Kazuya Nishida

Development and characterization of 23 polymorphic microsatellite markers for Sympetrum frequens

Twenty-three polymorphic microsatellite markers for Sympetrum frequens were developed and characterized. The number of distinct alleles per locus in 32 individuals ranged from 2 to 23. The observed heterozygosity ranged from 0.031 to 0.938, while the expected heterozygosity varied from 0.031 to 0.922. No loci deviated significantly from Hardy–Weinberg equilibrium, no linkage disequilibrium was observed between pairs of loci and no loci showed evidence of null alleles. These microsatellite markers are expected to contribute to future investigations of genetic variation and structure in S. frequens populations.

Influence of the domestic alien fish Rhynchocypris oxycephalus invasion on the distribution of the closely related native fish R. lagowskii in the Tama River Basin, Japan

In Japan, domestic freshwater fish are accidentally introduced into non-native freshwater habitats by human activity, such as the planting of fish. Introduction of the domestic alien fish may have a detrimental effect on native fish inhabitants. However, investigations on the distribution and establishment of such domestic alien fish in non-native river basins and their influence on native fish remains limited. Therefore, we investigated the distribution and establishment of the domestic alien fish Rhynchocypris oxycephalus and its influence on native fish in the Tama River Basin, Japan. Specifically, we used mitochondrial DNA and morphological analyses to clarify the influence of the invasion of this species on the distribution of the closely related fish R. lagowskii, which is native to the river basin. Fish sampled from the upstream section of the main river were mostly R. oxycephalus. This indicates that R. oxycephalus has replaced R. lagowskii in the upstream region. Fish sampled from the downstream section of the main river were mostly R. lagowskii. R. oxycephalus was also captured from agricultural canals linked to the Tama River, and in streams connected to the river via the canals. These observations indicate that the agricultural canal water networks facilitate the invasion of R. oxycephalus to peripheral habitats, such as canals and streams. In contrast, R. lagowskii was found in streams that flowed into the upstream section of the Tama River, with these streams having many large drop structures, indicating that drop structures prevent R. oxycephalus from invading aquatic habitats in these streams.

Thirty-two polymorphic microsatellite loci of the mysid crustacean Mesopodopsis tenuipes

Thirty-two polymorphic microsatellite loci were indentified and characterized from the mysid Crustacea Mesopodopsis tenuipes Hanamura et al., 2008. The number of observed alleles per locus in 32 individuals collected from its type locality in Malaysia ranged from 2 to 22. The observed heterozygosity ranged from 0.031 to 0.906, while the expected heterozygosity varied from 0.031 to 0.943. All loci conformed to Hardy–Weinberg equilibrium, no linkage disequilibrium was observed between pairs of loci and no loci showed evidence of null alleles. These 32 microsatellite loci could be used in future population genetics study of M. tenuipes.

Development of 18 novel polymorphic microsatellite markers for the mysid crustacean Mesopodopsis orientalis

We have developed microsatellite DNA markers for Mesopodopsisorientalis (Tattersall 1908), a widely distributed mysid crustacean in shallow waters of the coastal and estuarine systems across India to Indonesia and the Philippines. A total of 18 novel polymorphic microsatellite markers were identified in 32 individuals from a sandy beach at Teluk Kumbar in Penang Island, Malaysia. The number of alleles per locus ranged from 3 to 17. The observed and expected heterozygosities varied from 0.031–1.000 to 0.092–0.938, respectively. These polymorphic markers could be available for future investigations of genetic diversity and structure of M.orientalis populations.

Development and characterization of microsatellite loci for Rhinogobius sp. YB (Gobiidae)

Rhinogobius sp. YB (Gobiidae) distributed in the Ryukyu Archipelago is a fluvial species of gobies. We present 34 novel microsatellite loci that were tested on 32 individuals from the Okierabu-jima Island in Kagoshima Prefecture. Seventeen loci were polymorphic, while the remaining 17 were monomorphic. The number of alleles per the polymorphic loci ranged from 2 to 15. The observed heterozygosities ranged from 0.038 to 1.000 and the expected heterozygosities varied from 0.038 to 0.816. These microsatellite loci will enhance future investigations on the genetic differentiation and structure of populations of R. sp. YB.

