Development of polymorphic tri-and tetranucleotide repeat microsatellite loci in Fangzheng silver crucian carp(Carassius auratus gibelio(Bloch)) by magnetic beads

Magnetic beads enriched method was used to isolated polymorphic tri-and tetranucleotide repeat microsatellite DNA from Fangzheng silver crucian carp(Carassius auratus gibelio(Bloch)) combining the traditional radioisotope hybridization.As a result,652 positive clones were sequenced after the second selection.800 microsatellite sequences were isolated from these positive clones.There were 542(67.75%) perfect motifs,140(17.50%) imperfect motifs and 118(14.75%) compound in these sequences.163 pairs of primers from these microsatellite sequences were designed with the online software primer3plus and 76 pairs of primers were synthesized among them.Results showed that 58 pairs were successful to amplify special fragments,among which 30 pairs were polymorphism in the wild crucian carp population.The number of alleles ranged from 3～8,and the PIC ranged from 0.4066～0.8023.80% loci which PIC were greater than 0.5 were in high polymorphic.The results shows that the microsatellite library of Fangzheng silver crucian carp is a library of high quality and makes a contribution to construct linkage map and analyze the genomic structure.