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Element analysis of the eutardigrades Richtersius coronifer and Milnesium cf. asiaticum using particle induced X-ray emission (PIXE)

Nilsson, Charlotta LU ; Jonsson, Ingemar and Pallon, Jan LU (2013) In Journal of Limnology 72. p.92-101
Abstract
Semi-terrestrial tardigrades are well-known for their tolerance to a variety of environmental extremes, including desiccation, freezing and radiation. Despite several attempts to reveal the genetic and molecular mechanisms behind the resilience of tardigrades, it is still unknown how these animals are able to maintain the integrity of their cellular components under severe stress. Quantitative or qualitative changes in molecular compounds (e.g., carbohydrates, proteins) are expected, and have been the main line of research towards understanding the tolerance of tardigrades. In radiation tolerant bacteria, a tolerance mechanism based on manganese has been proposed. We evaluate this hypothesis in tardigrades and provide the first data on... (More)
Semi-terrestrial tardigrades are well-known for their tolerance to a variety of environmental extremes, including desiccation, freezing and radiation. Despite several attempts to reveal the genetic and molecular mechanisms behind the resilience of tardigrades, it is still unknown how these animals are able to maintain the integrity of their cellular components under severe stress. Quantitative or qualitative changes in molecular compounds (e.g., carbohydrates, proteins) are expected, and have been the main line of research towards understanding the tolerance of tardigrades. In radiation tolerant bacteria, a tolerance mechanism based on manganese has been proposed. We evaluate this hypothesis in tardigrades and provide the first data on element composition in desiccated and non-desiccated specimens of two eutardigrade species, Richtersius coronifer and Milnesium cf. asiaticum. A focused 2 MeV proton microbeam was utilised to determine the elemental content, distributions and concentrations, using the ion beam analytical technique particle induced X-ray emission (PIXE). The presence of six elements - phosphorus, sulphur, chlorine, potassium, calcium and iron - were confirmed in all tardigrade specimens, at levels up to a few mg g(-1). However, manganese was found in less than 10% of the analysed specimens, and in low amounts, thus our study provides no evidence for the manganese hypothesis. We also show that the distributions and/or concentrations of some elements differ between the two species as well as between the dehydrated and hydrated state. In particular, very low levels of iron were found in dehydrated M. cf. asiaticum. Our analysis shows that the PIXE technique is a useful tool for investigating questions on the distribution of elements both in dehydrated and hydrated tardigrades. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
tardigrades, Richtersius coronifer, Milnesium cf. asiaticum, PIXE, radiation tolerance
in
Journal of Limnology
volume
72
pages
92 - 101
publisher
Page Press
external identifiers
  • wos:000327485200011
  • scopus:84880805420
ISSN
1129-5767
DOI
10.4081/jlimnol.2013.s1.e11
language
English
LU publication?
yes
id
fd7498d0-4297-48ff-9f5a-1baf2e046f32 (old id 4275345)
date added to LUP
2014-01-28 11:13:30
date last changed
2019-02-20 07:17:56
@article{fd7498d0-4297-48ff-9f5a-1baf2e046f32,
  abstract     = {Semi-terrestrial tardigrades are well-known for their tolerance to a variety of environmental extremes, including desiccation, freezing and radiation. Despite several attempts to reveal the genetic and molecular mechanisms behind the resilience of tardigrades, it is still unknown how these animals are able to maintain the integrity of their cellular components under severe stress. Quantitative or qualitative changes in molecular compounds (e.g., carbohydrates, proteins) are expected, and have been the main line of research towards understanding the tolerance of tardigrades. In radiation tolerant bacteria, a tolerance mechanism based on manganese has been proposed. We evaluate this hypothesis in tardigrades and provide the first data on element composition in desiccated and non-desiccated specimens of two eutardigrade species, Richtersius coronifer and Milnesium cf. asiaticum. A focused 2 MeV proton microbeam was utilised to determine the elemental content, distributions and concentrations, using the ion beam analytical technique particle induced X-ray emission (PIXE). The presence of six elements - phosphorus, sulphur, chlorine, potassium, calcium and iron - were confirmed in all tardigrade specimens, at levels up to a few mg g(-1). However, manganese was found in less than 10% of the analysed specimens, and in low amounts, thus our study provides no evidence for the manganese hypothesis. We also show that the distributions and/or concentrations of some elements differ between the two species as well as between the dehydrated and hydrated state. In particular, very low levels of iron were found in dehydrated M. cf. asiaticum. Our analysis shows that the PIXE technique is a useful tool for investigating questions on the distribution of elements both in dehydrated and hydrated tardigrades.},
  author       = {Nilsson, Charlotta and Jonsson, Ingemar and Pallon, Jan},
  issn         = {1129-5767},
  keyword      = {tardigrades,Richtersius coronifer,Milnesium cf. asiaticum,PIXE,radiation tolerance},
  language     = {eng},
  pages        = {92--101},
  publisher    = {Page Press},
  series       = {Journal of Limnology},
  title        = {Element analysis of the eutardigrades Richtersius coronifer and Milnesium cf. asiaticum using particle induced X-ray emission (PIXE)},
  url          = {http://dx.doi.org/10.4081/jlimnol.2013.s1.e11},
  volume       = {72},
  year         = {2013},
}