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Godthi A, Min S, Das S, Cruz-Corchado J, Deonarine A, Misel-Wuchter K, Issuree PD, Prahlad V. Neuronal IL-17 controls Caenorhabditis elegans developmental diapause through CEP-1/p53. Proc Natl Acad Sci U S A 2024; 121:e2315248121. [PMID: 38483995 PMCID: PMC10963014 DOI: 10.1073/pnas.2315248121] [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: 09/01/2023] [Accepted: 02/06/2024] [Indexed: 03/19/2024] Open
Abstract
During metazoan development, how cell division and metabolic programs are coordinated with nutrient availability remains unclear. Here, we show that nutrient availability signaled by the neuronal cytokine, ILC-17.1, switches Caenorhabditis elegans development between reproductive growth and dormancy by controlling the activity of the tumor suppressor p53 ortholog, CEP-1. Specifically, upon food availability, ILC-17.1 signaling by amphid neurons promotes glucose utilization and suppresses CEP-1/p53 to allow growth. In the absence of ILC-17.1, CEP-1/p53 is activated, up-regulates cell-cycle inhibitors, decreases phosphofructokinase and cytochrome C expression, and causes larvae to arrest as stress-resistant, quiescent dauers. We propose a model whereby ILC-17.1 signaling links nutrient availability and energy metabolism to cell cycle progression through CEP-1/p53. These studies describe ancestral functions of IL-17 s and the p53 family of proteins and are relevant to our understanding of neuroimmune mechanisms in cancer. They also reveal a DNA damage-independent function of CEP-1/p53 in invertebrate development and support the existence of a previously undescribed C. elegans dauer pathway.
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Affiliation(s)
- Abhishiktha Godthi
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY14263
- Department of Biology, The University of Iowa, Iowa City, IA52242-1324
| | - Sehee Min
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY14263
- Department of Biology, The University of Iowa, Iowa City, IA52242-1324
| | - Srijit Das
- Department of Biology, The University of Iowa, Iowa City, IA52242-1324
| | - Johnny Cruz-Corchado
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY14263
- Department of Biology, The University of Iowa, Iowa City, IA52242-1324
| | - Andrew Deonarine
- Department of Biology, The University of Iowa, Iowa City, IA52242-1324
| | - Kara Misel-Wuchter
- Department of Internal Medicine, The University of Iowa, Iowa City, IA52242
| | - Priya D. Issuree
- Department of Internal Medicine, The University of Iowa, Iowa City, IA52242
| | - Veena Prahlad
- Department of Cell Stress Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY14263
- Department of Biology, The University of Iowa, Iowa City, IA52242-1324
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2
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Cheng M, Nie Y, Song M, Chen F, Yu Y. Forkhead box O proteins: steering the course of stem cell fate. CELL REGENERATION (LONDON, ENGLAND) 2024; 13:7. [PMID: 38466341 DOI: 10.1186/s13619-024-00190-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 02/26/2024] [Indexed: 03/13/2024]
Abstract
Stem cells are pivotal players in the intricate dance of embryonic development, tissue maintenance, and regeneration. Their behavior is delicately balanced between maintaining their pluripotency and differentiating as needed. Disruptions in this balance can lead to a spectrum of diseases, underscoring the importance of unraveling the complex molecular mechanisms that govern stem cell fate. Forkhead box O (FOXO) proteins, a family of transcription factors, are at the heart of this intricate regulation, influencing a myriad of cellular processes such as survival, metabolism, and DNA repair. Their multifaceted role in steering the destiny of stem cells is evident, as they wield influence over self-renewal, quiescence, and lineage-specific differentiation in both embryonic and adult stem cells. This review delves into the structural and regulatory intricacies of FOXO transcription factors, shedding light on their pivotal roles in shaping the fate of stem cells. By providing insights into the specific functions of FOXO in determining stem cell fate, this review aims to pave the way for targeted interventions that could modulate stem cell behavior and potentially revolutionize the treatment and prevention of diseases.
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Affiliation(s)
- Mengdi Cheng
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Yujie Nie
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Min Song
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
| | - Fulin Chen
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China
- Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, Xi'an, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, China
| | - Yuan Yu
- Laboratory of Tissue Engineering, College of Life Sciences, Northwest University, Xi'an, China.
- Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, Xi'an, China.
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, China.
