Transcriptomic responses to environmental temperature in eurythermal and stenothermal fishes

Area of Science:

• Comparative physiology
• Environmental genomics
• Ecology

Background:

• Ectothermic fish display varied thermal tolerance, with eurythermal species adapting to wide temperature fluctuations and stenothermal species to narrow ranges.
• Global warming necessitates understanding thermal specialization and plasticity in fish, driving research into physiological and molecular differences between stenothermal and eurythermal species.
• While the loss of inducible heat shock response (HSR) in stenothermal fish is known, transcriptomics allows broader investigation of gene expression (GE) across cellular processes.

Purpose of the Study:

• To review findings from transcriptomic studies on extreme eurythermal and stenothermal fishes.
• To examine genome-wide gene expression changes in response to acute and long-term temperature exposures.
• To explore molecular adaptations underlying thermal specialization in teleosts and identify future research directions.

Main Methods:

• Transcriptomic analysis of gene expression (GE) in non-model fish species.
• Comparative physiological studies of stenothermal and eurythermal fish.
• Review of existing literature on fish thermal specialization and climate change response.

Main Results:

• Transcriptomics enables genome-wide GE analysis in ecologically important fish beyond the heat shock response (HSR).
• Both acute and long-term temperature exposures reveal critical insights into thermal adaptation.
• Studies highlight differences in gene regulation underlying eurythermy and stenothermy.

Conclusions:

• Transcriptomic approaches are vital for understanding the molecular basis of fish thermal specialization.
• Investigating genome-wide gene expression provides a broader view of cellular processes involved in thermal adaptation.
• Further research in comparative environmental genomics is crucial for predicting fish responses to climate change.