Abstract:

3,295 ESTs from NCBI were mined to develop EST-SSR markers.By using SSRHunter soft tools, a total of 209 SSRs were identified from 196 ESTs. The frequency of EST-SSRs was 6.3%. The dinucleotide repeat motif was the most abundant SSR, accounting for 71.8%, followed by 9.1%, 8.1%, 5.7% and 5.3%, respectively,for tri-, hexa-, penta- and tetra-nucleotide repeats. Among the di- nucleotide repeats, AC/TG (31%)were the most abundant type. 22 primer pairs were designed f rom microsatellite,18 pairs could show clear PCR products by electrophoresis,and 6 pairs show highly polymorphism in Chinese Merino sheep. The mean PIC value was 0.7001, ranging from 0.5499 to 0.7607.These EST-SSR markers can be used for further study such as in genetic mapping, identification of quantitative trait loci (QTLs),and comparative genomics studies of sheep.