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3
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Godoy LF, Hochbaum D. Transcriptional and spatiotemporal regulation of the dauer program. Transcription 2023; 14:27-48. [PMID: 36951297 PMCID: PMC10353326 DOI: 10.1080/21541264.2023.2190295] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/24/2023] Open
Abstract
Caenorhabditis elegans can enter a diapause stage called "dauer" when it senses that the environment is not suitable for development. This implies a detour from the typical developmental trajectory and requires a tight control of the developmental clock and a massive tissue remodeling. In the last decades, core components of the signaling pathways that govern the dauer development decision have been identified, but the tissues where they function for the acquisition of dauer-specific traits are still under intense study. Growing evidence demonstrates that these pathways engage in complex cross-talk and feedback loops. In this review, we summarize the current knowledge regarding the transcriptional regulation of the dauer program and the relevant tissues for its achievement. A better understanding of this process will provide insight on how developmental plasticity is achieved and how development decisions are under a robust regulation to ensure an all-or-nothing response. Furthermore, this developmental decision can also serve as a simplified model for relevant developmental disorders.Abbreviations: AID Auxin Induced Degron DA dafachronic acid Daf-c dauer formation constitutive Daf-d dauer formation defective DTC Distal Tip Cells ECM modified extracellular matrix GPCRs G protein-coupled receptors IIS insulin/IGF-1 signaling ILPs insulin-like peptides LBD Ligand Binding Domain PDL4 Post Dauer L4 TGF-β transforming growth factor beta WT wild-type.
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Affiliation(s)
- Luciana F Godoy
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Daniel Hochbaum
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD) Universidad Maimónides, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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4
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Ma J, Wang YT, Chen LH, Yang BY, Jiang YZ, Wang LX, Chen ZQ, Ma GR, Fang LQ, Wang ZB. Dauer larva-derived extracellular vesicles extend the life of Caenorhabditis elegans. Biogerontology 2023:10.1007/s10522-023-10030-5. [PMID: 37052773 PMCID: PMC10267011 DOI: 10.1007/s10522-023-10030-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023]
Abstract
There is growing evidence that extracellular vesicles (EVs) play a functional role in tissue repair and anti-aging by transferring the contents of donor cells to recipient cells. We hypothesized that Dauer (C. elegans), known as "ageless" nematodes, can also secrete extracellular vesicles and influence the lifespan of C. elegans. Here, we isolated EVs of dauer larvae (dauer EVs). Dauer EVs were characterized using transmission electron microscopy, nanoparticle tracking analysis (NTA), and Western blot analysis. Wild-type C. elegans were fed in the presence or absence of dauer EVs and tested for a range of phenotypes, including longevity, mobility and reproductive capacity. Results showed that dauer EVs increased the average lifespan of nematodes by 15.74%, improved mobility, slowed age-related pigmentation as well as body length, and reduced the accumulation of reactive oxygen species and lipids, while not impairing nematode reproductive capacity. These findings suggest that dauer EVs can extend the lifespan of C. elegans as well as the healthy lifespan by reducing ROS accumulation, with potential anti-aging capacity.
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Affiliation(s)
- Jing Ma
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Yi-Ting Wang
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Ling-Hui Chen
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Bang-Ya Yang
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Yong-Zhu Jiang
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Lan-Xi Wang
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Zhi-Qi Chen
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Guan-Rong Ma
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China
| | - Liao-Qiong Fang
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China.
- National Engineering Research Center of Ultrasound Medicine, Chongqing, 401121, China.
| | - Zhi-Biao Wang
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, 400016, China.
- National Engineering Research Center of Ultrasound Medicine, Chongqing, 401121, China.
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5
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Cuko L, Cale AR, Rambo L, Knoblock ML, Karp X. Distinct daf-16 isoforms regulate specification of vulval precursor cells in Caenorhabditis elegans. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000706. [PMID: 36575736 PMCID: PMC9790082 DOI: 10.17912/micropub.biology.000706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/29/2022]
Abstract
FOXO transcription factors regulate development, longevity, and stress-resistance across species. The C. elegans FOXO ortholog, daf-16, has three major isoforms with distinct promoters and N-termini. Different combinations of isoforms regulate different processes. Adverse environments can induce dauer diapause after the second larval molt. During dauer, daf-16 blocks specification of vulval precursor cells, including EGFR/Ras-mediated 1˚ fate specification and LIN-12/Notch-mediated 2˚ fate specification. Using isoform-specific mutants, we find that daf-16a and daf-16f are functionally redundant for the block to the expression of 1˚ fate markers. In contrast, all three isoforms contribute to blocking the expression of 2˚ fate markers.
