1
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Yang M, Yu L, Jiang D, Deng C, Wang Z, Xu X, Wang J, Wu S, Zhang F, Hu X. Calcium stress reduces the reproductive capacity and pathogenicity of the pine wood nematode (Bursaphelenchus xylophilus) by inhibiting oxidative phosphorylation reaction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169531. [PMID: 38145666 DOI: 10.1016/j.scitotenv.2023.169531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 12/27/2023]
Abstract
The continuous use of chemical pesticides to control nematodes could result in the developing of pesticide-resistant nematodes. Novel nucleic acid pesticides are becoming the focus of pesticide research due to their strong specificity, high efficiency, and environmental friendliness. However, the limited known biochemical targets restrict the development of target pesticides for nematodes. The calcium stress experiments on pine wood nematodes (PWN) showed that 100 mmol/L Ca2+ resulted in longitudinal depression on the PWN body wall, reduced oviposition, and increased corrected mortality. To enrich the biological targets of nematode pesticides, we further investigated the response mechanism of PWN to calcium stress at the molecular level. Differentially expressed gene analysis showed that genes involved in the oxidative phosphorylation (OXPHOS) pathway were significantly enriched. RNA interference results of 6 key genes belonging to four mitochondrial complex I (BXNDUFA2), III (BXQCR8), IV (BXCOX17), V (BXV-ATPaseB, BXV-ATPaseE, BXV-ATPaseε) in non-stressed nematodes showed reduction in PWN oviposition, population size, feeding ability, and pathogenicity. The BXNDUFA2 gene interference had the highest inhibitory impact by decreasing the oviposition from 31.00 eggs to 6.75 eggs and PWN population size from 8.27 × 103 nematodes to 1.64 × 103 nematodes, respectively. Interestingly, RNA interference of these 6 key genes in calcium-stressed nematodes also led to increased mortality and decreased oviposition of PWN. In summary, calcium stress inhibited the reproductive capacity of PWN by down-regulating key genes BXNDUFA2, BXQCR8, BXV-ATPaseB, BXV-ATPaseE, BXV-ATPaseε, and BXCOX17, thereby reducing the pathogenicity. The current results enrich the RNAi targets in PWN and provide a scientific basis for developing novel nucleic nematicides.
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Affiliation(s)
- Meijiao Yang
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lu Yu
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Di Jiang
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Chao Deng
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zeguang Wang
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xuhuizi Xu
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jinda Wang
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Songqing Wu
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Feiping Zhang
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Xia Hu
- Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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2
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Wood BW, Shi X, Weil TT. F-actin coordinates spindle morphology and function in Drosophila meiosis. PLoS Genet 2024; 20:e1011111. [PMID: 38206959 PMCID: PMC10807755 DOI: 10.1371/journal.pgen.1011111] [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: 04/12/2023] [Revised: 01/24/2024] [Accepted: 12/13/2023] [Indexed: 01/13/2024] Open
Abstract
Meiosis is a highly conserved feature of sexual reproduction that ensures germ cells have the correct number of chromosomes prior to fertilization. A subset of microtubules, known as the spindle, are essential for accurate chromosome segregation during meiosis. Building evidence in mammalian systems has recently highlighted the unexpected requirement of the actin cytoskeleton in chromosome segregation; a network of spindle actin filaments appear to regulate many aspects of this process. Here we show that Drosophila oocytes also have a spindle population of actin that appears to regulate the formation of the microtubule spindle and chromosomal movements throughout meiosis. We demonstrate that genetic and pharmacological disruption of the actin cytoskeleton has a significant impact on spindle morphology, dynamics, and chromosome alignment and segregation during maturation and the metaphase-anaphase transition. We further reveal a role for calcium in maintaining the microtubule spindle and spindle actin. Together, our data highlights potential conservation of morphology and mechanism of the spindle actin during meiosis.
