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Darmasaputra GS, Geerlings CC, Chuva de Sousa Lopes SM, Clevers H, Galli M. Binucleated human hepatocytes arise through late cytokinetic regression during endomitosis M phase. J Cell Biol 2024; 223:e202403020. [PMID: 38727809 PMCID: PMC11090133 DOI: 10.1083/jcb.202403020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/15/2024] Open
Abstract
Binucleated polyploid cells are common in many animal tissues, where they arise by endomitosis, a non-canonical cell cycle in which cells enter M phase but do not undergo cytokinesis. Different steps of cytokinesis have been shown to be inhibited during endomitosis M phase in rodents, but it is currently unknown how human cells undergo endomitosis. In this study, we use fetal-derived human hepatocyte organoids (Hep-Orgs) to investigate how human hepatocytes initiate and execute endomitosis. We find that cells in endomitosis M phase have normal mitotic timings, but lose membrane anchorage to the midbody during cytokinesis, which is associated with the loss of four cortical anchoring proteins, RacGAP1, Anillin, SEPT9, and citron kinase (CIT-K). Moreover, reduction of WNT activity increases the percentage of binucleated cells in Hep-Orgs, an effect that is dependent on the atypical E2F proteins, E2F7 and E2F8. Together, we have elucidated how hepatocytes undergo endomitosis in human Hep-Orgs, providing new insights into the mechanisms of endomitosis in mammals.
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Affiliation(s)
- Gabriella S. Darmasaputra
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht, Utrecht, Netherlands
| | - Cindy C. Geerlings
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht, Utrecht, Netherlands
| | | | - Hans Clevers
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht, Utrecht, Netherlands
- Oncode Institute, Utrecht, Netherlands
| | - Matilde Galli
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht, Utrecht, Netherlands
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2
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Seetharaman A, Galagali H, Linarte E, Liu MHX, Cohen JD, Chetal K, Sadreyev R, Tate AJ, Montgomery TA, Ruvkun G. Caenorhabditis elegans SynMuv B gene activity is down-regulated during a viral infection to enhance RNA interference. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.12.603258. [PMID: 39071373 PMCID: PMC11275910 DOI: 10.1101/2024.07.12.603258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Small RNA pathways regulate eukaryotic antiviral defense. Many of the Caenorhabditis elegans mutations that were identified based on their enhanced RNAi, the synMuv B genes, also emerged from unrelated genetic screens for increased growth factor signaling. The dozen synMuv B genes encode homologues of the mammalian dREAM complex found in nearly all animals and plants, which includes the lin-35 /retinoblastoma oncogene. We show that a set of highly induced mRNAs in synMuv B mutants is congruent with mRNAs induced by Orsay RNA virus infection of C. elegans . In wild type animals, a combination of a synMuv A mutation and a synMuv B mutation are required for the Muv phenotype of increased growth factor signaling. But we show that Orsay virus infection of a single synMuv A mutant can induce a Muv phenotype, unlike the uninfected single synMuv A mutant. This suggests that decreased synMuv B activity, which activates the antiviral RNAi pathway, is a defense response to viral infection. Small RNA deep sequencing analysis of various dREAM complex mutants uncovers distinct siRNA profiles indicative of such an siRNA response. We conclude that the synMuv B mutants maintain an antiviral readiness state even in the absence of actual infection. The enhanced RNAi and conservation of the dREAM complex mutants suggests new therapeutic avenues to boost antiviral defenses.
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3
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Tandingan De Ley I, Kiontke K, Bert W, Sudhaus W, Fitch DHA. Pellioditis pelhamensis n. sp. (Nematoda: Rhabditidae) and Pellioditis pellio (Schneider, 1866), earthworm associates from different subclades within Pellioditis (syn. Phasmarhabditis Andrássy, 1976). PLoS One 2023; 18:e0288196. [PMID: 37672545 PMCID: PMC10482300 DOI: 10.1371/journal.pone.0288196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 07/27/2023] [Indexed: 09/08/2023] Open
Abstract
Recently, much attention has been focused on a group of rhabditid nematodes called Phasmarhabditis, a junior synonym of Pellioditis, as a promising source of biocontrol agents for invasive slugs. Pellioditis pelhamensis n. sp. was first isolated from earthworms near Pelham Bay Park in Bronx, New York, USA, in 1990 and has been found to be pathogenic to slugs as well as some earthworms. It has also been used in several comparative developmental studies. Here, we provide a description of this species, as well as a redescription of a similar earthworm-associated nematode, Pellioditis pellio Schneider, 1866, re-isolated from the type locality. Although P. pelhamensis n. sp. and P. pellio are morphologically similar, they are reproductively isolated. Molecular phylogenetic analysis places both species in a clade that includes all species previously described as Phasmarhabditis which are associated with gastropods. Phasmarhabditis Andrássy, 1976 is therefore a junior synonym of Pellioditis Dougherty, 1953. Also, Pellioditis bohemica Nermut', Půža, Mekete & Mráček, 2017, described to be a facultative parasite of slugs, is found to be a junior synonym of Pellioditis pellio (Schneider, 1866), adding to evidence that P. pellio is associated with both slugs and earthworms. The earthworm-associated species P. pelhamensis n. sp. and P. pellio represent different subclades within Pellioditis, suggesting that Pellioditis species in general have a broader host range than just slugs. Because of this, caution is warranted in using these species as biological control agents until more is understood about their ecology.
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Affiliation(s)
- Irma Tandingan De Ley
- Department of Nematology, University of California, Riverside, CA, United States of America
| | - Karin Kiontke
- Department of Biology, New York University, New York, NY, United States of America
| | - Wim Bert
- Nematology Unit, Department of Biology, Ghent University, Ghent, Belgium
| | - Walter Sudhaus
- Institut für Biologie/Zoologie, Freie Universität Berlin, Berlin, Germany
| | - David H. A. Fitch
- Department of Biology, New York University, New York, NY, United States of America
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4
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Uram Ł, Wróbel K, Walczak M, Szymaszek Ż, Twardowska M, Wołowiec S. Exploring the Potential of Lapatinib, Fulvestrant, and Paclitaxel Conjugated with Glycidylated PAMAM G4 Dendrimers for Cancer and Parasite Treatment. Molecules 2023; 28:6334. [PMID: 37687164 PMCID: PMC10489794 DOI: 10.3390/molecules28176334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/06/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Fulvestrant (F), lapatinib (L), and paclitaxel (P) are hydrophobic, anticancer drugs used in the treatment of estrogen receptor (ER) and epidermal growth factor receptor (EGFR)-positive breast cancer. In this study, glycidylated PAMAM G4 dendrimers, substituted with F, L, and/or P and targeting tumor cells, were synthesized and characterized, and their antitumor activity against glioma U-118 MG and non-small cell lung cancer A549 cells was tested comparatively with human non-tumorogenic keratinocytes (HaCaT). All cell lines were ER+ and EGFR+. In addition, the described drugs were tested in the context of antinematode therapy on C. elegans. The results show that the water-soluble conjugates of G4P, G4F, G4L, and G4PFL actively entered the tested cells via endocytosis due to the positive zeta potential (between 13.57-40.29 mV) and the nanoparticle diameter of 99-138 nm. The conjugates of G4P and G4PFL at nanomolar concentrations were the most active, and the least active conjugate was G4F. The tested conjugates inhibited the proliferation of HaCaT and A549 cells; in glioma cells, cytotoxicity was associated mainly with cell damage (mitochondria and membrane transport). The toxicity of the conjugates was proportional to the number of drug residues attached, with the exception of G4L; its action was two- and eight-fold stronger against glioma and keratinocytes, respectively, than the equivalent of lapatinib alone. Unfortunately, non-cancer HaCaT cells were the most sensitive to the tested constructs, which forced a change in the approach to the use of ER and EGFR receptors as a goal in cancer therapy. In vivo studies on C. elegans have shown that all compounds, most notably G4PFL, may be potentially useful in anthelmintic therapy.
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Affiliation(s)
- Łukasz Uram
- Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańcow Warszawy Ave., 35-959 Rzeszów, Poland; (Ł.U.); (M.W.); (Ż.S.); (M.T.)
| | - Konrad Wróbel
- Medical College, Rzeszów University, 1a Warzywna Street, 35-310 Rzeszów, Poland;
| | - Małgorzata Walczak
- Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańcow Warszawy Ave., 35-959 Rzeszów, Poland; (Ł.U.); (M.W.); (Ż.S.); (M.T.)
| | - Żaneta Szymaszek
- Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańcow Warszawy Ave., 35-959 Rzeszów, Poland; (Ł.U.); (M.W.); (Ż.S.); (M.T.)
| | - Magdalena Twardowska
- Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańcow Warszawy Ave., 35-959 Rzeszów, Poland; (Ł.U.); (M.W.); (Ż.S.); (M.T.)
| | - Stanisław Wołowiec
- Medical College, Rzeszów University, 1a Warzywna Street, 35-310 Rzeszów, Poland;
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Schvarzstein M, Alam F, Toure M, Yanowitz JL. An Emerging Animal Model for Querying the Role of Whole Genome Duplication in Development, Evolution, and Disease. J Dev Biol 2023; 11:26. [PMID: 37367480 PMCID: PMC10299280 DOI: 10.3390/jdb11020026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 06/28/2023] Open
Abstract
Whole genome duplication (WGD) or polyploidization can occur at the cellular, tissue, and organismal levels. At the cellular level, tetraploidization has been proposed as a driver of aneuploidy and genome instability and correlates strongly with cancer progression, metastasis, and the development of drug resistance. WGD is also a key developmental strategy for regulating cell size, metabolism, and cellular function. In specific tissues, WGD is involved in normal development (e.g., organogenesis), tissue homeostasis, wound healing, and regeneration. At the organismal level, WGD propels evolutionary processes such as adaptation, speciation, and crop domestication. An essential strategy to further our understanding of the mechanisms promoting WGD and its effects is to compare isogenic strains that differ only in their ploidy. Caenorhabditis elegans (C. elegans) is emerging as an animal model for these comparisons, in part because relatively stable and fertile tetraploid strains can be produced rapidly from nearly any diploid strain. Here, we review the use of Caenorhabditis polyploids as tools to understand important developmental processes (e.g., sex determination, dosage compensation, and allometric relationships) and cellular processes (e.g., cell cycle regulation and chromosome dynamics during meiosis). We also discuss how the unique characteristics of the C. elegans WGD model will enable significant advances in our understanding of the mechanisms of polyploidization and its role in development and disease.
