Title Genetic structure of chum salmon populations in Japan
Authers Shunpei SATO, and Shigehiko URAWA
Keywords chum salmon, genetic structure, genetic differentiation, allozyme, previous microsatellite data
Citation Bull. Fish. Res. Agen. No.39, 21-47, 2015
We examined the genetic structure of Japanese chum salmon populations using 20 allozyme markers. A total of 2,447 individuals from 35 populations of Hokkaido and northern Honshu was used to estimate mean allelic richness, observed (HO) and expected (HE) heterozygosities, a neighbor-joining (N-J) phylogeny, average pairwise FST values , and to conduct analysis of molecular variance (AMOVA). Some of these parameters were compared with the average number of alleles (A), mean effective number of alleles (Ae), and HE calculated based on allelic frequency data from microsatellite DNA marker analysis of Japanese chum salmon. In our allozyme study, HO and HE values of chum salmon populations in Honshu (HO, 0.200; HE, 0.199) were larger than those of Hokkaido (HO, 0.186; HE, 0.190). In contrast, the A, Ae, and HE values calculated with the reported microsatellite data were larger in the populations of Hokkaido (A, 27.5; Ae, 15.7; HE, 0.917) than those of Honshu (A, 24.2; Ae, 14.2; HE, 0.908). Both the N-J tree and AMOVA analysis with the allozyme data suggested seven regional groups, five in Hokkaido and two in Honshu. Furthermore, FST estimates demonstrated genetic differentiation between Hokkaido and Honshu regions (0.014-0.034). Similar genetic population structure was suggested by the N-J tree and FST estimates with the microsatellite data. The historical genetic characteristics or the remnants of past population structure in Japanese chum salmon remain intact, despite the hatchery program operating more than 120 years.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull39/39-04.pdf