Biochemical genetics of the Atlantic salmon Salmo salar L.

• Published in: Journal of Fish Biology
• Main Author: Wilkins, Noël P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1972
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1972.tb05697.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1972.tb05697.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1972.tb05697.x

In recent years, blood group and protein polymorphisms in Atlantic salmon have been investigated extensively with a view, primarily, to their use in identifying individuals of different spawning populations present in high seas fisheries. Erythrocyte antigens, haemoglobins, serum proteins and various tissue enzymes—mainly esterases and de‐hydrogenases—have been studied by electrophoretic and immunological techniques. These studies are reviewed here for the first time. Many of the protein systems exhibit multiple components and this fact, together with cytological evidence, indicates the occurrence of tetraploidy in the course of Salmonid evolution. The significance of a tetraploid origin in the evolution and ecological adaptation of Salmonids is discussed briefly. Some protein systems studied exhibit phylogenetic variation, and analyses of phenotype ratios and allele frequencies indicate that the populations of different river systems are genetically distinct. Allele frequencies have not yet been shown to be stable from generation to generation however, and some of the factors likely to affect allele frequencies are discussed. Different spawning populations can not be identified in high seas fisheries using these protein characters, although it may be possible to identify the continent of origin (N. America or Europe) of some individuals. Indeed, it has been proposed independently by two groups that North American and European populations of Atlantic salmon be assigned to different sub‐species viz. S. s. americanus and S. s. europaeus respectively. The contradictory evidence on which these taxa are proposed is discussed, together with the evidence for other population groups proposed in the European part of the salmon's range. The possible role and future direction of studies on the biochemical genetics of salmon are outlined.