Gene-environment interactions influence ecological consequences of transgenic animals

Area of Science:

• Ecology
• Genetics
• Environmental Science

Background:

• Concerns exist regarding the ecological impact of transgenic animals escaping into the wild.
• Previous assessments relied heavily on laboratory studies and theoretical models.

Purpose of the Study:

• To investigate how rearing conditions influence the phenotype and ecological effects of transgenic animals.
• To assess genotype-by-environment interactions in transgenic coho salmon.

Main Methods:

• Growth hormone transgenic and wild coho salmon (Oncorhynchus kisutch) were reared in both standard hatchery and naturalized stream environments.
• Phenotypic differences and predation effects were compared between transgenic and wild fish under different conditions.

Main Results:

• Under hatchery conditions, transgenic fish grew significantly larger and had stronger predation effects than wild fish.
• Under naturalized stream conditions, phenotypic differences and predation effects between transgenic and wild fish were substantially reduced.
• Genotype-by-environment interactions significantly altered the relative phenotypes.

Conclusions:

• Rearing conditions critically influence the phenotype of transgenic organisms and their ecological interactions.
• Ecological risk assessments based on laboratory environments may overestimate or underestimate actual risks.
• Naturalized environments are essential for reliable risk assessment of transgenic organisms before potential release.