Ecological comparison of cellular stress responses among populations – normalizing RT-qPCR values to investigate differential environmental adaptations

Annals of Occupational and Environmental Medicine

Stefan Koenigstein¹  Kevin Pöhlmann¹  Christoph Held¹  Doris Abele¹ 

[1] Alfred-Wegener-Institute for Polar and Marine Research, Am Handelshafen 12, BremerhavenD-27515, Germany

关键词: Nacella;    Intertidal;    Normalization;    Gene expression;    RT-qPCR;    Hsp70;    Cellular stress response;    Ecological physiology;   

Others  :  1085354
DOI  :  10.1186/1472-6785-13-21

 received in 2012-11-21, accepted in 2013-05-06,  发布年份 2013

【 摘 要 】

Background

Rising temperatures and other environmental factors influenced by global climate change can cause increased physiological stress for many species and lead to range shifts or regional population extinctions. To advance the understanding of species’ response to change and establish links between individual and ecosystem adaptations, physiological reactions have to be compared between populations living in different environments. Although changes in expression of stress genes are relatively easy to quantify, methods for reliable comparison of the data remain a contentious issue. Using normalization algorithms and further methodological considerations, we compare cellular stress response gene expression levels measured by RT-qPCR after air exposure experiments among different subpopulations of three species of the intertidal limpet Nacella.

Results

Reference gene assessment algorithms reveal that stable reference genes can differ among investigated populations and / or treatment groups. Normalized expression values point to differential defense strategies to air exposure in the investigated populations, which either employ a pronounced cellular stress response in the inducible Hsp70 forms, or exhibit a comparatively high constitutive expression of Hsps (heat shock proteins) while showing only little response in terms of Hsp induction.

Conclusions

This study serves as a case study to explore the methodological prerequisites of physiological stress response comparisons among ecologically and phylogenetically different organisms. To improve the reliability of gene expression data and compare the stress responses of subpopulations under potential genetic divergence, reference gene stability algorithms are valuable and necessary tools. As the Hsp70 isoforms have been shown to play different roles in the acute stress responses and increased constitutive defenses of populations in their different habitats, these comparative studies can yield insight into physiological strategies of adaptation to environmental stress and provide hints for the prudent use of the cellular stress response as a biomarker to study environmental stress and stress adaptation of populations under changing environmental conditions.

【 授权许可】

   
2013 Koenigstein et al.; licensee BioMed Central Ltd.

【 图 表 】

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