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Affiliation(s)
- Mara Schvarzstein
- Biology Department, Brooklyn College at the City University of New York, Brooklyn, NY 11210, USA
- Biology Department, The Graduate Center at the City University of New York, New York, NY 10016, USA
- Biochemistry Department, The Graduate Center at the City University of New York, New York, NY 10016, USA
| | - Fatema Alam
- Biology Department, Brooklyn College at the City University of New York, Brooklyn, NY 11210, USA
| | - Muhammad Toure
- Biology Department, Brooklyn College at the City University of New York, Brooklyn, NY 11210, USA
| | - Judith L. Yanowitz
- Magee-Womens Research Institute, Pittsburgh, PA 15213, USA;
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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6
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Lo WS, Roca M, Dardiry M, Mackie M, Eberhardt G, Witte H, Hong R, Sommer RJ, Lightfoot JW. Evolution and Diversity of TGF-β Pathways are Linked with Novel Developmental and Behavioral Traits. Mol Biol Evol 2022; 39:msac252. [PMID: 36469861 PMCID: PMC9733428 DOI: 10.1093/molbev/msac252] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/19/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022] Open
Abstract
Transforming growth factor-β (TGF-β) signaling is essential for numerous biologic functions. It is a highly conserved pathway found in all metazoans including the nematode Caenorhabditis elegans, which has also been pivotal in identifying many components. Utilizing a comparative evolutionary approach, we explored TGF-β signaling in nine nematode species and revealed striking variability in TGF-β gene frequency across the lineage. Of the species analyzed, gene duplications in the DAF-7 pathway appear common with the greatest disparity observed in Pristionchus pacificus. Specifically, multiple paralogues of daf-3, daf-4 and daf-7 were detected. To investigate this additional diversity, we induced mutations in 22 TGF-β components and generated corresponding double, triple, and quadruple mutants revealing both conservation and diversification in function. Although the DBL-1 pathway regulating body morphology appears highly conserved, the DAF-7 pathway exhibits functional divergence, notably in some aspects of dauer formation. Furthermore, the formation of the phenotypically plastic mouth in P. pacificus is partially influenced through TGF-β with the strongest effect in Ppa-tag-68. This appears important for numerous processes in P. pacificus but has no known function in C. elegans. Finally, we observe behavioral differences in TGF-β mutants including in chemosensation and the establishment of the P. pacificus kin-recognition signal. Thus, TGF-β signaling in nematodes represents a stochastic genetic network capable of generating novel functions through the duplication and deletion of associated genes.
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Affiliation(s)
- Wen-Sui Lo
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Marianne Roca
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior—Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Mohannad Dardiry
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Marisa Mackie
- Department of Biology, California State University, Northridge, CA
| | - Gabi Eberhardt
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Ray Hong
- Department of Biology, California State University, Northridge, CA
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - James W Lightfoot
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior—Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
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7
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Wighard SS, Athanasouli M, Witte H, Rödelsperger C, Sommer RJ. A New Hope: A Hermaphroditic Nematode Enables Analysis of a Recent Whole Genome Duplication Event. Genome Biol Evol 2022; 14:6868937. [PMID: 36461901 PMCID: PMC9763058 DOI: 10.1093/gbe/evac169] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/03/2022] [Accepted: 11/22/2022] [Indexed: 12/05/2022] Open
Abstract
Whole genome duplication (WGD) is often considered a major driver of evolution that leads to phenotypic novelties. However, the importance of WGD for evolution is still controversial because most documented WGD events occurred anciently and few experimental systems amenable to genetic analysis are available. Here, we report a recent WGD event in the hermaphroditic nematode Allodiplogaster sudhausi and present a comparison with a gonochoristic (male/female) sister species that did not undergo WGD. Self-fertilizing reproduction of A. sudhausi makes it amenable to functional analysis and an ideal system to study WGD events. We document WGD in A. sudhausi through karyotype analysis and whole genome sequencing, the latter of which allowed us to 1) identify functional bias in retention of protein domains and metabolic pathways, 2) show most duplicate genes are under evolutionary constraint, 3) show a link between sequence and expression divergence, and 4) characterize differentially expressed duplicates. We additionally show WGD is associated with increased body size and an abundance of repeat elements (36% of the genome), including a recent expansion of the DNA-hAT/Ac transposon family. Finally, we demonstrate the use of CRISPR/Cas9 to generate mutant knockouts, whereby two WGD-derived duplicate genes display functional redundancy in that they both need to be knocked out to generate a phenotype. Together, we present a novel experimental system that is convenient for examining and characterizing WGD-derived genes both computationally and functionally.
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Affiliation(s)
- Sara S Wighard
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
| | - Marina Athanasouli
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
| | - Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
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Torres TC, Moaddeli D, Averbukh M, Coakley A, Dutta N, Garcia G, Higuchi-Sanabria R. Surveying Low-Cost Methods to Measure Lifespan and Healthspan in Caenorhabditis elegans. JOURNAL OF VISUALIZED EXPERIMENTS : JOVE 2022:10.3791/64091. [PMID: 35665741 PMCID: PMC9881476 DOI: 10.3791/64091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The discovery and development of Caenorhabditis elegans as a model organism was influential in biology, particularly in the field of aging. Many historical and contemporary studies have identified thousands of lifespan-altering paradigms, including genetic mutations, transgenic gene expression, and hormesis, a beneficial, low-grade exposure to stress. With its many advantages, including a short lifespan, easy and low-cost maintenance, and fully sequenced genome with homology to almost two-thirds of all human genes, C. elegans has quickly been adopted as an outstanding model for stress and aging biology. Here, several standardized methods are surveyed for measuring lifespan and healthspan that can be easily adapted into almost any research environment, especially those with limited equipment and funds. The incredible utility of C. elegans is featured, highlighting the capacity to perform powerful genetic analyses in aging biology without the necessity of extensive infrastructure. Finally, the limitations of each analysis and alternative approaches are discussed for consideration.
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Affiliation(s)
- Toni Castro Torres
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089
| | - Darius Moaddeli
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089
| | - Maxim Averbukh
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089
| | - Aeowynn Coakley
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089
| | - Naibedya Dutta
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089
| | - Gilberto Garcia
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089.,correspondence: ;
| | - Ryo Higuchi-Sanabria
- Leonard Davis School of Gerontology, University of Southern California. 3715 McClintock Ave, University Park Campus, Los Angeles, CA 90089.,correspondence: ;
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9
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Wos G, Macková L, Kubíková K, Kolář F. Ploidy and local environment drive intraspecific variation in endoreduplication in Arabidopsis arenosa. AMERICAN JOURNAL OF BOTANY 2022; 109:259-271. [PMID: 35137947 DOI: 10.1002/ajb2.1818] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/28/2021] [Accepted: 09/28/2021] [Indexed: 06/14/2023]
Abstract
PREMISE Endoreduplication, nonheritable duplication of a nuclear genome, is widespread in plants and plays a role in developmental processes related to cell differentiation. However, neither ecological nor cytological factors influencing intraspecific variation in endoreduplication are fully understood. METHODS We cultivated plants covering the range-wide natural diversity of diploid and tetraploid populations of Arabidopsis arenosa in common conditions to investigate the effect of original ploidy level on endoreduplication. We also raised plants from several foothill and alpine populations from different lineages and of both ploidies to test for the effect of elevation. We determined the endoreduplication level in leaves of young plants by flow cytometry. Using RNA-seq data available for our populations, we analyzed gene expression analysis in individuals that differed in endoreduplication level. RESULTS We found intraspecific variation in endoreduplication that was mainly driven by the original ploidy level of populations, with significantly higher endoreduplication in diploids. An effect of elevation was also found within each ploidy, yet its direction exhibited rather regional-specific patterns. Transcriptomic analysis comparing individuals with high vs. low endopolyploidy revealed a majority of differentially expressed genes related to the stress and hormone response and to modifications especially in the cell wall and in chloroplasts. CONCLUSIONS Our results support the general assumption of higher potential of low-ploidy organisms to undergo endoreduplication and suggest that endoreduplication is further integrated within the stress response pathways for a fine-tune adjustment of the endoreduplication process to their local environment.
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Affiliation(s)
- Guillaume Wos
- Department of Botany, Charles University, Benátská 2, 12801 Prague, Czech Republic
| | - Lenka Macková
- Department of Botany, Charles University, Benátská 2, 12801 Prague, Czech Republic
| | - Kateřina Kubíková
- Department of Zoology, Charles University, Viničná 7, 12845 Prague, Czech Republic
| | - Filip Kolář
- Department of Botany, Charles University, Benátská 2, 12801 Prague, Czech Republic
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, CZ-252 43 Průhonice, Czech Republic
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10
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Braukmann F, Jordan D, Jenkins B, Koulman A, Miska EA. SID-2 negatively regulates development likely independent of nutritional dsRNA uptake. RNA Biol 2021; 18:888-899. [PMID: 33044912 PMCID: PMC8081039 DOI: 10.1080/15476286.2020.1827619] [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: 07/21/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 01/05/2023] Open
Abstract
RNA interference (RNAi) is a gene regulatory mechanism based on RNA-RNA interaction conserved through eukaryotes. Surprisingly, many animals can take-up human-made double stranded RNA (dsRNA) from the environment to initiate RNAi suggesting a mechanism for dsRNA-based information exchange between organisms and their environment. However, no naturally occurring example has been identified since the discovery of the phenomenon 22 years ago. Therefore it remains enigmatic why animals are able to take up dsRNA. Here, we explore other possible functions by performing phenotypic studies of dsRNA uptake deficient sid-2 mutants in Caenorhabditis elegans. We find that SID-2 does not have a nutritional role in feeding experiments using genetic sensitized mutants. Furthermore, we use robot assisted imaging to show that sid-2 mutants accelerate growth rate and, by maternal contribution, body length at hatching. Finally, we perform transcriptome and lipidome analysis showing that sid-2 has no effect on energy storage lipids, but affects signalling lipids and the embryo transcriptome. Overall, these results suggest that sid-2 has mild effects on development and is unlikely functioning in the nutritional uptake of dsRNA. These findings broaden our understanding of the biological role of SID-2 and motivate studies identifying the role of environmental dsRNA uptake.
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Affiliation(s)
- Fabian Braukmann
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - David Jordan
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Benjamin Jenkins
- Core Metabolomics and Lipidomics Laboratory, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Albert Koulman
- Core Metabolomics and Lipidomics Laboratory, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Eric Alexander Miska
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge, UK
- Department of Genetics, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Cambridge, UK
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11
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Tan C, Ginzberg MB, Webster R, Iyengar S, Liu S, Papadopoli D, Concannon J, Wang Y, Auld DS, Jenkins JL, Rost H, Topisirovic I, Hilfinger A, Derry WB, Patel N, Kafri R. Cell size homeostasis is maintained by CDK4-dependent activation of p38 MAPK. Dev Cell 2021; 56:1756-1769.e7. [PMID: 34022133 DOI: 10.1016/j.devcel.2021.04.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 02/08/2021] [Accepted: 04/28/2021] [Indexed: 02/07/2023]
Abstract
While molecules that promote the growth of animal cells have been identified, it remains unclear how such signals are orchestrated to determine a characteristic target size for different cell types. It is increasingly clear that cell size is determined by size checkpoints-mechanisms that restrict the cell cycle progression of cells that are smaller than their target size. Previously, we described a p38 MAPK-dependent cell size checkpoint mechanism whereby p38 is selectively activated and prevents cell cycle progression in cells that are smaller than a given target size. In this study, we show that the specific target size required for inactivation of p38 and transition through the cell cycle is determined by CDK4 activity. Our data suggest a model whereby p38 and CDK4 cooperate analogously to the function of a thermostat: while p38 senses irregularities in size, CDK4 corresponds to the thermostat dial that sets the target size.
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Affiliation(s)
- Ceryl Tan
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Miriam B Ginzberg
- Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Rachel Webster
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Seshu Iyengar
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, ON L5L 1C6, Canada
| | - Shixuan Liu
- Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - David Papadopoli
- Gerald Bronfman Department of Oncology and Lady Davis Institute, McGill University Montreal, QC H4A 3T2, Canada
| | - John Concannon
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Yuan Wang
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Douglas S Auld
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Jeremy L Jenkins
- Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Hannes Rost
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada
| | - Ivan Topisirovic
- Gerald Bronfman Department of Oncology and Lady Davis Institute, McGill University Montreal, QC H4A 3T2, Canada
| | - Andreas Hilfinger
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, ON L5L 1C6, Canada
| | - W Brent Derry
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Nish Patel
- Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Ran Kafri
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1A8, Canada; Cell Biology, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.
