中文摘要：

构建了马氏珠母贝的血液、足、鳃、胃、肝、心脏、外套膜、珍珠囊和感染多毛虫马氏珠母贝的血液（血感）等9个组织的cDNA文库，测序获得了6979个EST序列，从中查找到了268个重复序列，隶属于243个EST，含微卫星的EST数占EST总数的3．48％。珍珠囊cDNA文库含微卫星的序列所占比例最高，为6．16％，血感的最低，为1.65％。双碱基重复序列130个，占48．5％，（AT／AT）n类型最常见；三碱基类型的83个，占约31％，其中（AAT／ATT）n和（AAG／CTT）n较多；四碱基重复的有30个，占11．2％，（AAAT／ATIT）n占了该类型的约50％。一共能够设计151对微卫星引物，有130对可以扩增，占合成引物总数的86．09％，其中，多态性引物45对。多态性EST—SSR的筛选将为马氏珠母贝的分子遗传学研究、种质鉴定和野生资源保护等提供可靠的工具。

英文摘要：

Pinctada martensii is an important cultured marine mollusc in the southern China. In order to draw up tissue-specific gene expression map, nine cDNA libraries of P. martensii, including blood, foot, gill, stomach, liver, heart, mantle, pearl sac and Polydora ciliata infected blood, were constructed. Totally 6979 ESTs were obtained by sequencing clones from these cDNA libraries. Thoroughly screened with the software of Misa, at a criterion of at least 5, 4, 4, 4, 3 to the copy level of di-, tri-, tetra-, pentra-, hex- motif respectively, a total number of 268 simple repeat sequences were found. 243 ESTs （3.48%） have at least one microsatellite repeat. Among these 9 cDNA libraries, 6.16% pearl sac ESTs, the highest, contain microsatellite, while the lowest, 1.65% P. ciliata infected blood ESTs have at least one microsatellite. In the 268 repeat sequences, the number of the di-nucleotide repeats is 130, about 48.5 %, and the most among all of the repeat sequences. （AT/AT）n, the most, account for 29.1% of total repeat sequences. The second is the tri-nucleotide repeats, 83, almost 31%. More than 50% are the two most abundant tri-nucleotide repeats types of （AAT/ATT） n and （AAG/ CTT）n. The third is the tetra-nucleotide repeats, 30（11.2% ）, and （AAAT/ATIT） n nearly reaches 50% of tetra-nucleotide repeats. Primers can be designed in 151 microsatellite containing ESTs. 130 pairs of primers, about 86.09%, could be amplified in P. martensii DNA. There was no difference of microsatellite containing EST ratio among plasmid libraries and phage libraries. However, libraries constructed with ZAP-cDNA synthesis method have much higher ratio of microsatellite containing EST than those with SMART cDNA. 45 EST-SSRs were confirmed to be polymophic by PCR and PAGE electrophoresis in 8 individuals, 4 each from Sanya population and Indian population respectively. These polymophic EST-SSRs will be useful for molecular genetics study, identification and wild resource conservation.