditis elegans. Exp Gerontol 2017; 97:89-96. [PMID: 28750751 DOI: 10.1016/j.exger.2017.07.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 03/30/2017] [Accepted: 07/24/2017] [Indexed: 12/12/2022]
Abstract
Tea includes puer tea, black tea, green tea and many others. By using model organism Caenorhabditis elegans, the anti-aging and anti-oxidation effects of tea water extract were systemically examined in this study. We found that water extract of puer tea, black tea and green tea all increased the lifespan of worms, postponed Aβ-induced progressive paralysis in Alzheimer's disease transgenic worms, and improved the tolerance of worms to the oxidative stress induced by heavy metal Cr6+. Moreover, the anti-oxidation effects of tea water extract at low concentration were different among 4 kinds of brands of green tea. The underlying mechanisms were further explored using genetically manipulated-mutant worms. The anti-oxidative stress effects of green tea water extract depend on the dietary restriction and germline signaling pathways, but not the FOXO and mitochondrial respiratory chain signals. Therefore, tea water extract provides benefits of anti-aging, anti-AD and anti-oxidation.
Collapse
|
40
|
Abstract
Many stem cell niches contain support cells that increase contact with stem cells by enwrapping them in cellular processes. One example is the germ stem cell niche in C. elegans, which is composed of a single niche cell termed the distal tip cell (DTC) that extends cellular processes, constructing an elaborate plexus that enwraps germ stem cells. To identify genes required for plexus formation and to explore the function of this specialized enwrapping behavior, a series of targeted and tissue-specific RNAi screens were performed. Here we identify genes that promote stem cell enwrapment by the DTC plexus, including a set that specifically functions within the DTC, such as the chromatin modifier lin-40/MTA1, and others that act within the germline, such as the 14-3-3 signaling protein par-5. Analysis of genes that function within the germline to mediate plexus development reveal that they are required for expansion of the germ progenitor zone, supporting the emerging idea that germ stem cells signal to the niche to stimulate enwrapping behavior. Examination of wild-type animals with asymmetric plexus formation and animals with reduced DTC plexus elaboration via loss of two candidates including lin-40 indicate that cellular enwrapment promotes GLP-1/Notch signaling and germ stem cell fate. Together, our work identifies novel regulators of cellular enwrapment and suggests that reciprocal signaling between the DTC niche and the germ stem cells promotes enwrapment behavior and stem cell fate.
Collapse
|
41
|
Wan QL, Shi X, Liu J, Ding AJ, Pu YZ, Li Z, Wu GS, Luo HR. Metabolomic signature associated with reproduction-regulated aging in Caenorhabditis elegans. Aging (Albany NY) 2017; 9:447-474. [PMID: 28177875 PMCID: PMC5361674 DOI: 10.18632/aging.101170] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 01/31/2017] [Indexed: 12/15/2022]
Abstract
In Caenorhabditis elegans (C. elegans), ablation of germline stem cells (GSCs) leads to infertility, which extends lifespan. It has been reported that aging and reproduction are both inextricably associated with metabolism. However, few studies have investigated the roles of polar small molecules metabolism in regulating longevity by reproduction. In this work, we combined the nuclear magnetic resonance (NMR) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) to profile the water-soluble metabolome in C. elegans. Comparing the metabolic fingerprint between two physiological ages among different mutants, our results demonstrate that aging is characterized by metabolome remodeling and metabolic decline. In addition, by analyzing the metabolic profiles of long-lived germline-less glp-1 mutants, we discovered that glp-1 mutants regulate the levels of many age-variant metabolites to attenuate aging, including elevated concentrations of the pyrimidine and purine metabolism intermediates and decreased concentrations of the citric acid cycle intermediates. Interestingly, by analyzing the metabolome of daf-16;glp-1 double mutants, our results revealed that some metabolic exchange contributing to germline-mediated longevity was mediated by transcription factor FOXO/DAF-16, including pyrimidine metabolism and the TCA cycle. Based on a comprehensive metabolic analysis, we provide novel insight into the relationship between longevity and metabolism regulated by germline signals in C. elegans.