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12
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Glazier DS. Genome Size Covaries More Positively with Propagule Size than Adult Size: New Insights into an Old Problem. BIOLOGY 2021; 10:270. [PMID: 33810583 PMCID: PMC8067107 DOI: 10.3390/biology10040270] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/18/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022]
Abstract
The body size and (or) complexity of organisms is not uniformly related to the amount of genetic material (DNA) contained in each of their cell nuclei ('genome size'). This surprising mismatch between the physical structure of organisms and their underlying genetic information appears to relate to variable accumulation of repetitive DNA sequences, but why this variation has evolved is little understood. Here, I show that genome size correlates more positively with egg size than adult size in crustaceans. I explain this and comparable patterns observed in other kinds of animals and plants as resulting from genome size relating strongly to cell size in most organisms, which should also apply to single-celled eggs and other reproductive propagules with relatively few cells that are pivotal first steps in their lives. However, since body size results from growth in cell size or number or both, it relates to genome size in diverse ways. Relationships between genome size and body size should be especially weak in large organisms whose size relates more to cell multiplication than to cell enlargement, as is generally observed. The ubiquitous single-cell 'bottleneck' of life cycles may affect both genome size and composition, and via both informational (genotypic) and non-informational (nucleotypic) effects, many other properties of multicellular organisms (e.g., rates of growth and metabolism) that have both theoretical and practical significance.
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13
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Oliveira NR, Moens T, Fonseca G, Nagata RM, Custódio MR, Gallucci F. Response of life-history traits of estuarine nematodes to the surfactant sodium dodecyl sulfate. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2020; 227:105609. [PMID: 32906060 DOI: 10.1016/j.aquatox.2020.105609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Species responses to stress are expected to be dependent on their life-history strategy. In this study, we compare the responses of two free-living marine nematodes, Litoditis marina and Diplolaimella dievengatensis, both considered opportunistic, fast-growing, and stress-tolerant species, to the exposure to sublethal concentrations of sodium dodecyl sulfate (SDS) surfactant. Specifically, we evaluated the growth and reproduction rates, as well as the survival of individuals exposed from eggs and/or juveniles (J1) onwards. Exposure to SDS significantly affected the growth and reproduction rates of both species. However, whereas growth and reproduction rates of D. dievengatensis were significantly enhanced at low and intermediate concentrations of SDS (0.001% and 0.003%), for L. marina both parameters were significantly reduced by all SDS concentrations tested (0.001%, 0.003% and 0.006%). Exposure to SDS did not affect the survival of adult nematodes of D. dievengatensis, while for L. marina, survival of males exposed to 0.006% SDS was significantly reduced compared to the control. Responses of the life-history traits growth, fecundity and survival did not exhibit clear trade-offs. The contrasting responses of D. dievengatensis and L. marina indicate that biologically and ecologically similar species can have remarkably distinct tolerances to stress, and that, in agreement with recent studies, rhabditid nematodes cannot a priori be considered very stress tolerant. Consequently, single species traits and phylogenetic relatedness are poor predictors of nematode responses to toxic stress posed by anthropogenic activities.
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Affiliation(s)
- Nilvea Ramalho Oliveira
- Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Rua do Matão, trav. 14, n. 101, CEP 05508-090, Cidade Universitária, São Paulo - SP, Brazil; Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Av. Itália, km 8, CEP: 96203-900, Campus Carreiros, Rio Grande - RS, Brazil.
| | - Tom Moens
- Ghent University, Department of Biology, Marine Biology Research Unit, Krijgslaan 281/S8, 9000 Ghent, Belgium
| | - Gustavo Fonseca
- Universidade Federal de São Paulo, Instituto do Mar, Rua Carvalho de Mendonça, 144, CEP: 11070-100, Santos - SP, Brazil
| | - Renato Mitsuo Nagata
- Universidade Federal do Rio Grande, Instituto de Oceanografia, Laboratório de Zooplâncton, Av. Itália, Km 8, CEP: 96203-900, Campus Carreiros, Rio Grande - RS, Brazil
| | - Márcio Reis Custódio
- Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Rua do Matão, trav. 14, n. 101, CEP 05508-090, Cidade Universitária, São Paulo - SP, Brazil
| | - Fabiane Gallucci
- Universidade Federal de São Paulo, Instituto do Mar, Rua Carvalho de Mendonça, 144, CEP: 11070-100, Santos - SP, Brazil
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14
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Qiu X, Yang L, Ye J, Wang W, Zhao T, Hu H, Zhou G. Silencing of cyp-33C9 Gene Affects the Reproduction and Pathogenicity of the Pine Wood Nematode, Bursaphelenchus xylophilus. Int J Mol Sci 2019; 20:E4520. [PMID: 31547281 PMCID: PMC6770203 DOI: 10.3390/ijms20184520] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
Cytochrome P450 genes are very important for plant-parasitic nematodes to reproduce and to metabolize xenobiotic compounds generated by their host plants. The pine wood nematode (PWN), Bursaphelenchus xylophilus, causes very high annual economic losses by killing large numbers of pine trees across Asia and into Europe. In this study, we used RNA interference (RNAi) to analyze the function of the cyp-33C9 gene of PWN. Our results showed that expression of the cyp-33C9 gene was suppressed successfully after soaking nematodes for 24 h in cyp-33C9 double-stranded RNA (dsRNA). The silencing of the cyp-33C9 gene significantly decreased the feeding, reproduction, oviposition and egg hatch of B. xylophilus. Meanwhile, the migration speed of B. xylophilus in Pinus thunbergii was reduced in the early stages when the cyp-33C9 gene was silenced in the nematodes. Moreover, knockdown of the cyp-33C9 gene in B. xylophilus caused a decrease in pathogenicity to pine trees. These results suggest that the cyp-33C9 gene plays an important role in the reproduction and pathogenicity of B. xylophilus. This discovery identified several functions of the cyp-33C9 gene in B. xylophilus and provided useful information for understanding the molecular mechanism behind pine wilt disease caused by PWN.
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Affiliation(s)
- Xiuwen Qiu
- Poyang Lake Eco-economy Research Center, Jiujiang University, Jiujiang 332005, Jiangxi, China.
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, China.
- Office of Mountain-River-Lake Development Committee of Jiangxi Province, Nanchang 330046, Jiangxi, China.
| | - Lili Yang
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China.
| | - Jianren Ye
- College of Forestry, Nanjing Forestry University, Nanjing 210037, Jiangsu, China.
| | - Wei Wang
- Poyang Lake Eco-economy Research Center, Jiujiang University, Jiujiang 332005, Jiangxi, China.
| | - Tiantian Zhao
- Poyang Lake Eco-economy Research Center, Jiujiang University, Jiujiang 332005, Jiangxi, China.
| | - Hao Hu
- Poyang Lake Eco-economy Research Center, Jiujiang University, Jiujiang 332005, Jiangxi, China.
| | - Guixiang Zhou
- Poyang Lake Eco-economy Research Center, Jiujiang University, Jiujiang 332005, Jiangxi, China.
- College of Bioscience and Bioengineering, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, China.
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15
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Ng LF, Ng LT, van Breugel M, Halliwell B, Gruber J. Mitochondrial DNA Damage Does Not Determine C. elegans Lifespan. Front Genet 2019; 10:311. [PMID: 31031801 PMCID: PMC6473201 DOI: 10.3389/fgene.2019.00311] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 03/21/2019] [Indexed: 02/02/2023] Open
Abstract
The mitochondrial free radical theory of aging (mFRTA) proposes that accumulation of oxidative damage to macromolecules in mitochondria is a causative mechanism for aging. Accumulation of mitochondrial DNA (mtDNA) damage may be of particular interest in this context. While there is evidence for age-dependent accumulation of mtDNA damage, there have been only a limited number of investigations into mtDNA damage as a determinant of longevity. This lack of quantitative data regarding mtDNA damage is predominantly due to a lack of reliable assays to measure mtDNA damage. Here, we report adaptation of a quantitative real-time polymerase chain reaction (qRT-PCR) assay for the detection of sequence-specific mtDNA damage in C. elegans and apply this method to investigate the role of mtDNA damage in the aging of nematodes. We compare damage levels in old and young animals and also between wild-type animals and long-lived mutant strains or strains with modifications in ROS detoxification or production rates. We confirm an age-dependent increase in mtDNA damage levels in C. elegans but found that there is no simple relationship between mtDNA damage and lifespan. MtDNA damage levels were high in some mutants with long lifespan (and vice versa). We next investigated mtDNA damage, lifespan and healthspan effects in nematode subjected to exogenously elevated damage (UV- or γ-radiation induced). We, again, observed a complex relationship between damage and lifespan in such animals. Despite causing a significant elevation in mtDNA damage, γ-radiation did not shorten the lifespan of nematodes at any of the doses tested. When mtDNA damage levels were elevated significantly using UV-radiation, nematodes did suffer from shorter lifespan at the higher end of exposure tested. However, surprisingly, we also found hormetic lifespan and healthspan benefits in nematodes treated with intermediate doses of UV-radiation, despite the fact that mtDNA damage in these animals was also significantly elevated. Our results suggest that within a wide physiological range, the level of mtDNA damage does not control lifespan in C. elegans.
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Affiliation(s)
- Li Fang Ng
- Ageing Research Laboratory, Science Division, Yale-NUS College, Singapore, Singapore
| | - Li Theng Ng
- Ageing Research Laboratory, Science Division, Yale-NUS College, Singapore, Singapore.,Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, Singapore
| | - Michiel van Breugel
- Environmental Science Laboratory, Science Division, Yale-NUS College, Singapore, Singapore
| | - Barry Halliwell
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jan Gruber
- Ageing Research Laboratory, Science Division, Yale-NUS College, Singapore, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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16
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Developmental Control of the Cell Cycle: Insights from Caenorhabditis elegans. Genetics 2019; 211:797-829. [PMID: 30846544 PMCID: PMC6404260 DOI: 10.1534/genetics.118.301643] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
During animal development, a single fertilized egg forms a complete organism with tens to trillions of cells that encompass a large variety of cell types. Cell cycle regulation is therefore at the center of development and needs to be carried out in close coordination with cell differentiation, migration, and death, as well as tissue formation, morphogenesis, and homeostasis. The timing and frequency of cell divisions are controlled by complex combinations of external and cell-intrinsic signals that vary throughout development. Insight into how such controls determine in vivo cell division patterns has come from studies in various genetic model systems. The nematode Caenorhabditis elegans has only about 1000 somatic cells and approximately twice as many germ cells in the adult hermaphrodite. Despite the relatively small number of cells, C. elegans has diverse tissues, including intestine, nerves, striated and smooth muscle, and skin. C. elegans is unique as a model organism for studies of the cell cycle because the somatic cell lineage is invariant. Somatic cells divide at set times during development to produce daughter cells that adopt reproducible developmental fates. Studies in C. elegans have allowed the identification of conserved cell cycle regulators and provided insights into how cell cycle regulation varies between tissues. In this review, we focus on the regulation of the cell cycle in the context of C. elegans development, with reference to other systems, with the goal of better understanding how cell cycle regulation is linked to animal development in general.
