Parentage and relatedness determination in farmed Atlantic salmon (Salmo salar) using microsatellite markers

This study demonstrates how both parentage and relatedness can be determined in a mixed family aquaculture (Atlantic salmon) stock in the absence of physical tags and/or pedigree information. Under a number of different scenarios, both real and simulated, we could use microsatellite markers to assign parentage to offspring with varying degrees of accuracy. The precision of assignment to one correct parental pair depended not only on the number and variability of the microsatellite markers, but also on the number of potential pairings from which to choose, i.e., the more families in the breeding program the more microsatellites required to discriminate between them. Using eight highly variable markers resulted in an assignment of an individual to the correct parental pair of greater than 95% even when the number of possible parent pairs is > 12,000. These same microsatellite loci were capable of discriminating between related and unrelated individuals in a situation where no pedigree information is known. Based on these results we conclude that the use of a number of microsatellite markers represents a realistic and cost-effective alternative to physical tagging in a family selection program. (C) 2000 Elsevier Science B.V. All rights reserved.