Restriction fragment length polymorphism at the growth hormone 1 gene in Atlantic salmon (Salmo salar L.) and its association with weight among the offspring of a hatchery stock

Variation was studied within an 1825 bp fragment of the Atlantic salmon growth hormone 1 (GH1) gene, encompassing the sequence from the first to the fourth exon. Two novel polymorphisms were detected in a hatchery strain of landlocked salmon population from the Lake Vanern, Sweden (spawns in the River Gullspang) after PCR amplification and subsequent digestion of the GH1 fragment with TaqI restriction enzyme: restriction site polymorphism within a 562 bp fragment and length polymorphism of a 187 bp fragment. Altogether six different banding patterns were observed that arose from random association of three haplotypes. In order to study possible association of the detected variation with the weight of one-year-old fish, progeny of the hatchery strain was graded into three size groups. Significant heterogeneity of the GH1 haplotype and genotype frequencies among the size groups was detected (P < 0.05). However, the hypothesis that the samples with different genotypes or haplotypes have non-identical medians of weight distribution was rejected at the studied sample size (P > 0.05). (C) 1999 Elsevier Science B.V. All rights reserved.