Diversity analysis of mtDNA in the four species of snappers(Lutjanus)
4种笛鲷的线粒体DNA多样性分析

We used mtDNA-RFLP technique to analyse the genetic diversity of 4 species of snappers,Lutjanus erythopterus,Lutjanus argentimaculatus,Lutjanus russelli and Lutjanu johni.The mitochondrial DNAs(mtDNAs) from livers of these fishes were isolated by means of differential centrifugation and nuclease digestion followed by phenol extraction.The mtDNAs were digested by 19 varieties of restriction enzymes(((5 or 6)) base pairs): BamH I,Bgl I,Bgl II,EcoR I,EcoR V,Hind III,Hinf I,Hpa I,Kpn I,Mlu I,Pst I,Pvu II,Sal I,Sca I,Sma I,Sty I,Xba I and Xho I,analysed by using agarose gel electrophoresis and detected by Gel-Pro Analyzer.Restriction enzyme maps revealed that 4 kinds of haplotypes exsited in L.erythopterus,3 in L.russelli,6 in L.argentimaculatus and 5 in L.johni.We also discussed the mechanism of this phenomenon based on restriction sites variant,calculated the nucleotide diversity of inter-species genetic distance.The polymorphic degrees of mtDNAs from above four snappers were 0.002 9,0.005 5,0.001 2 and(0.002 0) respectively.