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Affiliation(s)
| | - Allison R Cale
- Central Michigan University
,
Current address: University of Michigan, Ann Arbor
| | - Loni Rambo
- Central Michigan University
,
Current address: University of Michigan, Ann Arbor
| | | | - Xantha Karp
- Central Michigan University
,
Correspondence to: Xantha Karp (
)
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6
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O'Keeffe C, Greenwald I. EGFR signal transduction is downregulated in C. elegans vulval precursor cells during dauer diapause. Development 2022; 149:dev201094. [PMID: 36227589 PMCID: PMC9793418 DOI: 10.1242/dev.201094] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022]
Abstract
Caenorhabditis elegans larvae display developmental plasticity in response to environmental conditions: in adverse conditions, second-stage larvae enter a reversible, long-lived dauer stage instead of proceeding to reproductive adulthood. Dauer entry interrupts vulval induction and is associated with a reprogramming-like event that preserves the multipotency of vulval precursor cells (VPCs), allowing vulval development to reinitiate if conditions improve. Vulval induction requires the LIN-3/EGF-like signal from the gonad, which activates EGFR-Ras-ERK signal transduction in the nearest VPC, P6.p. Here, using a biosensor and live imaging we show that EGFR-Ras-ERK activity is downregulated in P6.p in dauers. We investigated this process using gene mutations or transgenes to manipulate different steps of the pathway, and by analyzing LET-23/EGFR subcellular localization during dauer life history. We found that the response to EGF is attenuated at or upstream of Ras activation, and discuss potential membrane-associated mechanisms that could achieve this. We also describe other findings pertaining to the maintenance of VPC competence and quiescence in dauer larvae. Our analysis indicates that VPCs have L2-like and unique dauer stage features rather than features of L3 VPCs in continuous development.
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Affiliation(s)
- Catherine O'Keeffe
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Iva Greenwald
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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7
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daf-16/FOXO blocks adult cell fate in Caenorhabditis elegans dauer larvae via lin-41/TRIM71. PLoS Genet 2021; 17:e1009881. [PMID: 34780472 PMCID: PMC8629381 DOI: 10.1371/journal.pgen.1009881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/29/2021] [Accepted: 10/15/2021] [Indexed: 02/07/2023] Open
Abstract
Many tissue-specific stem cells maintain the ability to produce multiple cell types during long periods of non-division, or quiescence. FOXO transcription factors promote quiescence and stem cell maintenance, but the mechanisms by which FOXO proteins promote multipotency during quiescence are still emerging. The single FOXO ortholog in C. elegans, daf-16, promotes entry into a quiescent and stress-resistant larval stage called dauer in response to adverse environmental cues. During dauer, stem and progenitor cells maintain or re-establish multipotency to allow normal development to resume after dauer. We find that during dauer, daf-16/FOXO prevents epidermal stem cells (seam cells) from prematurely adopting differentiated, adult characteristics. In particular, dauer larvae that lack daf-16 misexpress collagens that are normally adult-enriched. Using col-19p::gfp as an adult cell fate marker, we find that all major daf-16 isoforms contribute to opposing col-19p::gfp expression during dauer. By contrast, daf-16(0) larvae that undergo non-dauer development do not misexpress col-19p::gfp. Adult cell fate and the timing of col-19p::gfp expression are regulated by the heterochronic gene network, including lin-41 and lin-29. lin-41 encodes an RNA-binding protein orthologous to LIN41/TRIM71 in mammals, and lin-29 encodes a conserved zinc finger transcription factor. In non-dauer development, lin-41 opposes adult cell fate by inhibiting the translation of lin-29, which directly activates col-19 transcription and promotes adult cell fate. We find that during dauer, lin-41 blocks col-19p::gfp expression, but surprisingly, lin-29 is not required in this context. Additionally, daf-16 promotes the expression of lin-41 in dauer larvae. The col-19p::gfp misexpression phenotype observed in dauer larvae with reduced daf-16 requires the downregulation of lin-41, but does not require lin-29. Taken together, this work demonstrates a novel role for daf-16/FOXO as a heterochronic gene that promotes expression of lin-41/TRIM71 to contribute to multipotent cell fate in a quiescent stem cell model. In adults and juveniles, tissue-specific stem cells divide as needed to replace cells that are lost due to injury or normal wear and tear. Many stem cells spend long periods of time in cellular quiescence, or non-division. During quiescence, stem cells remain multipotent, where they retain the ability to produce all cell types within their tissue. In this study, we define a new role for the FOXO protein DAF-16 in promoting multipotency during the quiescent C. elegans dauer larva stage. C. elegans larvae enter dauer midway through development in response to adverse environmental conditions. Epidermal stem cells are multipotent in C. elegans larvae but differentiate at adulthood, a process controlled by the “heterochronic” genes. We found that daf-16 blocks the expression of adult cell fate specifically in dauer larvae by promoting the expression of the heterochronic gene lin-41. lin-41 normally blocks adult fate by repressing the expression of another heterochronic gene, lin-29, but surprisingly, lin-29 is not needed for the expression of adult cell fate in this context. These findings may be relevant to mammals where the orthologs of daf-16 and lin-41 are important in stem cell maintenance and opposing differentiation.
