Anhydrobiosis in Tardigrades and Nematodes

Crowe, John H.; Madin, K. A. C.

doi:10.2307/3225155

Cited by 89 publications

(48 citation statements)

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“…Oxidation damage was involved in the reduced viability of dried invertebrates (Crowe, 1975;Örstan, 1998;Clegg et al, 2000), including the tardigrade Paramacrobiotus areolatus (Murray 1907) (Crowe and Madin, 1974), yeast (Pereira et al, 2003) and prokaryotes (Potts, 1994). In our experiments, tardigrades exposed to higher temperatures and higher humidity levels, in addition to oxygen, showed higher levels of damage in terms of increased mortality and/or D recovery.…”

Section: Discussionmentioning

confidence: 99%

Survival and DNA degradation in anhydrobiotic tardigrades

Rebecchi

Cesari

Altiero

et al. 2009

Journal of Experimental Biology

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SUMMARYAnhydrobiosis is a highly stable state of suspended animation in an organism due to its desiccation, which is followed by recovery after rehydration. Changes occurring during drying could damage molecules, including DNA. Using the anhydrobiotic tardigrade Paramacrobiotus richtersi as a model organism, we have evaluated the effects of environmental factors, such as temperature and air humidity level (RH), on the survival of desiccated animals and on the degradation of their DNA. Tardigrades naturally desiccated in leaf litter and tardigrades experimentally desiccated on blotting paper were considered. Replicates were kept at 37°C and at different levels of RH for 21 days. RH values and temperature, as well as time of exposure to these environmental factors, have a negative effect on tardigrade survival and on the time required by animals to recover active life after desiccation. DNA damages (revealed as single strand breaks) occurred only in desiccated tardigrades kept for a long time at high RH values. These results indicate that during the anhydrobiotic state, damages take place and accumulate with time. Two hypotheses can be formulated to explain the results: (i) oxidative damages occur in desiccated specimens of P. richtersi, and (ii) high temperatures and high RH values change the state of the disaccharide trehalose, reducing its protective role. Supplementary material available online at

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Section: Discussionmentioning

confidence: 99%

Survival and DNA degradation in anhydrobiotic tardigrades

Rebecchi

Cesari

Altiero

et al. 2009

Journal of Experimental Biology

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“…Based on the data presented here, P. murrayi exhibits extreme desiccation tolerance among nematodes and shows characteristic features of anhydrobiotic nematodes (e.g. cuticle, body shape) (Crowe and Madin, 1974;Treonis et al, 2000). However, given the prevalence of soil nematodes with high cuticular permeability in the Dry Valleys, similar physiological attributes may be widespread among nematodes when assessed under appropriate humidity conditions.…”

Section: Desiccation Survivalmentioning

confidence: 99%

Effect of slow desiccation and freezing on gene transcription and stress survival of an Antarctic nematode

Adhikari

Wall

Adams

2010

Journal of Experimental Biology

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Accepted 10 February 2010 SUMMARY Nematodes are the dominant soil animals of the Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however, little is known about gene regulation by Antarctic nematodes that can survive multiple types and incidences of environmental stress. In order to reveal the molecular response of anhydrobiotic survival, we investigated the genetic response of an Antarctic nematode, Plectus murrayi, which can survive desiccation and freezing. Using molecular approaches, we provide insight into the regulation of desiccation-induced transcripts during different stages of stress survival under conditions characteristic of the Antarctic Dry Valley environment. Our study revealed that exposure to slow desiccation and freezing plays an important role in the transcription of stress, metabolism and signal transduction-related genes and improves desiccation and freezing survival compared with nematodes exposed to fast desiccation and freezing. Temporal analyses of gene expression showed that pre-exposure to mild stress promotes survival of harsher stress. Our results further show that exposure to slow dehydration not only improves extreme desiccation survival but also promotes enhanced cold tolerance. We also provide evidence that slow dehydration can enhance freeze tolerance in an Antarctic nematode. Expression profiling of P. murrayi transcripts is an important step in understanding the genome-level response of this nematode to different environmental stressors.

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“…When tardigrades are desiccated en route to anhydrobiosis, they contract into a structure resembling a small ''tun'' to reduce the surface area of their body and thus to decrease dehydration rate (75). Most of desiccated anhydrobiotic nematodes form a coiled structure for the same reason (15,76). These are the morphological factors, that is, external factors for the successful induction of anhydrobiosis.…”

Section: Water Movement and Aquaporinsmentioning

confidence: 99%

The induction of anhydrobiosis in the sleeping chironomid: Current status of our knowledge

2011

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An African chironomid, Polypedilum vanderplanki, is the only insect known to be capable of extreme desiccation tolerance, or anhydrobiosis. In the 1950s and 1960s, Hinton strenuously studied anhydrobiosis in this insect from a physiological standpoint; however, nobody has afterward investigated the phenomenon. In 2000, research on mechanisms underlying anhydrobiosis was resumed due to successful establishment of a rearing system for P. vanderplanki. This review is focused on the latest findings on the physiological and molecular mechanisms underlying the induction of anhydrobiosis in P. vanderplanki. Early experiments demonstrated that the induction of anhydrobiosis was possible in isolated tissues and independent from the control of central nervous system. However, to achieve successful anhydrobiosis, larvae need a slow regime of desiccation, allowing them to synthesize molecules, which will protect cells and tissues against the deleterious effects of dehydration. Trehalose, a nonreducing disaccharide, which accumulates in P. vanderplanki larvae up to 20% of the dry body mass, is thought to replace the water in its tissues. Similarly, highly hydrophilic proteins called the late embryogenesis abundant (LEA) proteins are expressed in huge quantities and act as a molecular shield to protect biological molecules against aggregation and denaturation. This function is shared by heat shock proteins, which are also upregulated during the desiccation process. At the same time, desiccating larvae express various antioxidant molecules and enzymes, to cope with the massive oxidative stress, which is responsible for general damage to membranes, proteins, and DNA in dehydrating cells. Finally, specific water channels, called aquaporins, accelerate dehydration, and trehalose together with LEA proteins forms a glassy matrix, which protects the biological molecules and the structural integrity of larvae in the anhydrobiotic state. © 2011 IUBMB IUBMB Life, 63(6): 419–429, 2011

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Anhydrobiosis in Tardigrades and Nematodes

Cited by 89 publications

References 0 publications

Survival and DNA degradation in anhydrobiotic tardigrades

Survival and DNA degradation in anhydrobiotic tardigrades

Effect of slow desiccation and freezing on gene transcription and stress survival of an Antarctic nematode

The induction of anhydrobiosis in the sleeping chironomid: Current status of our knowledge

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