A standardized method for quantifying unidirectional genetic introgression.

Area of Science:

• Conservation Genetics
• Population Genetics
• Ecology

Background:

• Genetic introgression from domesticated to wild populations threatens genetic integrity and viability.
• Quantifying unidirectional gene flow is challenging due to population substructure, genetic drift, and inter-subpopulation migration.

Purpose of the Study:

• To develop and demonstrate a standardized method for quantifying and monitoring unidirectional gene flow from domesticated to wild populations.
• To provide a tool for assessing the genetic impact of escaped farmed fish on wild populations.

Main Methods:

• Developed an in silico analytical approach to establish reference points for farm and wild populations.
• Utilized individual-based analyses of genotypes (using STRUCTURE software) to estimate the probability of an individual being wild.
• Generated estimates of the proportion of the genome of domesticated origin in wild populations.

Main Results:

• The method provides estimates of domesticated genetic contribution to wild populations without requiring historical reference samples.
• Individual-based analyses yield estimates independent of other individuals, accounting for genetic processes within and between populations.
• The approach is applicable to any species with unidirectional gene flow, provided suitable genetic markers are available.

Conclusions:

• The developed method offers a standardized, interpretable, and powerful tool for managing and monitoring gene flow between domesticated and wild populations.
• This approach is particularly valuable for conservation management due to its independence from historical wild reference samples.