CHARACTERIZATION, DEVELOPMENT AND UTILIZATION OF EST-DERIVED MICROSATELLITES IN SINONOVACULA CONSTRICTA
缢蛏(Sinonovacula constricta)EST-SSR分布特征及引物开发利用

A set of 5296 expressed sequence tags (ESTs) of Sinonovacula constricta from NCBI were screened using CAP3.0 software. After assembly, a total of 3453 non-redundant EST sequences were mined and yielded 267 non-redundant sequences which contained 307 putative SSRs accounted for 8.89% of the total number of EST sequences. This is equivalent to one EST-SSR per 6.83kb of sequence. Di-, Tri- and Tetranucleotide repeats EST-SSRs were dominant, counting for 15.96%, 37.13% and 35.50% respectively. Forty primers were designed for partial EST-SSRs and used for PCR amplification with 29 primer pairs showing amplifications while 14 were polymorphic. These were used to conduct SSR analyses of genetic variations of the 40 individual samples of S. constricta collected in Yueqing Bay. A total of 61 alleles were detected, with the number of alleles ranging from 2 to 12. The observed heterozygosity (Ho), expected heterozygosity (He) and polymorphism information content (PIC) were 0.569, 0.490 and 0.449, respectively. All of these parameters indicate that the S. constricta of Yueqing Bay rich genetic variation.