Development Of Microsatellite Markers And Analysis Of Genetic Diversity Between Female And Male Group In Fenneropenaeus Penicillatus

Fenneropenaeus penicillatus was one of the most important commercial marine shrimps in the East and South China Seas in the last century.There were too much difference in appearance,size and growth rate between female and male individuals of Fenneropenaeus penicillatus,but the analysis and comparison of genetic diversity between the female and male group in Fenneropenaeus penicillatus have not been reported yet.In this study,we developed microsatellite markers through FIASCO method,then analysed and compared the genetic diversity between the female and male group of Fenneropenaeus penicillatus through microsatellite markers and AFLP.The results were as follows:The enriched genomic library was constructed through FIASCO method.581 colonies ranging between 400-1200 bp in size were sequenced,509 positive colonies which contained microsatellite loci fulfilled the requirements,then 209 pairs of primers were designed.44 pairs of polymorphic and 11 pairs of monomorphic primers were successfully selected by amplifying the genomic DNA of 30 wild individuals captured in Ningde,China.Of the 44 polymorphic loci,the number of alleles per locus ranged from 3 to 7,with an average of 4.39.The polymorphism information content ranged from 0.121 to 0.794,with a mean of 0.5023.The observed heterozygosities ranged from 0.0000 to 1.0000,with a mean of 0.3865.The expected heterozygosities ranged from 0.1111 to 0.8129,with a mean of 0.4926.20 pairs of microsatellite primers were used for analysis and comparision of the genetic diversity between the female and male group in Fenneropenaeus penicillatus.The average number of alleles per locus of female and male group were 4.25 and 4.55,respectively.The average observed heterozygosities of female and male group were 0.3335 and 0.3611.The average expected heterozygosities of female and male group were 0.5291 and 0.5407.The average polymorphism information content of female and male group were 0.5532 and 0.5575.It showed that the genetic diversity of female and male group was not very high,and there was not so much difference in genetic diversity between female and male group.The genetic distance and genetic identity between female and male group were 0.2358 and 0.7899,respectively.Between female and male group,the F_itt value,F_iss value and F_stt value were 0.3944,0.3343 and 0.0903,respectively.The result showed that medium degree of genetic differentiation was observed between female and male group.We found 24 alleles that only observed in female group,30 alleles that only observed in male group.We also found that the ratio of 8 alleles frequence between female and male group was higher than 5.Using 10 pairs of selective amplification primer,we analysed and compared the genetic diversity and genetic structure between female and male group of Fenneropenaeus penicillatus.Of the female and male group,558 and 546 loci were observed,the average percentage of polymorphic loci were 65.38%and 63.62%,the average number of alleles per locus were 1.6538and 1.6362,the average effective number of alleles per locus were 1.1961 and 1.1891,the Nei's gene diversity were 0.1264 and 0.1225,the Shannon's information index were 0.2074 and 0.2013.It showed that the genetic diversity of male and female group was not very high,and there was not so much difference in genetic diversity between male and female group.The conclusion was the same as the conclusion using the microsatellite makers.The genetic distance and genetic identity between female and male group were 0.0141 and 0.9860,respectively.Between female and male group,the H_t value,H_s value and G_stt value were 0.1317,0.1245 and 0.0544,respectively.The result showed that medium degree of genetic differentiation was observed between female and male group.The conclusion was the same as the conclusion using the microsatellite makers.We found78 loci that only observed in female group,65 loci that only observed in male group.We also found that the ratio of 49 loci frequence between female and male group was higher than 3,the ratio of 9 loci frequence was higher than 6.Above all,for the female and male group of Fenneropenaeus penicillatus that captured in Dongshan,the genetic diversity was not very high,there was not so much difference in genetic diversity between them,medium degree of genetic differentiation was observed between them.