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McIntyre DC, Nance J. Niche cells regulate primordial germ cell quiescence in response to basement membrane signaling. Development 2023; 150:dev201640. [PMID: 37497562 PMCID: PMC10445801 DOI: 10.1242/dev.201640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023]
Abstract
Stem cell quiescence, proliferation and differentiation are controlled by interactions with niche cells and a specialized extracellular matrix called basement membrane (BM). Direct interactions with adjacent BM are known to regulate stem cell quiescence; however, it is less clear how niche BM relays signals to stem cells that it does not contact. Here, we examine how niche BM regulates Caenorhabditis elegans primordial germ cells (PGCs). BM regulates PGC quiescence even though PGCs are enwrapped by somatic niche cells and do not contact the BM; this can be demonstrated by depleting laminin, which causes normally quiescent embryonic PGCs to proliferate. We show that following laminin depletion, niche cells relay proliferation-inducing signals from the gonadal BM to PGCs via integrin receptors. Disrupting the BM proteoglycan perlecan blocks PGC proliferation when laminin is depleted, indicating that laminin functions to inhibit a proliferation-inducing signal originating from perlecan. Reducing perlecan levels in fed larvae hampers germline growth, suggesting that BM signals regulate germ cell proliferation under physiological conditions. Our results reveal how BM signals can regulate stem cell quiescence indirectly, by activating niche cell integrin receptors.
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Affiliation(s)
- Daniel C. McIntyre
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
- University of Virginia, Department of Biology, 90 Geldard Drive, Physical Life Science Building Room 318, Charlottesville, VA 22904, USA
| | - Jeremy Nance
- Skirball Institute of Biomolecular Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
- Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
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2
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From primordial germ cells to spermatids in Caenorhabditis elegans. Semin Cell Dev Biol 2021; 127:110-120. [PMID: 34930663 DOI: 10.1016/j.semcdb.2021.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/17/2021] [Accepted: 12/07/2021] [Indexed: 12/24/2022]
Abstract
Development of a syncytial germline for gamete formation requires complex regulation of cytokinesis and cytoplasmic remodeling. Recently, several uncovered cellular events have been investigated in the Caenorhabditis elegans (C. elegans) germline. In these cellular processes, the factors involved in contractility are highly conserved with those of mitosis and meiosis. However, the underlying regulatory mechanisms are far more complicated than previously thought, likely due to the single syncytial germline structure. In this review, we highlight how the proteins involved in contractility ensure faithful cell division in different cellular contexts and how they contribute to maintaining intercellular bridge stability. In addition, we discuss the current understanding of the cellular events of cytokinesis and cytoplasmic remodeling during the development of the C. elegans germline, including progenitor germ cells, germ cells, and spermatocytes. Comparisons are made with relevant systems in Drosophila melanogaster (D. melanogaster) and other animal models.
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Sherwood DR. Basement membrane remodeling guides cell migration and cell morphogenesis during development. Curr Opin Cell Biol 2021; 72:19-27. [PMID: 34015751 DOI: 10.1016/j.ceb.2021.04.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 01/31/2023]
Abstract
Basement membranes (BMs) are thin, dense forms of extracellular matrix that underlie or surround most animal tissues. BMs are enormously complex and harbor numerous proteins that provide essential signaling, mechanical, and barrier support for tissues during their development and normal functioning. As BMs are found throughout animal tissues, cells frequently migrate, change shape, and extend processes along BMs. Although sometimes used only as passive surfaces by cells, studies in developmental contexts are finding that BMs are often actively modified to help guide cell motility and cell morphogenesis. Here, I provide an overview of recent work revealing how BMs are remodeled in remarkably diverse ways to direct cell migration, cell orientation, axon guidance, and dendrite branching events during animal development.
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Affiliation(s)
- David R Sherwood
- Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA; Regeneration Next, Duke University, Durham 27710, USA.
