Characterization of novel polymorphic microsatellite markers from the cDNA library of Japanese scallop Mizuhopecten yessoensis and cross-species amplification in bay scallop Argopecten irradians

Abstract

The 165 microsatellites were found in 3061 nonreduntant expressed sequence tags (ESTs) from Mizuhopecten yessoensis cDNA library. Among thesemicrosatellites, 97.58% were perfect microsatellites. In the microsatellite sequences with two bases, the repeat bases (AT)n/(TA)n was the most common. Out of these 165 microsatellites, 16 were found to be polymorphic in bay scallop (Argopecten irradians). These 16 markers had alleles between two and five. Observed and expected heterozygosity ranged from 0 to 0.922 and 0.226 to 0.752, respectively. There was no genotypic linkage disequilibrium (LD) observed between any pair of microsatellite loci. The results of polymorphism information content (PIC) values showed that seven loci were highly polymorphic, six exhibited medium polymorphism, and the remaining had low polymorphism. These microsatellite markers provide useful tools for studies of population genetics, marker-assist selective breeding, and linkage mapping of A. irradians. Bay scallop (Argopecten irradians) is a common estuarine species along the eastern and southern coasts of North America from Massachusetts to Texas (Kim et al. 2006). Because of its fast growth rate and short grow out time, the industry of bay scallop culture in China expanded rapidly after it was introduced from America in 1982 (Song et al. 2006). However, in recent years, because of deterioration of breeding conditions and loss of genetic variation, bay scallop production experienced increased larval and juvenile mortality, and decreased growth in China (Li et al. 2008). Microsatellites are nucleotide sequence repeats distributing randomly in genome and are used widely in kinship analysis, marker-assist selective breeding in fisheries animals