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17
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Thapa S, Gates MK, Reuter-Carlson U, Androwski RJ, Schroeder NE. Convergent evolution of saccate body shapes in nematodes through distinct developmental mechanisms. EvoDevo 2019; 10:5. [PMID: 30911368 PMCID: PMC6416850 DOI: 10.1186/s13227-019-0118-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 03/01/2019] [Indexed: 12/02/2022] Open
Abstract
Background The vast majority of nematode species have vermiform (worm-shaped) body plans throughout post-embryonic development. However, atypical body shapes have evolved multiple times. The plant-parasitic Tylenchomorpha nematode Heterodera glycines hatches as a vermiform infective juvenile. Following infection and the establishment of a feeding site, H. glycines grows disproportionately greater in width than length, developing into a saccate adult. Body size in Caenorhabditis elegans was previously shown to correlate with post-embryonic divisions of laterally positioned stem cell-like ‘seam’ cells and endoreduplication of seam cell epidermal daughters. To test if a similar mechanism produces the unusual body shape of saccate parasitic nematodes, we compared seam cell development and epidermal ploidy levels of H. glycines to C. elegans. To study the evolution of body shape development, we examined seam cell development of four additional Tylenchomorpha species with vermiform or saccate body shapes. Results We confirmed the presence of seam cell homologs and their proliferation in H. glycines. This results in the adult female epidermis having approximately 1800 nuclei compared with the 139 nuclei in the primary epidermal syncytium of C. elegans. Similar to C. elegans, we found a significant correlation between H. glycines body volume and the number and ploidy level of epidermal nuclei. While we found that the seam cells also proliferate in the independently evolved saccate nematode Meloidogyne incognita following infection, the division pattern differed substantially from that seen in H. glycines. Interestingly, the close relative of H. glycines, Rotylenchulus reniformis does not undergo extensive seam cell proliferation during its development into a saccate form. Conclusions Our data reveal that seam cell proliferation and epidermal nuclear ploidy correlate with growth in H. glycines. Our finding of distinct seam cell division patterns in the independently evolved saccate species M. incognita and H. glycines is suggestive of parallel evolution of saccate forms. The lack of seam cell proliferation in R. reniformis demonstrates that seam cell proliferation and endoreduplication are not strictly required for increased body volume and atypical body shape. We speculate that R. reniformis may serve as an extant transitional model for the evolution of saccate body shape.
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Affiliation(s)
- Sita Thapa
- 1Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Michael K Gates
- 1Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Ursula Reuter-Carlson
- 1Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Rebecca J Androwski
- 2Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Nathan E Schroeder
- 1Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL USA.,2Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL USA
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18
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Bhosale R, Boudolf V, Cuevas F, Lu R, Eekhout T, Hu Z, Van Isterdael G, Lambert GM, Xu F, Nowack MK, Smith RS, Vercauteren I, De Rycke R, Storme V, Beeckman T, Larkin JC, Kremer A, Höfte H, Galbraith DW, Kumpf RP, Maere S, De Veylder L. A Spatiotemporal DNA Endoploidy Map of the Arabidopsis Root Reveals Roles for the Endocycle in Root Development and Stress Adaptation. THE PLANT CELL 2018; 30:2330-2351. [PMID: 30115738 PMCID: PMC6241279 DOI: 10.1105/tpc.17.00983] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 06/18/2018] [Accepted: 08/08/2018] [Indexed: 05/21/2023]
Abstract
Somatic polyploidy caused by endoreplication is observed in arthropods, molluscs, and vertebrates but is especially prominent in higher plants, where it has been postulated to be essential for cell growth and fate maintenance. However, a comprehensive understanding of the physiological significance of plant endopolyploidy has remained elusive. Here, we modeled and experimentally verified a high-resolution DNA endoploidy map of the developing Arabidopsis thaliana root, revealing a remarkable spatiotemporal control of DNA endoploidy levels across tissues. Fitting of a simplified model to publicly available data sets profiling root gene expression under various environmental stress conditions suggested that this root endoploidy patterning may be stress-responsive. Furthermore, cellular and transcriptomic analyses revealed that inhibition of endoreplication onset alters the nuclear-to-cellular volume ratio and the expression of cell wall-modifying genes, in correlation with the appearance of cell structural changes. Our data indicate that endopolyploidy might serve to coordinate cell expansion with structural stability and that spatiotemporal endoreplication pattern changes may buffer for stress conditions, which may explain the widespread occurrence of the endocycle in plant species growing in extreme or variable environments.
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Affiliation(s)
- Rahul Bhosale
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, B-9052 Ghent, Belgium
- Center for Plant Integrative Biology, University of Nottingham, Sutton Bonington LE12 5RD, United Kingdom
| | - Veronique Boudolf
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Fabiola Cuevas
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Ran Lu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Thomas Eekhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Zhubing Hu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, 475004 Kaifeng, China
| | - Gert Van Isterdael
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- VIB Flow Core, B-9052 Ghent, Belgium
| | | | - Fan Xu
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Moritz K Nowack
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Richard S Smith
- Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany
| | - Ilse Vercauteren
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Riet De Rycke
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- VIB Bio Imaging Core, B-9052 Ghent, Belgium
| | - Veronique Storme
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Tom Beeckman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - John C Larkin
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Anna Kremer
- Center for Plant Integrative Biology, University of Nottingham, Sutton Bonington LE12 5RD, United Kingdom
- VIB Bio Imaging Core, B-9052 Ghent, Belgium
| | - Herman Höfte
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - David W Galbraith
- School of Plant Sciences, University of Arizona, Tucson, Arizona 85721
- Key Laboratory of Plant Stress Biology, State Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng 475004, China
| | - Robert P Kumpf
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
| | - Steven Maere
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
- Bioinformatics Institute Ghent, Ghent University, B-9052 Ghent, Belgium
| | - Lieven De Veylder
- Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, B-9052 Ghent, Belgium
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19
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Han Z, Thapa S, Reuter-Carlson U, Reed H, Gates M, Lambert KN, Schroeder NE. Immobility in the sedentary plant-parasitic nematode H. glycines is associated with remodeling of neuromuscular tissue. PLoS Pathog 2018; 14:e1007198. [PMID: 30114260 PMCID: PMC6095618 DOI: 10.1371/journal.ppat.1007198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/05/2018] [Indexed: 12/22/2022] Open
Abstract
The sedentary plant-parasitic nematodes are considered among the most economically damaging pathogens of plants. Following infection and the establishment of a feeding site, sedentary nematodes become immobile. Loss of mobility is reversed in adult males while females never regain mobility. The structural basis for this change in mobility is unknown. We used a combination of light and transmission electron microscopy to demonstrate cell-specific muscle atrophy and sex-specific renewal of neuromuscular tissue in the sedentary nematode Heterodera glycines. We found that both females and males undergo body wall muscle atrophy and loss of attachment to the underlying cuticle during immobile developmental stages. Male H. glycines undergo somatic muscle renewal prior to molting into a mobile adult. In addition, we found developmental changes to the organization and number of motor neurons in the ventral nerve cord correlated with changes in mobility. To further examine neuronal changes associated with immobility, we used a combination of immunohistochemistry and molecular biology to characterize the GABAergic nervous system of H. glycines during mobile and immobile stages. We cloned and confirmed the function of the putative H. glycines GABA synthesis-encoding gene hg-unc-25 using heterologous rescue in C. elegans. We found a reduction in gene expression of hg-unc-25 as well as a reduction in the number of GABA-immunoreactive neurons during immobile developmental stages. Finally, we found evidence of similar muscle atrophy in the phylogenetically diverged plant-parasitic nematode Meloidogyne incognita. Together, our data demonstrate remodeling of neuromuscular structure and function during sedentary plant-parasitic nematode development.
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Affiliation(s)
- Ziduan Han
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Sita Thapa
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Ursula Reuter-Carlson
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Hannah Reed
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Michael Gates
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Kris N. Lambert
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Nathan E. Schroeder
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
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20
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Woodruff GC, Willis JH, Phillips PC. Dramatic evolution of body length due to postembryonic changes in cell size in a newly discovered close relative of Caenorhabditis elegans. Evol Lett 2018; 2:427-441. [PMID: 30283693 PMCID: PMC6121821 DOI: 10.1002/evl3.67] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 12/24/2022] Open
Abstract
Understanding morphological diversity-and morphological constraint-has been a central question in evolutionary biology since its inception. Nematodes of the genus Caenorhabditis, which contains the well-studied model organism C. elegans, display remarkable morphological consistency in the face of extensive genetic divergence. Here, we provide a description of the broad developmental patterns of a newly discovered species, C. sp. 34, which was isolated from fresh figs in Okinawa and which is among the closest known relatives of C. elegans. C. sp. 34 displays an extremely large body size; it can grow to be nearly twice as long as C. elegans and all other known members of the genus. Observations of the timing of developmental milestones reveal that C. sp. 34 develops about twice as slowly as C. elegans. Measurements of embryonic and larval size show that the size difference between C. sp. 34 and C. elegans is largely due to postembryonic events, particularly during the transition from larval to adult stages. This difference in size is not attributable to differences in germ line chromosome number or the number of somatic cells. The overall difference in body size is therefore largely attributable to changes in cell size via increased cytoplasmic volume. Because of its close relationship to C. elegans, the distinctness of C. sp. 34 provides an ideal system for the detailed analysis of evolutionary diversification. The context of over 40 years of C. elegans developmental genetics also reveals clues into how natural selection and developmental constraint act jointly to promote patterns of morphological stasis and divergence in this group.
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Affiliation(s)
- Gavin C. Woodruff
- Forestry and Forest Products Research InstituteForest Pathology LaboratoryTsukubaJapan
- Department of Biology, Institute of Ecology and EvolutionUniversity of OregonEugeneOregon97403
| | - John H. Willis
- Department of Biology, Institute of Ecology and EvolutionUniversity of OregonEugeneOregon97403
| | - Patrick C. Phillips
- Department of Biology, Institute of Ecology and EvolutionUniversity of OregonEugeneOregon97403
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21
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Liang J, De Castro A, Flores L. Detecting Protein Subcellular Localization by Green Fluorescence Protein Tagging and 4',6-Diamidino-2-phenylindole Staining in Caenorhabditis elegans. J Vis Exp 2018. [PMID: 30102267 DOI: 10.3791/57914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In this protocol, a green fluorescence protein (GFP) fusion protein and 4',6-diamidino-2-phenylindole (DAPI) staining are used to track protein subcellular localization changes; in particular, a nuclear translocation under a heat stress condition. Proteins react correspondingly to external and internal signals. A common mechanism is to change its subcellular localization. This article describes a protocol to track protein localization that does not require an antibody, radioactive labeling, or a confocal microscope. In this article, GFP is used to tag the target protein EXL-1 in C. elegans, a member of the chloride intracellular channel proteins (CLICs) family, including mammalian CLIC4. An integrated translational exl-1::gfp transgenic line (with a promoter and a full gene sequence) was created by transformation and γ-radiation, and stably expresses the gene and gfp. Recent research showed that upon heat stress, not oxidative stress, EXL-1::GFP accumulates in the nucleus. Overlapping the GFP signal with both the nuclei structure and the DAPI signals confirms the EXL-1 subcellular localization changes under stress. This protocol presents two different fixation methods for DAPI staining: ethanol fixation and acetone fixation. The DAPI staining protocol presented in this article is fast and efficient and preserves both the GFP signal and the protein subcellular localization changes. This method only requires a fluorescence microscope with Nomarski, a FITC filter, and a DAPI filter. It is suitable for a small laboratory setting, undergraduate student research, high school student research, and biotechnology classrooms.
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Affiliation(s)
- Jun Liang
- Department of Science, Borough of Manhattan Community College/CUNY;
| | - Aijo De Castro
- Department of Science, Borough of Manhattan Community College/CUNY
| | - Lizette Flores
- Department of Science, Borough of Manhattan Community College/CUNY
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22
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Clarke EK, Rivera Gomez KA, Mustachi Z, Murph MC, Schvarzstein M. Manipulation of Ploidy in Caenorhabditis elegans. J Vis Exp 2018. [PMID: 29608173 PMCID: PMC5931776 DOI: 10.3791/57296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mechanisms that involve whole genome polyploidy play important roles in development and evolution; also, an abnormal generation of tetraploid cells has been associated with both the progression of cancer and the development of drug resistance. Until now, it has not been feasible to easily manipulate the ploidy of a multicellular animal without generating mostly sterile progeny. Presented here is a simple and rapid protocol for generating tetraploid Caenorhabditis elegans animals from any diploid strain. This method allows the user to create a bias in chromosome segregation during meiosis, ultimately increasing ploidy in C. elegans. This strategy relies on the transient reduction of expression of the rec-8 gene to generate diploid gametes. A rec-8 mutant produces diploid gametes that can potentially produce tetraploids upon fertilization. This tractable scheme has been used to generate tetraploid strains carrying mutations and chromosome rearrangements to gain insight into chromosomal dynamics and interactions during pairing and synapsis in meiosis. This method is efficient for generating stable tetraploid strains without genetic markers, can be applied to any diploid strain, and can be used to derive triploid C. elegans. This straightforward method is useful for investigating other fundamental biological questions relevant to genome instability, gene dosage, biological scaling, extracellular signaling, adaptation to stress, development of resistance to drugs, and mechanisms of speciation.
