Rapid, broad-scale gene expression evolution in experimentally harvested fish populations

Area of Science:

• Evolutionary biology
• Genomics
• Fisheries science

Background:

• Human-induced selection pressures, such as fishing, can drive adaptive evolution.
• Demonstrating rapid, evolution-driven gene expression changes in natural populations is challenging.
• Size-selective harvesting creates strong evolutionary pressure against large body size.

Purpose of the Study:

• To experimentally investigate gene expression changes induced by size-selective harvesting in zebrafish (Danio rerio).
• To assess the speed and magnitude of fisheries-induced evolution at the molecular level.
• To examine genetic convergence and allele frequency shifts following harvesting cessation and captive breeding.

Main Methods:

• Utilizing wild-origin zebrafish (Danio rerio) as a model organism.
• Implementing size-selective harvesting over five generations.
• Analyzing gene expression and allele frequencies.
• Comparing harvested groups with control stocks after nine generations of captive breeding.

Main Results:

• Five generations of size-selective harvesting induced broad-scale gene expression changes.
• Significant allele frequency changes were observed in differentially expressed genes.
• Limited genetic convergence occurred after harvesting ceased.
• Nine generations of captive breeding led to substantial gene expression changes in control stocks.

Conclusions:

• Fisheries-induced selection can cause rapid and extensive gene expression changes.
• Evolutionary changes in gene expression may not be quickly reversible after selection pressure is removed.
• Inadvertent selection in captive breeding environments can also induce significant gene expression alterations.
• Evolutionary principles are crucial for developing sustainable fisheries management strategies.