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McCarthy JS, Brown KE, King CK, Nielsen UN, Plaisted K, Wallace SMN, Reichman SM. Population growth of two limno-terrestrial Antarctic microinvertebrates in different aqueous soil media. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:33086-33097. [PMID: 38676867 PMCID: PMC11133119 DOI: 10.1007/s11356-024-32905-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 03/10/2024] [Indexed: 04/29/2024]
Abstract
Terrestrial microinvertebrates provide important carbon and nutrient cycling roles in soil environments, particularly in Antarctica where larger macroinvertebrates are absent. The environmental preferences and ecology of rotifers and tardigrades in terrestrial environments, including in Antarctica, are not as well understood as their temperate aquatic counterparts. Developing laboratory cultures is critical to provide adequate numbers of individuals for controlled laboratory experimentation. In this study, we explore aspects of optimising laboratory culturing for two terrestrially sourced Antarctic microinvertebrates, a rotifer (Habrotrocha sp.) and a tardigrade (Acutuncus antarcticus). We tested a soil elutriate and a balanced salt solution (BSS) to determine their suitability as culturing media. Substantial population growth of rotifers and tardigrades was observed in both media, with mean rotifer population size increasing from 5 to 448 ± 95 (soil elutriate) and 274 ± 78 (BSS) individuals over 60 days and mean tardigrade population size increasing from 5 to 187 ± 65 (soil elutriate) and 138 ± 37 (BSS) over 160 days. We also tested for optimal dilution of soil elutriate in rotifer cultures, with 20-80% dilutions producing the largest population growth with the least variation in the 40% dilution after 36 days. Culturing methods developed in this study are recommended for use with Antarctica microinvertebrates and may be suitable for similar limno-terrestrial microinvertebrates from other regions.
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Affiliation(s)
- Jordan S McCarthy
- Centre for Anthropogenic Pollution Impact and Management (CAPIM), University of Melbourne, Parkville, VIC, 3010, Australia
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kathryn E Brown
- Environmental Stewardship Program, Australian Antarctic Division, 203 Channel Highway, Kingston, TAS, 7050, Australia
| | - Catherine K King
- Environmental Stewardship Program, Australian Antarctic Division, 203 Channel Highway, Kingston, TAS, 7050, Australia
| | - Uffe N Nielsen
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2750, Australia
| | - Katie Plaisted
- Centre for Anthropogenic Pollution Impact and Management (CAPIM), University of Melbourne, Parkville, VIC, 3010, Australia
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Stephanie M N Wallace
- Centre for Anthropogenic Pollution Impact and Management (CAPIM), University of Melbourne, Parkville, VIC, 3010, Australia
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Suzie M Reichman
- Centre for Anthropogenic Pollution Impact and Management (CAPIM), University of Melbourne, Parkville, VIC, 3010, Australia.
- School of BioSciences, University of Melbourne, Parkville, VIC, 3010, Australia.
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2
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A Draft Mitogenome of Plectus Murrayi. J Nematol 2022; 54:20220035. [PMID: 36338426 PMCID: PMC9583411 DOI: 10.2478/jofnem-2022-0035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Indexed: 11/06/2022] Open
Abstract
Plectus murrayi is a free-living microbivorous nematode endemic to Antarctic soils. Our draft assembly of its mitogenome was 15,656 bp long, containing 12 protein-coding, eight transfer RNA (tRNA), and two ribosomal RNA (rRNA) genes. Mitophylogenomic analyses extend our understanding of mitochondrial evolution in Nematoda
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3
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Kuramochi M, Zhu S, Takanashi C, Yang Y, Arai T, Shinkai Y, Doi M, Mio K, Tsuda S, Sasaki YC. A mutation to a fish ice-binding protein synthesized in transgenic Caenorhabditis elegans modulate its cold tolerance. Biochem Biophys Res Commun 2022; 628:98-103. [PMID: 36084557 DOI: 10.1016/j.bbrc.2022.08.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/02/2022]
Abstract
A cryoprotectant known as ice-binding protein (IBP) is thought to facilitate the cold survival of plants, insects, and fungi. Here, we prepared a genetically modified Caenorhabditis elegans strain to synthesize fish-derived IBPs in its body wall muscles and examined whether the antifreeze activity modification of this IBP by point mutation affects the cold tolerance of this worm. We chose a 65-residue IBP identified from notched-fin eelpout, for which the replacement of the 20th alanine residue (A20) modifies its antifreeze activity. These mutant proteins are denoted A20L, A20G, A20T, A20V, and A20I along with the wild-type (WT) protein. We evaluated the survival rate (%) of the transgenic C. elegans that synthesized each IBP mutant following 24 h of preservation at -5, +2, and +5 °C. Significantly, a dramatic improvement in the survival rate was detected for the worms synthesizing the activity-enhanced mutants (A20T and A20I), especially at +2 °C. In contrast, the rate was not improved by the expression of the defective mutants (A20L, A20G, WT and A20V). The survival rate (%) probably correlates with the antifreeze activity of the IBP. These data suggest that IBP protects the cell membrane by employing its ice-binding mechanism, which ultimately improves the cold tolerance of an IBP-containing animal.