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Affiliation(s)
- Benjamin W. Wood
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Xingzhu Shi
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
| | - Timothy T. Weil
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom
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3
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Wilby EL, Weil TT. Relating the Biogenesis and Function of P Bodies in Drosophila to Human Disease. Genes (Basel) 2023; 14:1675. [PMID: 37761815 PMCID: PMC10530015 DOI: 10.3390/genes14091675] [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: 07/31/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 09/29/2023] Open
Abstract
Drosophila has been a premier model organism for over a century and many discoveries in flies have furthered our understanding of human disease. Flies have been successfully applied to many aspects of health-based research spanning from behavioural addiction, to dysplasia, to RNA dysregulation and protein misfolding. Recently, Drosophila tissues have been used to study biomolecular condensates and their role in multicellular systems. Identified in a wide range of plant and animal species, biomolecular condensates are dynamic, non-membrane-bound sub-compartments that have been observed and characterised in the cytoplasm and nuclei of many cell types. Condensate biology has exciting research prospects because of their diverse roles within cells, links to disease, and potential for therapeutics. In this review, we will discuss processing bodies (P bodies), a conserved biomolecular condensate, with a particular interest in how Drosophila can be applied to advance our understanding of condensate biogenesis and their role in disease.
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Affiliation(s)
| | - Timothy T. Weil
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK;
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4
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Katano D, Kang W, Harada Y, Kawano N, Miyado M, Saito T, Fukuoka M, Yamada M, Miyado K. Sodium Hexametaphosphate Serves as an Inducer of Calcium Signaling. Biomolecules 2023; 13:biom13040577. [PMID: 37189325 DOI: 10.3390/biom13040577] [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: 02/21/2023] [Revised: 03/19/2023] [Accepted: 03/21/2023] [Indexed: 05/17/2023] Open
Abstract
In bacteria, polymers of inorganic phosphates, particularly linear polyphosphate, are used as alternative phosphate donors for adenosine triphosphate production. A six-chain form of sodium metaphosphate, sodium hexametaphosphate (SHMP), is believed to have no physiological functions in mammalian cells. In this study, we explored the possible effects of SHMP on mammalian cells, using mouse oocytes, which are useful for observing various spatiotemporal intracellular changes. Fertilization-competent oocytes were isolated from the oviducts of superovulated mice and cultured in an SHMP-containing medium. In the absence of co-incubation with sperm, SHMP-treated oocytes frequently formed pronuclei and developed into two-cell embryos owing to the increase in calcium concentration in the cytoplasm. We discovered an intriguing role for SHMP as an initiator of calcium rise in mouse oocytes, presumably in a wide variety of mammalian cells.
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Affiliation(s)
- Daiki Katano
- Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Kawasaki 214-8571, Japan
- Department of Reproductive Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya 157-8535, Japan
| | - Woojin Kang
- Department of Reproductive Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya 157-8535, Japan
- Laboratory Animal Resource Center, Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Yuichirou Harada
- Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku 192-0397, Japan
| | - Natsuko Kawano
- Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Kawasaki 214-8571, Japan
| | - Mami Miyado
- Department of Food and Nutrition, Beppu University, 82 Kita-Ishigaki, Beppu 874-8501, Japan
- Department of Molecular Endocrinology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya 157-8535, Japan
| | - Takako Saito
- Department of Applied Life Sciences, Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan
- Shizuoka Institute for the Study of Marine Biology and Chemistry, Shizuoka University, 836 Ohya, Shizuoka 422-8529, Japan
| | - Mio Fukuoka
- Department of Obstetrics and Gynecology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku 160-8582, Japan
| | - Mitsutoshi Yamada
- Department of Obstetrics and Gynecology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku 160-8582, Japan
| | - Kenji Miyado
- Department of Reproductive Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya 157-8535, Japan
- Division of Diversity Research, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya 157-8535, Japan
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5
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Abdulsamad HMR, Murtaza ZF, AlMuhairi HM, Bafleh WS, AlMansoori SA, AlQubaisi SA, Hamdan H, Kashir J. The Therapeutic and Diagnostic Potential of Phospholipase C Zeta, Oocyte Activation, and Calcium in Treating Human Infertility. Pharmaceuticals (Basel) 2023; 16:441. [PMID: 36986540 PMCID: PMC10056371 DOI: 10.3390/ph16030441] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/19/2023] [Accepted: 03/06/2023] [Indexed: 03/17/2023] Open
Abstract
Oocyte activation, a fundamental event during mammalian fertilisation, is initiated by concerted intracellular patterns of calcium (Ca2+) release, termed Ca2+ oscillations, predominantly driven by testis-specific phospholipase C zeta (PLCζ). Ca2+ exerts a pivotal role in not just regulating oocyte activation and driving fertilisation, but also in influencing the quality of embryogenesis. In humans, a failure of Ca2+ release, or defects in related mechanisms, have been reported to result in infertility. Furthermore, mutations in the PLCζ gene and abnormalities in sperm PLCζ protein and RNA, have been strongly associated with forms of male infertility where oocyte activation is deficient. Concurrently, specific patterns and profiles of PLCζ in human sperm have been linked to parameters of semen quality, suggesting the potential for PLCζ as a powerful target for both therapeutics and diagnostics of human fertility. However, further to PLCζ and given the strong role played by Ca2+ in fertilisation, targets down- and up-stream of this process may also present a significantly similar level of promise. Herein, we systematically summarise recent advancements and controversies in the field to update expanding clinical associations between Ca2+-release, PLCζ, oocyte activation and human fertility. We discuss how such associations may potentially underlie defective embryogenesis and recurrent implantation failure following fertility treatments, alongside potential diagnostic and therapeutic avenues presented by oocyte activation for the diagnosis and treatment of human infertility.