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8
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Biglou SG, Bendena WG, Chin-Sang I. An overview of the insulin signaling pathway in model organisms Drosophila melanogaster and Caenorhabditis elegans. Peptides 2021; 145:170640. [PMID: 34450203 DOI: 10.1016/j.peptides.2021.170640] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/01/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022]
Abstract
The insulin/insulin-like growth factor signaling pathway is an evolutionary conserved pathway across metazoans and is required for development, metabolism and behavior. This pathway is associated with various human metabolic disorders and cancers. Thus, model organisms including Drosophila melanogaster and Caenorhabditis elegans provide excellent opportunities to examine the structure and function of this pathway and its influence on cellular metabolism and proliferation. In this review, we will provide an overview of human insulin and the human insulin signaling pathway and explore the recent discoveries in model organisms Drosophila melanogaster and Caenorhabditis elegans. Our review will provide information regarding the various insulin-like peptides in model organisms as well as the conserved functions of insulin signaling pathways. Further investigation of the insulin signaling pathway in model organisms could provide a promising opportunity to develop novel therapies for various metabolic disorders and insulin-mediated cancers.
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Affiliation(s)
- Sanaz G Biglou
- Department of Biology, Queen's University Kingston, ON, K7L3N6, Canada
| | - William G Bendena
- Department of Biology, Queen's University Kingston, ON, K7L3N6, Canada; Centre for Neuroscience, Queen's University, Kingston, ON, K7L3N6, Canada.
| | - Ian Chin-Sang
- Department of Biology, Queen's University Kingston, ON, K7L3N6, Canada
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9
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Karp X. Hormonal Regulation of Diapause and Development in Nematodes, Insects, and Fishes. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.735924] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Diapause is a state of developmental arrest adopted in response to or in anticipation of environmental conditions that are unfavorable for growth. In many cases, diapause is facultative, such that animals may undergo either a diapause or a non-diapause developmental trajectory, depending on environmental cues. Diapause is characterized by enhanced stress resistance, reduced metabolism, and increased longevity. The ability to postpone reproduction until suitable conditions are found is important to the survival of many animals, and both vertebrate and invertebrate species can undergo diapause. The decision to enter diapause occurs at the level of the whole animal, and thus hormonal signaling pathways are common regulators of the diapause decision. Unlike other types of developmental arrest, diapause is programmed, such that the diapause developmental trajectory includes a pre-diapause preparatory phase, diapause itself, recovery from diapause, and post-diapause development. Therefore, developmental pathways are profoundly affected by diapause. Here, I review two conserved hormonal pathways, insulin/IGF signaling (IIS) and nuclear hormone receptor signaling (NHR), and their role in regulating diapause across three animal phyla. Specifically, the species reviewed are Austrofundulus limnaeus and Nothobranchius furzeri annual killifishes, Caenorhabditis elegans nematodes, and insect species including Drosophila melanogaster, Culex pipiens, and Bombyx mori. In addition, the developmental changes that occur as a result of diapause are discussed, with a focus on how IIS and NHR pathways interact with core developmental pathways in C. elegans larvae that undergo diapause.
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10
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de la Cova CC, Townley R, Greenwald I. Negative feedback by conserved kinases patterns the degradation of Caenorhabditis elegans Raf in vulval fate patterning. Development 2020; 147:226094. [PMID: 33144396 DOI: 10.1242/dev.195941] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/27/2020] [Indexed: 11/20/2022]
Abstract
Activation of a canonical EGFR-Ras-Raf-ERK cascade initiates patterning of multipotent vulval precursor cells (VPCs) of Caenorhabditis elegans We have previously shown that this pathway includes a negative-feedback component in which MPK-1/ERK activity targets the upstream kinase LIN-45/Raf for degradation by the SEL-10/FBXW7 E3 ubiquitin ligase. This regulation requires a Cdc4 phosphodegron (CPD) in LIN-45 that is conserved in BRAF. Here, we identify and characterize the minimal degron that encompasses the CPD and is sufficient for SEL-10-mediated, MPK-1-dependent protein degradation. A targeted screen of conserved protein kinase-encoding genes yielded gsk-3 (an ortholog of human GSK3B) and cdk-2 (a CDK2-related kinase) as required for LIN-45 degron-mediated turnover. Genetic analysis revealed that LIN-45 degradation is blocked at the second larval stage due to cell cycle quiescence, and that relief of this block during the third larval stage relies on activation of CDKs. Additionally, activation of MPK-1 provides spatial pattern to LIN-45 degradation but does not bypass the requirement for gsk-3 and cdk-2 This analysis supports a model whereby MPK-1/ERK, GSK-3/GSK3 and CDK-2/CDK2, along with SEL-10/FBXW7, constitute a regulatory network that exerts spatial and temporal control of LIN-45/Raf degradation during VPC patterning.
