MULTILOCUS DNA-FINGERPRINTING OF CHANNEL CATFISH ICTALURUS-PUNCTATUS

Similarities among multi-locus DNA fingerprints of five channel catfis h Ictalurus punctatus strains and the ability to identify the strain o f a fish based on its fingerprint pattern were investigated. Five rest riction enzymes and 13 multi-locus DNA probes were screened to identif y enzyme-probe combination useful for DNA fingerprinting channel catfi sh. Restriction enzymes Hinf I and Dpn II, in combination with probes (CAC)n, (CGC)n, (CTC)n, (ATCC)n, and (GATA)n, produced useful fingerpr ints (20-30 resolvable bands for each enzyme-probe combination). Thirt y individuals (3 pools of 10 individuals each) from each of five chann el catfish strains (albino, Mississippi normal, USDA-102, USDA-102 sel ect, and USDA-103) were fingerprinted with all useful enzyme-probe com binations. Band sharing among samples was higher within strains than a mong strains and band sharing among strains was higher for strains who se breeding history indicated a high degree of relatedness. Individual fingerprints of 18 fish from each of the USDA-102 select and USDA-103 strains revealed no strain-spe cific bands, but several diagnostic ba nds (present at high frequencies in either USDA-102 select or USDA-103 strains and at a low frequencies in other strains) were identified. B and sharing at diagnostic bands was used to correctly identify fish as USDA-102 select or USDA-103 strains with 82% accuracy from fingerprin ts of 17 USDA-102 select strain fish, 18 USDA-103 strain fish, and 38 fish collected from three commercial farms.