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Dubois C, Gupta S, Mugler A, Félix MA. Temporally regulated cell migration is sensitive to variation in body size. Development 2021; 148:dev196949. [PMID: 33593818 PMCID: PMC10683003 DOI: 10.1242/dev.196949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 01/14/2021] [Indexed: 12/15/2022]
Abstract
Few studies have measured the robustness to perturbations of the final position of a long-range migrating cell. In the nematode Caenorhabditis elegans, the QR neuroblast migrates anteriorly, while undergoing three division rounds. We study the final position of two of its great-granddaughters, the end of migration of which was previously shown to depend on a timing mechanism. We find that the variance in their final position is similar to that of other long-range migrating neurons. As expected from the timing mechanism, the position of QR descendants depends on body size, which we varied by changing maternal age or using body size mutants. Using a mathematical model, we show that body size variation is partially compensated for. Applying environmental perturbations, we find that the variance in final position increased following starvation at hatching. The mean position is displaced upon a temperature shift. Finally, highly significant variation was found among C. elegans wild isolates. Overall, this study reveals that the final position of these neurons is quite robust to stochastic variation, shows some sensitivity to body size and to external perturbations, and varies in the species.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- Clément Dubois
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, 75005 Paris, France
| | - Shivam Gupta
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA
| | - Andrew Mugler
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907, USA
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, 75005 Paris, France
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Niche Cell Wrapping Ensures Primordial Germ Cell Quiescence and Protection from Intercellular Cannibalism. Curr Biol 2020; 30:708-714.e4. [PMID: 32008902 DOI: 10.1016/j.cub.2019.12.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 11/12/2019] [Accepted: 12/06/2019] [Indexed: 12/25/2022]
Abstract
Niche cells often wrap membrane extensions around stem cell surfaces. Niche wrapping has been proposed to retain stem cells in defined positions and affect signaling [e.g., 1, 2]. To test these hypotheses and uncover additional functions of wrapping, we investigated niche wrapping of primordial germ cells (PGCs) in the C. elegans embryonic gonad primordium. The gonad primordium contains two PGCs that are wrapped individually by two somatic gonad precursor cells (SGPs). SGPs are known to promote PGC survival during embryogenesis and exit from quiescence after hatching, although how they do so is unknown [3]. Here, we identify two distinct functions of SGP wrapping that are critical for PGC quiescence and survival. First, niche cell wrapping templates a laminin-based basement membrane around the gonad primordium. Laminin and the basement membrane receptor dystroglycan function to maintain niche cell wrapping, which is critical for normal gonad development. We find that laminin also preserves PGC quiescence during embryogenesis. Exit from quiescence following laminin depletion requires glp-1/Notch and is accompanied by inappropriate activation of the GLP-1 target sygl-1 in PGCs. Independent of basement membrane, SGP wrapping performs a second, crucial function to ensure PGC survival. Endodermal cells normally engulf and degrade large lobes extended by the PGCs [4]. When SGPs are absent, we show that endodermal cells can inappropriately engulf and cannibalize the PGC cell body. Our findings demonstrate how niche cell wrapping protects germ cells by manipulating their signaling environment and by shielding germ cells from unwanted cellular interactions that can compromise their survival.
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Ou HL, Kim CS, Uszkoreit S, Wickström SA, Schumacher B. Somatic Niche Cells Regulate the CEP-1/p53-Mediated DNA Damage Response in Primordial Germ Cells. Dev Cell 2020; 50:167-183.e8. [PMID: 31336098 DOI: 10.1016/j.devcel.2019.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/13/2019] [Accepted: 06/17/2019] [Indexed: 12/26/2022]
Abstract
Genome integrity in primordial germ cells (PGCs) is a prerequisite for fertility and species maintenance. In C. elegans, PGCs require global-genome nucleotide excision repair (GG-NER) to remove UV-induced DNA lesions. Failure to remove the lesions leads to the activation of the C. elegans p53, CEP-1, resulting in mitotic arrest of the PGCs. We show that the eIF4E2 translation initiation factor IFE-4 in somatic gonad precursor (SGP) niche cells regulates the CEP-1/p53-mediated DNA damage response (DDR) in PGCs. We determine that the IFE-4 translation target EGL-15/FGFR regulates the non-cell-autonomous DDR that is mediated via FGF-like signaling. Using hair follicle stem cells as a paradigm, we demonstrate that the eIF4E2-mediated niche cell regulation of the p53 response in stem cells is highly conserved in mammals. We thus reveal that the somatic niche regulates the CEP-1/p53-mediated DNA damage checkpoint in PGCs. Our data suggest that the somatic niche impacts the stability of heritable genomes.
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Affiliation(s)
- Hui-Ling Ou
- Institute for Genome Stability in Ageing and Disease, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Christine S Kim
- Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Paul Gerson Unna Group "Skin Homeostasis and Ageing," Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, D-50931 Cologne, Germany
| | - Simon Uszkoreit
- Institute for Genome Stability in Ageing and Disease, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Sara A Wickström
- Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Paul Gerson Unna Group "Skin Homeostasis and Ageing," Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, D-50931 Cologne, Germany; Helsinki Institute of Life Science, Biomedicum Helsinki, University of Helsinki, FI-00014 Helsinki, Finland; Wihuri Research Institute, Biomedicum Helsinki, University of Helsinki, FI-00014 Helsinki, Finland
| | - Björn Schumacher
- Institute for Genome Stability in Ageing and Disease, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany.