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Affiliation(s)
- Claire C de la Cova
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.,Department of Biological Sciences, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
| | - Robert Townley
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.,Department of Biological Sciences, University of Wisconsin Milwaukee, Milwaukee, WI 53201, USA
| | - Iva Greenwald
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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11
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Baugh LR, Hu PJ. Starvation Responses Throughout the Caenorhabditiselegans Life Cycle. Genetics 2020; 216:837-878. [PMID: 33268389 PMCID: PMC7768255 DOI: 10.1534/genetics.120.303565] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/17/2020] [Indexed: 02/07/2023] Open
Abstract
Caenorhabditis elegans survives on ephemeral food sources in the wild, and the species has a variety of adaptive responses to starvation. These features of its life history make the worm a powerful model for studying developmental, behavioral, and metabolic starvation responses. Starvation resistance is fundamental to life in the wild, and it is relevant to aging and common diseases such as cancer and diabetes. Worms respond to acute starvation at different times in the life cycle by arresting development and altering gene expression and metabolism. They also anticipate starvation during early larval development, engaging an alternative developmental program resulting in dauer diapause. By arresting development, these responses postpone growth and reproduction until feeding resumes. A common set of signaling pathways mediates systemic regulation of development in each context but with important distinctions. Several aspects of behavior, including feeding, foraging, taxis, egg laying, sleep, and associative learning, are also affected by starvation. A variety of conserved signaling, gene regulatory, and metabolic mechanisms support adaptation to starvation. Early life starvation can have persistent effects on adults and their descendants. With its short generation time, C. elegans is an ideal model for studying maternal provisioning, transgenerational epigenetic inheritance, and developmental origins of adult health and disease in humans. This review provides a comprehensive overview of starvation responses throughout the C. elegans life cycle.
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Affiliation(s)
- L Ryan Baugh
- Department of Biology, Center for Genomic and Computational Biology, Duke University, Durham, North Carolina 27708 and
| | - Patrick J Hu
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
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12
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Richardson CE, Yee C, Shen K. A hormone receptor pathway cell-autonomously delays neuron morphological aging by suppressing endocytosis. PLoS Biol 2019; 17:e3000452. [PMID: 31589601 PMCID: PMC6797217 DOI: 10.1371/journal.pbio.3000452] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 10/17/2019] [Accepted: 09/05/2019] [Indexed: 01/12/2023] Open
Abstract
Neurons have a lifespan that parallels that of the organism and are largely irreplaceable. Their unusually long lifespan predisposes neurons to neurodegenerative disease. We sought to identify physiological mechanisms that delay neuron aging in Caenorhabditis elegans by asking how neuron morphological aging is arrested in the long-lived, alternate organismal state, the dauer diapause. We find that a hormone signaling pathway, the abnormal DAuer Formation (DAF) 12 nuclear hormone receptor (NHR) pathway, functions cell-intrinsically in the dauer diapause to arrest neuron morphological aging, and that same pathway can be cell-autonomously manipulated during normal organismal aging to delay neuron morphological aging. This delayed aging is mediated by suppressing constitutive endocytosis, which alters the subcellular localization of the actin regulator T cell lymphoma Invasion And Metastasis 1 (TIAM-1), thereby decreasing age-dependent neurite growth. Intriguingly, we show that suppressed endocytosis appears to be a general feature of cells in diapause, suggestive that this may be a mechanism to halt the growth and other age-related programs supported by most endosome recycling.
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Affiliation(s)
- Claire E. Richardson
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Callista Yee
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, California, United States of America
- * E-mail:
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13
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Kadekar P, Roy R. AMPK regulates germline stem cell quiescence and integrity through an endogenous small RNA pathway. PLoS Biol 2019; 17:e3000309. [PMID: 31166944 PMCID: PMC6576793 DOI: 10.1371/journal.pbio.3000309] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 06/17/2019] [Accepted: 05/16/2019] [Indexed: 01/07/2023] Open
Abstract
During suboptimal growth conditions, Caenorhabditis elegans larvae undergo a global developmental arrest called "dauer." During this stage, the germline stem cells (GSCs) become quiescent in an AMP-activated Protein Kinase (AMPK)-dependent manner, and in the absence of AMPK, the GSCs overproliferate and lose their reproductive capacity, leading to sterility when mutant animals resume normal growth. These defects correlate with the altered abundance and distribution of a number of chromatin modifications, all of which can be corrected by disabling components of the endogenous small RNA pathway, suggesting that AMPK regulates germ cell integrity by targeting an RNA interference (RNAi)-like pathway during dauer. The expression of AMPK in somatic cells restores all the germline defects, potentially through the transmission of small RNAs. Our findings place AMPK at a pivotal position linking energy stress detected in the soma to a consequent endogenous small RNA-mediated adaptation in germline gene expression, thereby challenging the "permeability" of the Weismann barrier.
