Joint Segregation of Biochemical Loci in Salmonidae: Results from Experiments with Salvelinus and Review of the Literature on Other Species

Abstract

An extensive survey of joint segregation is described involving 37 pairwise comparisons of 12 biochemical loci in 11 single pair matings of brook trout (Salvelinus fonlinalis) and 38 pairwise comparisons of 9 loci in an F1 splake (lake trout, Salvelinus namaycush × brook trout) backcross to brook trout mating. We report pseudolinkage of two duplicated malate dehydrogenase loci (MDH-3 and MDH-4) and statistically highly significant nonrandom segregation of MDH-1 with an alphaglycerophosphate dehydrogenase locus (AGP-1). Several additional cases of aberrant joint segregation are described. All known examinations of joint segregation in Salmonidae are reviewed. A uniform system of nomenclature and guidelines for future investigations are discussed. Key words: joint segregation, brook trout, splake hybrid, inheritance, electrophoresis, pseudolinkage, duplicate-genes