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Kc S, Nguyen KH, Nicholson V, Walgren A, Trent T, Gollub E, Ramero S, Holehouse AS, Sukenik S, Boothby TC. Disordered proteins interact with the chemical environment to tune their protective function during drying. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582506. [PMID: 38464187 PMCID: PMC10925285 DOI: 10.1101/2024.02.28.582506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
The conformational ensemble and function of intrinsically disordered proteins (IDPs) are sensitive to their solution environment. The inherent malleability of disordered proteins combined with the exposure of their residues accounts for this sensitivity. One context in which IDPs play important roles that is concomitant with massive changes to the intracellular environment is during desiccation (extreme drying). The ability of organisms to survive desiccation has long been linked to the accumulation of high levels of cosolutes such as trehalose or sucrose as well as the enrichment of IDPs, such as late embryogenesis abundant (LEA) proteins or cytoplasmic abundant heat soluble (CAHS) proteins. Despite knowing that IDPs play important roles and are co-enriched alongside endogenous, species-specific cosolutes during desiccation, little is known mechanistically about how IDP-cosolute interactions influence desiccation tolerance. Here, we test the notion that the protective function of desiccation-related IDPs is enhanced through conformational changes induced by endogenous cosolutes. We find that desiccation-related IDPs derived from four different organisms spanning two LEA protein families and the CAHS protein family, synergize best with endogenous cosolutes during drying to promote desiccation protection. Yet the structural parameters of protective IDPs do not correlate with synergy for either CAHS or LEA proteins. We further demonstrate that for CAHS, but not LEA proteins, synergy is related to self-assembly and the formation of a gel. Our results suggest that functional synergy between IDPs and endogenous cosolutes is a convergent desiccation protection strategy seen among different IDP families and organisms, yet, the mechanisms underlying this synergy differ between IDP families.
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Yoshida Y, Tanaka S. Deciphering the Biological Enigma-Genomic Evolution Underlying Anhydrobiosis in the Phylum Tardigrada and the Chironomid Polypedilum vanderplanki. INSECTS 2022; 13:557. [PMID: 35735894 PMCID: PMC9224920 DOI: 10.3390/insects13060557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 02/04/2023]
Abstract
Anhydrobiosis, an ametabolic dehydrated state triggered by water loss, is observed in several invertebrate lineages. Anhydrobiotes revive when rehydrated, and seem not to suffer the ultimately lethal cell damage that results from severe loss of water in other organisms. Here, we review the biochemical and genomic evidence that has revealed the protectant molecules, repair systems, and maintenance pathways associated with anhydrobiosis. We then introduce two lineages in which anhydrobiosis has evolved independently: Tardigrada, where anhydrobiosis characterizes many species within the phylum, and the genus Polypedilum, where anhydrobiosis occurs in only two species. Finally, we discuss the complexity of the evolution of anhydrobiosis within invertebrates based on current knowledge, and propose perspectives to enhance the understanding of anhydrobiosis.
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Affiliation(s)
- Yuki Yoshida
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan
| | - Sae Tanaka
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan
- Institute for Advanced Biosciences, Keio University, 341-1 Mizukami, Tsuruoka 997-0052, Japan
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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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4
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Abstract
Living systems at all scales aggregate in large numbers for a variety of functions including mating, predation, and survival. The majority of such systems consist of unconnected individuals that collectively flock, school, or swarm. However, some aggregations involve physically entangled individuals, which can confer emergent mechanofunctional material properties to the collective. Here, we study in laboratory experiments and rationalize in theoretical and robophysical models the dynamics of physically entangled and motile self-assemblies of 1-cm-long California blackworms (Lumbriculus variegatus, Annelida: Clitellata: Lumbriculidae). Thousands of individual worms form braids with their long, slender, and flexible bodies to make a three-dimensional, soft, and shape-shifting "blob." The blob behaves as a living material capable of mitigating damage and assault from environmental stresses through dynamic shape transformations, including minimizing surface area for survival against desiccation and enabling transport (negative thermotaxis) from hazardous environments (like heat). We specifically focus on the locomotion of the blob to understand how an amorphous entangled ball of worms can break symmetry to move across a substrate. We hypothesize that the collective blob displays rudimentary differentiation of function across itself, which when combined with entanglement dynamics facilitates directed persistent blob locomotion. To test this, we develop a robophysical model of the worm blobs, which displays emergent locomotion in the collective without sophisticated control or programming of any individual robot. The emergent dynamics of the living functional blob and robophysical model can inform the design of additional classes of adaptive mechanofunctional living materials and emergent robotics.
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Sugi T, Ito H, Nishimura M, Nagai KH. C. elegans collectively forms dynamical networks. Nat Commun 2019; 10:683. [PMID: 30778072 PMCID: PMC6379388 DOI: 10.1038/s41467-019-08537-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/16/2019] [Indexed: 11/16/2022] Open
Abstract
Understanding physical rules underlying collective motions requires perturbation of controllable parameters in self-propelled particles. However, controlling parameters in animals is generally not easy, which makes collective behaviours of animals elusive. Here, we report an experimental system in which a conventional model animal, Caenorhabditis elegans, collectively forms dynamical networks of bundle-shaped aggregates. We investigate the dependence of our experimental system on various extrinsic parameters (material of substrate, ambient humidity and density of worms). Taking advantage of well-established C. elegans genetics, we also control intrinsic parameters (genetically determined motility) by mutations and by forced neural activation via optogenetics. Furthermore, we develop a minimal agent-based model that reproduces the dynamical network formation and its dependence on the parameters, suggesting that the key factors are alignment of worms after collision and smooth turning. Our findings imply that the concepts of active matter physics may help us to understand biological functions of animal groups. Understanding collective motions in a group of interacting animal is a challenge owing to the lack of control over, for example, real fish schools. Here, the authors study the aggregation of C. elegans at controllable conditions and reproduce the experimental observations using a minimal model.
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Affiliation(s)
- Takuma Sugi
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan.
| | - Hiroshi Ito
- Faculty of Design, Kyushu University, Fukuoka, 815-8540, Japan.
| | - Masaki Nishimura
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan
| | - Ken H Nagai
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292, Japan.