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Affiliation(s)
- Erlyana K Clarke
- Brooklyn College, Biology Department, City University of New York
| | - Katherine A Rivera Gomez
- Brooklyn College, Biology Department, City University of New York; The Graduate Center, Biology Department, City University of New York
| | - Zaki Mustachi
- Brooklyn College, Biology Department, City University of New York
| | - Mikaela C Murph
- Brooklyn College, Biology Department, City University of New York; Advanced Science Research Center, City University of New York
| | - Mara Schvarzstein
- Brooklyn College, Biology Department, City University of New York; The Graduate Center, Biology Department, City University of New York; Advanced Science Research Center, City University of New York;
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23
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Doyle SR, Laing R, Bartley DJ, Britton C, Chaudhry U, Gilleard JS, Holroyd N, Mable BK, Maitland K, Morrison AA, Tait A, Tracey A, Berriman M, Devaney E, Cotton JA, Sargison ND. A Genome Resequencing-Based Genetic Map Reveals the Recombination Landscape of an Outbred Parasitic Nematode in the Presence of Polyploidy and Polyandry. Genome Biol Evol 2018; 10:396-409. [PMID: 29267942 PMCID: PMC5793844 DOI: 10.1093/gbe/evx269] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2017] [Indexed: 12/27/2022] Open
Abstract
The parasitic nematode Haemonchus contortus is an economically and clinically important pathogen of small ruminants, and a model system for understanding the mechanisms and evolution of traits such as anthelmintic resistance. Anthelmintic resistance is widespread and is a major threat to the sustainability of livestock agriculture globally; however, little is known about the genome architecture and parameters such as recombination that will ultimately influence the rate at which resistance may evolve and spread. Here, we performed a genetic cross between two divergent strains of H. contortus, and subsequently used whole-genome resequencing of a female worm and her brood to identify the distribution of genome-wide variation that characterizes these strains. Using a novel bioinformatic approach to identify variants that segregate as expected in a pseudotestcross, we characterized linkage groups and estimated genetic distances between markers to generate a chromosome-scale F1 genetic map. We exploited this map to reveal the recombination landscape, the first for any helminth species, demonstrating extensive variation in recombination rate within and between chromosomes. Analyses of these data also revealed the extent of polyandry, whereby at least eight males were found to have contributed to the genetic variation of the progeny analyzed. Triploid offspring were also identified, which we hypothesize are the result of nondisjunction during female meiosis or polyspermy. These results expand our knowledge of the genetics of parasitic helminths and the unusual life-history of H. contortus, and enhance ongoing efforts to understand the genetic basis of resistance to the drugs used to control these worms and for related species that infect livestock and humans throughout the world. This study also demonstrates the feasibility of using whole-genome resequencing data to directly construct a genetic map in a single generation cross from a noninbred nonmodel organism with a complex lifecycle.
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Affiliation(s)
- Stephen R Doyle
- Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Roz Laing
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - David J Bartley
- Moredun Research Institute, Pentlands Science Park, Penicuik, United Kingdom
| | - Collette Britton
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Umer Chaudhry
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, United Kingdom
| | - John S Gilleard
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Alberta, Canada
| | - Nancy Holroyd
- Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Barbara K Mable
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Kirsty Maitland
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Alison A Morrison
- Moredun Research Institute, Pentlands Science Park, Penicuik, United Kingdom
| | - Andy Tait
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Alan Tracey
- Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Eileen Devaney
- Institute of Biodiversity Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - James A Cotton
- Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom
| | - Neil D Sargison
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, United Kingdom
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24
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Heyman J, Polyn S, Eekhout T, De Veylder L. Tissue-Specific Control of the Endocycle by the Anaphase Promoting Complex/Cyclosome Inhibitors UVI4 and DEL1. PLANT PHYSIOLOGY 2017; 175:303-313. [PMID: 28698355 PMCID: PMC5580769 DOI: 10.1104/pp.17.00785] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 07/07/2017] [Indexed: 05/03/2023]
Abstract
The endocycle represents a modified mitotic cell cycle that in plants is often coupled to cell enlargement and differentiation. Endocycle onset is controlled by activity of the Anaphase Promoting Complex/Cyclosome (APC/C), a multisubunit E3 ubiquitin ligase targeting cell-cycle factors for destruction. CELL CYCLE SWITCH52 (CCS52) proteins represent rate-limiting activator subunits of the APC/C. In Arabidopsis (Arabidopsis thaliana), mutations in either CCS52A1 or CCS52A2 activators result in a delayed endocycle onset, whereas their overexpression triggers increased DNA ploidy levels. Here, the relative contribution of the APC/CCCS52A1 and APC/CCCS52A2 complexes to different developmental processes was studied through analysis of their negative regulators, being the ULTRAVIOLET-B-INSENSITIVE4 protein and the DP-E2F-Like1 transcriptional repressor, respectively. Our data illustrate cooperative activity of the APC/CCCS52A1 and APC/CCCS52A2 complexes during root and trichome development, but functional interdependency during leaf development. Furthermore, we found APC/CCCS52A1 activity to control CCS52A2 expression. We conclude that interdependency of CCS52A-controlled APC/C activity is controlled in a tissue-specific manner.
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Affiliation(s)
- Jefri Heyman
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium and Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Stefanie Polyn
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium and Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Thomas Eekhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium and Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
| | - Lieven De Veylder
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium and Center for Plant Systems Biology, VIB, 9052 Ghent, Belgium
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25
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EGFR-dependent TOR-independent endocycles support Drosophila gut epithelial regeneration. Nat Commun 2017; 8:15125. [PMID: 28485389 PMCID: PMC5436070 DOI: 10.1038/ncomms15125] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 03/02/2017] [Indexed: 12/21/2022] Open
Abstract
Following gut epithelial damage, epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) signalling triggers Drosophila intestinal stem cells to produce enteroblasts (EBs) and enterocytes (ECs) that regenerate the gut. As EBs differentiate into ECs, they become postmitotic, but undergo extensive growth and DNA endoreplication. Here we report that EGFR/RAS/MAPK signalling is required and sufficient to drive damage-induced EB/EC growth. Endoreplication occurs exclusively in EBs and newborn ECs that inherit EGFR and active MAPK from fast-dividing progenitors. Mature ECs lack EGF receptors and are refractory to growth signalling. Genetic tests indicated that stress-dependent EGFR/MAPK promotes gut regeneration via a novel mechanism that operates independently of Insulin/Pi3K/TOR signalling, which is nevertheless required in nonstressed conditions. The E2f1 transcription factor is required for and sufficient to drive EC endoreplication, and Ras/Raf signalling upregulates E2f1 levels posttranscriptionally. We illustrate how distinct signalling mechanisms direct stress-dependent versus homeostatic regeneration, and highlight the importance of postmitotic cell growth in gut epithelial repair. In response to gut epithelial damage, Drosophila stem cells proliferate to produce large polyploid enterocytes (EC), which comprise the bulk of the epithelium. Here, the authors show that stress-dependent EGFR/MAP kinase signalling drives both endoreplication and cell growth in newborn ECs.
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26
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Bar DZ, Charar C, Dorfman J, Yadid T, Tafforeau L, Lafontaine DLJ, Gruenbaum Y. Cell size and fat content of dietary-restricted Caenorhabditis elegans are regulated by ATX-2, an mTOR repressor. Proc Natl Acad Sci U S A 2016; 113:E4620-9. [PMID: 27457958 PMCID: PMC4987808 DOI: 10.1073/pnas.1512156113] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dietary restriction (DR) is a metabolic intervention that extends the lifespan of multiple species, including yeast, flies, nematodes, rodents, and, arguably, rhesus monkeys and humans. Hallmarks of lifelong DR are reductions in body size, fecundity, and fat accumulation, as well as slower development. We have identified atx-2, the Caenorhabditis elegans homolog of the human ATXN2L and ATXN2 genes, as the regulator of these multiple DR phenotypes. Down-regulation of atx-2 increases the body size, cell size, and fat content of dietary-restricted animals and speeds animal development, whereas overexpression of atx-2 is sufficient to reduce the body size and brood size of wild-type animals. atx-2 regulates the mechanistic target of rapamycin (mTOR) pathway, downstream of AMP-activated protein kinase (AMPK) and upstream of ribosomal protein S6 kinase and mTOR complex 1 (TORC1), by its direct association with Rab GDP dissociation inhibitor β, which likely regulates RHEB shuttling between GDP-bound and GTP-bound forms. Taken together, this work identifies a previously unknown mechanism regulating multiple aspects of DR, as well as unknown regulators of the mTOR pathway. They also extend our understanding of diet-dependent growth retardation, and offers a potential mechanism to treat obesity.
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Affiliation(s)
- Daniel Z Bar
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Chayki Charar
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Jehudith Dorfman
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Tam Yadid
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel
| | - Lionel Tafforeau
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles (ULB), BioPark Campus, Gosselies B-6041, Belgium
| | - Denis L J Lafontaine
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles (ULB), BioPark Campus, Gosselies B-6041, Belgium
| | - Yosef Gruenbaum
- Department of Genetics, Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel;
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27
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Xu Y, Jin W, Li N, Zhang W, Liu C, Li C, Li Y. UBIQUITIN-SPECIFIC PROTEASE14 Interacts with ULTRAVIOLET-B INSENSITIVE4 to Regulate Endoreduplication and Cell and Organ Growth in Arabidopsis. THE PLANT CELL 2016; 28:1200-14. [PMID: 27099260 PMCID: PMC4904675 DOI: 10.1105/tpc.16.00007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/19/2016] [Indexed: 05/19/2023]
Abstract
Organ growth is determined by a coordinated combination of cell proliferation and cell growth and differentiation. Endoreduplication is often coupled with cell growth and differentiation, but the genetic and molecular mechanisms that link endoreduplication with cell and organ growth are largely unknown. Here, we describe UBIQUITIN-SPECIFIC PROTEASE14 (UBP14), encoded by the DA3 gene, which functions as a negative regulator of endoreduplication. The Arabidopsis thaliana da3-1 mutant shows large cotyledons, leaves, and flowers with higher ploidy levels. UBP14 acts along with UV-B-INSENSITIVE4 (UVI4), an inhibitor of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase, to repress endoreduplication. Also, UBP14 functions antagonistically with CELL CYCLE SWITCH52 A1 (CCS52A1), an activator of APC/C, to regulate endoreduplication. UBP14 physically associates with UVI4 both in vitro and in vivo but does not directly interact with CCS52A1. Further results reveal that UBP14 influences the stability of cyclin A2;3 (CYCA2;3) and cyclin-dependent kinase B1;1 (CDKB1;1), two downstream components of the APC/C Thus, our findings show how endoreduplication is linked with cell and organ growth by revealing important genetic and molecular functions for the ubiquitin-specific protease UBP14 and for the key cell cycle regulators UVI4, CCS52A1, CYCA2;3, and CDKB1;1.
