著者

小山 直人 北川 忠生

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.56, no.2, pp.153-157, 2009 (Released:2014-03-05)

参考文献数

12

被引用文献数

1

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In order to examine genetic introgression from the orange-red type commercial strain of Oryzias latipes (himedaka) to wild medaka populations, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome b gene was conducted for 45 populations from the Yamato River system, Nara Prefecture and two fish farm populations from special product grounds of himedaka (Yamatokoriyama and Yatomi Cities). Orange-red type fish only were collected from three sites, and a mixture of wild and orange-red types from sympatric populations at four other sites in theYamato R. system. Most orange-red type specimens had the B27 mitotype, being identical with that of the typical orange-red type Hd-rR strain. Although most of the wild type fish individuals had mitotype B1a, inferred as one of the native mitotypes in the Yamato R., four from three sites had mitotype B27, implying genetic introgression from himedaka to wild medaka populations.

著者

小山 直人

出版者

公益社団法人 日本数学教育学会

雑誌

日本数学教育学会誌 (ISSN:0021471X)

巻号頁・発行日

vol.94, no.3, pp.9, 2012 (Released:2021-04-01)

著者

石井 文子 安齋 有紀子 伊藤 玲香 小山 直人 北川 忠生

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.58, no.1, pp.65-74, 2011 (Released:2014-03-07)

参考文献数

19

被引用文献数

1

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The Yoshino diversion (Yoshino Bunsui) was established to supply irrigation water from the Yoshino River to the Yamato plain. In order to examine fish introductions through the canals of the Yoshino Bunsui, the genetic structure of 17 populations of dark chub Zacco temminckii collected from the Yamato and Yoshino rivers were analyzed and their mtDNA ND2 sequences studied. A total of 16 haplotypes were detected in 261 individuals, 6 haplotypes being present in both rivers. In the Yamato River, the shared haplotypes were found to be associated with the locations of inflows from the Yoshino Bunsui. On the other hand, the majority of haplotypes found in individuals from the Yamato River were not found in those from the Yoshino River. This study confirmed the secondary introduction of dark chub from the Yoshino River into the Yamato River via the Yoshino Bunsui.

著者

小山 直人 森 幹大 中井 宏施 北川 忠生

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.58, no.1, pp.81-86, 2011

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Genetic disturbance in wild populations of Medaka (Oryzias latipes) has resulted from the introduction of populations originating from commercial strains. To clarify the genetic composition of orange-red type and wild type commercial strains of O. latipes ('himedaka' and 'kuromedaka', respectively), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing analyses of the mitochondrial cytochrome b gene were conducted for Medaka populations cultured in 2 fish farms and others purchased from 21 aquarium fish shops. All 'himedaka' populations showed a high frequency of the B27 mitotype, an original mitotype of 'himedaka', and a low frequency of the B1a mitotype, an introduced mitotype from wild populations in Okayama or Nara Prefectures. 'Kuromedaka' populations, originating from cultured populations, were characterized primarily by the B27 and B1a mitotypes, being a result of hybridization between wild populations and 'himedaka'. All 'kuromedaka' populations originating from wild populations had their own native mitotypes, although some also had the B1a mitotype, which was inferred as being of 'himedaka' origin.