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Affiliation(s)
- Haia M. R. Abdulsamad
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Zoha F. Murtaza
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Hessa M. AlMuhairi
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Wjdan S. Bafleh
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Salma A. AlMansoori
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Shaikha A. AlQubaisi
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Hamdan Hamdan
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Junaid Kashir
- Department of Biology, College of Arts and Science, Khalifa University, Abu Dhabi 127788, United Arab Emirates
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia
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6
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Ready DF, Chang HC. Calcium waves facilitate and coordinate the contraction of endfeet actin stress fibers in Drosophila interommatidial cells. Development 2021; 148:272616. [PMID: 34698814 DOI: 10.1242/dev.199700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 10/18/2021] [Indexed: 01/04/2023]
Abstract
Actomyosin contraction shapes the Drosophila eye's panoramic view. The convex curvature of the retinal epithelium, organized in ∼800 close-packed ommatidia, depends upon a fourfold condensation of the retinal floor mediated by contraction of actin stress fibers in the endfeet of interommatidial cells (IOCs). How these tensile forces are coordinated is not known. Here, we discover a novel phenomenon: Ca2+ waves regularly propagate across the IOC network in pupal and adult eyes. Genetic evidence demonstrates that IOC waves are independent of phototransduction, but require inositol 1,4,5-triphosphate receptor (IP3R), suggesting these waves are mediated by Ca2+ releases from ER stores. Removal of IP3R disrupts stress fibers in IOC endfeet and increases the basal retinal surface by ∼40%, linking IOC waves to facilitating stress fiber contraction and floor morphogenesis. Further, IP3R loss disrupts the organization of a collagen IV network underneath the IOC endfeet, implicating ECM and its interaction with stress fibers in eye morphogenesis. We propose that coordinated cytosolic Ca2+ increases in IOC waves promote stress fiber contractions, ensuring an organized application of the planar tensile forces that condense the retinal floor.
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Affiliation(s)
- Donald F Ready
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907-2054, USA
| | - Henry C Chang
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907-2054, USA
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7
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Sankaranarayanan M, Emenecker RJ, Wilby EL, Jahnel M, Trussina IREA, Wayland M, Alberti S, Holehouse AS, Weil TT. Adaptable P body physical states differentially regulate bicoid mRNA storage during early Drosophila development. Dev Cell 2021; 56:2886-2901.e6. [PMID: 34655524 PMCID: PMC8555633 DOI: 10.1016/j.devcel.2021.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 07/22/2021] [Accepted: 09/23/2021] [Indexed: 01/01/2023]
Abstract
Ribonucleoprotein condensates can exhibit diverse physical states in vitro and in vivo. Despite considerable progress, the relevance of condensate physical states for in vivo biological function remains limited. Here, we investigated the physical properties of processing bodies (P bodies) and their impact on mRNA storage in mature Drosophila oocytes. We show that the conserved DEAD-box RNA helicase Me31B forms viscous P body condensates, which adopt an arrested physical state. We demonstrate that structurally distinct proteins and protein-protein interactions, together with RNA, regulate the physical properties of P bodies. Using live imaging and in situ hybridization, we show that the arrested state and integrity of P bodies support the storage of bicoid (bcd) mRNA and that egg activation modulates P body properties, leading to the release of bcd for translation in the early embryo. Together, this work provides an example of how physical states of condensates regulate cellular function in development.