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Seybold AC, Wharton DA, Thorne MAS, Marshall CJ. Investigating trehalose synthesis genes after cold acclimation in the Antarctic nematode Panagrolaimus sp. DAW1. Biol Open 2017; 6:1953-1959. [PMID: 29175859 PMCID: PMC5769639 DOI: 10.1242/bio.023341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Panagrolaimus sp. DAW1 is a freeze-tolerant Antarctic nematode which survives extensive intracellular ice formation. The molecular mechanisms of this extreme adaptation are still poorly understood. We recently showed that desiccation-enhanced RNA interference (RNAi) soaking can be used in conjunction with quantitative polymerase chain reaction (qPCR) to screen for phenotypes associated with reduced expression of candidate genes in Panagrolaimus sp. DAW1. Here, we present the use of this approach to investigate the role of trehalose synthesis genes in this remarkable organism. Previous studies have shown that acclimating Panagrolaimus sp. DAW1 at 5°C before freezing or desiccation substantially enhances survival. In this study, the expression of tps-2 and other genes associated with trehalose metabolism, as well as lea-1, hsp-70 and gpx-1, in cold-acclimated and non-acclimated nematodes was analyzed using qPCR. Pd-tps-2 and Pd-lea-1 were significantly upregulated after cold acclimation, indicating an inducible expression in the cold adaptation of Panagrolaimus sp. DAW1. The role of trehalose synthesis genes in Panagrolaimus sp. DAW1 was further investigated by RNAi. Compared to the controls, Pd-tps-2a(RNAi)-treated and cold-acclimated nematodes showed a significant decrease in mRNA, but no change in trehalose content or freezing survival. The involvement of two other trehalose synthesis genes (tps-2b and gob-1) was also investigated. These findings provide the first functional genomic investigation of trehalose synthesis genes in the non-model organism Panagrolaimus sp. DAW1. The presence of several trehalose synthesis genes with different RNAi sensitivities suggests the existence of multiple backup systems in Panagrolaimus sp. DAW1, underlining the importance of this sugar in preparation for freezing. Summary: Functional genomics was used to investigate trehalose synthesis genes after cold acclimation in Panagrolaimus sp. DAW1, an Antarctic nematode with the ability to survive intracellular freezing.
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Affiliation(s)
- Anna C Seybold
- Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand
| | - David A Wharton
- Department of Zoology, University of Otago, Dunedin 9054, New Zealand
| | - Michael A S Thorne
- British Antarctic Survey, Natural Environment Research Council, Cambridge, CB3 0ET, United Kingdom
| | - Craig J Marshall
- Department of Biochemistry, University of Otago, Dunedin 9054, New Zealand .,Genetics Otago, University of Otago, Dunedin 9054, New Zealand
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Reichert D, Gröger S, Hackel C. New insights into the interaction of proteins and disaccharides-The effect of pH and concentration. Biopolymers 2017; 107:39-45. [PMID: 27677543 DOI: 10.1002/bip.22990] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 11/09/2022]
Abstract
To gain new insights into the interaction of proteins and disaccharides, we investigated the hydrodynamic radii, RhProt, of lysozyme molecules in solution and in a ternary protein-sugar-water system by PFG-NMR. Our approach is based on the assumption that the anhydrobiotic properties of disaccharides like trehalose are based on aggregation of sugar molecules to the proteins, i.e., accumulation of sugar molecules close to the protein, and that this process can be investigated by the experimentally detectable RhProt value of the protein. The Rh values are calculated from the experimentally determined diffusion coefficients and the application of a viscosity correction using the inert molecule dioxane as an internal viscosity reference. The experiments were performed as a function of sugar concentration, the overall particle concentration and the pH value. We investigated the disaccharides trehalose and sucrose, mainly for the reason that trehalose has well know cryptobiotic properties while sucrose, which is similar in size and structure, lacks these properties. The results show the formation of a protective sugar shell around the proteins over a wider range of concentrations and pH values in the case of trehalose.
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Affiliation(s)
- Detlef Reichert
- Department of Physics, University of Halle, Halle, 06120, Germany
| | - Stefan Gröger
- Department of Physics, University of Halle, Halle, 06120, Germany
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Kondo K, Kubo T, Kunieda T. Suggested Involvement of PP1/PP2A Activity and De Novo Gene Expression in Anhydrobiotic Survival in a Tardigrade, Hypsibius dujardini, by Chemical Genetic Approach. PLoS One 2015; 10:e0144803. [PMID: 26690982 PMCID: PMC4686906 DOI: 10.1371/journal.pone.0144803] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/24/2015] [Indexed: 12/19/2022] Open
Abstract
Upon desiccation, some tardigrades enter an ametabolic dehydrated state called anhydrobiosis and can survive a desiccated environment in this state. For successful transition to anhydrobiosis, some anhydrobiotic tardigrades require pre-incubation under high humidity conditions, a process called preconditioning, prior to exposure to severe desiccation. Although tardigrades are thought to prepare for transition to anhydrobiosis during preconditioning, the molecular mechanisms governing such processes remain unknown. In this study, we used chemical genetic approaches to elucidate the regulatory mechanisms of anhydrobiosis in the anhydrobiotic tardigrade, Hypsibius dujardini. We first demonstrated that inhibition of transcription or translation drastically impaired anhydrobiotic survival, suggesting that de novo gene expression is required for successful transition to anhydrobiosis in this tardigrade. We then screened 81 chemicals and identified 5 chemicals that significantly impaired anhydrobiotic survival after severe desiccation, in contrast to little or no effect on survival after high humidity exposure only. In particular, cantharidic acid, a selective inhibitor of protein phosphatase (PP) 1 and PP2A, exhibited the most profound inhibitory effects. Another PP1/PP2A inhibitor, okadaic acid, also significantly and specifically impaired anhydrobiotic survival, suggesting that PP1/PP2A activity plays an important role for anhydrobiosis in this species. This is, to our knowledge, the first report of the required activities of signaling molecules for desiccation tolerance in tardigrades. The identified inhibitory chemicals could provide novel clues to elucidate the regulatory mechanisms underlying anhydrobiosis in tardigrades.
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Affiliation(s)
- Koyuki Kondo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Takeo Kubo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113–0033, Japan
| | - Takekazu Kunieda
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113–0033, Japan
- * E-mail:
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9
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Affiliation(s)
- D A Wharton
- Department of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand
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10
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Banton MC, Tunnacliffe A. MAPK phosphorylation is implicated in the adaptation to desiccation stress in nematodes. J Exp Biol 2012; 215:4288-98. [DOI: 10.1242/jeb.074799] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Summary
Some nematodes can survive almost complete desiccation by entering an ametabolic state called anhydrobiosis requiring the accumulation of protective molecules such as trehalose and LEA proteins. However, it is not known how anhydrobiotic organisms sense and regulate the response to water loss. Mitogen-activated protein kinases (MAPKs) are highly conserved signalling proteins that regulate adaptation to various stresses. Here, we first compared the anhydrobiotic potential of three nematode species, Caenorhabditis elegans (Maupas, 1900), Aphelenchus avenae (Bastian, 1865) and Panagrolaimus superbus (Fuchs, 1930), and then determined the phosphorylation status of the MAPKs p38, JNK and ERK during desiccation and rehydration. C. elegans was unable to undergo anhydrobiosis even after an initial phase of slow drying (preconditioning), while A. avenae did survive desiccation after preconditioning. In contrast, P. superbus withstood desiccation under rapid drying conditions, although survival rates improved with preconditioning. These results characterise C. elegans as desiccation sensitive, A. avenae as a slow desiccation strategist anhydrobiote, and P. superbus as a fast desiccation strategist anhydrobiote. Both C. elegans and A. avenae showed increased MAPK phosphorylation during drying, consistent with an attempt to mount protection systems against desiccation stress. In P. superbus, however, MAPK phosphorylation was apparent prior to water loss and then decreased on dehydration, suggesting that signal transduction pathways are constitutively active in this nematode. Inhibition of p38 and JNK in P. superbus decreased its desiccation tolerance. This is consistent with the designation of P. superbus as a fast desiccation strategist and its high level of preparedness for anhydrobiosis in the hydrated state. These findings show that MAPKs play an important role in the survival of organisms during anhydrobiosis.