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Abstract
Primordial germ cells (PGCs) must complete a complex and dynamic developmental program during embryogenesis to establish the germline. This process is highly conserved and involves a diverse array of tasks required of PGCs, including migration, survival, sex differentiation, and extensive epigenetic reprogramming. A common theme across many organisms is that PGC success is heterogeneous: only a portion of all PGCs complete all these steps while many other PGCs are eliminated from further germline contribution. The differences that distinguish successful PGCs as a population are not well understood. Here, we examine variation that exists in PGCs as they navigate the many stages of this developmental journey. We explore potential sources of PGC heterogeneity and their potential implications in affecting germ cell behaviors. Lastly, we discuss the potential for PGC development to function as a multistage selection process that assesses heterogeneity in PGCs to refine germline quality.
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Affiliation(s)
- Daniel H Nguyen
- Department of Obstetrics, Gynecology and Reproductive Science, Center for Reproductive Sciences, Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, United States
| | - Rebecca G Jaszczak
- Department of Obstetrics, Gynecology and Reproductive Science, Center for Reproductive Sciences, Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, United States
| | - Diana J Laird
- Department of Obstetrics, Gynecology and Reproductive Science, Center for Reproductive Sciences, Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA, United States.
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Gordon KL, Payne SG, Linden-High LM, Pani AM, Goldstein B, Hubbard EJA, Sherwood DR. Ectopic Germ Cells Can Induce Niche-like Enwrapment by Neighboring Body Wall Muscle. Curr Biol 2019; 29:823-833.e5. [PMID: 30799241 DOI: 10.1016/j.cub.2019.01.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/18/2019] [Accepted: 01/23/2019] [Indexed: 12/20/2022]
Abstract
Niche cell enwrapment of stem cells and their differentiating progeny is common and provides a specialized signaling and protective environment. Elucidating the mechanisms underlying enwrapment behavior has important basic and clinical significance in not only understanding how niches are formed and maintained but also how they can be engineered and how they are misregulated in human pathologies, such as cancer. Previous work in C. elegans found that, when germ cells, which are enwrapped by somatic gonadal niche cells, are freed into the body cavity, they embed into other tissues. We investigated this phenomenon using live-cell imaging and discovered that ectopic germ cells preferentially induce body-wall muscle to extend cellular processes that enwrap the germ cells, the extent of which was strikingly similar to the distal tip cell (DTC)-germ stem cell niche. Enwrapment was specific for escaped germ cells, and genetic analysis revealed it did not depend on pathways that control cell death and engulfment or muscle arm extension. Instead, using a large-scale RNAi screen and GFP knockin strains, we discovered that the enwrapping behavior of muscle relied upon the same suite of cell-cell adhesion molecules that functioned in the endogenous niche: the C. elegans E-cadherin HMR-1, its intracellular associates α-catenin (HMP-1) and β-catenin (HMP-2), and the L1CAM protein SAX-7. This ectopic niche-like behavior resembles the seed-and-soil model of cancer metastasis and offers a new model to understand factors regulating ectopic niche formation.
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Affiliation(s)
- Kacy L Gordon
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Sara G Payne
- Department of Biology, Duke University, Durham, NC 27708, USA
| | | | - Ariel M Pani
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Bob Goldstein
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - David R Sherwood
- Department of Biology, Duke University, Durham, NC 27708, USA; Regeneration Next, Duke University, Durham, NC 27708, USA.
