Loss of genetic variation at
microsatellite loci in hatchery strains of the Pacific abalone (Haliotis
discus hannai)
Q. Li, Ch. Park, T. Endo, A. Kijima-2004
Aquaculture, 235(1-4): 207-222
Abstract:
In order to assess the utility of microsatellite DNA
markers for detecting changes of genetic diversity in hatchery strains and
for estimating their genetic relationships, we used six microsatellite
markers to estimate the level of genetic diversity within three hatchery
strains and two wild populations of Pacific abalone, and compared the degree
of genetic differentiation between them. High polymorphism at the
microsatellite loci was found within both hatchery and wild abalone
populations. Compared to wild populations, all the hatchery strains showed
less genetic variation as revealed in lower number of alleles and lower
expected heterozygosity, indicating that bottleneck effects occurred when
each strain was founded. Significant differentiation was found between the
hatchery strains, and between the hatchery strains and wild populations (Fst
range: 0.059–0.427; Rst range: 0.056–0.351), and no
obvious difference was detected between the wild populations (Fst=0.004;
Rst=0.007). According to the neighbor-joining tree
topology constructed on the basis of genetic distances among individuals,
almost all individuals from each hatchery strain were closely clustered,
demonstrating the feasibility of microsatellite analysis for discrimination
between hatchery strains. The results obtained in this study indicate that
it is necessary to genetically characterize the abalone strains that are
being released every year in order to monitor the effect on the genetic
diversity of wild populations.
(Fisheries College, Ocean University of China,
Qingdao 266003, China, e-mail of Qi Li: qili66@mail.ouc.edu.cn)