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11
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Guidetti R, Altiero T, Rebecchi L. On dormancy strategies in tardigrades. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:567-76. [PMID: 21402076 DOI: 10.1016/j.jinsphys.2011.03.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 03/02/2011] [Accepted: 03/03/2011] [Indexed: 05/19/2023]
Abstract
In this review we analyze the dormancy strategies of metazoans inhabiting "hostile to life" habitats, which have a strong impact on their ecology and in particular on the traits of their life history. Tardigrades are here considered a model animal, being aquatic organisms colonizing terrestrial habitats. Tardigrades evolved a large variety of dormant stages that can be ascribed to diapause (encystment, cyclomorphosis, resting eggs) and cryptobiosis (anhydrobiosis, cryobiosis, anoxibiosis). In tardigrades, diapause and cryptobiosis can occur separately or simultaneously, consequently the adoption of one adaptive strategy is not necessarily an alternative to the adoption of the other. Encystment and cyclomorphosis are characterized by seasonal cyclic changes in morphology and physiology of the animals. They share several common features and their evolution is strictly linked to the molting process. A bet-hedging strategy with different patterns of egg hatching time has been observed in a tardigrade species. Four categories of eggs have been identified: subitaneous, delayed-hatching, abortive and diapause resting eggs, which needs a stimulus to hatch (rehydration after a period of desiccation). Cryptobiotic tardigrades are able to withstand desiccation (anhydrobiosis) and freezing (cryobiosis) at any stage of their life-cycle. This ability involves a complex array of factors working at molecular (bioprotectans), physiological and structural levels. Animal survival and the accumulation of molecular damage are related to the time spent in the cryptobiotic state, to the abiotic parameters during the cryptobiotic state, and to the conditions during initial and final phases of the process. Cryptobiosis evolved independently at least two times in tardigrades, in eutardigrades and in echiniscoids. Within each evolutionary line, the absence of cryptobiotic abilities is more related to selective pressures to local habitat adaptation than to phylogenetic relationships. The selective advantages of cryptobiosis (e.g. persistency in "hostile to life" habitats, reduction of competitors, parasites and predators, escaping in time from stressful conditions) could explain the high tardigrade species diversity and number of specimens found in habitats that dry out compared to freshwater habitats.
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Affiliation(s)
- Roberto Guidetti
- Department of Biology, University of Modena and Reggio Emilia, via Campi 213/D, 41125 Modena, Italy.
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12
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Reardon W, Chakrabortee S, Pereira TC, Tyson T, Banton MC, Dolan KM, Culleton BA, Wise MJ, Burnell AM, Tunnacliffe A. Expression profiling and cross-species RNA interference (RNAi) of desiccation-induced transcripts in the anhydrobiotic nematode Aphelenchus avenae. BMC Mol Biol 2010; 11:6. [PMID: 20085654 PMCID: PMC2825203 DOI: 10.1186/1471-2199-11-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 01/19/2010] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Some organisms can survive extreme desiccation by entering a state of suspended animation known as anhydrobiosis. The free-living mycophagous nematode Aphelenchus avenae can be induced to enter anhydrobiosis by pre-exposure to moderate reductions in relative humidity (RH) prior to extreme desiccation. This preconditioning phase is thought to allow modification of the transcriptome by activation of genes required for desiccation tolerance. RESULTS To identify such genes, a panel of expressed sequence tags (ESTs) enriched for sequences upregulated in A. avenae during preconditioning was created. A subset of 30 genes with significant matches in databases, together with a number of apparently novel sequences, were chosen for further study. Several of the recognisable genes are associated with water stress, encoding, for example, two new hydrophilic proteins related to the late embryogenesis abundant (LEA) protein family. Expression studies confirmed EST panel members to be upregulated by evaporative water loss, and the majority of genes was also induced by osmotic stress and cold, but rather fewer by heat. We attempted to use RNA interference (RNAi) to demonstrate the importance of this gene set for anhydrobiosis, but found A. avenae to be recalcitrant with the techniques used. Instead, therefore, we developed a cross-species RNAi procedure using A. avenae sequences in another anhydrobiotic nematode, Panagrolaimus superbus, which is amenable to gene silencing. Of 20 A. avenae ESTs screened, a significant reduction in survival of desiccation in treated P. superbus populations was observed with two sequences, one of which was novel, while the other encoded a glutathione peroxidase. To confirm a role for glutathione peroxidases in anhydrobiosis, RNAi with cognate sequences from P. superbus was performed and was also shown to reduce desiccation tolerance in this species. CONCLUSIONS This study has identified and characterised the expression profiles of members of the anhydrobiotic gene set in A. avenae. It also demonstrates the potential of RNAi for the analysis of anhydrobiosis and provides the first genetic data to underline the importance of effective antioxidant systems in metazoan desiccation tolerance.
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Affiliation(s)
- Wesley Reardon
- Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Sohini Chakrabortee
- Institute of Biotechnology, Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK
| | - Tiago Campos Pereira
- Institute of Biotechnology, Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK
- Department of Biology, FFCLRP, University of Sao Paulo, 14040-901, Brazil
| | - Trevor Tyson
- Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Matthew C Banton
- Institute of Biotechnology, Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK
| | - Katharine M Dolan
- Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
- Applied Biosystems, Lingley House, 120 Birchwood Boulevard, Warrington, Cheshire, WA3 7QH, UK
| | - Bridget A Culleton
- Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Michael J Wise
- School of Biomedical and Chemical Sciences, University of Western Australia, Crawley WA 6009, Australia
| | - Ann M Burnell
- Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Alan Tunnacliffe
- Institute of Biotechnology, Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK
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Abstract
SUMMARYThe ability of certain species of parasitic nematodes to survive desiccation for considerable periods is a fascinating example of adaptation to the demands of fluctuating environments that occasionally can become extreme and life threatening. Behavioural and morphological adaptations associated with desiccation survival serve primarily to reduce the rate of drying, either to prolong the time taken for the nematode's water content to reach lethal low levels or, in true anhydrobiotes, to enable the structural and biochemical changes required for long-term survival to take place. Examples of these adaptations are reviewed, together with information on the factors involved in rehydration that ensure successful exit from the dormant state. Information on desiccation survival is central to effective management and control options for parasitic nematodes. It is also required to assess the feasibility of enhancing the longevity of commercial formulations of entomopathogenic nematodes, both before and after application; current research and future prospects for enhancing survival of these bio-insecticides are discussed.