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4
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Cold Tolerance in Pinewood Nematode Bursaphelenchus xylophilus Promoted Multiple Invasion Events in Mid-Temperate Zone of China. FORESTS 2022. [DOI: 10.3390/f13071100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Pinewood nematode (Bursaphelenchus xylophilus) is a highly destructive invasive species, causing extensive economic and ecological losses across Eurasia. It has recently invaded mid-temperate zone of northern China, threating large areas of coniferous forests. Herein, we evaluated the physiological and molecular basis of cold tolerance in pinewood nematode isolates from different temperature zones of China. After exposure to −5 °C and −10 °C, the survival rates of five pinewood nematode isolates from different temperature zones were 93.94%–94.77% and 43.26%–45.58% after 8 h, and 93.04%–94.85% and 9.93%–10.56% after 24 h, without significant differences among isolates. In a comparison of an isolate from a mid-temperate zone and an isolate from a subtropical zone under gradient cooling, the survival rates remained steady at nearly 95% when minimum temperature ranged from −5 °C to −15 °C, with no significant difference between isolates. In addition, phylogenetic and population structure analyses based on whole genome resequencing data suggested that isolates from mid-temperate and warm temperate zones are clustered with different isolates from subtropical zone, with no obvious geographic pattern. We did not detect significant variation in cold tolerance ability and selected gene among pinewood nematode isolates from different temperature zones. The recently invaded pinewood nematodes in the mid-temperate zone of northern China may spread by multiple invasion events from southern China, without adaptive revolution. Our research implies that it is important to reinforce quarantine inspection to control the rapid spread of pinewood nematode.
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5
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Wan X, Saito JA, Hou S, Geib SM, Yuryev A, Higa LM, Womersley CZ, Alam M. The Aphelenchus avenae genome highlights evolutionary adaptation to desiccation. Commun Biol 2021; 4:1232. [PMID: 34711923 PMCID: PMC8553787 DOI: 10.1038/s42003-021-02778-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 10/09/2021] [Indexed: 02/08/2023] Open
Abstract
Some organisms can withstand complete body water loss (losing up to 99% of body water) and stay in ametabolic state for decades until rehydration, which is known as anhydrobiosis. Few multicellular eukaryotes on their adult stage can withstand life without water. We still have an incomplete understanding of the mechanism for metazoan survival of anhydrobiosis. Here we report the 255-Mb genome of Aphelenchus avenae, which can endure relative zero humidity for years. Gene duplications arose genome-wide and contributed to the expansion and diversification of 763 kinases, which represents the second largest metazoan kinome to date. Transcriptome analyses of ametabolic state of A. avenae indicate the elevation of ATP level for global recycling of macromolecules and enhancement of autophagy in the early stage of anhydrobiosis. We catalogue 74 species-specific intrinsically disordered proteins, which may facilitate A. avenae to survive through desiccation stress. Our findings refine a molecular basis evolving for survival in extreme water loss and open the way for discovering new anti-desiccation strategies.
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Affiliation(s)
- Xuehua Wan
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, HI, USA.