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Affiliation(s)
- M Sankaranarayanan
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
| | - Ryan J Emenecker
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Center for Science and Engineering of Living Systems, Washington University in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Elise L Wilby
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Marcus Jahnel
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Irmela R E A Trussina
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Matt Wayland
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Simon Alberti
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Center for Science and Engineering of Living Systems, Washington University in St. Louis, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Timothy T Weil
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
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8
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York-Andersen AH, Wood BW, Wilby EL, Berry AS, Weil TT. Osmolarity-regulated swelling initiates egg activation in Drosophila. Open Biol 2021; 11:210067. [PMID: 34343463 PMCID: PMC8331238 DOI: 10.1098/rsob.210067] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Egg activation is a series of highly coordinated processes that prepare the mature oocyte for embryogenesis. Typically associated with fertilization, egg activation results in many downstream outcomes, including the resumption of the meiotic cell cycle, translation of maternal mRNAs and cross-linking of the vitelline membrane. While some aspects of egg activation, such as initiation factors in mammals and environmental cues in sea animals, have been well-documented, the mechanics of egg activation in insects are less well-understood. For many insects, egg activation can be triggered independently of fertilization. In Drosophila melanogaster, egg activation occurs in the oviduct resulting in a single calcium wave propagating from the posterior pole of the oocyte. Here we use physical manipulations, genetics and live imaging to demonstrate the requirement of a volume increase for calcium entry at egg activation in ex vivo mature Drosophila oocytes. The addition of water, modified with sucrose to a specific osmolarity, is sufficient to trigger the calcium wave in the mature oocyte and the downstream events associated with egg activation. We show that the swelling process is regulated by the conserved osmoregulatory channels, aquaporins and DEGenerin/Epithelial Na+ channels. Furthermore, through pharmacological and genetic disruption, we reveal a concentration-dependent requirement of transient receptor potential M channels to transport calcium, most probably from the perivitelline space, across the plasma membrane into the mature oocyte. Our data establish osmotic pressure as a mechanism that initiates egg activation in Drosophila and are consistent with previous work from evolutionarily distant insects, including dragonflies and mosquitos, and show remarkable similarities to the mechanism of egg activation in some plants.
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Affiliation(s)
- Anna H York-Andersen
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Benjamin W Wood
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Elise L Wilby
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Alexander S Berry
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Timothy T Weil
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
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9
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Limatola N, Chun JT, Santella L. Effects of Salinity and pH of Seawater on the Reproduction of the Sea Urchin Paracentrotus lividus. THE BIOLOGICAL BULLETIN 2020; 239:13-23. [PMID: 32812816 DOI: 10.1086/710126] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
AbstractFertilization and early development are usually the most vulnerable stages in the life of marine animals, and the biological processes during this period are highly sensitive to the environment. In nature, sea urchin gametes are shed in seawater, where they undergo external fertilization and embryonic development. In a laboratory, it is possible to follow the exact morphological and biochemical changes taking place in the fertilized eggs and the developing embryos. Thus, observation of successful fertilization and the subsequent embryonic development of sea urchin eggs can be used as a convenient biosensor to assess the quality of the marine environment. In this paper, we have examined how salinity and pH changes affect the normal fertilization process and the following development of Paracentrotus lividus. The results of our studies using confocal microscopy, scanning and transmission electron microscopy, and time-lapse Ca2+ image recording indicated that both dilution and acidification of seawater have subtle but detrimental effects on many aspects of the fertilization process. They include Ca2+ signaling and coordinated actin cytoskeletal changes, leading to a significantly reduced rate of successful fertilization and, eventually, to abnormal or delayed embryonic development.
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10
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Hu Q, Wolfner MF. Regulation of Trpm activation and calcium wave initiation during Drosophila egg activation. Mol Reprod Dev 2020; 87:880-886. [PMID: 32735035 DOI: 10.1002/mrd.23403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/24/2020] [Accepted: 07/15/2020] [Indexed: 12/12/2022]
Abstract
The transition from a developmentally arrested mature oocyte to a developing embryo requires a series of highly conserved events, collectively known as egg activation. All of these events are preceded by a ubiquitous rise of intracellular calcium, which results from influx of external calcium and/or calcium release from internal storage. In Drosophila, this calcium rise initiates from the pole(s) of the oocyte by influx of external calcium in response to mechanical triggers. It is thought to trigger calcium responsive kinases and/or phosphatases, which in turn alter the oocyte phospho-proteome to initiate downstream events. Recent studies revealed that external calcium enters the activating Drosophila oocyte through Trpm channels, a feature conserved in mouse. The local entry of calcium raises the question of whether Trpm channels are found locally at the poles of the oocyte or are localized around the oocyte periphery, but activated only at the poles. Here, we show that Trpm is distributed all around the oocyte. This requires that it thus be specially regulated at the poles to allow calcium wave initiation. We show that neither egg shape nor local pressure is sufficient to explain this local activation of Trpm channels.