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14
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Ricci C, Fontaneto D. The importance of being a bdelloid: Ecological and evolutionary consequences of dormancy. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/11250000902773484] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Teramoto N, Sachinvala ND, Shibata M. Trehalose and trehalose-based polymers for environmentally benign, biocompatible and bioactive materials. Molecules 2008; 13:1773-816. [PMID: 18794785 PMCID: PMC6245314 DOI: 10.3390/molecules13081773] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2008] [Accepted: 08/11/2008] [Indexed: 12/20/2022] Open
Abstract
Trehalose is a non-reducing disaccharide that is found in many organisms but not in mammals. This sugar plays important roles in cryptobiosis of selaginella mosses, tardigrades (water bears), and other animals which revive with water from a state of suspended animation induced by desiccation. The interesting properties of trehalose are due to its unique symmetrical low-energy structure, wherein two glucose units are bonded face-to-face by 1→1-glucoside links. The Hayashibara Co. Ltd., is credited for developing an inexpensive, environmentally benign and industrial-scale process for the enzymatic conversion of α-1,4-linked polyhexoses to α,α-d-trehalose, which made it easy to explore novel food, industrial, and medicinal uses for trehalose and its derivatives. Trehalose-chemistry is a relatively new and emerging field, and polymers of trehalose derivatives appear environmentally benign, biocompatible, and biodegradable. The discriminating properties of trehalose are attributed to its structure, symmetry, solubility, kinetic and thermodynamic stability and versatility. While syntheses of trehalose-based polymer networks can be straightforward, syntheses and characterization of well defined linear polymers with tailored properties using trehalose-based monomers is challenging, and typically involves protection and deprotection of hydroxyl groups to attain desired structural, morphological, biological, and physical and chemical properties in the resulting products. In this review, we will overview known literature on trehalose’s fascinating involvement in cryptobiology; highlight its applications in many fields; and then discuss methods we used to prepare new trehalose-based monomers and polymers and explain their properties.
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Affiliation(s)
- Naozumi Teramoto
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan; E-mail:
- Author to whom correspondence should be addressed; E-Mail:
| | - Navzer D. Sachinvala
- Retired, Southern Regional Research Center, USDA-ARS, New Orleans, LA, USA; Home: 2261 Brighton Place, Harvey, LA 70058; E-mail:
| | - Mitsuhiro Shibata
- Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan; E-mail:
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16
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Ricci C, Caprioli M, Fontaneto D, Melone G. Volume and morphology changes of a bdelloid rotifer species (Macrotrachela quadricornifera) during anhydrobiosis. J Morphol 2008; 269:233-9. [PMID: 17957710 DOI: 10.1002/jmor.10579] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Following a study on the changes occurring in a bdelloid species (Macrotrachela quadricornifera, Rotifera, Bdelloidea) when entering anhydrobiosis, we investigated the changes in morphology, including weight and volume during the transition from the active hydrated to the dormant anhydrobiotic state by scanning electron microscopy, confocal microscopy and light microscopy. We compared sizes and morphologies of hydrated extended, hydrated contracted and anhydrobiotic specimens. Bdelloid musculature is defined: longitudinal muscles are contracted in the hydrated contracted animal (head and foot are retracted inside the trunk), but appear loose in the anhydrobiotic animal. When anhydrobiotic, M. quadricornifera appears much smaller in size, with a volume reduction of about 60% of the hydrated volume, and its internal organization undergoes remarkable modifications. Internal body cavities, clearly distinguishable in the hydrated extended and contracted specimens, are no longer visible in the anhydrobiotic specimen. Concomitantly, M. quadricornifera loses more than 95% of its weight when anhydrobiotic; this is more than expected from the volume reduction data and could indicate the presence of space-filling molecular species in the dehydrated animal. We estimate that the majority of body mass loss and volume reduction can be ascribed to the water loss from the body cavity during desiccation.
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Affiliation(s)
- Claudia Ricci
- Department of Biology, State University of Milan, 20133 Milan, Italy.
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17
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França MB, Panek AD, Eleutherio ECA. Oxidative stress and its effects during dehydration. Comp Biochem Physiol A Mol Integr Physiol 2007; 146:621-31. [PMID: 16580854 DOI: 10.1016/j.cbpa.2006.02.030] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Revised: 02/14/2006] [Accepted: 02/21/2006] [Indexed: 10/25/2022]
Abstract
Water is usually thought to be required for the living state, but several organisms are capable of surviving complete dehydration (anhydrobiotes). Elucidation of the mechanisms of tolerance against dehydration may lead to development of new methods for preserving biological materials that do not normally support drying, which is of enormous practical importance in industry, in clinical medicine as well as in agriculture. One of the molecular mechanisms of damage leading to death in desiccation-sensitive cells upon drying is free-radical attack to phospholipids, DNA and proteins. This review aims to summarize the strategies used by anhydrobiotes to cope with the danger of oxygen toxicity and to present our recent results about the importance of some antioxidant defense systems in the dehydration tolerance of Saccharomyces cerevisiae, a usual model in the study of stress response.