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China.
| | - Jennifer A Saito
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, HI, USA
| | - Shaobin Hou
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, HI, USA
| | - Scott M Geib
- Tropical Crop and Commodity Protection Research Unit, USDA-ARS Pacific Basin Agricultural Research Center, Hilo, HI, USA
| | - Anton Yuryev
- Elsevier Life Sciences Solutions, Rockville, MD, USA
| | - Lynne M Higa
- School of Life Sciences, University of Hawaii, Honolulu, HI, USA
| | | | - Maqsudul Alam
- Advanced Studies in Genomics, Proteomics and Bioinformatics, University of Hawaii, Honolulu, HI, USA
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6
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Zawierucha K, Porazinska DL, Ficetola GF, Ambrosini R, Baccolo G, Buda J, Ceballos JL, Devetter M, Dial R, Franzetti A, Fuglewicz U, Gielly L, Łokas E, Janko K, Novotna Jaromerska T, Kościński A, Kozłowska A, Ono M, Parnikoza I, Pittino F, Poniecka E, Sommers P, Schmidt SK, Shain D, Sikorska S, Uetake J, Takeuchi N. A hole in the nematosphere: tardigrades and rotifers dominate the cryoconite hole environment, whereas nematodes are missing. J Zool (1987) 2020. [DOI: 10.1111/jzo.12832] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- K. Zawierucha
- Department of Animal Taxonomy and Ecology Adam Mickiewicz University Poznań Poland
| | - D. L. Porazinska
- Department of Entomology and Nematology University of Florida Gainesville FL USA
| | - G. F. Ficetola
- Department of Environmental Science and Policy University of Milan Milan Italy
- Laboratoire d'Ecologie Alpine University Grenoble Alpes Univ. Savoie Mont Blanc CNRS LECA Grenoble France
| | - R. Ambrosini
- Department of Environmental Science and Policy University of Milan Milan Italy
| | - G. Baccolo
- Earth and Environmental Sciences Department University of Milano‐Bicocca Milan Italy
| | - J. Buda
- Department of Animal Taxonomy and Ecology Adam Mickiewicz University Poznań Poland
| | - J. L. Ceballos
- Institute of Hydrology, Meteorology and Environmental Studies IDEAM Bogota' Colombia
| | - M. Devetter
- Institute of soil Biology Biology Centre CAS České Budějovice Czech Republic
- Centre for Polar Ecology Faculty of Science University of South Bohemia České Budějovice Czech Republic
| | - R. Dial
- Institute of Culture and the Environment Alaska Pacific University Anchorage AK USA
| | - A. Franzetti
- Earth and Environmental Sciences Department University of Milano‐Bicocca Milan Italy
| | | | - L. Gielly
- Laboratoire d'Ecologie Alpine University Grenoble Alpes Univ. Savoie Mont Blanc CNRS LECA Grenoble France
| | - E. Łokas
- Department of Mass Spectroscopy Institute of Nuclear Physics Polish Academy of Sciences Kraków Poland
| | - K. Janko
- Laboratory of Fish Genetics Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Biology and Ecology Faculty of Science University of Ostrava Ostrava Czech Republic
| | | | | | - A. Kozłowska
- Department of Animal Taxonomy and Ecology Adam Mickiewicz University Poznań Poland
| | - M. Ono
- Graduate School of Science and Engineering Chiba University Chiba Japan
| | - I. Parnikoza
- State Institution National Antarctic Center of Ministry of Education and Science of Ukraine Kyiv Ukraine
- Institute of Molecular Biology and Genetics National Academy of Sciences of Ukraine Kyiv Ukraine
| | - F. Pittino
- Earth and Environmental Sciences Department University of Milano‐Bicocca Milan Italy
| | - E. Poniecka
- School of Earth and Ocean Sciences Cardiff University Cardiff UK
| | - P. Sommers
- Ecology and Evolutionary Biology Department University of Colorado Boulder CO USA
| | - S. K. Schmidt
- Ecology and Evolutionary Biology Department University of Colorado Boulder CO USA
| | - D. Shain
- Biology Department Rutgers, The State University of New Jersey Camden NJ USA
| | - S. Sikorska
- Department of Animal Taxonomy and Ecology Adam Mickiewicz University Poznań Poland
| | - J. Uetake
- The Arctic Environment Research Center National Institute of Polar Research Tachikawa Japan
| | - N. Takeuchi
- Department of Earth Sciences Graduate School of Science Chiba University Chiba Japan
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7
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Ma J, Gao B, Wang R, Li X, Chen S. Transcriptome analyses of Ditylenchus destructor in responses to cold and desiccation stress. Genet Mol Biol 2020; 43:e20180057. [PMID: 32232317 PMCID: PMC7198036 DOI: 10.1590/1678-4685-gmb-2018-0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/03/2019] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to identify molecular responses in Ditylenchus destructor to cold and desiccation by means of transcriptomes analyses. A total of 102,517 unigenes were obtained, with an average length of 1,076 bp, in which 58,453 (57%) had a functional annotation. A total of 1154 simple sequence repeats (SSRs) distributed over 1078 unigenes were detected. Gene expression profiles in response to cold and desiccation stress and the expression of specific stress-related genes were compared. Gene ontology analysis and pathway-based analysis were used to further investigate the functions of the differentially expressed genes. The reliability of the sequencing data was verified through quantitative real-time PCR analysis of 19 stress-related genes. RNA interference used to further assess the functions of the cold-related unigenes 15628 and 15596 showed that the knockdown of each of these genes led to decreased cold tolerance of D. destructor. Hence, this study revealed molecular processes and pathways active in cold- or dessication-treated nematodes. The transcriptome profiles presented in this study provide insight into the transcriptome complexity and will contribute to further understand stress tolerance in D. destructor.
