John B. Taggart

Allozyme variation in the brown trout ( Salmo trutta L.): Single locus and joint segregation inheritance studies

Inheritance studies have confirmed the genetic interpretations of previously described polymorphisms, detected by starch gel electrophoresis, at 13 enzyme coding loci in the brown trout. Biopsy techniques facilitated the prior typing of broodstock, enabling the careful planning of informative matings. Joint segregation analyses of 49 different pairwise comparisons of loci revealed apparent non-random assortment between four pairs; sAat-1,2 and sMdh-2, sAat-1,2 and Ck-2, sMdh-3,4 and Pgi-2, Dia and Pgi-2. In conjunction with published data, these results indicate conservatism of the sAat-1,2/sMdh-2 linkage association between Salmo and Salvelinus.

An electrophoretically-detectable genetic tag for hatchery-reared brown trout (Salmo trutta L.)

Abstract The feasibility of incorporating a unique genetic marker into a hatchery strain of brown trout is investigated. The allele Pgi-3(110) is shown to have a very limited distribution among native trout populations in Great Britain and Ireland yet is present, at low frequency, in all three hatchery stocks examined. The potential therefore exists to breed a strain of hatchery brown trout homozygous for the Pgi-3(110) allele. Individuals of such a strain could be unambiguously distinguished from virtually all native stocks. The usefulness of the genetic tag is enhanced by the strong expression of Pgi-3 in adipose fin, permitting simple biopsying. Data from population surveys and the monitoring of experimental progeny suggest selective equivalence among Pgi-3 genotypes.