No.271 研究課題 / Project
多摩川で回復したカジカ個体群の系統分類に関する研究Research concerning the systematic taxonomy of recovering cottus pollux populations in the Tama River| 学術研究 Academic Research |
No.271 |
|---|---|
| 代表研究者 Principal Investigator |
糸井 史朗 Shiro Itoi |
| 所属（採択当時） Affiliation |
日本大学 生物資源科学部 助手 Assistant at the College of Bioresource Science, Nihon University |
| 研究内容要約 Research Summary |
近年多摩川でカジカの個体数が回復しつつあるとされているが、これが人為的放流によるものか、在来個体群の増加によるのか明らかにすることを目的として研究を行った。まず、多摩川水系および日本各地の河川でカジカ試料を採取した。試料から全DNAを抽出し、ミトコンドリアDNAの調節領域を対象にDNA塩基配列分析後、集団遺伝学的解析を行った。その結果、一部例外はあるものの、水系間での遺伝的分化には有意差が認められ、各地で在来個体群が維持されている可能性が示唆された。また、多摩川の個体群についても、特定のハプロタイプを核としてそれから派生する近縁のハプロタイプの個体群から構成されており、近年認められる個体数の増加は、在来個体群の増加によることが強く示唆された。さらに、本研究を進める中で、いわゆるカジカとよばれるものの中に3型が存在することが確認され、それらの分布域が明らかとなった。 In recent years, it has been stated that cottus pollux populations in the Tama River are recovering; this research was conducted with the aim of clarifying whether this was due to release by humans or resulted from increases in indigenous populations. Firstly, we collected cottus pollux samples from the Tama River system and from rivers across Japan. We extracted the complete DNA of the samples and, after conducting DNA base sequence analysis of the regulatory region of mitochondrial DNA, we conducted a population genetics analysis. As a result, while there were some exceptions, it was observed that there were significant differences in the genetic differentiation between water systems, suggesting the possibility that indigenous populations were being maintained in each area. Moreover, the populations in the Tama River consisted of populations with a nucleus with a specific haplotype and populations derived from this with a closely related haplotype, which strongly suggested that the increase in populations observed in recent years was due to an increase in indigenous populations. Furthermore, in the course of this research, it was ascertained that there were three types among the creatures that could be called cottus pollux, and the distribution areas of these were clarified. |
| 共同研究者 Collaborators |
齊藤高志、鷲尾明佳（日本大学生物資源科学部 大学院生） Takashi Saitoh, Asuka Washio (Graduate Students, College of Bioresource Sciences, Nihon University) |
| 研究全文 Full Text |
全文をダウンロード Download (Japanese Only) |