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Affiliation(s)
- Juan Ma
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Bo Gao
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Rongyan Wang
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Xiuhua Li
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
| | - Shulong Chen
- Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences /IPM centre of Hebei Province/ Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, China
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8
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Kuramochi M, Takanashi C, Yamauchi A, Doi M, Mio K, Tsuda S, Sasaki YC. Expression of Ice-Binding Proteins in Caenorhabditis elegans Improves the Survival Rate upon Cold Shock and during Freezing. Sci Rep 2019; 9:6246. [PMID: 31092839 PMCID: PMC6520345 DOI: 10.1038/s41598-019-42650-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/04/2019] [Indexed: 01/01/2023] Open
Abstract
Ice-binding proteins (IBPs) are capable of binding ice crystals and inhibiting their growth at freezing temperatures. IBPs are also thought to stabilize the cell membrane at non-freezing temperatures near 0 °C. These two effects have been assumed to reduce cold- and freezing-induced damage to cells and tissues. However, knowledge regarding the effects of IBP on the living animals is limited. Here, we characterized the relationship between the IBP effects and the physiological role by using the nematode Caenorhabditis elegans. The expression of fish (NfeIBPs)- and fungus-derived IBPs (AnpIBPs and TisIBP8) in C. elegans improved its survival rate during exposure to 0 and −2 °C (cold shock) and −5 °C (freezing). The observed cold tolerance of C. elegans after cold shock is attributable to the stabilization of cell-membrane lipids with IBPs, and the freezing tolerance at −5 °C can be attributed to the inhibition of ice-crystal growth by the IBPs. Significantly, the survival rate of C. elegans at −5 °C was improved by expression of wild-type AnpIBP and maximized by that of TisIBP8, whereas it was lowered when a defective AnpIBP mutant was expressed. These results suggest that the ice-binding ability of IBP has a good correlation with the survival rate of C. elegans during freezing.
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Affiliation(s)
- Masahiro Kuramochi
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan. .,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan. .,Molecular Neurobiology Research Group and DAI-LAB, Biomedical Research Institute, National Institute of Advance Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan.
| | - Chiaki Takanashi
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Akari Yamauchi
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan.,Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, 062-8517, Japan
| | - Motomichi Doi
- Molecular Neurobiology Research Group and DAI-LAB, Biomedical Research Institute, National Institute of Advance Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan
| | - Kazuhiro Mio
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan
| | - Sakae Tsuda
- AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan. .,Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan. .,Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo, 062-8517, Japan.
| | - Yuji C Sasaki
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, 277-8561, Japan. .,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Kashiwa, 277-8565, Japan.
