Stress transcriptomics in fish: a role for genomic cortisol signaling

Area of Science:

• * Fish physiology and molecular biology
• * Comparative genomics and stress response

Background:

• * Physiological stress responses in teleosts are known, but molecular mechanisms remain unclear.
• * The hypothalamus-pituitary-interrenal (HPI) axis activation and cortisol release are common stress responses in fish.
• * cDNA microarray technology enables global gene expression analysis in fish.

Purpose of the Study:

• * To discuss gene expression changes in fish following acute stress.
• * To highlight the role of cortisol in the adaptive stress response.
• * To explore molecular programming in fish liver and other tissues during stress.

Main Methods:

• * Utilized cDNA microarray technology to analyze global gene expression.
• * Investigated gene expression changes in response to acute stressor exposure.
• * Examined the modulation of stress-responsive genes by glucocorticoid receptor activation.

Main Results:

• * Identified several genes with transient expression changes after acute stress in fish.
• * Demonstrated that many stress-responsive genes are modulated by glucocorticoid receptor activation.
• * Indicated that elevated cortisol during stress signals target tissues for molecular programming.

Conclusions:

• * Cortisol elevation is a key signal for molecular programming essential for stress adaptation in fish.
• * Genomic studies in liver and other tissues reveal stress-activated gene networks modulated by cortisol.
• * Understanding these networks provides a framework for characterizing cortisol's role in stress adaptation.