|Document Type:||Journal Article|
|Title:||Gene duplication within the family Salmonidae III: linkage between two duplicated loci coding for aspartate aminotransferase in the cutthroat trout (Salmo clarki)|
|Author:||Fred W. Allendorf, Fred M. Utter|
The genetic control of the supernatant form of aspartate aminotransferase (AAT) was studied in the cutthroat trout (Salmo clarki) through a series of experimental matings. We examined 509 individuals from eight families to determine (1) the number of loci, (2) the mode of inheritance (i.e. disomic or tetrasomic), and (3) the linkage relationship of loci involved. Observed variation was controlled by a duplicated locus resulting from a presumed tetraploid event of an ancestral salmonid. Inheritance experiments revealed the presence of two disomic loci rather than a single tetrasomic locus, indicating that disomy has been reestablished for the chromosomes carrying the AAT loci. The two families in which linkage between these loci could be tested displayed significant nonrandom segregation between these loci with an estimated frequency of recombination of 30.6%. These results are discussed in regard to the proposed evolution of tetraploidy in the family Salmonidae.