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9
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Knox MA, Andriuzzi WS, Buelow HN, Takacs-Vesbach C, Adams BJ, Wall DH. Decoupled responses of soil bacteria and their invertebrate consumer to warming, but not freeze-thaw cycles, in the Antarctic Dry Valleys. Ecol Lett 2017; 20:1242-1249. [PMID: 28797136 DOI: 10.1111/ele.12819] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 06/30/2017] [Accepted: 07/09/2017] [Indexed: 11/30/2022]
Abstract
Altered temperature profiles resulting in increased warming and freeze-thaw cycle (FTC) frequency pose great ecological challenges to organisms in alpine and polar ecosystems. We performed a laboratory microcosm experiment to investigate how temperature variability affects soil bacterial cell numbers, and abundance and traits of soil microfauna (the microbivorous nematode Scottnema lindsayae) from McMurdo Dry Valleys, Antarctica. FTCs and constant freezing shifted nematode body size distribution towards large individuals, driven by higher mortality among smaller individuals. FTCs reduced both bacterial and nematode abundance, but bacterial cell numbers also declined under warming, demonstrating decoupled consumer-prey responses. We predict that higher occurrence of FTCs in cold ecosystems will select for large body size within soil microinvertebrates and overall reduce their abundance. In contrast, warm temperatures without FTCs could lead to divergent responses in soil bacteria and their microinvertebrate consumers, potentially affecting energy and nutrient transfer rates in soil food webs of cold ecosystems.
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Affiliation(s)
- Matthew A Knox
- Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA.,Hopkirk Research Institute, IVABS, Massey University, Private Bag 11-222, Palmerston North, 4474, New Zealand
| | - Walter S Andriuzzi
- Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Heather N Buelow
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | | | - Byron J Adams
- Department of Biology, Evolutionary Ecology Laboratories, and Monte L. Bean Museum, Brigham Young University, Provo, UT, 84602, USA
| | - Diana H Wall
- Department of Biology, Colorado State University, Fort Collins, CO, 80523, USA.,School of Global Environmental Sustainability, Colorado State University, Fort Collins, CO, 80523, USA
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10
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Wharton DA, Marshall CJ, Egeter B. Comparisons between two Antarctic nematodes: cultured Panagrolaimus sp. DAW1 and field-sourced Panagrolaimus davidi. NEMATOLOGY 2017. [DOI: 10.1163/15685411-00003066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Antarctic nematodePanagrolaimus davidican survive intracellular freezing. Genetic studies indicate the culture strain (now designated asPanagrolaimussp. DAW1) is a different species to theP. davidiof field origin. This paper reports further attempts both to isolate DAW1 from Antarctic soils and to cultureP. davidiitself. Sequencing of the 18S rRNA gene of 151 individuals indicates that DAW1 is rare in the field, but characterising two new isolates shows that, nevertheless, it is present.Panagrolaimus davidiis common in the field, but cannot be cultured using the media tested here. These two species are difficult to distinguish morphologically, apart from the absence of males in DAW1 and its longer recurved tail. Whilst it is possible that DAW1 is an introduced species, the sites at Shackleton’s hut at Cape Royds are dominated byP. davidi, which is clearly an endemic species.
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Affiliation(s)
- David A. Wharton
- Department of Zoology, Otago, University of Otago, P.O. Box 56, Dunedin, New Zealand
| | - Craig J. Marshall
- Department of Biochemistry/Genetics, Otago, University of Otago, P.O. Box 56, Dunedin, New Zealand
| | - Bastian Egeter
- Department of Zoology, Otago, University of Otago, P.O. Box 56, Dunedin, New Zealand
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11
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McGill LM, Fitzpatrick DA, Pisani D, Burnell AM. Estimation of phylogenetic divergence times in Panagrolaimidae and other nematodes using relaxed molecular clocks calibrated with insect and crustacean fossils. NEMATOLOGY 2017. [DOI: 10.1163/15685411-00003096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study presents the use of relaxed molecular clock methods to infer the dates of divergence between Panagrolaimus species. Autocorrelated relaxed tree methods, combined with well characterised fossil calibration dates, yield estimates of nematode divergence dates in accordance with the palaeontological age of fossil ascarid eggs and with the previously estimated date of 18 Ma (range 11.6 to 29.9 Ma) for the divergence of the Caenorhabditis lineage. Our data indicate that Panagrolaimus davidi from Antarctica separated ca 21.98 Ma from its currently known, most closely related strain. Thus, P. davidi may have existed in Antarctica prior to the Last Glacial Maximum, although this seems unlikely as it shares physiological and life history traits with closely related nematodes from temperate climates. These traits may have facilitated colonisation of Antarctica by P. davidi after the quaternary glaciation, analogous to the colonisation of Surtsey Island, Iceland, by P. superbus after its volcanic formation. This study demonstrates that autocorrelated relaxed tree methods combined with well characterised fossil calibration dates may be used as a method to estimate the divergence dates within nematodes in order to gain insight into their evolutionary history.
