Genetic Diversity Analysis Of Three Mudskipper Populations In Hainan Island

In this study,mitochondrial molecular markers（COⅠ gene and D-loop region）and S7 markers were used to analyze genetic diversity,genetic structure,and demographic history among nine populations of three mudskipper common species（Periophthalmus modestus,Boleophthalmus pectinirostris,Periophthalmus magnuspinnatus）.Samples were collected from nine localities（Haikou,Wenchang,Chengmai,Lingao,Danzhou,Changjiang Li Autonomous County,Dongfang,Ledong Li Autonomous County,Sanya）.The results are as follows:1.Analysis of three mudskipper species based on the COⅠ of mt DNAIn the present study,the haplotype diversity of the overall P.modestus population was 0.861;the nucleotide diversity was 0.00439.The haplotype diversity of the overall B.pectinirostris population was 0.598;the nucleotide diversity was 0.00153.The haplotype diversity of the overall P.magnuspinnatus population was 0.598;the nucleotide diversity was 0.00153.Among the three mudskipper species,P.modestus possessed the highest genetic diversity,B.pectinirostris possessed the lowest genetic diversity.The F_st of P.mode stus show that genetic differentiation among SY and LG,DF populations were moderate difference.AMOVA analysis indicated that genetic divergence was mainly distributed within populations.The overall population of P.modestus in Hainan Island did not have significant genetic differentiation.A high rate of gene flow between different populations.The F_st of B.pectinirostris from-0.02789 to0.00479.AMOVA analysis indicated that genetic divergence was mainly distributed within populations,the overall population of B.pectinirostris in Hainan Island did not have significant genetic differentiation.there is no significant differentiation within east and west stock.A high rate of gene flow between different populations.Both mismatch distribution analysis and neutrality tests indicate some local groups of P.modestus and B.pectinirostris and northeastern,western stock of B.pectinirostris in Hainan Island have experienced expansion.2.Analysis of three mudskipper species based on the D-loop of mt DNAIn this study,the haplotype diversity of overall P.modestus population was0.9989;the nucleotide diversity was 0.01968.The haplotype diversity of the overall B.pectinirostris population was 0.964;the nucleotide diversity was 0.00926.The haplotype diversity of the overall P.magnuspinnatus population was 0.971;the nucleotide diversity was 0.01515.Among the three mudskipper species,P.modestus possessed the highest genetic diversity,B.pectinirostris possessed the lowest genetic diversity.Analyses of P.modestus AMOVA suggested that genetic variation was attributed to variability within populations.A high rate of gene flow between different populations.The neighbor-joining tree and haplotype network revealed the existence of two lineages,AMOVA suggested that genetic differentiation among lineages A and lineages B were represented extremely difference.The F_st of B.pectinirostris shows that genetic differentiation among WC and DF populations were a high difference.Analyses of B.pectinirostris AMOVA suggested that genetic variation was attributed to variability within populations.The overall population of B.pectinirostris in Hainan Island has moderate genetic differentiation.There is certain degree of differentiation in the northeastern and western populations.Lineages B of P.modestus and WC of B.pectinirostris in Hainan Island have experienced expansion.3.Analysis of three mudskipper species based on the S7 nuclear genesIn the present study,the haplotype diversity of overall P.modestus population was 0.956;the nucleotide diversity was 0.01376.The haplotype diversity of the overall B.pectinirostris population was 0.900;the nucleotide diversity was 0.00195.The haplotype diversity of the overall P.magnuspinnatus population was 0.846;the nucleotide diversity was 0.00204.Among the three mudskipper species,P.modestus possessed the highest genetic diversity,B.pectinirostris possessed the lowest genetic diversity.F_st of P.modestus shows that genetic differentiation among LG and some populations was difference;genetic differentiation among SY and some populations was difference.Analyses of P.modestus AMOVA suggested that genetic variation was attributed to variability within populations.The overall population of P.modestus in Hainan Island have moderate genetic differentiation.The neighbor-joining tree and haplotype network revealed the existence of two lineages,AMOVA suggested that genetic differentiation among lineages A and lineages B was represented extremelydifference.Both mismatch distribution analysis and neutrality tests indicated lineages A and lineages B of P.modestus in Hainan Island have experienced expansion.It was suggested that the preservation of the three mudskippers population genetic diversity should be timely intensified.B.pectinirostris population was recommended to be protected in priority.