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Affiliation(s)
- Pratik Kadekar
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Richard Roy
- Department of Biology, McGill University, Montreal, Quebec, Canada
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Cell Non-autonomous Function of daf-18/PTEN in the Somatic Gonad Coordinates Somatic Gonad and Germline Development in C. elegans Dauer Larvae. Curr Biol 2019; 29:1064-1072.e8. [PMID: 30827916 DOI: 10.1016/j.cub.2019.01.076] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 12/21/2022]
Abstract
C. elegans larvae integrate environmental information and developmental decisions [1-3]. In favorable conditions, worms develop rapidly and continuously through four larval stages into reproductive adulthood. However, if conditions are unfavorable through the second larval stage, worms enter dauer diapause, a state of global and reversible developmental arrest in which precursor cells remain quiescent and preserve developmental potential, anticipating developmental progression if conditions improve. Signaling from neurons, hypodermis, and intestine regulate the appearance and behavior of dauer larvae and many aspects of developmental arrest of the non-gonadal soma [1, 4, 5]. Here, we show that the decision of somatic gonad blast cells (SGBs) and germline stem cells (GSCs) to be quiescent or progress developmentally is regulated differently from the non-gonadal soma: daf-18/PTEN acts non-autonomously within the somatic gonad to maintain developmental quiescence of both SGBs and GSCs. Our analysis suggests that daf-18 acts in somatic gonad cells to produce a "pro-quiescence" signal (or signals) that acts inter se and between the somatic gonad and the germline. The inferred signal does not require DAF-2/insulin receptor or maintain quiescence of the nearby sex myoblasts, and developmental progression in daf-18(0) does not require dafachronic acids. Abrogating quiescence in dauer results in post-dauer sterility. Our results implicate the somatic gonad as an endocrine organ to synchronize somatic gonad and germline development during dauer diapause and recovery, and our finding that PTEN acts non-autonomously to control blast cell quiescence may be relevant to its function as a tumor suppressor in mammals and to combating parasitic nematodes.
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15
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Coraggio F, Püschel R, Marti A, Meister P. Polycomb and Notch signaling regulate cell proliferation potential during Caenorhabditis elegans life cycle. Life Sci Alliance 2019; 2:e201800170. [PMID: 30599047 PMCID: PMC6306570 DOI: 10.26508/lsa.201800170] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 12/27/2022] Open
Abstract
Stable cell fate is an essential feature for multicellular organisms in which individual cells achieve specialized functions. Caenorhabditis elegans is a great model to analyze the determinants of cell fate stability because of its invariant lineage. We present a tractable cell fate challenge system that uses the induction of fate-specifying transcription factors. We show that wild-type differentiated animals are highly resistant to fate challenge. Removal of heterochromatin marks showed marked differences: the absence of histone 3 lysine 9 methylation (H3K9) has no effect on fate stability, whereas Polycomb homolog mes-2 mutants lacking H3K27 methylation terminally arrest larval development upon fate challenge. Unexpectedly, the arrest correlated with widespread cell proliferation rather than transdifferentiation. Using a candidate RNAi larval arrest-rescue screen, we show that the LIN-12Notch pathway is essential for hyperplasia induction. Moreover, Notch signaling appears downstream of food-sensing pathways, as dauers and first larval stage diapause animals are resistant to fate challenge. Our results demonstrate an equilibrium between proliferation and differentiation regulated by Polycomb and Notch signaling in the soma during the nematode life cycle.
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Affiliation(s)
- Francesca Coraggio
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Ringo Püschel
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Alisha Marti
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Peter Meister
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, Bern, Switzerland
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Abstract
Dauer diapause is a stress-resistant, developmentally quiescent, and long-lived larval stage adopted by Caenorhabditis elegans when conditions are unfavorable for growth and reproduction. This chapter contains methods to induce dauer larva formation, to isolate dauer larvae, and to study pre- and post-dauer stages.
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Affiliation(s)
- Xantha Karp
- Department of Biology, Central Michigan University, Mount Pleasant, MI 48859 USA
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17
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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.
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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.