Collapse
Affiliation(s)
- Qin-Li Wan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- University of Chinese Academy of Sciences, Beijing 100039, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
| | - Xiaohuo Shi
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
| | - Jiangxin Liu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
| | - Ai-Jun Ding
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- University of Chinese Academy of Sciences, Beijing 100039, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
| | - Yuan-Zhu Pu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- University of Chinese Academy of Sciences, Beijing 100039, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
| | - Zhigang Li
- Shineway Pharmaceutical Co., Ltd, Sanhe, Hebei 065201, China
| | - Gui-Sheng Wu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Huai-Rong Luo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
- Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming, Yunnan 650201, China
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| |
Collapse
|
42
|
Robertson SM, Medina J, Oldenbroek M, Lin R. Reciprocal signaling by Wnt and Notch specifies a muscle precursor in the C. elegans embryo. Development 2017; 144:419-429. [PMID: 28049659 DOI: 10.1242/dev.145391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/12/2016] [Indexed: 11/20/2022]
Abstract
The MS blastomere produces one-third of the body wall muscles (BWMs) in the C. elegans embryo. MS-derived BWMs require two distinct cell-cell interactions, the first inhibitory and the second, two cell cycles later, required to overcome this inhibition. The inductive interaction is not required if the inhibitory signal is absent. Although the Notch receptor GLP-1 was implicated in both interactions, the molecular nature of the two signals was unknown. We now show that zygotically expressed MOM-2 (Wnt) is responsible for both interactions. Both the inhibitory and the activating interactions require precise spatiotemporal expression of zygotic MOM-2, which is dependent upon two distinct Notch signals. In a Notch mutant defective only in the inductive interaction, MS-derived BWMs can be restored by preventing zygotic MOM-2 expression, which removes the inhibitory signal. Our results suggest that the inhibitory interaction ensures the differential lineage specification of MS and its sister blastomere, whereas the inductive interaction promotes the expression of muscle-specifying genes by modulating TCF and β-catenin levels. These results highlight the complexity of cell fate specification by cell-cell interactions in a rapidly dividing embryo.
Collapse
Affiliation(s)
- Scott M Robertson
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jessica Medina
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Marieke Oldenbroek
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rueyling Lin
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| |
Collapse
|
43
|
Abstract
The nematode Caenorhabditis elegans is a simple metazoan animal that is widely used as a model to understand the genetic control of development. The completely sequenced C. elegans genome contains 22 T-box genes, and they encode factors that show remarkable diversity in sequence, DNA-binding specificity, and function. Only three of the C. elegans T-box factors can be grouped into the conserved subfamilies found in other organisms, while the remaining factors are significantly diverged and unlike those in most other animals. While some of the C. elegans factors can bind canonical T-box binding elements, others bind and regulate target gene expression through distinct sequences. The nine genetically characterized T-box factors have varied functions in development and morphogenesis of muscle, hypodermal tissues, and neurons, as well as in early blastomere fate specification, cell migration, apoptosis, and sex determination, but the functions of most of the C. elegans T-box factors have not yet been extensively characterized. Like T-box factors in other animals, interaction with a Groucho-family corepressor and posttranslational SUMOylation have been shown to affect C. elegans T-box factor activity, and it is likely that additional mechanisms affecting T-box factor activity will be discovered using the effective genetic approaches in this organism.
Collapse
|
44
|
Microsporidia Intracellular Development Relies on Myc Interaction Network Transcription Factors in the Host. G3-GENES GENOMES GENETICS 2016; 6:2707-16. [PMID: 27402359 PMCID: PMC5015929 DOI: 10.1534/g3.116.029983] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Microsporidia are ubiquitous parasites that infect a wide range of animal hosts, and these fungal-related microbes undergo their entire replicative lifecycle inside of host cells. Despite being widespread in the environment and causing medical and agricultural harm, virtually nothing is known about the host factors important to facilitate their growth and development inside of host cells. Here, we perform a genetic screen to identify host transcription factors important for development of the microsporidian pathogen Nematocida parisii inside intestinal cells of its natural host, the nematode Caenorhabditis elegans. Through this screen, we identified the C. elegans Myc family of transcription factors as key host regulators of microsporidia growth and development. The Mad-like transcription factor MDL-1, and the Max-like transcription factors MXL-1 and MXL-2 promote pathogen levels, while the Myc-Mondo-like transcription factor MML-1 inhibits pathogen levels. We used epistasis analysis to show that MDL-1 and MXL-1, which are thought to function as a heterodimer, appear to be acting canonically. In contrast, MXL-2 and MML-1, which are also thought to function as a heterodimer, appear to be acting in separate pathways (noncanonically) in the context of pathogen infection. We also found that both MDL-1::GFP and MML-1::GFP are expressed in intestinal cells during infection. These findings provide novel insight into the host transcription factors that regulate microsporidia development.
