Microsatellite And D-LOOP Sequence Analysis Of 5 Species Of Lutjanus In South China Sea

Fish of genus Lutjanus Bloch, which are primarily inhabitants of shallow coral reefs, are distributed throughout thotropical and subtropical oceans worldwide. Some species of snappers are important fishery resource and have been cultured in South China Sea.In order to study genetic information of snappers, microsatellite technique and D-loop sequence analysis were used to detect the genetic diversity in protospecies and cultured populations of Lutjanus erythopterus and Lutjanus argentimaculatus from Sanya waters; cultured populations of Lutjanus sebae,protospecies populations of Lutjanus bengalensis and Lutjanus kasmira from Zhanjiang and Sanya waters.With the methods of polymerase chain reaction and polyacrylamide gelelectrophoresis, the population genetic structures of 10 populations of 5 species of snappers (L.erythopterus, L.argentimaculatus, L.sebae, L.bengalensis and L. kasmira)were revealed based on the microsatellite primers screened from Lutjanus campechanus and Lutjanus russellii. 13 pairs of primers could be amplified successfully with genome DNA of L.sebae; 12 pairs of primers could be amplified successfully with genome DNA of L.argentimaculatus and L.bengalensis; 10 pairs with L.erythopterus and L. kasmira .The amplified products of genomic DNA by microsatellite markers indicated that mean polymorphism information content (PIC) and mean expected heterozygosity(He) ranged from 0.3854~0.5660 and 0.4843~0.6141 respectively. All of these showed that the genetic diversity of 10 populations snappers was at high level, except cultured populations of L.sebae.Mitochondrial D-loop complete gene segment of 84 individuals were amplified with PCR technique and sequenced. There were 78 haplotypes of all 84 individuals. The haplotype diversity, nucleotide diversity and average number of nucleotide differences of six populations were 0.8930~1.0000, 0.0035~0.0229 and 3.0560~19.8570 separately. The result of D-loop sequence analysis and SSR were similar. The genetic differentiation between wild and cultured populations of L.argentimaculatus was 0.1900 which showed there was high differentiation. And the genetic differentiation between Zhanjiang and Sanya cultured populations of L.sebae was 0.0050 which showed there was low differentiation.