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18
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Pekar O, Ow MC, Hui KY, Noyes MB, Hall SE, Hubbard EJA. Linking the environment, DAF-7/TGFβ signaling and LAG-2/DSL ligand expression in the germline stem cell niche. Development 2017; 144:2896-2906. [PMID: 28811311 DOI: 10.1242/dev.147660] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 07/01/2017] [Indexed: 02/04/2023]
Abstract
The developmental accumulation of proliferative germ cells in the C. elegans hermaphrodite is sensitive to the organismal environment. Previously, we found that the TGFβ signaling pathway links the environment and proliferative germ cell accumulation. Neuronal DAF-7/TGFβ causes a DAF-1/TGFβR signaling cascade in the gonadal distal tip cell (DTC), the germline stem cell niche, where it negatively regulates a DAF-3 SMAD and DAF-5 Sno-Ski. LAG-2, a founding DSL ligand family member, is produced in the DTC and activates the GLP-1/Notch receptor on adjacent germ cells to maintain germline stem cell fate. Here, we show that DAF-7/TGFβ signaling promotes expression of lag-2 in the DTC in a daf-3-dependent manner. Using ChIP and one-hybrid assays, we find evidence for direct interaction between DAF-3 and the lag-2 promoter. We further identify a 25 bp DAF-3 binding element required for the DTC lag-2 reporter response to the environment and to DAF-7/TGFβ signaling. Our results implicate DAF-3 repressor complex activity as a key molecular mechanism whereby the environment influences DSL ligand expression in the niche to modulate developmental expansion of the germline stem cell pool.
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Affiliation(s)
- Olga Pekar
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, New York, NY 10016, USA
| | - Maria C Ow
- Department of Biology, Syracuse University, Syracuse, NY 13244, USA
| | - Kailyn Y Hui
- Institute for Systems Genetics, NYU School of Medicine, New York, NY 10016, USA
| | - Marcus B Noyes
- Institute for Systems Genetics, NYU School of Medicine, New York, NY 10016, USA
| | - Sarah E Hall
- Department of Biology, Syracuse University, Syracuse, NY 13244, USA
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, NYU School of Medicine, New York, NY 10016, USA
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Integration of EGFR and LIN-12/Notch Signaling by LIN-1/Elk1, the Cdk8 Kinase Module, and SUR-2/Med23 in Vulval Precursor Cell Fate Patterning in Caenorhabditis elegans. Genetics 2017; 207:1473-1488. [PMID: 28954762 DOI: 10.1534/genetics.117.300192] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 09/26/2017] [Indexed: 01/25/2023] Open
Abstract
Six initially equivalent, multipotential Vulval Precursor Cells (VPCs) in Caenorhabditis elegans adopt distinct cell fates in a precise spatial pattern, with each fate associated with transcription of different target genes. The pattern is centered on a cell that adopts the "1°" fate through Epidermal Growth Factor Receptor (EGFR) activity, and produces a lateral signal composed of ligands that activate LIN-12/Notch in the two flanking VPCs to cause them to adopt "2°" fate. Here, we investigate orthologs of a transcription complex that acts in mammalian EGFR signaling-lin-1/Elk1, sur-2/Med23, and the Cdk8 Kinase module (CKM)-previously implicated in aspects of 1° fate in C. elegans and show they act in different combinations for different processes for 2° fate. When EGFR is inactive, the CKM, but not SUR-2, helps to set a threshold for LIN-12/Notch activity in all VPCs. When EGFR is active, all three factors act to resist LIN-12/Notch, as revealed by the reduced ability of ectopically-activated LIN-12/Notch to activate target gene reporters. We show that overcoming this resistance in the 1° VPC leads to repression of lateral signal gene reporters, suggesting that resistance to LIN-12/Notch helps ensure that P6.p becomes a robust source of the lateral signal. In addition, we show that sur-2/Med23 and lin-1/Elk1, and not the CKM, are required to promote endocytic downregulation of LIN-12-GFP in the 1° VPC. Finally, our analysis using cell fate reporters reveals that both EGFR and LIN-12/Notch signal transduction pathways are active in all VPCs in lin-1/Elk1 mutants, and that lin-1/Elk1 is important for integrating EGFR and lin-12/Notch signaling inputs in the VPCs so that the proper gene complement is transcribed.