Collapse
|
45
|
Seelk S, Adrian-Kalchhauser I, Hargitai B, Hajduskova M, Gutnik S, Tursun B, Ciosk R. Increasing Notch signaling antagonizes PRC2-mediated silencing to promote reprograming of germ cells into neurons. eLife 2016; 5. [PMID: 27602485 PMCID: PMC5045294 DOI: 10.7554/elife.15477] [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: 02/23/2016] [Accepted: 09/06/2016] [Indexed: 12/12/2022] Open
Abstract
Cell-fate reprograming is at the heart of development, yet very little is known about the molecular mechanisms promoting or inhibiting reprograming in intact organisms. In the C. elegans germline, reprograming germ cells into somatic cells requires chromatin perturbation. Here, we describe that such reprograming is facilitated by GLP-1/Notch signaling pathway. This is surprising, since this pathway is best known for maintaining undifferentiated germline stem cells/progenitors. Through a combination of genetics, tissue-specific transcriptome analysis, and functional studies of candidate genes, we uncovered a possible explanation for this unexpected role of GLP-1/Notch. We propose that GLP-1/Notch promotes reprograming by activating specific genes, silenced by the Polycomb repressive complex 2 (PRC2), and identify the conserved histone demethylase UTX-1 as a crucial GLP-1/Notch target facilitating reprograming. These findings have wide implications, ranging from development to diseases associated with abnormal Notch signaling. DOI:http://dx.doi.org/10.7554/eLife.15477.001 The DNA in genes encodes the basic information needed to build an organism or control its day-to-day operations. Most cells in an organism contain the same genetic information, but different types of cell use the information differently. For example, many of the genes that are active in a muscle cell are different from those that are active in a skin cell. These different patterns of gene activation largely determine a cell’s identity and are brought about by DNA-binding proteins or chemical modifications to the DNA (which are both forms of so-called epigenetic regulation). Nevertheless, cells occasionally change their identities – a phenomenon that is referred to as reprograming. This process allows tissues to be regenerated after wounding, but, due to technical difficulties, reprograming has been often studied in isolated cells grown in a dish. Seelk, Adrian-Kalchhauser et al. set out to understand how being surrounded by intact tissue influences reprograming. The experiments made use of C. elegans worms, because disturbing how this worm’s DNA is packaged can trigger its cells to undergo reprograming. Seelk, Adrian-Kalchhauser et al. show that a signaling pathway that is found in many different animals enhances this kind of reprograming in C. elegans. On the one hand, these findings help in understanding how epigenetic regulation can be altered by a specific tissue environment. On the other hand, the findings also suggest that abnormal signaling can result in altered epigenetic control of gene expression and lead to cells changing their identity. Indeed, increased signaling is linked to a major epigenetic mechanism seen in specific blood tumors, suggesting that the regulatory principles uncovered using this simple worm model could eventually provide insights into a human disease. A future challenge will be to determine precisely how the studied signaling pathway interacts with the epigenetic regulator that controls reprograming. Understanding this interaction in molecular detail could help to devise strategies for controlling reprograming. These strategies could in turn lead to treatments for people with conditions that cause specific cells types to be lost, such as Alzheimer’s disease or injuries. DOI:http://dx.doi.org/10.7554/eLife.15477.002
Collapse
Affiliation(s)
- Stefanie Seelk
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | | | - Balázs Hargitai
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Martina Hajduskova
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Silvia Gutnik
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Baris Tursun
- Berlin Institute for Medical Systems Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| |
Collapse
|
46
|
Kato Y, Miyaji M, Zhang-Akiyama QM. FUdR extends the lifespan of the short-lived AP endonuclease mutant in Caenorhabditis elegans in a fertility-dependent manner. Genes Genet Syst 2016; 91:201-207. [PMID: 27582048 DOI: 10.1266/ggs.15-00064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The anticancer drug 5-fluorouracil (5-FU) and its metabolite 5-fluoro-2'-deoxyuridine (FUdR) inhibit thymidylate synthase and induce uracil bases in DNA. FUdR is commonly used for inhibiting fertility when measuring the lifespan of the nematode Caenorhabditis elegans. However, it is not known whether DNA damage induced by FUdR affects lifespan. EXO-3 is an apurinic/apyrimidinic endonuclease in C. elegans, and we reported previously that deletion of the exo-3 gene causes reproductive abnormalities and decreased lifespan. In this study, we found that FUdR extended the lifespan of exo-3 mutants. We measured the lifespan of multiple germline mutants to examine whether this lifespan extension effect was dependent on fertility. In the presence of a fem-1 mutation, which causes a deficiency in sperm production, FUdR did not extend the lifespan of the exo-3 mutant. In glp-1 mutants, which do not develop gonads, the exo-3 mutant was not short-lived, and FUdR did not extend its lifespan. These results suggest that the lifespan extension effect of FUdR depends on fertility and the presence of gonads. fem-3 mutants, which do not produce oocytes, had increased lifespan in the presence of FUdR, independent of the exo-3 mutation. It is possible that the fem-3 mutant was susceptible to the lifespan extension effect of FUdR. From these results, we suggest that FUdR affects the lifespan of C. elegans in two ways: by interfering with fertility, which extends lifespan, and by inducing DNA base damage, which reduces lifespan.
