THE EVOLVING TECHNOLOGY OF DNA-FINGERPRINTING AND ITS APPLICATION TO FISHERIES AND AQUACULTURE

In 1985, Alec Jeffreys reported the development of multilocus DNA fing erprinting by Southern blot-detection of hypervariable minisatellites or variable number of tandem repeat (VNTR) loci. This technology found immediate application to various forensic and scientific problems, in cluding fisheries and aquaculture. By 1989, however, it was recognized by many researchers that inherent problems exist in the application o f multilocus fingerprinting to large sample sizes as might occur in fi sheries and aquaculture genetic studies. As such, individual VNTRs wer e cloned for single-locus DNA fingerprinting. Although single-locus fi ngerprinting ameliorates many of the problems associated with multiloc us DNA fingerprinting, it suffers from the problem that electrophorect ic anomalies of band migration within and between gels necessitates bi nning of alleles, thus underestimating genetic variability in a given population. Amplification of microsatellite loci by the polymerase cha in reaction, however, solved many of the problems of Southern blot-bas ed DNA fingerprinting. Moreover, microsatellites exhibit attributes th at make them particularly suitable as genetic markers for numerous app lications in aquaculture and fisheries research: (1) they are abundant in the genome; (2) they display varying levels of polymorphism; (3) a lleles exhibit codominant Mendelian inheritance; (4) minute amounts of tissue are required for assay (e.g., dried scales or otoliths); (5) l oci are conserved in related species; (6) potential for automated assa y. Recent innovations in DNA fingerprinting technology developed over the past 5 years are discussed with special emphasis on microsatellite s and their application to fisheries and aquaculture, e.g., behavioura l and population genetics of wild species, and selection and breeding programmes for aquaculture broodstock. (C) 1995 The Fisheries Society of the British Isles