Genetic Variation in Wild and Cultured Populations of the Sea Squirt Halocynthia roretzi Inferred from Microsatellite DNA Analysis

ABSTRACT. Populations of the Pacific abalone, Haliotis discus hannai, have been severely overexploited over the past few decades in Korea. Information regarding the levels of genetic variability and structure within populations is insufficient for the development of effective strategies for conservation of genetic diversity of this species. To assess the genetic status of this species, we examined variation at six microsatellite loci in 842 individuals of Pacific abalone collected from three hatchery stocks of the main aquaculture areas and eight wild populations, which were two from the East Sea, two from the West Sea and three from the South Sea. High levels of polymorphism at these microsatellite loci were found in both the wild and hatchery populations. The genetic variation in the hatchery stocks [overall number of alleles (N A ) = 24.00; allelic richness (A R ) = 19.71; observed heterozygosity (H O ) = 0.733] was similar to that of the wild (overall N A = 28.13; A R = 22.62; H O = 0.775) populations. Low levels of inbreeding and significant Hardy-Weinberg equilibrium deviations were detected in both the wild and hatchery populations. Significant F ST values were observed for the hatchery stocks and in most cases between the wild and hatchery populations (overall F ST = 0.017, P < 0.01); however, only a Population genetics of Pacific abalone in Korea minor portion of the genetic diversity was distributed between the wild and hatchery populations. These results reflect intensive seedling and stocking practices. This preliminary study showed genetic separation between the eastern and pooled western and southern wild populations in Korea, which was based on the F ST value, phylogenetic tree clustering, PCA and MDS analyses, structure analysis, and AMOVA. This strong biogeographic structure of H. d. hannai in Korea may be considered to be independent management units. This study demonstrates the feasibility of microsatellite analyses for the monitoring of genetic diversity and for revealing the population structure of the wild Pacific abalone. This information will be useful for the proper management and conservation of H. d. hannai in Korea.

Section: Discussionmentioning

confidence: 79%

Population genetics of the Pacific abalone (Haliotis discus hannai) in Korea inferred from microsatellite marker analysis

Lee²,

Park³

2012

“…Molecular markers have proven to be excellent indicators of genetic variation within and between populations for many fishery animals (Kitanish et al, 2007;An et al, 2011a,b;Yoon et al, 2011;Choi and Kim, 2012;Han et al, 2012;Hong et al, 2012;Lee and Hur, 2012). Microsatellite DNA markers, in particular, have relatively high levels of polymorphism.…”

Section: Introductionmentioning

confidence: 99%

Mitochondrial and microsatellite DNA analyses showed comparative genetic diversity between parent and offspring populations of Korean black rockfish in a hatchery facility

An¹,

Lee²,

Park³

et al. 2013

ABSTRACT. The black rockfish, Sebastes inermis (Sebastidae), is an important commercial fishery resource in Korea. As a preliminary investigation into the effect of artificial reproduction in a hatchery facility, the genetic divergence between parent and offspring populations of black rockfish was accessed using 10 polymorphic nuclear microsatellite DNA loci and a mitochondrial (mt) control gene. All loci that were screened showed marked polymorphisms. mtDNA control region sequences were also highly variable. Of approximately 350 base pairs (bp) sequenced, 52 variable sites, comprising 56 base substitutions, were found among 233 individuals. Offspring populations showed less genetic variability than the parent population in terms of numbers of microsatellite alleles and mtDNA haplotypes, as well as mtDNA haplotype diversity. Statistical analysis of the fixation index (Φ ST and F ST ) and analysis of molecular variance using both DNA markers showed significant genetic differences between the parent and offspring populations. These results suggest that random genetic drift and/or inbreeding events, as well as artificial selection and founder effects, occurred when the offspring strain was reproduced in a hatchery facility despite thousands of males and females from different hatcheries being maintained for artificial reproduction. Therefore, it is necessary to improve current hatchery programs by monitoring genetic variation in both the broodstock and progeny and controlling inbreeding within stocks in commercial breeding facilities to maintain the production of high-quality black rockfish. This information will be useful for determining suitable guidelines for establishing and maintaining cultured stocks and the aquaculture industry of S. inermis.

“…The use of molecular markers has proved to be a useful tool for complex taxonomic identification and genetic relationship determination where morphological characteristics are ambiguous or cryptic (Miura et al, 2005;Yoon et al, 2011;An et al, 2005An et al, , 2012Choi and Kim, 2012;Han et al, 2012;Hong et al, 2012;Lee and Hur, 2012). The random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) technique is a relatively simple and cheap method that allows differentiation of taxa without the need to know their genomes (Williams et al, 1990).…”

Section: Introductionmentioning

confidence: 99%

Genetic relationships of Pacific abalone (Haliotidae) species determined using universal rice primer-polymerase chain reaction fingerprinting

Park²,

Myeong³

et al. 2013

ABSTRACT. Random amplified polymorphic DNA (RAPD) with universal rice primers (URP) was used to identify species and to determine phylogenetic relationships for the 6 economically important Korean Pacific abalone species: Haliotis discus hannai, H. discus discus, H. madaka, H. gigantea, H. diversicolor supertexta, and H. diversicolor diversicolor, whose morphological differentiation is difficult. Of the 12 URPs used in this study, 7 were effective in producing reproducible RAPD markers for these 6 species. Amplifications with the 7 URP primers yielded 129 reproducible amplified fragments ranging between 100 and 6000 bp in length. The dendrogram generated by the unweighted pairgroup method using arithmetic averages showed that the 6 species were divided into 4 groups at 0.44 similarity level, indicating that they were genetically distant from each other and had little internal phylogenetic resolution. One group included H. discus hannai, H. discus discus, H. madaka, and H. gigantea, which were divided into 2 groups at 0.52 similarity level: one group of H. discus hannai, H. discus discus, and H. madaka, and the other of H. gigantea. H. diversicolor supertexta and H. diversicolor diversicolor belonged to the other group. Furthermore, the reproducible pattern of amplified DNA bands by URP primers indicated the possibility of using these as molecular markers for the discrimination of the 6 Pacific abalone species. These results suggest that the URP-PCR approach will be a useful tool for obtaining accurate taxonomic identification and genetic relationship of Korean Pacific abalones, which is one of the first prerequisites in effective conservation programs.