Genetic Differentiation between Natural and Hatchery Stocks of Japanese Scallop (Mizuhopecten yessoensis) as Revealed by AFLP Analysis

Wei-Dong Liu,Hong-Jun Li,Chong-Bo He,Xiang-Bo Bao,Zhan-Jiang Liu,Yun-Feng Li,Xiang-Gang Gao

doi:10.3390/ijms11103933

Abstract

Japanese scallop (Mizuhopecten yessoensis) is a cold-tolerant bivalve that was introduced to China for aquaculture in 1982. In this study, amplified fragment length polymorphism (AFLP) markers were used to investigate levels of genetic diversity within M. yessoensis cultured stocks and compare them with wild populations. Six pairs of primer combinations generated 368 loci among 332 individuals, in four cultured and three wild populations. High polymorphism at AFLP markers was found within both cultured and wild M. yessoensis populations. The percentage of polymorphic loci ranged from 61.04% to 72.08%, while the mean heterozygosity ranged from 0.2116 to 0.2596. Compared with wild populations, the four hatchery populations showed significant genetic changes, such as lower expected heterozygosity and percentage of polymorphic loci, and smaller frequency of private alleles, all indicative of a reduction in genetic diversity. Some genetic structures were associated with the geographical distribution of samples; with all samples from Dalian and Japan being closely related, while the population from Russia fell into a distinct clade in the phylogenetic analysis. The genetic information derived from this study indicated that intentional or accidental release of selected Japanese scallops into natural sea areas might result in disturbance of local gene pools and loss of genetic variability. We recommend monitoring the genetic variability of selected hatchery populations to enhance conservation of natural Japanese scallop resources.

Highlights

IntroductionVos et al [1], which combines the strengths of restriction fragment length polymorphism (RFLP) and random amplification of polymorphic DNA (RAPD)
Amplified fragment length polymorphism (AFLP) is a multilocus marker technique developed byVos et al [1], which combines the strengths of restriction fragment length polymorphism (RFLP) and random amplification of polymorphic DNA (RAPD)
All the scallop populations cultured in Dalian today are the progeny of the small and limited population introduced in the past, which may be the main reason for the reduced genetic diversity of Chinese Japanese scallop culture stocks

Summary

Introduction

Vos et al [1], which combines the strengths of restriction fragment length polymorphism (RFLP) and random amplification of polymorphic DNA (RAPD). AFLP has the capability to produce multi-locus fingerprints in a single polymerase chain reaction (PCR) analysis, significantly reducing the cost of analysis and increasing the possibility of detecting polymorphisms. Because of such advantages, AFLP markers have emerged as a major type of genetic marker with wide applications in genetic diversity, population structure and construction of linkage maps [4]. In 1982, M. yessoensis (332 individuals) were first introduced into China from

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