Identification of microsatellite DNA primers in mud carp Cirrhinus molitorella and applicability detection

A group of wild mud carp samples collected from Xijiang River was amplified by PCR using 14 pairs of microsatellite primers isolated from four species of Cyprinidae. The bands were cloned and then sequenced. The products of primer pairs MFW1, MFW2, MFW15, MFW17, Cc7, Cc11 and Bgon22 contained microsatellite sequences. The primers for loci MFW1, MFW2, and Cc7 were redesigned and named as Cm1, Cm2 and Cm3, respectively. The new primers gave more specific amplification in mud carp. The applicability of primer pairs Cm1, Cm2, Cm3, Cc7, MFW15, MFW17 and Bgon22 on wild mud carp samples from Xijiang River was explored, and the genetic diversity of the wild samples was analyzed. The results showed that the detected numbers of alleles within the samples for each primer pair ranged from 2 to 16. Except for the primer pairs MFW15,Cc11, the amplified profiles of the other five (Cm1, Cm2, Cm3, MFW17 and Bgon22) showed high polymorphism.The range of observed heterozygosities and expected heterozygosities were from 0 to 1 (Ho) and 0 to 0.9038（He） with an average of 0.7772（SD=0.1931）and 0.6881（SD=0.1819）, respectively.Significant (P＜0.05）linkage disequilibrium(LD) exhibited in the sample only between locus Cm1 and Bgon22. The average genetic diversity of the samples was 0.6823, showing the level of polymorphism within the samples was high relatively. This study showed that the seven primer pairs of microsatellite locis screened were suitable for genetic diversity analysis of mud carp.