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Affiliation(s)
- Lorraine M. McGill
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - David A. Fitzpatrick
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
| | - Davide Pisani
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
- School of Biological Sciences and School of Earth Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK
| | - Ann M. Burnell
- Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
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12
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Affiliation(s)
- Maya Bar Dolev
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agricultural, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; ,
| | - Ido Braslavsky
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agricultural, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel; ,
| | - Peter L. Davies
- Department of Biomedical and Molecular Science, Queen's University, Kingston, Ontario K7L 3N6, Canada;
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13
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Raymond MR, Wharton DA. The ability to survive intracellular freezing in nematodes is related to the pattern and distribution of ice formed. J Exp Biol 2016; 219:2060-5. [DOI: 10.1242/jeb.137190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 04/27/2016] [Indexed: 11/20/2022]
Abstract
A few species of nematodes can survive extensive intracellular freezing throughout all their tissues, an event that is usually thought to be fatal to cells. How are they able to survive in this remarkable way? The pattern and distribution of ice formed, after freezing at -10°C, can be observed using freeze substitution and transmission electron microscopy, which preserves the former position of ice as white spaces. We compared the pattern and distribution of ice formed in a nematode that survives intracellular freezing well (Panagrolaimus sp. DAW1), one that survives poorly (Panagrellus redivivus) and one with intermediate levels of survival (Plectus murrayi). We also examined Panagrolaimus sp. in which the survival of freezing had been compromised by starvation. Levels of survival were as expected and the use of vital dyes indicated cellular damage in those that survived poorly (starved Panagrolaimus sp. and P. murrayi). In fed Panagrolaimus sp. the intracellular ice spaces were small and uniform, whilst in P. redivivus and starved Panagrolaimus sp. there were some large spaces that may be causing cellular damage. The pattern and distribution of ice formed was different in P. murrayi, with a greater number of individuals having no ice or only small intracellular ice spaces. Control of the size of the ice formed is thus important for the survival of intracellular freezing in nematodes.
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Affiliation(s)
- Méliane R. Raymond
- Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand
| | - David A. Wharton
- Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand
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Infective Juveniles of the Entomopathogenic Nematode, Steinernema feltiae Produce Cryoprotectants in Response to Freezing and Cold Acclimation. PLoS One 2015; 10:e0141810. [PMID: 26509788 PMCID: PMC4625012 DOI: 10.1371/journal.pone.0141810] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/13/2015] [Indexed: 11/19/2022] Open
Abstract
Steinernema feltiae is a moderately freeze-tolerant entomopathogenic nematode which survives intracellular freezing. We have detected by gas chromatography that infective juveniles of S. feltiae produce cryoprotectants in response to cold acclimation and to freezing. Since the survival of this nematode varies with temperature, we analyzed their cryoprotectant profiles under different acclimation and freezing regimes. The principal cryoprotectants detected were trehalose and glycerol with glucose being the minor component. The amount of cryoprotectants varied with the temperature and duration of exposure. Trehalose was accumulated in higher concentrations when nematodes were acclimated at 5°C for two weeks whereas glycerol level decreased from that of the non-acclimated controls. Nematodes were seeded with a small ice crystal and held at -1°C, a regime that does not produce freezing of the nematodes but their bodies lose water to the surrounding ice (cryoprotective dehydration). This increased the levels of both trehalose and glycerol, with glycerol reaching a higher concentration than trehalose. Nematodes frozen at -3°C, a regime that produces freezing of the nematodes and results in intracellular ice formation, had elevated glycerol levels while trehalose levels did not change. Steinernema feltiae thus has two strategies of cryoprotectant accumulation: one is an acclimation response to low temperature when the body fluids are in a cooled or supercooled state and the infective juveniles produce trehalose before freezing. During this process a portion of the glycerol is converted to trehalose. The second strategy is a rapid response to freezing which induces the production of glycerol but trehalose levels do not change. These low molecular weight compounds are surmised to act as cryoprotectants for this species and to play an important role in its freezing tolerance.
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