Comparison of genetic diversity at microsatellite loci and quantitative traits in hatchery populations of Japanese flounder Paralichthys olivaceus

Abstract

Relationships of genetic diversity at microsatellite loci and quantitative traits were examined in hatchery-produced populations of Japanese flounder using a relatively straightforward experiment. Five hatchery populations produced by wild-caught and domesticated broodstocks were used to examine the effects of different levels (one to three generations) of domestication on the genetic characteristics of hatchery populations. Allelic richness at seven microsatellite loci in all hatchery populations was lower than that in a wild population. Genetic variation measured by allelic richness and heterozygosity tended to decrease with an increase in generations of domestication. In addition, the degree of genetic differentiation from a wild population increased with an increase in generations of domestication. Significant differences in three morphometric traits (dorsal and anal fin ray counts and vertebral counts) and three physiological traits (high temperature, salinity and formalin tolerance) were observed among the hatchery populations. The degree of phenotypic difference among populations was larger in morphometric traits than in physiological traits. The divergence pattern of some quantitative traits was similar to that observed at microsatellite loci, suggesting that domestication causes the decrease of genetic variation and the increase of genetic differentiation for some quantitative traits concomitantly with those for microsatellite loci. Significant positive correlation was observed between F ST and the degree of phenotypic difference in the three morphometric traits and formalin tolerance, indicating that genetic variation at microsatellite loci predicts the degree of phenotypic divergence in some quantitative traits.

Loss of genetic integrity correlates with stocking intensity in brook charr (Salvelinus fontinalis)

“…Our findings of higher genetic diversity in stocked lakes contrast with the usual perception that domestic fish should harbor lower genetic diversity (Hutchings & Fraser 2008; Shikano et al. 2008; Karaiskou et al.…”

“…2008). As well, domestic fish are typically genetically distinct from wild populations, both in terms of allelic composition and genetic diversity (reviewed in Hutchings & Fraser 2008; Finnegan & Stevens 2008; Shikano et al. 2008).…”

Population structure of the olive flounder (Paralichthys olivaceus) in Korea inferred from microsatellite marker analysis

“…The lower allelic diversity of two of the hatchery populations compared with that of the wild populations may be associated with non‐random mating, small effective population sizes or both, although no historical genetic data are available. Several studies using molecular markers also have shown that cultured P. olivaceus tend to show reduced genetic variability compared with wild populations (Sekino et al , 2002; Liu et al , 2005; Kang et al , 2006; Shikano et al , 2008). The heterozygosity values of MS loci did not show pronounced differences between wild and hatchery populations, suggesting that allelic diversity is a more sensitive measure of genetic variation between wild and hatchery populations.…”

Population genetic structure of wild and hatchery black rockfish Sebastes inermis in Korea, assessed using cross-species microsatellite markers

“…When the overall level of diversity of hatchery stocks was compared with that of the wild populations examined here, 94.1% of the allelic richness, on average, observed within the three wild samples was present in the hatchery samples, and the hatchery population displayed a slightly lower overall level of heterozygosity. Loss of genetic variation in hatchery strains, compared with wild populations, has been documented in several studies (Ryman and Ståhl, 1980;Liu et al, 2005;Shikano et al, 2008). The heterozygosity values of MS loci did not differ markedly between wild and hatchery populations, suggesting that allelic diversity is a more sensitive measure of genetic variation between wild and hatchery populations.…”