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Affiliation(s)
- M B França
- Departamento de Bioquímica, Instituto de Química, UFRJ, 21949-900, Rio de Janeiro, RJ, Brazil
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18
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Jagdale GB, Grewal PS. Storage temperature influences desiccation and ultra violet radiation tolerance of entomopathogenic nematodes. J Therm Biol 2007. [DOI: 10.1016/j.jtherbio.2006.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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19
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Shannon AJ, Browne JA, Boyd J, Fitzpatrick DA, Burnell AM. The anhydrobiotic potential and molecular phylogenetics of species and strains of Panagrolaimus (Nematoda, Panagrolaimidae). ACTA ACUST UNITED AC 2005; 208:2433-45. [PMID: 15939782 DOI: 10.1242/jeb.01629] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Members of the genus Panagrolaimus are bacterial-feeding nematodes that occupy a diversity of niches ranging from Antarctic and temperate soils to terrestrial mosses. Some members of this genus are able to survive extreme desiccation by entering into a state of suspended animation known as anhydrobiosis. We have assembled a collection of Panagrolaimus species and strains and have investigated their anhydrobiotic phenotypes. Our data show that within the genus Panagrolaimus there is a continuum of strains ranging from those unable to survive exposure to low relative humidity (RH) without prior preconditioning at high RH (slow desiccation strategists), through strains that have limited ability to survive rapid desiccation but whose anhydrobiotic ability improves upon preconditioning, to strains such as P. superbus that can readily survive immediate exposure to severe desiccation (fast desiccation strategists). Using this panel of nematodes we investigated the effect of preincubation at high RH on the accumulation of trehalose and on the nematodes' anhydrobiotic potential. We found that there is a strong correlation between trehalose induction and anhydrobiotic survival in Panagrolaimus. Furthermore, the high trehalose levels observed in fully hydrated P. superbus (10% dry mass) suggest that constitutive expression of trehalose pre-adapts this fast dehydration strategist to combat desiccation. All the strains observed, regardless of survival rates, undertook both coiling and clumping, which has the effect of reducing surface area and slowing the rate of water loss during desiccation. Phylogenetic analyses were carried out to investigate whether the observed anhydrobiotic phenotypes were the result of convergent evolution or represented a single phylogenetic lineage. These analyses, derived from alignments of the rDNA ITS and D3 sequences, indicate that the strongly anhydrobiotic strains of Panagrolaimus form a single phylogenetic lineage, which is separate from the weakly anhydrobiotic strains. The weakly anhydrobiotic strains are also phylogenetically divergent from each other. Our data indicate that Panagrolaimus has the potential to be an excellent model system for the investigation of molecular aspects of nematode anhydrobiosis.
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Affiliation(s)
- Adam J Shannon
- Institute of Bioengineering and Agroecology, Department of Biology, National University of Ireland Maynooth, Maynooth, Co Kildare, Ireland
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20
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Li F, Neher DA, Darby BJ, Weicht TR. Observed differences in life history characteristics of nematodes Aphelenchus and Acrobeloides upon exposure to copper and benzo(a)pyrene. ECOTOXICOLOGY (LONDON, ENGLAND) 2005; 14:419-29. [PMID: 16385736 DOI: 10.1007/s10646-004-1347-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Maturity index values reflect life history characteristics often inferred by morphology. We tested the hypothesis that Acrobeloides and Aphelenchus are sensitive to chemical pollutants, opposite of what their colonizer-persister (CP) value of 2 suggests. Acrobeloides and Aphelenchus were reared at 19 degrees C and provided diets of Escherichia coli and Rhizoctonia solani, respectively. LC50 values for Aphelenchus exposed to copper or benzo(a)pyrene (BaP) are greater than Acrobeloides. Copper impedes growth of Acrobeloides at 10 microg/g, and results in 100% mortality at 20 microg/g. In contrast, Aphelenchus is more resilient, with no visible impact at 20 microg/g. Acrobeloides and Aphelenchus were sensitive to much lower concentrations of BaP than copper, i.e., 0.5 microg/g inhibited development of Acrobeloides and 2 microg/g for Aphelenchus. Egg size and hatch were unaffected at 15 microg/g copper. In contrast, 0.5 microg/g BaP reduced both egg size and hatch for Aphelenchus but not Acrobeloides. Survival of Acrobeloides and reproduction of Aphelenchus responded differently to copper and BaP, implying the relationship between this classification and their sensitivity to short-term effects may be less straightforward than presumed. Refinement of index values based on empirical evidence can be used to improve sensitivity and interpretation of nematode community indices for environmental monitoring.
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Affiliation(s)
- Fafeng Li
- Department of Earth, Ecological and Environmental Sciences, University of Toledo, OH 43606, USA
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21
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Goyal K, Browne JA, Burnell AM, Tunnacliffe A. Dehydration-induced tps gene transcripts from an anhydrobiotic nematode contain novel spliced leaders and encode atypical GT-20 family proteins. Biochimie 2005; 87:565-74. [PMID: 15935281 DOI: 10.1016/j.biochi.2005.01.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Revised: 01/20/2005] [Accepted: 01/21/2005] [Indexed: 11/21/2022]
Abstract
Accumulation of the non-reducing disaccharide trehalose is associated with desiccation tolerance during anhydrobiosis in a number of invertebrates, but there is little information on trehalose biosynthetic genes in these organisms. We have identified two trehalose-6-phosphate synthase (tps) genes in the anhydrobiotic nematode Aphelenchus avenae and determined full length cDNA sequences for both; for comparison, full length tps cDNAs from the model nematode, Caenorhabditis elegans, have also been obtained. The A. avenae genes encode very similar proteins containing the catalytic domain characteristic of the GT-20 family of glycosyltransferases and are most similar to tps-2 of C. elegans; no evidence was found for a gene in A. avenae corresponding to Ce-tps-1. Analysis of A. avenae tps cDNAs revealed several features of interest, including alternative trans-splicing of spliced leader sequences in Aav-tps-1, and four different, novel SL1-related trans-spliced leaders, which were different to the canonical SL1 sequence found in all other nematodes studied. The latter observation suggests that A. avenae does not comply with the strict evolutionary conservation of SL1 sequences observed in other species. Unusual features were also noted in predicted nematode TPS proteins, which distinguish them from homologues in other higher eukaryotes (plants and insects) and in micro-organisms. Phylogenetic analysis confirmed their membership of the GT-20 glycosyltransferase family, but indicated an accelerated rate of molecular evolution. Furthermore, nematode TPS proteins possess N- and C-terminal domains, which are unrelated to those of other eukaryotes: nematode C-terminal domains, for example, do not contain trehalose-6-phosphate phosphatase-like sequences, as seen in plant and insect homologues. During onset of anhydrobiosis, both tps genes in A. avenae are upregulated, but exposure to cold or increased osmolarity also results in gene induction, although to a lesser extent. Trehalose seems likely therefore to play a role in a number of stress responses in nematodes.
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Affiliation(s)
- K Goyal
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK
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22
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Browne JA, Dolan KM, Tyson T, Goyal K, Tunnacliffe A, Burnell AM. Dehydration-specific induction of hydrophilic protein genes in the anhydrobiotic nematode Aphelenchus avenae. EUKARYOTIC CELL 2004; 3:966-75. [PMID: 15302829 PMCID: PMC500876 DOI: 10.1128/ec.3.4.966-975.2004] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Accepted: 06/01/2004] [Indexed: 11/20/2022]
Abstract
Some organisms can survive exposure to extreme desiccation by entering a state of suspended animation known as anhydrobiosis. The free-living nematode Aphelenchus avenae can be induced to enter the anhydrobiotic state by exposure to a moderate reduction in relative humidity. During this preconditioning period, the nematode accumulates large amounts of the disaccharide trehalose, which is thought to be necessary, but not sufficient, for successful anhydrobiosis. To identify other adaptations that are required for anhydrobiosis, we developed a novel SL1-based mRNA differential display technique to clone genes that are upregulated by dehydration in A. avenae. Three such genes, Aav-lea-1, Aav-ahn-1, and Aav-glx-1, encode, respectively, a late embryogenesis abundant (LEA) group 3 protein, a novel protein that we named anhydrin, and the antioxidant enzyme glutaredoxin. Strikingly, the predicted LEA and anhydrin proteins are highly hydrophilic and lack significant secondary structure in the hydrated state. The dehydration-induced upregulation of Aav-lea-1 and Aav-ahn-1 was confirmed by Northern hybridization and quantitative PCR experiments. Both genes were also upregulated by an osmotic upshift, but not by cold, heat, or oxidative stress. Experiments to investigate the relationship between mRNA levels and protein expression for these genes are in progress. LEA proteins occur commonly in plants, accumulating during seed maturation and desiccation stress; the presence of a gene encoding an LEA protein in an anhydrobiotic nematode suggests that some mechanisms of coping with water loss are conserved between plants and animals.