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Li H, Su B, Qin G, Ye Z, Elaswad A, Alsaqufi A, Perera DA, Qin Z, Odin R, Vo K, Drescher D, Robinson D, Dong S, Zhang D, Shang M, Abass N, Das SK, Bangs M, Dunham RA. Repressible Transgenic Sterilization in Channel Catfish, Ictalurus punctatus, by Knockdown of Primordial Germ Cell Genes with Copper-Sensitive Constructs. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2018; 20:324-342. [PMID: 29679251 DOI: 10.1007/s10126-018-9819-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 11/24/2017] [Indexed: 06/08/2023]
Abstract
Repressible knockdown approaches were investigated to manipulate for transgenic sterilization in channel catfish, Ictalurus punctatus. Two primordial germ cell (PGC) marker genes, nanos and dead end, were targeted for knockdown and an off-target gene, vasa, was monitored. Two potentially copper-sensitive repressible promoters, yeast ctr3 (M) and ctr3-reduced (Mctr), were coupled with four knockdown strategies separately including: ds-sh RNA targeting the 5' end (N1) or 3' end (N2) of channel catfish nanos, full-length cDNA sequence of channel catfish nanos for overexpression (cDNA), and ds-sh RNA-targeting channel catfish dead end (DND). Each construct had an untreated group and treated group with copper sulfate as the repressor compound. Spawning rates of full-sibling P1 fish exposed or not exposed to the constructs as treated and untreated embryos were 85 and 54%, respectively, indicating potential sterilization of fish and repression of the constructs. In F1 fish, mRNA expressions of PGC marker genes for most constructs were downregulated in the untreated group and the knockdown was repressed in the treated group. Gonad development in transgenic, untreated F1 channel catfish was reduced compared to non-transgenic fish for MctrN2, MN1, MN2, and MDND. For 3-year-old adults, gonad size in the transgenic untreated group was 93.4% smaller than the non-transgenic group for females and 92.3% for males. However, mean body weight of transgenic females (781.8 g) and males (883.8 g) was smaller than of non-transgenic counterparts (984.2 and 1254.3 g) at 3 years of age, a 25.8 and 41.9% difference for females and males, respectively. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but negative pleiotropic effects can result.
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Affiliation(s)
- Hanbo Li
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Baofeng Su
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- National and Local United Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fisheries Sciences, Harbin, 150070, China
| | - Guyu Qin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Zhi Ye
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Ahmed Elaswad
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Department of Animal Wealth Development, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt
| | - Ahmed Alsaqufi
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Department of Aquaculture and Animal Production, King Faisal University, Al Ahsa, 31982, Saudi Arabia
| | - Dayan A Perera
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Research and Development Corporation, Gus R. Douglass Institute, West Virginia State University, Institute, WV, 25112, USA
| | - Zhenkui Qin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Key Laboratory of Marine Genetics and Breeding, Ministry of Education, Ocean University of China, Qingdao, 266003, China
| | - Ramji Odin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Khoi Vo
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - David Drescher
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Dalton Robinson
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Sheng Dong
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Dan Zhang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Mei Shang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- National and Local United Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fisheries Sciences, Harbin, 150070, China
| | - Nermeen Abass
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Sanjay K Das
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | - Max Bangs
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Rex A Dunham
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
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Developmentally programmed germ cell remodelling by endodermal cell cannibalism. Nat Cell Biol 2016; 18:1302-1310. [PMID: 27842058 PMCID: PMC5129868 DOI: 10.1038/ncb3439] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/13/2016] [Indexed: 02/06/2023]
Abstract
Primordial germ cells (PGCs) in many species associate intimately with endodermal cells, but the significance of such interactions is largely unexplored. Here, we show that Caenorhabditis elegans PGCs form lobes that are removed and digested by endodermal cells, dramatically altering PGC size and mitochondrial content. We demonstrate that endodermal cells do not scavenge lobes PGCs shed, but rather, actively remove lobes from the cell body. CED-10 (Rac)-induced actin, DYN-1 (dynamin) and LST-4 (SNX9) transiently surround lobe necks and are required within endodermal cells for lobe scission, suggesting that scission occurs through a mechanism resembling vesicle endocytosis. These findings reveal an unexpected role for endoderm in altering the contents of embryonic PGCs, and define a form of developmentally programmed cell remodelling involving intercellular cannibalism. Active roles for engulfing cells have been proposed in several neuronal remodelling events, suggesting that intercellular cannibalism may be a more widespread method used to shape cells than previously thought.
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Basement Membranes in the Worm: A Dynamic Scaffolding that Instructs Cellular Behaviors and Shapes Tissues. CURRENT TOPICS IN MEMBRANES 2015; 76:337-71. [PMID: 26610919 DOI: 10.1016/bs.ctm.2015.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The nematode worm Caenorhabditis elegans has all the major basement membrane proteins found in vertebrates, usually with a smaller gene family encoding each component. With its powerful forward genetics, optical clarity, simple tissue organization, and the capability to functionally tag most basement membrane components with fluorescent proteins, C. elegans has facilitated novel insights into the assembly and function of basement membranes. Although basement membranes are generally thought of as static structures, studies in C. elegans have revealed their active properties and essential functions in tissue formation and maintenance. Here, we review discoveries from C. elegans development that highlight dynamic aspects of basement membrane assembly, function, and regulation during organ growth, tissue polarity, cell migration, cell invasion, and tissue attachment. These studies have helped transform our view of basement membranes from static support structures to dynamic scaffoldings that play broad roles in regulating tissue organization and cellular behavior that are essential for development and have important implications in human diseases.
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