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Affiliation(s)
- Yingxiu Xu
- State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weihuan Jin
- State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Na Li
- State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenjuan Zhang
- State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Cuimin Liu
- State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yunhai Li
- State Key Laboratory of Plant Cell and Chromosome, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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28
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Neiman M, Beaton MJ, Hessen DO, Jeyasingh PD, Weider LJ. Endopolyploidy as a potential driver of animal ecology and evolution. Biol Rev Camb Philos Soc 2015; 92:234-247. [PMID: 26467853 DOI: 10.1111/brv.12226] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 09/15/2015] [Accepted: 09/16/2015] [Indexed: 01/20/2023]
Abstract
Endopolyploidy - the existence of higher-ploidy cells within organisms that are otherwise of a lower ploidy level (generally diploid) - was discovered decades ago, but remains poorly studied relative to other genomic phenomena, especially in animals. Our synthetic review suggests that endopolyploidy is more common in animals than often recognized and probably influences a number of fitness-related and ecologically important traits. In particular, we argue that endopolyploidy is likely to play a central role in key traits such as gene expression, body and cell size, and growth rate, and in a variety of cell types, including those responsible for tissue regeneration, nutrient storage, and inducible anti-predator defences. We also summarize evidence for intraspecific genetic variation in endopolyploid levels and make the case that the existence of this variation suggests that endopolyploid levels are likely to be heritable and thus a potential target for natural selection. We then discuss why, in light of evident benefits of endopolyploidy, animals remain primarily diploid. We conclude by highlighting key areas for future research such as comprehensive evaluation of the heritability of endopolyploidy and the adaptive scope of endopolyploid-related traits, the extent to which endopolyploid induction incurs costs, and characterization of the relationships between environmental variability and endopolyploid levels.
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Affiliation(s)
- Maurine Neiman
- Department of Biology, University of Iowa, 143 Biology Building, Iowa City, IA 52242, U.S.A
| | - Margaret J Beaton
- Biology Department, Mount Allison University, Sackville, NB E4L 1G7, Canada
| | - Dag O Hessen
- Department of Biosciences, University of Oslo, Box 1066, Blindern, 0316 Oslo, Norway
| | - Punidan D Jeyasingh
- Department of Integrative Biology, Oklahoma State University, 501 Life Sciences West, Stillwater, OK 74078, U.S.A
| | - Lawrence J Weider
- Department of Biology, Program in Ecology and Evolutionary Biology, University of Oklahoma, 730 Van Vleet Oval, Room 304, Norman, OK 73019, U.S.A
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29
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Crowder ME, Flynn JR, McNally KP, Cortes DB, Price KL, Kuehnert PA, Panzica MT, Andaya A, Leary JA, McNally FJ. Dynactin-dependent cortical dynein and spherical spindle shape correlate temporally with meiotic spindle rotation in Caenorhabditis elegans. Mol Biol Cell 2015; 26:3030-46. [PMID: 26133383 PMCID: PMC4551317 DOI: 10.1091/mbc.e15-05-0290] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 06/24/2015] [Indexed: 11/11/2022] Open
Abstract
Cytoplasmic dynein accumulates on the cortex of Caenorhabditis elegans female meiotic spindles just before they rotate in a dynein-dependent manner. These spindles also shorten to a spherical shape that might reduce the drag that opposes cortical pulling by dynein. Oocyte meiotic spindles orient with one pole juxtaposed to the cortex to facilitate extrusion of chromosomes into polar bodies. In Caenorhabditis elegans, these acentriolar spindles initially orient parallel to the cortex and then rotate to the perpendicular orientation. To understand the mechanism of spindle rotation, we characterized events that correlated temporally with rotation, including shortening of the spindle in the pole-to pole axis, which resulted in a nearly spherical spindle at rotation. By analyzing large spindles of polyploid C. elegans and a related nematode species, we found that spindle rotation initiated at a defined spherical shape rather than at a defined spindle length. In addition, dynein accumulated on the cortex just before rotation, and microtubules grew from the spindle with plus ends outward during rotation. Dynactin depletion prevented accumulation of dynein on the cortex and prevented spindle rotation independently of effects on spindle shape. These results support a cortical pulling model in which spindle shape might facilitate rotation because a sphere can rotate without deforming the adjacent elastic cytoplasm. We also present evidence that activation of spindle rotation is promoted by dephosphorylation of the basic domain of p150 dynactin.
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Affiliation(s)
- Marina E Crowder
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Jonathan R Flynn
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Karen P McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Daniel B Cortes
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Kari L Price
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Paul A Kuehnert
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Michelle T Panzica
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Armann Andaya
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Julie A Leary
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
| | - Francis J McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616
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30
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Bi Z, Gong Y, Huang X, Yu H, Bai L, Hu J. Efficacy of Four Nematicides Against the Reproduction and Development of Pinewood Nematode, Bursaphelenchus xylophilus. J Nematol 2015; 47:126-132. [PMID: 26170474 PMCID: PMC4492287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Indexed: 06/04/2023] Open
Abstract
To understand the efficacy of emamectin benzoate, avermectin, milbemectin, and thiacloprid on the reproduction and development of Bursaphelenchus xylophilus, seven parameters, namely population growth, fecundity, egg hatchability, larval lethality, percent larval development, body size, and sexual ratio, were investigated using sublethal (LC20) doses of these compounds in the laboratory. Emamectin benzoate treatment led to a significant suppression in population size, brood size, and percent larval development with 411, 3.50, and 49.63%, respectively, compared to 20850, 24.33, and 61.43% for the negative control. The embryonic and larval lethality increased obviously from 12.47% and 13.70% to 51.37% and 75.30%, respectively. In addition, the body length was also significantly reduced for both males and females in the emamectin benzoate treatment. Avermectin and milbemectin were also effective in suppressing population growth by increasing larval lethality and reducing larval development, although they did not affect either brood size or embryonic lethality. Body length for both male and female worms was increased by avermectin. Thiacloprid caused no adverse reproductive effects, although it suppressed larval development. Sexual ratio was not affected by any of these four nematicides. Our results indicate that emamectin benzoate, milbemectin, and avermectin are effective against the reproduction of B. xylophilus. We think these three nematicides can be useful for the control of pine wilt disease.
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Affiliation(s)
- Zhenzhen Bi
- Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, Zhejiang Agricultural & Forestry University, Lin'an, Zhejiang Province, 311300, P.R. China
| | - Yanting Gong
- Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, Zhejiang Agricultural & Forestry University, Lin'an, Zhejiang Province, 311300, P.R. China
| | - Xiaojuan Huang
- Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, Zhejiang Agricultural & Forestry University, Lin'an, Zhejiang Province, 311300, P.R. China
| | - Hongshi Yu
- Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, Zhejiang Agricultural & Forestry University, Lin'an, Zhejiang Province, 311300, P.R. China
| | - Liqun Bai
- Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, Zhejiang Agricultural & Forestry University, Lin'an, Zhejiang Province, 311300, P.R. China
| | - Jiafu Hu
- Zhejiang Provincial Key Laboratory of Chemical Utilization of Forestry Biomass, Zhejiang Agricultural & Forestry University, Lin'an, Zhejiang Province, 311300, P.R. China. ; Collaborative Innovation Center of Sustaintable Forestry in Southern China, Nanjing Forestry University
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31
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Orr-Weaver TL. When bigger is better: the role of polyploidy in organogenesis. Trends Genet 2015; 31:307-15. [PMID: 25921783 DOI: 10.1016/j.tig.2015.03.011] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 03/29/2015] [Accepted: 03/30/2015] [Indexed: 12/28/2022]
Abstract
Defining how organ size is regulated, a process controlled not only by the number of cells but also by the size of the cells, is a frontier in developmental biology. Large cells are produced by increasing DNA content or ploidy, a developmental strategy employed throughout the plant and animal kingdoms. The widespread use of polyploidy during cell differentiation makes it important to define how this hypertrophy contributes to organogenesis. I discuss here examples from a variety of animals and plants in which polyploidy controls organ size, the size and function of specific tissues within an organ, or the differentiated properties of cells. In addition, I highlight how polyploidy functions in wound healing and tissue regeneration.
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Affiliation(s)
- Terry L Orr-Weaver
- Whitehead Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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Rangel J, Strauss K, Seedorf K, Hjelmen CE, Johnston JS. Endopolyploidy changes with age-related polyethism in the honey bee, Apis mellifera. PLoS One 2015; 10:e0122208. [PMID: 25881205 PMCID: PMC4400096 DOI: 10.1371/journal.pone.0122208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/10/2015] [Indexed: 11/25/2022] Open
Abstract
Honey bees (Apis mellifera) exhibit age polyethism, whereby female workers assume increasingly complex colony tasks as they age. While changes in DNA methylation accompany age polyethism, other DNA modifications accompanying age polyethism are less known. Changes in endopolyploidy (DNA amplification in the absence of cell division) with increased larval age are typical in many insect cells and are essential in adults for creating larger cells, more copies of essential loci, or greater storage capacity in secretory cells. However, changes in endopolyploidy with increased adult worker age and polyethism are unstudied. In this study, we examined endopolyploidy in honey bee workers ranging in age from newly emerged up to 55 days old. We found a nonsignificant increase in ploidy levels with age (P < 0.1) in the most highly endopolyploid secretory cells, the Malpighian tubules. All other cell types decreased ploidy levels with age. Endopolyploidy decreased the least amount (nonsignificant) in neural (brain) cells and the stinger (P < 0.1). There was a significant reduction of endopolyploidy with age in leg (P < 0.05) and thoracic (P < 0.001) muscles. Ploidy in thoracic muscle dropped from an average of 0.5 rounds of replication in newly emerged workers to essentially no rounds of replication (0.125) in the oldest workers. Ploidy reduction in flight muscle cells is likely due to the production of G1 (2C) nuclei by amitotic division in the multinucleate striated flight muscles that are essential to foragers, the oldest workers. We suggest that ploidy is constrained by the shape, size and makeup of the multinucleate striated muscle cells. Furthermore, the presence of multiple 2C nuclei might be optimal for cell function, while higher ploidy levels might be a dead-end strategy of some aging adult tissues, likely used to increase cell size and storage capacity in secretory cells.
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Affiliation(s)
- Juliana Rangel
- Department of Entomology, Texas A&M University, College Station, Texas 77843, United States of America
| | - Kim Strauss
- Department of Entomology, Texas A&M University, College Station, Texas 77843, United States of America
| | - Kaileah Seedorf
- Department of Entomology, Texas A&M University, College Station, Texas 77843, United States of America
| | - Carl E. Hjelmen
- Department of Entomology, Texas A&M University, College Station, Texas 77843, United States of America
| | - J. Spencer Johnston
- Department of Entomology, Texas A&M University, College Station, Texas 77843, United States of America
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Dpp/Gbb signaling is required for normal intestinal regeneration during infection. Dev Biol 2015; 399:189-203. [DOI: 10.1016/j.ydbio.2014.12.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 12/08/2014] [Accepted: 12/10/2014] [Indexed: 12/20/2022]
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Peng Y, Chen L, Lu Y, Wu Y, Dumenil J, Zhu Z, Bevan MW, Li Y. The ubiquitin receptors DA1, DAR1, and DAR2 redundantly regulate endoreduplication by modulating the stability of TCP14/15 in Arabidopsis. THE PLANT CELL 2015; 27:649-62. [PMID: 25757472 PMCID: PMC4558651 DOI: 10.1105/tpc.114.132274] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 02/11/2015] [Accepted: 02/26/2015] [Indexed: 05/18/2023]
Abstract
Organ growth involves the coordination of cell proliferation and cell growth with differentiation. Endoreduplication is correlated with the onset of cell differentiation and with cell and organ size, but little is known about the molecular mechanisms linking cell and organ growth with endoreduplication. We have previously demonstrated that the ubiquitin receptor DA1 influences organ growth by restricting cell proliferation. Here, we show that DA1 and its close family members DAR1 and DAR2 are redundantly required for endoreduplication during leaf development. DA1, DAR1, and DAR2 physically interact with the transcription factors TCP14 and TCP15, which repress endoreduplication by directly regulating the expression of cell-cycle genes. We also show that DA1, DAR1, and DAR2 modulate the stability of TCP14 and TCP15 proteins in Arabidopsis thaliana. Genetic analyses demonstrate that DA1, DAR1, and DAR2 function in a common pathway with TCP14/15 to regulate endoreduplication. Thus, our findings define an important genetic and molecular mechanism involving the ubiquitin receptors DA1, DAR1, and DAR2 and the transcription factors TCP14 and TCP15 that links endoreduplication with cell and organ growth.
