Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.

Reports that low-intensity microwave radiation induces heat-shock reporter gene expression in the nematode, Caenorhabditis elegans, have recently been reinterpreted as a subtle thermal effect caused by slight heating. This study used a microwave exposure system (1.0 GHz, 0.5 W power input; SAR 0.9-...

Full description

Bibliographic Details
Main Authors: Dawe, Adam S., Bodhicharla, Rakesh, Graham, Neil, May, Sean, Reader, Tom, Loader, Benjamin, Gregory, Andrew, Swicord, Mays, Bit-Babik, Giorgi, de Pomerai, David I.
Format: Article
Published: Wiley 2009
Online Access:https://eprints.nottingham.ac.uk/1980/
_version_ 1848790696536834048
author Dawe, Adam S.
Bodhicharla, Rakesh
Graham, Neil
May, Sean
Reader, Tom
Loader, Benjamin
Gregory, Andrew
Swicord, Mays
Bit-Babik, Giorgi
de Pomerai, David I.
author_facet Dawe, Adam S.
Bodhicharla, Rakesh
Graham, Neil
May, Sean
Reader, Tom
Loader, Benjamin
Gregory, Andrew
Swicord, Mays
Bit-Babik, Giorgi
de Pomerai, David I.
author_sort Dawe, Adam S.
building Nottingham Research Data Repository
collection Online Access
description Reports that low-intensity microwave radiation induces heat-shock reporter gene expression in the nematode, Caenorhabditis elegans, have recently been reinterpreted as a subtle thermal effect caused by slight heating. This study used a microwave exposure system (1.0 GHz, 0.5 W power input; SAR 0.9-3 mW kg-1 for 6-well plates) that minimises temperature differentials between sham and exposed conditions (≤0.1 °C). Parallel measurement and simulation studies of SAR distribution within this exposure system are presented. We compared 5 Affymetrix gene-arrays of pooled triplicate RNA populations from sham-exposed L4/adult worms against 5 gene-arrays of pooled RNA from microwave-exposed worms (taken from the same source population in each run). No genes showed consistent expression changes across all 5 comparisons, and all expression changes appeared modest after normalisation (≤ 40% up- or down-regulated). The number of statistically significant differences in gene expression (846) was less than the false-positive rate expected by chance (1131). We conclude that the pattern of gene expression in L4/adult C. elegans is substantially unaffected by low-intensity microwave radiation; the minor changes observed in this study could well be false positives. As a positive control, we compared RNA samples from N2 worms subjected to a mild heat-shock treatment (30ºC) against controls at 26 ºC (2 gene arrays per condition). As expected, heat-shock genes are strongly up-regulated at 30ºC, particularly an hsp-70 family member (C12C8.1) and hsp-16.2 . Under these heat-shock conditions, we confirmed that an hsp-16.2::GFP transgene was strongly up-regulated, whereas two non-heat-inducible transgenes (daf-16::GFP; cyp-34A9::GFP) showed little change in expression.
first_indexed 2025-11-14T18:16:43Z
format Article
id nottingham-1980
institution University of Nottingham Malaysia Campus
institution_category Local University
last_indexed 2025-11-14T18:16:43Z
publishDate 2009
publisher Wiley
recordtype eprints
repository_type Digital Repository
spelling nottingham-19802020-05-04T20:26:42Z https://eprints.nottingham.ac.uk/1980/ Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans. Dawe, Adam S. Bodhicharla, Rakesh Graham, Neil May, Sean Reader, Tom Loader, Benjamin Gregory, Andrew Swicord, Mays Bit-Babik, Giorgi de Pomerai, David I. Reports that low-intensity microwave radiation induces heat-shock reporter gene expression in the nematode, Caenorhabditis elegans, have recently been reinterpreted as a subtle thermal effect caused by slight heating. This study used a microwave exposure system (1.0 GHz, 0.5 W power input; SAR 0.9-3 mW kg-1 for 6-well plates) that minimises temperature differentials between sham and exposed conditions (≤0.1 °C). Parallel measurement and simulation studies of SAR distribution within this exposure system are presented. We compared 5 Affymetrix gene-arrays of pooled triplicate RNA populations from sham-exposed L4/adult worms against 5 gene-arrays of pooled RNA from microwave-exposed worms (taken from the same source population in each run). No genes showed consistent expression changes across all 5 comparisons, and all expression changes appeared modest after normalisation (≤ 40% up- or down-regulated). The number of statistically significant differences in gene expression (846) was less than the false-positive rate expected by chance (1131). We conclude that the pattern of gene expression in L4/adult C. elegans is substantially unaffected by low-intensity microwave radiation; the minor changes observed in this study could well be false positives. As a positive control, we compared RNA samples from N2 worms subjected to a mild heat-shock treatment (30ºC) against controls at 26 ºC (2 gene arrays per condition). As expected, heat-shock genes are strongly up-regulated at 30ºC, particularly an hsp-70 family member (C12C8.1) and hsp-16.2 . Under these heat-shock conditions, we confirmed that an hsp-16.2::GFP transgene was strongly up-regulated, whereas two non-heat-inducible transgenes (daf-16::GFP; cyp-34A9::GFP) showed little change in expression. Wiley 2009 Article PeerReviewed Dawe, Adam S., Bodhicharla, Rakesh, Graham, Neil, May, Sean, Reader, Tom, Loader, Benjamin, Gregory, Andrew, Swicord, Mays, Bit-Babik, Giorgi and de Pomerai, David I. (2009) Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans. Bioelectromagnetics, 30 (8). pp. 602-610. ISSN 1521-186X http://onlinelibrary.wiley.com/doi/10.1002/bem.20515/abstract doi:10.1002/bem.20515 doi:10.1002/bem.20515
spellingShingle Dawe, Adam S.
Bodhicharla, Rakesh
Graham, Neil
May, Sean
Reader, Tom
Loader, Benjamin
Gregory, Andrew
Swicord, Mays
Bit-Babik, Giorgi
de Pomerai, David I.
Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.
title Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.
title_full Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.
title_fullStr Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.
title_full_unstemmed Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.
title_short Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult Caenorhabditis elegans.
title_sort low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult caenorhabditis elegans.
url https://eprints.nottingham.ac.uk/1980/
https://eprints.nottingham.ac.uk/1980/
https://eprints.nottingham.ac.uk/1980/