Collapse
Affiliation(s)
- Yuichi Kato
- Laboratory of Stress Response Biology, Graduate School of Science, Kyoto University
| | | | | |
Collapse
|
47
|
Huber P, Crum T, Okkema PG. Function of the C. elegans T-box factor TBX-2 depends on interaction with the UNC-37/Groucho corepressor. Dev Biol 2016; 416:266-276. [PMID: 27265867 DOI: 10.1016/j.ydbio.2016.05.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 05/10/2016] [Accepted: 05/31/2016] [Indexed: 11/26/2022]
Abstract
T-box transcription factors are important regulators of development in all animals, and altered expression of T-box factors has been identified in an increasing number of diseases and cancers. Despite these important roles, the mechanism of T-box factor activity is not well understood. We have previously shown that the Caenorhabditis elegans Tbx2 subfamily member TBX-2 functions as a transcriptional repressor to specify ABa-derived pharyngeal muscle, and that this function depends on SUMOylation. Here we show that TBX-2 function also depends on interaction with the Groucho-family corepressor UNC-37. TBX-2 interacts with UNC-37 in yeast two-hybrid assays via a highly conserved engrailed homology 1 (eh1) motif located near the TBX-2 C-terminus. Reducing unc-37 phenocopies tbx-2 mutants, resulting in a specific loss of anterior ABa-derived pharyngeal muscles and derepression of the tbx-2 promoter. Moreover, double mutants containing hypomorphic alleles of unc-37 and tbx-2 exhibit enhanced phenotypes, providing strong genetic evidence that unc-37 and tbx-2 share common functions in vivo. To test whether interaction with UNC-37 is necessary for TBX-2 activity, we developed a transgene rescue assay using a tbx-2 containing fosmid and found that mutating the tbx-2 eh1 motif reduced rescue of a tbx-2 null mutant. These results indicate that TBX-2 function in vivo depends on interaction with UNC-37. As many T-box factors contain eh1 motifs, we suggest that interaction with Groucho-family corepressors is a common mechanism contributing to their activity.
Collapse
Affiliation(s)
- Paul Huber
- Department of Biological Sciences, Molecular, Cellular & Developmental Biology Research Group, University of Illinois at Chicago, Chicago, IL, USA
| | - Tanya Crum
- Department of Biological Sciences, Molecular, Cellular & Developmental Biology Research Group, University of Illinois at Chicago, Chicago, IL, USA
| | - Peter G Okkema
- Department of Biological Sciences, Molecular, Cellular & Developmental Biology Research Group, University of Illinois at Chicago, Chicago, IL, USA.
| |
Collapse
|
48
|
N-Ethyl-N-Nitrosourea (ENU) Mutagenesis Reveals an Intronic Residue Critical for Caenorhabditis elegans 3' Splice Site Function in Vivo. G3-GENES GENOMES GENETICS 2016; 6:1751-6. [PMID: 27172199 PMCID: PMC4889670 DOI: 10.1534/g3.116.028662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Metazoan introns contain a polypyrimidine tract immediately upstream of the AG dinucleotide that defines the 3' splice site. In the nematode Caenorhabditis elegans, 3' splice sites are characterized by a highly conserved UUUUCAG/R octamer motif. While the conservation of pyrimidines in this motif is strongly suggestive of their importance in pre-mRNA splicing, in vivo evidence in support of this is lacking. In an N-ethyl-N-nitrosourea (ENU) mutagenesis screen in Caenorhabditis elegans, we have isolated a strain containing a point mutation in the octamer motif of a 3' splice site in the daf-12 gene. This mutation, a single base T-to-G transversion at the -5 position relative to the splice site, causes a strong daf-12 loss-of-function phenotype by abrogating splicing. The resulting transcript is predicted to encode a truncated DAF-12 protein generated by translation into the retained intron, which contains an in-frame stop codon. Other than the perfectly conserved AG dinucleotide at the site of splicing, G at the -5 position of the octamer motif is the most uncommon base in C. elegans 3' splice sites, occurring at closely paired sites where the better match to the splicing consensus is a few bases downstream. Our results highlight both the biological importance of the highly conserved -5 uridine residue in the C. elegans 3' splice site octamer motif as well as the utility of using ENU as a mutagen to study the function of polypyrimidine tracts and other AU- or AT-rich motifs in vivo.
