 |
 |
GEO help: Mouse over screen elements for information. |
|
| Status |
Public on Mar 12, 2009 |
| Title |
Low-intensity microwave irradiation does not substantially alter gene expression in late larval and adult C. elegans |
| Organism |
Caenorhabditis elegans |
| Experiment type |
Expression profiling by array
|
| Summary |
Reports that low-intensity microwave radiation can induce heat-shock reporter gene expression in the nematode, Caenorhabditis elegans, have recently been reinterpreted as a subtle thermal effect caused by very 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 the temperature differential between sham and exposed conditions to ≤ 0.1°C. Comparable 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). Few genes showed consistent expression changes across all 5 comparisons, and all such expression changes appeared modest after applying standard normalisation procedures (≤ 30% 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). As one example, an apparent up-regulation of the vit-3 vitellogenin gene by microwave exposure was not mirrored by similar changes affecting the other co-regulated members of the same vit gene family. We conclude that the pattern of gene expression in L4/adult C elegans is not substantially perturbed by low-intensity microwave radiation, and that the minor changes observed in this study may well be explicable as false positives. As a check on the sensitivity of the Affymetrix gene-arrays used, we also compared RNA samples from N2 worms subjected to a sub-heat-shock treatment (28ºC) against controls kept at 26 ºC (but using only 2 gene arrays per condition). After similar normalisation, many more genes (3712) showed substantial expression changes (i.e. > 2-fold at p < 0.05), including a group of six heat-shock genes which were strongly but unexpectedly down-regulated (by > 10-fold). However, further replication and confirmation by real-time RT-PCR would be needed to establish how many of these changes might also be false positives.
Experimenter name: Adam Dawe
Experimenter phone: +27 21 959 2364
adam@sanbi.ac.za
Experimenter institute: South African National Bioinformatics Institute
Experimenter address: University of Western Cape, Old Chemistry Building, University of Western Cape, Modderdam Road, Bellville 7530, Capetown
Experimenter zip/postal_code: 7530
Experimenter country: South Africa
Keywords: Microwave radiation, gene expression, gene arrays, Caenorhabditis elegans
|
| |
|
| Overall design |
14 samples were used in this experiment
|
| |
|
| Contributor(s) |
Dawe A, Bodhicharla R, Graham N, May S, Reader T, Loader B, Gregory A, de Pomerai D, Swicord M, Bit-Babik G |
| Citation(s) |
19533680 |
| |
| Submission date |
Mar 11, 2008 |
| Last update date |
Jul 06, 2016 |
| Contact name |
Nottingham Arabidopsis Stock Centre (NASC) |
| E-mail(s) |
affy@arabidopsis.info
|
| Phone |
+44 (0)115 951 3237
|
| Fax |
+44 (0)115 951 3297
|
| URL |
http://arabidopsis.info/
|
| Organization name |
Nottingham Arabidopsis Stock Centre (NASC)
|
| Department |
School of Biosciences, University of Nottingham
|
| Street address |
Sutton Bonington Campus
|
| City |
Loughborough |
| ZIP/Postal code |
LE12 5RD |
| Country |
United Kingdom |
| |
|
| Platforms (1) |
| GPL200 |
[Celegans] Affymetrix C. elegans Genome Array |
|
| Samples (14)
|
|
| Relations |
| BioProject |
PRJNA107477 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE10787_RAW.tar |
89.6 Mb |
(http)(custom) |
TAR (of CEL, CHP, EXP, RPT) |
| Processed data included within Sample table |
| Processed data provided as supplementary file |
|
|
|
|
 |
Less...
More...