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Affiliation(s)
- John A Browne
- Institute of Bioengineering and Agroecology, Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland
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23
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Tunnacliffe A, Lapinski J. Resurrecting Van Leeuwenhoek's rotifers: a reappraisal of the role of disaccharides in anhydrobiosis. Philos Trans R Soc Lond B Biol Sci 2004; 358:1755-71. [PMID: 14561331 PMCID: PMC1693263 DOI: 10.1098/rstb.2002.1214] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In 1702, Van Leeuwenhoek was the first to describe the phenomenon of anhydrobiosis in a species of bdelloid rotifer, Philodina roseola. It is the purpose of this review to examine what has been learned since then about the extreme desiccation tolerance in rotifers and how this compares with our understanding of anhydrobiosis in other organisms. Remarkably, much of what is known today about the requirements for successful anhydrobiosis, and the degree of biostability conferred by the dry state, was already determined in principle by the time of Spallanzani in the late 18th century. Most modern research on anhydrobiosis has emphasized the importance of the non-reducing disaccharides trehalose and sucrose, one or other sugar being present at high concentrations during desiccation of anhydrobiotic nematodes, brine shrimp cysts, bakers' yeast, resurrection plants and plant seeds. These sugars are proposed to act as water replacement molecules, and as thermodynamic and kinetic stabilizers of biomolecules and membranes. In apparent contradiction of the prevailing models, recent experiments from our laboratory show that bdelloid rotifers undergo anhydrobiosis without producing trehalose or any analogous molecule. This has prompted us to critically re-examine the association of disaccharides with anhydrobiosis in the literature. Surprisingly, current hypotheses are based almost entirely on in vitro data: there is very limited information which is more than simply correlative in the literature on living systems. In many species, disaccharide accumulation occurs at approximately the same time as desiccation tolerance is acquired. However, several studies indicate that these sugars are not sufficient for anhydrobiosis; furthermore, there is no conclusive evidence, through mutagenesis or functional knockout experiments, for example, that sugars are necessary for anhydrobiosis. Indeed, some plant seeds and micro-organisms, like the rotifer, exhibit excellent desiccation tolerance in the absence of high intracellular sugar concentrations. Accordingly, it seems appropriate to call for a re-evaluation of our understanding of anhydrobiosis and to embark on new experimental programmes to determine the key molecular mechanisms involved.
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Affiliation(s)
- A Tunnacliffe
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK.
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24
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Abstract
Eukaryotes able to withstand desiccation enter a state of suspended animation known as anhydrobiosis, which is thought to require accumulation of the non-reducing disaccharides trehalose (animals, fungi) and sucrose (plants), acting as water replacement molecules and vitrifying agents. We now show that clonal populations of bdelloid rotifers Philodina roseola and Adineta vaga exhibit excellent desiccation tolerance, but that trehalose and other disaccharides are absent from carbohydrate extracts of dried animals. Furthermore, trehalose synthase genes (tps) were not found in rotifer genomes. This first observation of animal anhydrobiosis without trehalose challenges our current understanding of the phenomenon and calls for a re-evaluation of existing models.
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Affiliation(s)
- Jens Lapinski
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, CB2 1QT Cambridge, UK
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25
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Ricci C, Melone G, Santo N, Caprioli M. Morphological response of a bdelloid rotifer to desiccation. J Morphol 2003; 257:246-53. [PMID: 12833383 DOI: 10.1002/jmor.10120] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We desiccated bdelloid rotifers (Macrotrachela quadricornifera), submitting the animals to four desiccation procedures (protocols A, B, C, D) that differed in the rate of water evaporation, in the time of desiccation, and in the substrates provided. We observed external morphological changes of the rotifer bodies during drying with scanning electron microscopy and, in parallel, assessed rates of recovery after a 7-day period of dormancy. Two protocols produced disorganized morphologies of the anhydrobiotic animals, with no (A) or very poor (B) recovery. Protocols C and D gave rather high rates of recovery and dry rotifers appeared unaltered and well organized. The different protocols affected rotifer morphology during the 7-day anhydrobiosis and rates of recovery after the 7-day anhydrobiosis; high recovery rates corresponded to well-organized morphologies of anhydrobiotic bdelloids, suggesting that a proper contraction of the body into a tun shape and probably a rigorous packing of internal structures are necessary for survival after anhydrobiosis. These features are affected by the time between water shortage and full desiccation, but also by the surrounding relative humidity and by the nature of the substrate. Possible adaptations of anhydrobiotic rotifers are discussed.
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Affiliation(s)
- Claudia Ricci
- Department of Biology, State University of Milan, 20133 Milano, Italy.
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26
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Goyal K, Tisi L, Basran A, Browne J, Burnell A, Zurdo J, Tunnacliffe A. Transition from natively unfolded to folded state induced by desiccation in an anhydrobiotic nematode protein. J Biol Chem 2003; 278:12977-84. [PMID: 12569097 DOI: 10.1074/jbc.m212007200] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Late embryogenesis abundant (LEA) proteins are associated with desiccation tolerance in resurrection plants and in plant seeds, and the recent discovery of a dehydration-induced Group 3 LEA-like gene in the nematode Aphelenchus avenae suggests a similar association in anhydrobiotic animals. Despite their importance, little is known about the structure of Group 3 LEA proteins, although computer modeling and secondary structure algorithms predict a largely alpha-helical monomer that forms coiled coil oligomers. We have therefore investigated the structure of the nematode protein, AavLEA1, in the first such analysis of a well characterized Group 3 LEA-like protein. Immunoblotting and subunit cross-linking experiments demonstrate limited oligomerization of AavLEA1, but analytical ultracentrifugation and gel filtration show that the vast majority of the protein is monomeric. Moreover, CD, fluorescence emission, and Fourier transform-infrared spectroscopy indicate an unstructured conformation for the nematode protein. Therefore, in solution, no evidence was found to support structure predictions; instead, AavLEA1 seems to be natively unfolded with a high degree of hydration and low compactness. Such proteins can, however, be induced to fold into more rigid structures by partner molecules or by altered physiological conditions. Because AavLEA1 is associated with desiccation stress, its Fourier transform-infrared spectrum in the dehydrated state was examined. A dramatic but reversible increase in alpha-helix and, possibly, coiled coil formation was observed on drying, indicating that computer predictions of secondary structure may be correct for the solid state. This unusual finding offers the possibility that structural shifts in Group 3 LEA proteins occur on dehydration, perhaps consistent with their role in anhydrobiosis.