Development of nineteen novel polymorphic microsatellite loci of Clupeichthys aesarnensis

We developed and characterized a total of 19 novel polymorphic microsatellite loci from the genome of Clupeichthys aesarnensis. Flanking PCR primers were developed and used to show that all loci were polymorphic with the number of observed alleles per locus in 30 individuals ranging from two to 15. The observed heterozygosity ranged from 0.033 to 0.933, while the expected heterozygosity varied from 0.033 to 0.898. All loci conformed to the Hardy–Weinberg equilibrium, none of the loci combinations showed significant linkage disequilibrium, and no loci showed evidence of null alleles. These 19 microsatellite loci can be useful for conducting future investigations into the genetic differentiation and structure of populations of C. aesarnensis.

Characterization of twenty-four polymorphic microsatellite loci of Rasbora borapetensis

Twenty-four microsatellite loci were isolated and characterized from the genome of Rasbora borapetensis. Flanking polymerase chain reaction primers were designed and used to amplify these loci in 32 individuals. All loci were polymorphic with allele numbers ranging from 2 to 27, observed heterozygosity from 0.031 to 1.000 and expected heterozygosity from 0.031 to 0.965. All loci conformed to the Hardy–Weinberg equilibrium and no evidence of null alleles was observed. Pairwise comparisons between alleles did not detect any linkage disequilibrium. The high level of polymorphisms observed in these microsatellite loci will enhance future investigations on the genetic differentiation and structure of populations of Rasbora borapetensis.

Isolation and characterization of 40 polymorphic microsatellite markers from Parambassis siamensis

We isolated and characterized a total of 40 polymorphic microsatellite loci from the genome of Parambassis siamensis. Flanking Polymerase Chain Reaction primers were developed and used to show that all loci were polymorphic with the number of observed alleles per locus in 32 individuals ranging from 2 to 29. The observed heterozygosity ranged from 0.063 to 0.969, while the expected heterozygosity varied from 0.062 to 0.960. All loci conformed to Hardy–Weinberg equilibrium, none of the loci combinations showed significant linkage disequilibrium, and no loci showed evidence of null alleles. These 40 microsatellite loci should be useful for conducting future investigations into the genetic differentiation and structure of populations of P. siamensis.

Development and characterization of 29 polymorphic microsatellite loci for Esomusmetallicus

Twenty-nine microsatellite loci were isolated and characterized from the genome of Esomus metallicus. Flanking polymerase chain reaction primers were designed and used to amplify these loci in 32 individuals. All loci were polymorphic; with allele numbers ranged from 2 to 27, observed heterozygosity from 0.031 to 0.969 and expected heterozygosity from 0.031 to 0.957. All conformed to Hardy–Weinberg equilibrium and no evidence of null alleles was observed. Pairwise comparisons between alleles did not detect any cases of linkage disequilibrium. The high level of polymorphisms observed in these microsatellite loci should enhance future investigation of the genetic differentiation and structure of populations of E. metallicus.

Isolation and characterization of 21 polymorphic microsatellite loci in the Japanese dace (Tribolodon hakonensis)

Twenty one polymorphic microsatellite loci for the Japanese dace (Tribolodon hakonensis) were isolated and characterized. The number of observed alleles per locus in 32 individuals ranged from 3 to 30. The observed and expected heterozygosities ranged from 0.125 to 0.969 and from 0.175 to 0.973, respectively. All loci conformed to Hardy–Weinberg equilibrium, no linkage disequilibrium was observed between pairs of loci and no loci showed evidence of null alleles. These microsatellite loci will be useful for investigating the intraspecific genetic variation and population structure of this species.