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Affiliation(s)
- Qinan Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
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11
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Santella L, Limatola N, Chun JT. Cellular and molecular aspects of oocyte maturation and fertilization: a perspective from the actin cytoskeleton. ZOOLOGICAL LETTERS 2020; 6:5. [PMID: 32313685 PMCID: PMC7158055 DOI: 10.1186/s40851-020-00157-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 03/26/2020] [Indexed: 05/06/2023]
Abstract
ABSTRACT Much of the scientific knowledge on oocyte maturation, fertilization, and embryonic development has come from the experiments using gametes of marine organisms that reproduce by external fertilization. In particular, echinoderm eggs have enabled the study of structural and biochemical changes related to meiotic maturation and fertilization owing to the abundant availability of large and transparent oocytes and eggs. Thus, in vitro studies of oocyte maturation and sperm-induced egg activation in starfish are carried out under experimental conditions that resemble those occurring in nature. During the maturation process, immature oocytes of starfish are released from the prophase of the first meiotic division, and acquire the competence to be fertilized through a highly programmed sequence of morphological and physiological changes at the oocyte surface. In addition, the changes in the cortical and nuclear regions are essential for normal and monospermic fertilization. This review summarizes the current state of research on the cortical actin cytoskeleton in mediating structural and physiological changes during oocyte maturation and sperm and egg activation in starfish and sea urchin. The common denominator in these studies with echinoderms is that exquisite rearrangements of the egg cortical actin filaments play pivotal roles in gamete interactions, Ca2+ signaling, exocytosis of cortical granules, and control of monospermic fertilization. In this review, we also compare findings from studies using invertebrate eggs with what is known about the contributions made by the actin cytoskeleton in mammalian eggs. Since the cortical actin cytoskeleton affects microvillar morphology, movement, and positioning of organelles and vesicles, and the topography of the egg surface, these changes have impacts on the fertilization process, as has been suggested by recent morphological studies on starfish oocytes and eggs using scanning electron microscopy. Drawing the parallelism between vitelline layer of echinoderm eggs and the zona pellucida of mammalian eggs, we also discuss the importance of the egg surface in mediating monospermic fertilization. GRAPHICAL ABSTRACT
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Affiliation(s)
- Luigia Santella
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy
| | - Nunzia Limatola
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy
| | - Jong Tai Chun
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, Napoli 80121, Italy
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12
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York-Andersen AH, Hu Q, Wood BW, Wolfner MF, Weil TT. A calcium-mediated actin redistribution at egg activation in Drosophila. Mol Reprod Dev 2019; 87:293-304. [PMID: 31880382 PMCID: PMC7044060 DOI: 10.1002/mrd.23311] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 12/12/2019] [Indexed: 12/24/2022]
Abstract
Egg activation is the essential process in which mature oocytes gain the competency to proceed into embryonic development. Many events of egg activation are conserved, including an initial rise of intracellular calcium. In some species, such as echinoderms and mammals, changes in the actin cytoskeleton occur around the time of fertilization and egg activation. However, the interplay between calcium and actin during egg activation remains unclear. Here, we use imaging, genetics, pharmacological treatment, and physical manipulation to elucidate the relationship between calcium and actin in living Drosophila eggs. We show that, before egg activation, actin is smoothly distributed between ridges in the cortex of the dehydrated mature oocytes. At the onset of egg activation, we observe actin spreading out as the egg swells though the intake of fluid. We show that a relaxed actin cytoskeleton is required for the intracellular rise of calcium to initiate and propagate. Once the swelling is complete and the calcium wave is traversing the egg, it leads to a reorganization of actin in a wavelike manner. After the calcium wave, the actin cytoskeleton has an even distribution of foci at the cortex. Together, our data show that calcium resets the actin cytoskeleton at egg activation, a model that we propose to be likely conserved in other species.
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Affiliation(s)
| | - Qinan Hu
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Benjamin W Wood
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Timothy T Weil
- Department of Zoology, University of Cambridge, Cambridge, UK
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