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Affiliation(s)
- Kshamata Goyal
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, United Kingdom
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27
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Qiu L, Bedding RA. Characteristics of protectant synthesis of infective juveniles of Steinernema carpocapsae and importance of glycerol as a protectant for survival of the nematodes during osmotic dehydration. Comp Biochem Physiol B Biochem Mol Biol 2002; 131:757-65. [PMID: 11923088 DOI: 10.1016/s1096-4959(02)00019-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two hypotheses on the synthesis of the protectants glycerol and trehalose of the infective juveniles (IJs) of Steinernema carpocapsae during osmotic dehydration were tested and utilised to evaluate the function and importance of glycerol on survival of the nematodes during osmotic dehydration. This was achieved by comparing the changes in survival, morphology, behaviour and levels of glycerol, trehalose and permeated compounds of the IJs dehydrated in seven hypertonic solutions at two temperature regimes: (1) 5 degrees C for 15 days; and (2) 23 degrees C for 1 day followed by 5 degrees C for another 14 days. The results substantiate both hypotheses tested: (1) the permeability of the IJs to various compounds, such as sucrose or ethylene glycol, when they are dehydrated in hypertonic solutions of these compounds; and (2) suppression of the synthesis of protectant glycerol but not trehalose when IJs are dehydrated at low temperature. The results also showed that: (1) although trehalose was the preferred dehydration protectant, glycerol played an important role in rapidly balancing the osmotic pressure when IJs were exposed in hypertonic solutions; (2) the presence of glycerol was essential for the IJs to survive and function properly even under moderate osmotic dehydration, especially when IJs were dehydrated in salt solutions; and (3) some exogenous compounds permeated into IJs during osmotic dehydration such as ethylene glycol, may function in the same way as glycerol and significantly improve the survival and function of the IJs. The results indicate that each of the protectants glycerol and trehalose has a specific function and neither is replaceable by the other.
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Affiliation(s)
- Lihong Qiu
- The State Key Lab for Biocontrol, Zhongshan University, 510275, Guangzhou, PR China
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28
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Abstract
When subjected to drought conditions, some organisms enter a state of suspended animation known as anhydrobiosis, surviving for indefinite periods until rehydration allows them to resume normal metabolism. We have identified a gene in the anhydrobiotic nematode Aphelenchus avenae that is upregulated in response to desiccation stress and whose encoded protein shares sequence similarity with a late-embryonic gene that is induced in many plants when they are deprived of water. This finding suggests that animals and plants that undergo anhydrobiosis may use common protective strategies against dehydration, and provides a unifying insight into the mechanism of anhydrobiosis.
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Affiliation(s)
- John Browne
- Department of Biology and Institute of Bioengineering and Agroecology, National University of Ireland Maynooth, County Kildare, Ireland
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29
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Treonis AM, Wall DH, Virginia RA. The use of anhydrobiosis by soil nematodes in the Antarctic Dry Valleys. Funct Ecol 2001. [DOI: 10.1046/j.1365-2435.2000.00442.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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30
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Sjursen H, Bayley M, Holmstrup M. Enhanced drought tolerance of a soil-dwelling springtail by pre-acclimation to a mild drought stress. JOURNAL OF INSECT PHYSIOLOGY 2001; 47:1021-1027. [PMID: 11472765 DOI: 10.1016/s0022-1910(01)00078-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The springtail Folsomia candida has a highly permeable cuticle, but is able to survive several weeks at 98.2%RH. This corresponds to a water potential deficit of about 17bars between the environment and the normal osmotic pressure of the body fluids of this animal. Recent studies have shown a water vapour absorption mechanism by accumulation of sugars and polyols (SP) in F. candida, which explains how this species can survive dehydrating conditions. In the present study, adult F. candida were pre-acclimated at 98.2%RH to induce the accumulation of SP, and were subsequently exposed for additional desiccating conditions from 98 to 94%RH. Activity level, water content, osmotic pressure of body fluids and SP composition were investigated. After the desiccation period, the animals were rehydrated at 100%RH and survival was assessed. The results showed that F. candida survived a more severe drought stress when it had been pre-acclimated to 98.2%RH before exposure to lower humidity. This species was able to maintain hyperosmosity to the surroundings at 95.5%RH, suggesting that it can absorb water vapour down to this limit. Below this limit, trehalose levels increased while myo-inositol levels decreased. We propose that this is a change of survival strategy where F. candida at mild desiccation levels seek to retain water by colligative means (remain hyperosmotic), but at severe desiccation levels switches to an anhydrobiotic strategy.
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Affiliation(s)
- H Sjursen
- Department of Terrestrial Ecology, National Environmental Research Institute, Vejlsøvej 25, PO Box 314, DK-8600, Silkeborg, Denmark
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31
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Abstract
Many of the mechanisms used by active insects to maintain water balance are not available to dormant individuals. Physiological and biochemical mechanisms of dehydration tolerance and resistance in dormant insects and some other invertebrates are reviewed, as well as linkages of dehydration with energy use and metabolism, with cold hardiness, and with diapause. Many dormant insects combine several striking adaptations to maintain water balance that-in addition to habitat choice-may include especially reduction of body water content, decreased cuticular permeability, absorption of water vapour, and tolerance of low body water levels. Many such features require energy and hence that metabolism, albeit much reduced, continues during dormancy. Four types of progressively dehydrated states are recognized: water is managed internally by solute or ion transport; relatively high concentrations of solutes modify the behaviour of water in solutions; still higher concentrations of certain carbohydrates lead to plasticized rubbers or glasses with very slow molecular kinetics; and anhydrobiosis eliminates metabolism.
