栉江珧(Atrina pectinata)EST-SSR标记的开发与应用

Development and Application of the EST-SSR Markers in Atrina pectinata

中文关键词: 栉江珧  EST-SSR  遗传多样性  杂合度

英文关键词: Atrina pectinate  EST-SSR  Genetic diversity  Heterozygosity

中文摘要:

      本研究以前期获得的栉江珧(Atrina pectinata)转录组数据为基础，筛选获得10550条微卫星标记(SSR)，检出率为8.2%，平均9.01 kb出现1个SSR位点。设计并合成120对SSR引物，筛选得到36对能够稳定扩增的引物，并利用已获得的36对SSR引物对青岛海区栉江珧进行了群体遗传多样性分析。结果显示，12对引物的扩增片段表现出多态性，共产生42个等位基因，平均每个位点产生3.5个等位基因，平均观测杂合度(Ho)、平均期望杂合度(He)和平均多态信息含量(PIC)分别为0.417、0.604和0.526，表明青岛海区栉江珧群体的遗传多样性较高。本研究获得的EST-SSR标记和群体遗传信息为栉江珧的种质资源保护提供了重要的参考资料。

英文摘要:

      Atrina pectinata is a large deep-water mollusk species that has high economic values. It is distributed in the coastal areas of China, from the Liaodong Peninsula in the north to the Qiongzhou Strait in the south. Its habitat is adjacent to China’s provinces such as Fujian, Guangdong, Liaoning and Shandong. In recent decades, the natural resource of A. pectinata has declined due to the environment destruction and overfishing. To better protect the resource of A. pectinata, we need to understand its population genetic structure. Microsatellites is a widely used method to assess the genetic diversity in farmed aquatic species and construct QTL due to its characteristics such as the abundant polymorphism, the rich information, the co-dominance and conservation. The EST-SSR marker is inexpensive and is probably associated with functional regions of the genome. Therefore, in this research, we developed a series of EST-SSR markers using a transcriptome-based platform to study the genetic diversity of A. pectinata. We identified 10550 EST-SSR (8.2%) using MISA software, and the corresponding frequency was 1 EST-SSR per 9.01 kb of the sequence. Dinucleotide repeats were dominant among all EST-SSRs, counting for 77.08%. We designed 120 primers for PCR, and 36 out of 120 resulted in successful amplification. Fragments amplified with 12 primers were polymorphic. Next we used these SSR primers to explore the genetic variation of 30 A. pectinata samples collected from the Qingdao Bay. The number of alleles for the 12 SSR makers varied from 2 to 5 in these samples with an average of 3.5 alleles per locus. The observed heterozygosity ranged from 0.1667 to 0.6667, and the expected heterozygosity varied from 0.4316 to 0.7938. Polymorphic information content ranged from 0.3679 to 0.7459. These indicated high genetic diversity of the A. pectinata population in the Qingdao Bay. Moreover, we verified that the polymorphic EST-SSR markers could be a useful tool in comparative mapping, gene tagging and QTL mapping.