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Affiliation(s)
- Yuancheng Peng
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China School of Life Sciences, Anhui Agricultural University, Hefei 230036, China
| | - Liangliang Chen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yaru Lu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China College of Biological Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Yingbao Wu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jack Dumenil
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Zhengge Zhu
- College of Biological Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Michael W Bevan
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, United Kingdom
| | - Yunhai Li
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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Dineen A, Gaudet J. TGF-β signaling can act from multiple tissues to regulate C. elegans body size. BMC DEVELOPMENTAL BIOLOGY 2014; 14:43. [PMID: 25480452 PMCID: PMC4278669 DOI: 10.1186/s12861-014-0043-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 11/25/2014] [Indexed: 11/23/2022]
Abstract
Background Regulation of organ and body size is a fundamental biological phenomenon, requiring tight coordination between multiple tissues to ensure accurate proportional growth. In C. elegans, a TGF-β pathway is the major regulator of body size and also plays a role in the development of the male tail, and is thus referred to as the TGF-β/Sma/Mab (for small and male abnormal) pathway. Mutations in components of this pathway result in decreased growth of animals during larval stages, with Sma mutant adults of the core pathway as small as ~60-70% the length of normal animals. The currently accepted model suggests that TGF-β/Sma/Mab pathway signaling in the C. elegans hypodermis is both necessary and sufficient to control body length. However, components of this signaling pathway are expressed in other organs, such as the intestine and pharynx, raising the question of what the function of the pathway is in these organs. Results Here we show that TGF-β/Sma/Mab signaling is required for the normal growth of the pharynx. We further extend the current model and show that the TGF-β/Sma/Mab pathway can function in multiple tissues to regulate body and organ length. Specifically, we find that pharyngeal expression of the SMAD protein SMA-3 partially rescues both pharynx length and body length of sma-3 mutants. Conclusions Overall, our results support a model in which the TGF-β/Sma/Mab signaling pathway can act in multiple tissues, activating one or more downstream secreted signals that act non cell-autonomously to regulate overall body length in C. elegans. Electronic supplementary material The online version of this article (doi:10.1186/s12861-014-0043-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aidan Dineen
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, T2N 4 N1, Alberta, Canada.
| | - Jeb Gaudet
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, T2N 4 N1, Alberta, Canada.
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36
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Mulligan KL, Hiebert TC, Jeffery NW, Gregory TR. First estimates of genome size in ribbon worms (phylum Nemertea) using flow cytometry and Feulgen image analysis densitometry. CAN J ZOOL 2014. [DOI: 10.1139/cjz-2014-0068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ribbon worms (phylum Nemertea) are among several animal groups that have been overlooked in past studies of genome-size diversity. Here, we report genome-size estimates for eight species of nemerteans, including representatives of the major lineages in the phylum. Genome sizes in these species ranged more than fivefold, and there was some indication of a positive relationship with body size. Somatic endopolyploidy also appears to be common in these animals. Importantly, this study demonstrates that both of the most common methods of genome-size estimation (flow cytometry and Feulgen image analysis densitometry) can be used to assess genome size in ribbon worms, thereby facilitating additional efforts to investigate patterns of variability in nuclear DNA content in this phylum.
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Affiliation(s)
- Kelly L. Mulligan
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Terra C. Hiebert
- Oregon Institute of Marine Biology, University of Oregon, Charleston, OR 97420, USA
| | - Nicholas W. Jeffery
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - T. Ryan Gregory
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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37
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Schultz RD, Bennett EE, Ellis EA, Gumienny TL. Regulation of extracellular matrix organization by BMP signaling in Caenorhabditis elegans. PLoS One 2014; 9:e101929. [PMID: 25013968 PMCID: PMC4094471 DOI: 10.1371/journal.pone.0101929] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 06/13/2014] [Indexed: 12/22/2022] Open
Abstract
In mammals, Bone Morphogenetic Protein (BMP) pathway signaling is important for the growth and homeostasis of extracellular matrix, including basement membrane remodeling, scarring, and bone growth. A conserved BMP member in Caenorhabditis elegans, DBL-1, regulates body length in a dose-sensitive manner. Loss of DBL-1 pathway signaling also results in increased anesthetic sensitivity. However, the physiological basis of these pleiotropic phenotypes is largely unknown. We created a DBL-1 over-expressing strain and show that sensitivity to anesthetics is inversely related to the dose of DBL-1. Using pharmacological, genetic analyses, and a novel dye permeability assay for live, microwave-treated animals, we confirm that DBL-1 is required for the barrier function of the cuticle, a specialized extracellular matrix. We show that DBL-1 signaling is required to prevent animals from forming tail-entangled aggregates in liquid. Stripping lipids off the surface of wild-type animals recapitulates this phenotype. Finally, we find that DBL-1 signaling affects ultrastructure of the nematode cuticle in a dose-dependent manner, as surface lipid content and cuticular organization are disrupted in animals with genetically altered DBL-1 levels. We propose that the lipid layer coating the nematode cuticle normally prevents tail entanglement, and that reduction of this layer by loss of DBL-1 signaling promotes aggregation. This work provides a physiological mechanism that unites the DBL-1 signaling pathway roles of not only body size regulation and drug responsiveness, but also the novel Hoechst 33342 staining and aggregation phenotypes, through barrier function, content, and organization of the cuticle.
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Affiliation(s)
- Robbie D. Schultz
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States of America
- Interdisciplinary Program in Genetics, Texas A&M University, College Station, Texas, United States of America
| | - Emily E. Bennett
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States of America
| | - E. Ann Ellis
- Microscopy & Imaging Center, Texas A&M University, College Station, Texas, United States of America
| | - Tina L. Gumienny
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, Texas, United States of America
- Interdisciplinary Program in Genetics, Texas A&M University, College Station, Texas, United States of America
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38
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Matus DQ, Chang E, Makohon-Moore SC, Hagedorn MA, Chi Q, Sherwood DR. Cell division and targeted cell cycle arrest opens and stabilizes basement membrane gaps. Nat Commun 2014; 5:4184. [PMID: 24924309 PMCID: PMC4138880 DOI: 10.1038/ncomms5184] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 05/21/2014] [Indexed: 12/13/2022] Open
Abstract
Large gaps in basement membrane (BM) occur during organ remodelling and cancer cell invasion. Whether dividing cells, which temporarily reduce their attachment to BM, influence these breaches is unknown. Here we analyse uterine-vulval attachment during development across 21 species of rhabditid nematodes and find that the BM gap that forms between these organs is always bounded by a non-dividing vulval cell. Through cell cycle manipulation and live cell imaging in Caenorhabditis elegans, we show that actively dividing vulval cells facilitate enlargement of this breach by promoting BM movement. In contrast, targeted cell cycle arrest halts BM movement and limits gap opening. Further, we demonstrate that the BM component laminin accumulates at the BM gap edge and promotes increased integrin levels in non-dividing vulval cells, stabilizing gap position. Together, these studies reveal that cell division can be used as a mechanism to regulate BM breaches, thus controlling the exchange of cells between tissues.
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Affiliation(s)
- David Q Matus
- 1] Department of Biology, Duke University, Durham, North Carolina 27705, USA [2]
| | - Emily Chang
- 1] Department of Biology, Duke University, Durham, North Carolina 27705, USA [2]
| | | | - Mary A Hagedorn
- Department of Biology, Duke University, Durham, North Carolina 27705, USA
| | - Qiuyi Chi
- Department of Biology, Duke University, Durham, North Carolina 27705, USA
| | - David R Sherwood
- Department of Biology, Duke University, Durham, North Carolina 27705, USA
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39
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SUMV-1 antagonizes the activity of synthetic multivulva genes in Caenorhabditis elegans. Dev Biol 2014; 392:266-82. [PMID: 24882710 DOI: 10.1016/j.ydbio.2014.05.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 05/20/2014] [Accepted: 05/22/2014] [Indexed: 11/22/2022]
Abstract
Chromatin regulators contribute to the developmental control of gene expression. In the nematode Caenorhabditis elegans, the roles of chromatin regulation in development have been explored in several contexts, including vulval differentiation. The synthetic multivulva (synMuv) genes are regulators of vulval development in C. elegans and the proteins encoded by these genes include components of several histone modification and chromatin remodelling complexes. By inhibiting ectopic expression of the epidermal growth factor (LIN-3) in the nematode hypodermis, the synMuv genes prevent inappropriate vulval induction. In a forward genetic screen for modifiers of the expression of a hypodermal reporter gene, we identified a mutation that results in increased expression of the reporter. This mutation also suppresses ectopic vulval induction in synMuv mutants and we have consequently named the affected gene suppressor of synthetic multivulva-1 (sumv-1). We show that SUMV-1 is required in the hypodermis for the synMuv phenotype and that loss of sumv-1 function suppresses ectopic expression of lin-3 in synMuv mutant animals. In yeast two-hybrid assays SUMV-1 physically interacts with SUMV-2, and reduction of sumv-2 function also suppresses the synMuv phenotype. We identified similarities between SUMV-1 and SUMV-2 and mammalian proteins KAT8 NSL2 and KAT8 NSL3, respectively, which are components of the KAT8/MOF histone acetyltransferase complex. Reduction of function of mys-2, which encodes the enzymatic component of the KAT8/MOF complex, also suppresses the synMuv phenotype, and MYS-2 physically interacts with SUMV-2 in yeast two-hybrid assays. Together these observations suggest that SUMV-1 and SUMV-2 may function together with MYS-2 in a nematode KAT8/MOF-like complex to antagonise the activity of the synMuv genes.
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40
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Gegas VC, Wargent JJ, Pesquet E, Granqvist E, Paul ND, Doonan JH. Endopolyploidy as a potential alternative adaptive strategy for Arabidopsis leaf size variation in response to UV-B. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2757-66. [PMID: 24470468 PMCID: PMC4047990 DOI: 10.1093/jxb/ert473] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The extent of endoreduplication in leaf growth is group- or even species-specific, and its adaptive role is still unclear. A survey of Arabidopsis accessions for variation at the level of endopolyploidy, cell number, and cell size in leaves revealed extensive genetic variation in endopolyploidy level. High endopolyploidy is associated with increased leaf size, both in natural and in genetically unstructured (mapping) populations. The underlying genes were identified as quantitative trait loci that control endopolyploidy in nature by modulating the progression of successive endocycles during organ development. This complex genetic architecture indicates an adaptive mechanism that allows differential organ growth over a broad geographic range and under stressful environmental conditions. UV-B radiation was identified as a significant positive climatic predictor for high endopolyploidy. Arabidopsis accessions carrying the increasing alleles for endopolyploidy also have enhanced tolerance to UV-B radiation. UV-absorbing secondary metabolites provide an additional protective strategy in accessions that display low endopolyploidy. Taken together, these results demonstrate that high constitutive endopolyploidy is a significant predictor for organ size in natural populations and is likely to contribute to sustaining plant growth under high incident UV radiation. Endopolyploidy may therefore form part of the range of UV-B tolerance mechanisms that exist in natural populations.