Collapse
|
49
|
Gabdank I, Ramakrishnan S, Villeneuve AM, Fire AZ. A streamlined tethered chromosome conformation capture protocol. BMC Genomics 2016; 17:274. [PMID: 27036078 PMCID: PMC4818521 DOI: 10.1186/s12864-016-2596-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 03/16/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Identification of locus-locus contacts at the chromatin level provides a valuable foundation for understanding of nuclear architecture and function and a valuable tool for inferring long-range linkage relationships. As one approach to this, chromatin conformation capture-based techniques allow creation of genome spatial organization maps. While such approaches have been available for some time, methodological advances will be of considerable use in minimizing both time and input material required for successful application. RESULTS Here we report a modified tethered conformation capture protocol that utilizes a series of rapid and efficient molecular manipulations. We applied the method to Caenorhabditis elegans, obtaining chromatin interaction maps that provide a sequence-anchored delineation of salient aspects of Caenorhabditis elegans chromosome structure, demonstrating a high level of consistency in overall chromosome organization between biological samples collected under different conditions. In addition to the application of the method to defining nuclear architecture, we found the resulting chromatin interaction maps to be of sufficient resolution and sensitivity to enable detection of large-scale structural variants such as inversions or translocations. CONCLUSION Our streamlined protocol provides an accelerated, robust, and broadly applicable means of generating chromatin spatial organization maps and detecting genome rearrangements without a need for cellular or chromatin fractionation.
Collapse
Affiliation(s)
- Idan Gabdank
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94304, USA
| | - Sreejith Ramakrishnan
- Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, California, 94304, USA
| | - Anne M Villeneuve
- Departments of Developmental Biology and Genetics, Stanford University School of Medicine, Stanford, California, 94304, USA
| | - Andrew Z Fire
- Departments of Pathology and Genetics, Stanford University School of Medicine, Stanford, California, 94304, USA.
| |
Collapse
|
50
|
Sallee MD, Aydin T, Greenwald I. Influences of LIN-12/Notch and POP-1/TCF on the Robustness of Ventral Uterine Cell Fate Specification in Caenorhabditis elegans Gonadogenesis. G3 (BETHESDA, MD.) 2015; 5:2775-82. [PMID: 26483009 PMCID: PMC4683648 DOI: 10.1534/g3.115.022608] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 10/09/2015] [Indexed: 12/03/2022]
Abstract
The prospective ventral uterus of the hermaphrodite gonad primordium consists of two pairs of sister cells, with each pair consisting of a proximal "α" cell and a distal "β" cell. All four cells initially are competent to become the anchor cell (AC), a unique cell type that acts as the organizer of subsequent uterine and vulval development. However, the β cells soon lose this competence and always become ventral uterine precursor cells (VUs), whereas the α cells maintain their AC competence longer, until lin-12/Notch-mediated interactions between them specify one as the AC and the other as a VU. Here, we investigate this asymmetry in developmental potential and VU fate specification between the α and β sister cells. We find evidence that lin-12 activity contributes to the robustness of βVU fate at elevated temperature, that the Caenorhabditis elegans Notch paralog glp-1 is not functionally redundant with lin-12 in specifying βVU fate, and that the activity of POP-1, the sole C. elegans TCF ortholog, influences βVU fate. We propose a model for how Wnt and LIN-12/Notch signaling together lead to robust specification of the βVU fate.
Collapse
Affiliation(s)
- Maria D Sallee
- Department of Genetics and Development, Columbia University Medical Center, New York 10032
| | - Taner Aydin
- Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York 10032
| | - Iva Greenwald
- Department of Genetics and Development, Columbia University Medical Center, New York 10032 Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York 10032
| |
Collapse
|