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Affiliation(s)
- HV Danks
- Biological Survey of Canada (Terrestrial Arthropods), Canadian Museum of Nature, P.O. Box 3443, Station "D", Ottawa, Canada
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32
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Wharton DA, Lemmon J. Ultrastructural changes during desiccation of the anhydrobiotic nematode Ditylenchus dipsaci. Tissue Cell 1998; 30:312-23. [PMID: 10091336 DOI: 10.1016/s0040-8166(98)80044-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Ultrastructural changes during desiccation of the anhydrobiotic nematode Ditylenchus dipsaci were followed and quantified after preparation of material at different levels of hydration using freeze substitution techniques. Some shrinkage was caused by processing in the more hydrated specimens but the changes observed correspond to those observed in live nematodes by light microscopy, indicating that the technique is useful for following changes during desiccation. The overall pattern of changes was a rapid decrease in the magnitude of the measured parameter during the first 5 min of desiccation, followed by a slower rate of decrease upon further desiccation. This was observed in the cuticle, the lateral hypodermal cords and the muscle cells and is consistent with the pattern of water loss of the nematode. The contractile region of the muscle cells, however, proved an exception and the muscle fibres appear to resist shrinkage and packing until water loss becomes severe. The mitochondria swell and then shrink during desiccation, which may indicate disruption of the permeability of the mitochondrial membrane. A decrease in the thickness of the cortical zone was the most prominent change in the cuticle and this may be related to the permeability slump which occurs during the first 5 min of desiccation.
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Affiliation(s)
- D A Wharton
- Department of Zoology, University of Otago, Dunedin, New Zealand.
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33
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Nwaka S, Holzer H. Molecular biology of trehalose and the trehalases in the yeast Saccharomyces cerevisiae. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1997; 58:197-237. [PMID: 9308367 DOI: 10.1016/s0079-6603(08)60037-9] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The present state of knowledge of the role of trehalose and trehalose hydrolysis catalyzed by trehalase (EC 3.2.1.28) in the yeast Saccharomyces cerevisiae is reviewed. Trehalose is believed to function as a storage carbohydrate because its concentration is high during nutrient limitations and in resting cells. It is also believed to function as a stress metabolite because its concentration increases during certain adverse environmental conditions, such as heat and toxic chemicals. The exact way trehalose may perform the stress function is not understood, and conditions exist under which trehalose accumulation and tolerance to certain stress situations cannot be correlated. Three trehalases have been described in S. cerevisiae: 1) the cytosolic neutral trehalase encoded by the NTH1 gene, and regulated by cAMP-dependent phosphorylation process, nutrients, and temperature; 2) the vacuolar acid trehalase encoded by the ATH1 gene, and regulated by nutrients; and 3) a putative trehalase Nth1p encoded by the NTH2 gene (homolog of the NTH1 gene) and regulated by nutrients and temperature. The neutral trehalase is responsible for intracellular hydrolysis of trehalose, in contrast to the acid trehalase, which is responsible for utilization of extracellular trehalose. The role of the putative trehalase Nth2p in trehalose metabolism is not known. The NTH1 and NTH2 genes are required for recovery of cells after heat shock at 50 degrees C, consistent with their heat inducibility and sequence similarity. Other stressors, such as toxic chemicals, also induce the expression of these genes. We therefore propose that the NTH1 and NTH2 genes have stress-related function and the gene products may be called stress proteins. Whether the stress function of the trehalase genes is linked to trehalose is not clear, and possible mechanisms of stress protective function of the trehalases are discussed.
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Affiliation(s)
- S Nwaka
- Institut für Biochemie und Molekularbiologie, Universität Freiburg, Germany
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Abstract
The sugar trehalose, an alpha-1-linked non-reducing disaccharide of glucose, is important in the physiology of many micro-organisms as well as in some groups of metazoan organisms, including insects and nematodes. Trehalose is a stress protectant in biological systems as it interacts with and directly protects lipid membranes and proteins from the damage caused by environmental stresses such as desiccation and freezing. Trehalose is present in many nematode species where its concentration often exceeds that of glucose but is usually lower than that of glycogen. In Ascaris suum it is found in all tissues, with highest concentrations in muscle, haemolymph and the female and male reproductive organs. Trehalose acts as an energy reserve in some nematodes and their eggs, and may be important in uptake of glucose; it appears to function as the major circulating blood sugar. Trehalose accumulates in nematodes that can withstand dehydration and may be important in supercooling of nematodes or eggs that can withstand freezing. In many nematodes trehalose is also important in the process of egg hatching. The combined action of 2 enzymes, trehalose 6-phosphate (T6P) synthase and T6P phosphatase, catalyses the synthesis of trehalose in most organisms. Hydrolysis of trehalose glucose is catalysed by trehalase. These enzymes to have been detected in nematodes but the processes regulating their activity are unknown. Trehalose metabolism may provide new molecular targets for attack in nematodes parasitic in mammals.
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Affiliation(s)
- C A Behm
- Division of Biochemistry and Molecular Biology, School of Life Sciences, Australian National University, Canberra, Australia.
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Patel MN, Perry RN, Wright DJ. Desiccation survival and water contents of entomopathogenic nematodes, Steinernema spp. (Rhabditida:Steinernematidae). Int J Parasitol 1997; 27:61-70. [PMID: 9076530 DOI: 10.1016/s0020-7519(96)00154-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The survival of exsheathed infective juveniles (IJs) of 4 Steinernema species, S. glaseri (NC), S. feltiae (UK76), S. carpocapsae (All) and S. riobravis (Biosys355), was assessed following fast and slow drying on glass slides and 1% (w/v) agarose, respectively. Freshly harvested and aged (75-day-old) IJs were desiccated on glass slides after removal of superficial water, at 0, 20, 40, 60 and 80% relative humidity (r.h.). Survival was assessed after rehydration with water, and movement was used as the criterion for survival. Evidence for an intrinsic mechanism to control water loss and survive desiccation was found in freshly harvested S. carpocapsae IJs. At all r.h.s tested, S. carpocapsae had the greatest survival and the slowest rate of water loss. For example, at 80% r.h. the survival time for 50% (S50) of S. carpocapsae IJs was ca. 45 min compared with 5-20 min for the other species. Survival of aged IJs was markedly reduced in the case of S. carpocapsae and S. riobravis, and to a lesser extent in S. feltiae and S. glaseri. The 2nd stage juvenile cuticle (sheath) was not important in aiding desiccation survival of S. carpocapsae and S. glaseri. Drying IJs slowly on 1% agarose at 80% r.h. greatly improved the survival of all 4 species, particularly S. glaseri and S. feltiae. The work is discussed in relation to possible mechanisms for survival of IJs during fast and slow drying.
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Affiliation(s)
- M N Patel
- Department of Biology, Imperial College of Science, Technology & Medicine, Ascot, Berkshire, U.K.
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Synthetic glycolipids as membrane-bound cryoprotectants in the freezedrying process of liposomes. Eur J Pharm Sci 1996. [DOI: 10.1016/0928-0987(95)00054-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Holmstrup M, Westh P. Effects of dehydration on water relations and survival of lumbricid earthworm egg capsules. J Comp Physiol B 1995. [DOI: 10.1007/bf00387308] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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