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Long-Term High-Resolution Imaging of Developing C. elegans Larvae with Microfluidics. Dev Cell 2016; 40:202-214. [PMID: 28041904 DOI: 10.1016/j.devcel.2016.11.022] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 10/24/2016] [Accepted: 11/22/2016] [Indexed: 12/31/2022]
Abstract
Long-term studies of Caenorhabditis elegans larval development traditionally require tedious manual observations because larvae must move to develop, and existing immobilization techniques either perturb development or are unsuited for young larvae. Here, we present a simple microfluidic device to simultaneously follow development of ten C. elegans larvae at high spatiotemporal resolution from hatching to adulthood (∼3 days). Animals grown in microchambers are periodically immobilized by compression to allow high-quality imaging of even weak fluorescence signals. Using the device, we obtain cell-cycle statistics for C. elegans vulval development, a paradigm for organogenesis. We combine Nomarski and multichannel fluorescence microscopy to study processes such as cell-fate specification, cell death, and transdifferentiation throughout post-embryonic development. Finally, we generate time-lapse movies of complex neural arborization through automated image registration. Our technique opens the door to quantitative analysis of time-dependent phenomena governing cellular behavior during C. elegans larval development.
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Fluorescent Beads Are a Versatile Tool for Staging Caenorhabditis elegans in Different Life Histories. G3-GENES GENOMES GENETICS 2016; 6:1923-33. [PMID: 27172224 PMCID: PMC4938646 DOI: 10.1534/g3.116.030163] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Precise staging of Caenorhabditis elegans is essential for developmental studies in different environmental conditions. In favorable conditions, larvae develop continuously through four larval stages separated by molting periods. Distinguishing molting from intermolt larvae has been achieved using transgenes with molting reporters, therefore requiring strain constructions, or careful observation of individuals for pharyngeal pumping or behavioral quiescence. In unfavorable conditions, larvae can enter the stress-resistant and developmentally arrested dauer larva stage. Identifying dauer larvae has been based on their ability to withstand detergent selection, precluding identification of recovering animals or of mutants with defects in dauer morphogenesis. Here, we describe a simple method to distinguish molting larvae or dauer larvae from intermolt larvae that bypasses the limitations of current methods. Fluorescent latex beads are mixed with the bacterial food source and ingested by intermolt larvae and adults. Molting and dauer larvae do not feed, and therefore lack beads in their digestive tract. The presence of beads can be determined using a dissecting microscope at magnifications as low as 100 ×, or by using a wormsorter for high-throughput experiments. We find that continuously developing bead-lacking larvae display hallmarks of molting, including expression of the mlt-10::gfp molting marker and a lack of pharyngeal pumping. Furthermore, wild-type and mutant dauer larvae produced by any of three common methods are accurately identified by a lack of beads. Importantly, this method is effective in SDS-sensitive mutant backgrounds and can identify recovering dauer larvae, a stage for which there is no other method of positive selection.
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Hand SC, Denlinger DL, Podrabsky JE, Roy R. Mechanisms of animal diapause: recent developments from nematodes, crustaceans, insects, and fish. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1193-211. [PMID: 27053646 PMCID: PMC4935499 DOI: 10.1152/ajpregu.00250.2015] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 03/11/2016] [Indexed: 01/22/2023]
Abstract
Life cycle delays are beneficial for opportunistic species encountering suboptimal environments. Many animals display a programmed arrest of development (diapause) at some stage(s) of their development, and the diapause state may or may not be associated with some degree of metabolic depression. In this review, we will evaluate current advancements in our understanding of the mechanisms responsible for the remarkable phenotype, as well as environmental cues that signal entry and termination of the state. The developmental stage at which diapause occurs dictates and constrains the mechanisms governing diapause. Considerable progress has been made in clarifying proximal mechanisms of metabolic arrest and the signaling pathways like insulin/Foxo that control gene expression patterns. Overlapping themes are also seen in mechanisms that control cell cycle arrest. Evidence is emerging for epigenetic contributions to diapause regulation via small RNAs in nematodes, crustaceans, insects, and fish. Knockdown of circadian clock genes in selected insect species supports the importance of clock genes in the photoperiodic response that cues diapause. A large suite of chaperone-like proteins, expressed during diapause, protects biological structures during long periods of energy-limited stasis. More information is needed to paint a complete picture of how environmental cues are coupled to the signal transduction that initiates the complex diapause phenotype, as well as molecular explanations for how the state is terminated. Excellent examples of molecular memory in post-dauer animals have been documented in Caenorhabditis elegans It is clear that a single suite of mechanisms does not regulate diapause across all species and developmental stages.
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Affiliation(s)
- Steven C Hand
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana;
| | - David L Denlinger
- Departments of Entomology and Evolution, Ecology and Organismal Biology, Ohio State University, Columbus, Ohio
| | - Jason E Podrabsky
- Department of Biology, Portland State University, Portland, Oregon; and
| | - Richard Roy
- Department of Biology, McGill University, Montréal, Québec, Canada
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