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Affiliation(s)
- Vasilis C Gegas
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Jason J Wargent
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Edouard Pesquet
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Emma Granqvist
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - Nigel D Paul
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - John H Doonan
- IBERS, Aberystwyth University, Aberystwyth SY23 2AX, UK
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41
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Beiriger A, Sears KE. Cellular basis of differential limb growth in postnatal gray short-tailed opossums (Monodelphis domestica). JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 322:221-9. [PMID: 24500902 DOI: 10.1002/jez.b.22556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/06/2013] [Accepted: 12/16/2013] [Indexed: 01/07/2023]
Abstract
While growth has been studied extensively in invertebrates, the mechanisms by which it is controlled in vertebrates, particularly in mammals, remain poorly understood. In this study, we investigate the cellular basis of differential limb growth in postnatal Monodelphis domestica, the gray short-tailed opossum, to gain insights into the mechanisms regulating mammalian growth. Opossums are an ideal model for the study of growth because they are born with relatively large, well-developed forelimbs and small hind limbs that must "catch up" to the forelimb before the animal reaches adulthood. Postnatal Days 1-17 were identified as a key period of growth for the hind limbs, during which they undergo accelerated development and nearly quadruple in length. Histology performed on fore- and hind limbs from this period indicates a higher rate of cellular differentiation in the long bones of the hind limbs. Immunohistochemical assays indicate that cellular proliferation is also occurring at a significantly greater rate in the long bones of the hind limb at 6 days after birth. Taken together, these results suggest that a faster rate of cellular proliferation and differentiation in the long bones of the hind limb relative to those of the forelimb generates a period of accelerated growth through which the adult limb phenotype of M. domestica is achieved. Assays for gene expression suggest that the molecular basis of this differential growth differs from that previously identified for differential pre-natal growth in opossum fore- and hind limbs.
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42
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Tuck S. The control of cell growth and body size in Caenorhabditis elegans. Exp Cell Res 2013; 321:71-6. [PMID: 24262077 DOI: 10.1016/j.yexcr.2013.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 11/08/2013] [Accepted: 11/11/2013] [Indexed: 01/02/2023]
Abstract
One of the most important ways in which animal species vary is in their size. Individuals of the largest animal ever thought to have lived, the blue whale (Balaenoptera musculus), can reach a weight of 190 t and a length of over 30 m. At the other extreme, among the smallest multicellular animals are males of the parasitic wasp, Dicopomorpha echmepterygis, which even as adults are just 140 μm in length. In terms of volume, these species differ by more than 14 orders of magnitude. Since size has such profound effects on an organism's ecology, anatomy and physiology, an important task for evolutionary biology and ecology is to account for why organisms grow to their characteristic sizes. Equally, a full description of an organism's development must include an explanation of how its growth and body size are regulated. Here I review research on how these processes are controlled in the nematode, Caenorhabditis elegans. Analyses of small and long mutants have revealed that in the worm, DBL-1, a ligand in the TGFβ superfamily family, promotes growth in a dose-dependent manner. DBL-1 signaling affects body size by stimulating the growth of syncytial hypodermal cells rather than controlling cell division. Signals from chemosensory neurons and from the gonad also modulate body size, in part, independently of DBL-1-mediated signaling. Organismal size and morphology is heavily influenced by the cuticle, which acts as the exoskeleton. Finally, I summarize research on several genes that appear to regulate body size by cell autonomously regulating cell growth throughout the worm.
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Affiliation(s)
- Simon Tuck
- Umeå Center for Molecular Medicine, Umeå University, SE-901 87 Umeå, Sweden.
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43
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So S, Garan Y, Miyahara K, Ohshima Y. Body size change in various nematodes depending on bacterial food, sex and growth temperature. WORM 2013; 1:93-7. [PMID: 24058830 PMCID: PMC3670232 DOI: 10.4161/worm.20175] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We previously reported significant body size change in the nematode Caenorhabditis elegans, depending on the food strain of E. coli. Here, we examined this body size change in 11 other nematode species as well, and found that it is common to most of these nematodes. Furthermore, this food-dependent body size change is influenced by sex and growth temperature.
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Affiliation(s)
- Shuhei So
- Department of Applied Life Science; Sojo University; Ikeda, Kumamoto, Japan
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44
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Abstract
Transforming Growth Factor-β (TGF-β) superfamily ligands regulate many aspects of cell identity, function, and survival in multicellular animals. Genes encoding five TGF-β family members are present in the genome of C. elegans. Two of the ligands, DBL-1 and DAF-7, signal through a canonical receptor-Smad signaling pathway; while a third ligand, UNC-129, interacts with a noncanonical signaling pathway. No function has yet been associated with the remaining two ligands. Here we summarize these signaling pathways and their biological functions.
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Affiliation(s)
- Tina L Gumienny
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, TX 77843, USA
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45
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A negative-feedback loop between the detoxification/antioxidant response factor SKN-1 and its repressor WDR-23 matches organism needs with environmental conditions. Mol Cell Biol 2013; 33:3524-37. [PMID: 23836880 DOI: 10.1128/mcb.00245-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Negative-feedback loops between transcription factors and repressors in responses to xenobiotics, oxidants, heat, hypoxia, DNA damage, and infection have been described. Although common, the function of feedback is largely unstudied. Here, we define a negative-feedback loop between the Caenorhabditis elegans detoxification/antioxidant response factor SKN-1/Nrf and its repressor wdr-23 and investigate its function in vivo. Although SKN-1 promotes stress resistance and longevity, we find that tight regulation by WDR-23 is essential for growth and reproduction. By disabling SKN-1 transactivation of wdr-23, we reveal that feedback is required to set the balance between growth/reproduction and stress resistance/longevity. We also find that feedback is required to set the sensitivity of a core SKN-1 target gene to an electrophile. Interestingly, the effect of feedback on target gene induction is greatly reduced when the stress response is strongly activated, presumably to ensure maximum activation of cytoprotective genes during potentially fatal conditions. Our work provides a framework for understanding the function of negative feedback in inducible stress responses and demonstrates that manipulation of feedback alone can shift the balance of competing animal processes toward cell protection, health, and longevity.
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46
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Scholes DR, Suarez AV, Paige KN. Can endopolyploidy explain body size variation within and between castes in ants? Ecol Evol 2013; 3:2128-37. [PMID: 23919157 PMCID: PMC3728952 DOI: 10.1002/ece3.623] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 04/30/2013] [Accepted: 05/06/2013] [Indexed: 11/13/2022] Open
Abstract
Endoreduplication is the process by which the nuclear genome is repeatedly replicated without mitotic cell division, resulting in nuclei that contain numerous additional genome copies. Endoreduplication occurs widely throughout Eucarya and is particularly common in angiosperms and insects. Although endoreduplication is an important process in the terminal differentiation of some specialized cell types, and often increases cell size and metabolism, the direct effects of increasing nuclear ploidy on cell function are not well resolved. Here, we examine if endoreduplication may play a role in body size and/or caste differentiation in ants. Nuclear ploidy was measured by flow cytometry of whole individuals (providing the basis for overall body size patterns) and individual body segments for multiple polymorphic ant species. We used cell cycle values, interpreted as the mean number of endocycles performed by each cell in the sample, as our measure of overall endoreduplication. Among females of four polymorphic ant species, endoreduplication was positively related with size within the worker caste, but was not related to caste generally in two species where we also examined queens. Additionally, abdomens had the greatest endoreduplication of all body parts regardless of caste or size. We also found that males, having derived from haploid unfertilized eggs, had the highest rates of endoreduplication and may compensate for their haploid origin by performing an additional endocycle relative to females. These results suggest that endoreduplication may play a role in body size variation in eusocial insects and the development of some segment-specific tissues.
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Affiliation(s)
- Daniel R Scholes
- Program in Ecology Evolution and Conservation Biology, University of Illinois at Urbana-Champaign 515 Morrill Hall, 505 S Goodwin Ave, Urbana, Illinois, 61801
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47
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Lee JI, Mukherjee S, Yoon K, Dwivedi M, Bandyopadhyay J. The multiple faces of calcineurin signaling in Caenorhabditis elegans: Development, behaviour and aging. J Biosci 2013; 38:417-31. [DOI: 10.1007/s12038-013-9319-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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48
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Kureck IM, Nicolai B, Foitzik S. Similar Performance of Diploid and Haploid Males in an Ant Species without Inbreeding Avoidance. Ethology 2013. [DOI: 10.1111/eth.12073] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ilka M. Kureck
- Department Biology; Johannes Gutenberg University of Mainz; Mainz; Germany
| | - Beate Nicolai
- Department Biology; Johannes Gutenberg University of Mainz; Mainz; Germany
| | - Susanne Foitzik
- Department Biology; Johannes Gutenberg University of Mainz; Mainz; Germany
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49
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Stegen JC, Enquist BJ, Ferrière R. Eco-evolutionary community dynamics: covariation between diversity and invasibility across temperature gradients. Am Nat 2012; 180:E110-26. [PMID: 22976016 DOI: 10.1086/667577] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Understanding biodiversity gradients is a long-standing challenge, and progress requires theory unifying ecology and evolution. Here, we unify concepts related to the speed of evolution, the influence of species richness on diversification, and niche-based coexistence. We focus on the dynamics, through evolutionary time, of community invasibility and species richness across a broad thermal gradient. In our framework, the evolution of body size influences the ecological structure and dynamics of a trophic network, and organismal metabolism ties temperature to eco-evolutionary processes. The framework distinguishes ecological invasibility (governed by ecological interactions) from evolutionary invasibility (governed by local ecology and constraints imposed by small phenotypic effects of mutation). The model yields four primary predictions: (1) ecological invasibility declines through time and with increasing temperature; (2) average evolutionary invasibility across communities increases and then decreases through time as the richness-temperature gradient flattens; (3) in the early stages of diversification, richness and evolutionary invasibility both increase with increasing temperature; and (4) at equilibrium, richness does not vary with temperature, yet evolutionary invasibility decreases with increasing temperature. These predictions emerge from the "evolutionary-speed" hypothesis, which attempts to account for latitudinal species richness gradients by invoking faster biological rates in warmer, tropical regions. The model contrasts with predictions from other richness-gradient hypotheses, such as "niche conservatism" and "species energy." Empirically testing our model's predictions should help distinguish among these hypotheses.
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Affiliation(s)
- James C Stegen
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
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50
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Chisholm AD, Hsiao TI. The Caenorhabditis elegans epidermis as a model skin. I: development, patterning, and growth. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 1:861-78. [PMID: 23539299 DOI: 10.1002/wdev.79] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The skin of the nematode Caenorhabditis elegans is composed of a simple epidermal epithelium and overlying cuticle. The skin encloses the animal and plays central roles in body morphology and physiology; its simplicity and accessibility make it a tractable genetic model for several aspects of skin biology. Epidermal precursors are specified by a hierarchy of transcriptional regulators. Epidermal cells form on the dorsal surface of the embryo and differentiate to form the epidermal primordium, which then spreads out in a process of epiboly to enclose internal tissues. Subsequent elongation of the embryo into a vermiform larva is driven by cell shape changes and cell fusions in the epidermis. Most epidermal cells fuse in mid-embryogenesis to form a small number of multinucleate syncytia. During mid-embryogenesis the epidermis also becomes intimately associated with underlying muscles, performing a tendon-like role in transmitting muscle force. Post-embryonic development of the epidermis involves growth by addition of new cells to the syncytia from stem cell-like epidermal seam cells and by an increase in cell size driven by endoreplication of the chromosomes in epidermal nuclei.
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Affiliation(s)
- Andrew D Chisholm
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA.
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