Transcriptomic characterization of temperature stress responses in larval zebrafish

Area of Science:

• * Molecular Biology
• * Genomics
• * Ecology

Background:

• * Temperature significantly impacts fish physiology and life history, yet molecular acclimation mechanisms are poorly understood.
• * Previous research focused on adult fish, leaving larval responses to temperature stress largely uncharacterized.

Purpose of the Study:

• * To investigate the transcriptional responses of larval zebrafish to cold and heat stress.
• * To identify temperature-specific and temporally regulated genes and pathways involved in fish temperature acclimation.

Main Methods:

• * Microarray analysis was employed to profile gene expression in 96-hour post-fertilization (hpf) zebrafish larvae.
• * Larvae were exposed to cold (16 °C) and heat (34 °C) stress for 2 and 48 hours, with a control group at 28 °C.
• * Bioinformatic analysis was used to identify overrepresented biological processes and signaling pathways.

Main Results:

• * A total of 2680 genes were found to be differentially expressed in response to cold or heat stress.
• * Gene expression patterns were largely temperature-specific and temporally regulated.
• * Early stress responses involved transcription regulation, nucleosome assembly, chromatin organization, and protein folding. Later cold stress responses enriched RNA processing, metal ion homeostasis, and protein transport. Cold-induced pathways included mTOR signaling, p53 signaling, and circadian rhythm, while heat-induced pathways involved adipocytokine signaling, protein export, and amino acid metabolism.

Conclusions:

• * This study elucidates the complex transcriptional landscape of larval zebrafish under thermal stress.
• * Identified genes and pathways provide crucial insights into the molecular basis of fish temperature acclimation.
• * Findings highlight both distinct and common molecular strategies employed by fish to cope with thermal challenges.