Identification of 15 novel polymorphic microsatellite loci in pearl oyster (Pinctada fucata).

The pearl oyster Pinctada fucata is a commercially important marine shellfish. As a result, genetic improvement and selective-breeding program have been conducted for this species. Polymorphic microsatellites are effective molecular markers to investigate molecular marker-assisted selection and genetic variance. In this study, microsatellite DNAs were screened and characterized based on the partial genome sequence of P. fucata. We identified 111 microsatellite DNA motifs through mining the published draft genome sequence of P. fucata. Forty-two loci were screened with 8 P. fucata individuals, and 15 were found to be polymorphic and were therefore further evaluated using 40 wild individuals from the Daya Bay, Shenzhen City, Guangdong Province, China. The number of alleles per locus ranged from 3 to 8, with an average of 5.2667 for the 15 polymorphic loci. Observed and expected heterozygosities ranged from 0.1154 to 0.6216 (0.3321 on average) and 0.4950 to 0.8491 (0.6768 on average), respectively. Of the 15 polymorphic loci, 12 loci deviated from Hardy-Weinberg equilibrium after Bonferroni correction (P < 0.0033). Polymorphism information content ranged from 0.44 to 0.83 with a mean value of 0.63. The results suggest that the markers isolated in this study can be used for research on molecular marker-assisted selection and genetic variance of P. fucata.