| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
Five species of the Euplotes (Ciliophora, Hypotrichida), E. woodruffi, E eury-stomus, E.aediculatus, E.patella and E.harpa, were collected in Hokkaido, Honsyu, Shikoku and Kyusyu District in Japan. As mate killer stocks have been found only in E.woodruffi syngen (sibling species) 3, the study for the mate killer was mainly carried out in E.woodruffi complex (syngen 1, syngen 2, syngen 3, autogamy group). When crosses were made between a killer strain and a sensi-tive one, nuclear changes in micro- and macronucleus progressed normally during conjugation, but one exconjugant of each pair swelled and then ruptured within two days after pair separation. In the cytoplasm of mate killers, no endosym-bionts like mu in Paramecium aurella have ever been observed, except for the common ornlicron, Polynucleobacter sp. Using two doublet mate-killer stocks of complementary mating types of E.woodruffi syngen 3, which were produced experimentally, were used as testers. Many stocks of this syngen were collected in Shimane (Uyagawa river), Nagasaki (Shirachi-ko lake) Kumamoto (Ezu-ko lake, Suizenji-ko lake), Kagoshima (Ikeda-ko lake, Unagi-ike lake, Satsuma-ko lake) and Okinawa Prefecture (ponds of Biosu-no-oka and Tonan-syokubutu-rakuen). Of 698 stocks isolated, 287 (41%) were mate killers, which were collected in Suizenji-ko lake and Eztl-ko lake and ponds of Biosu-no-oka and Tonan-syokubutu -rakuen. In the other four places, only sensitive stocks were found. When mate killer stocks from Ezu-ko lake mated with those from Tonan-syokubutu-rakuen pond, both mate killer stocks killed each other. The killer stocks from Ezu-ko lake and Tonan-syokubutu-rakuen pond might belong to the different kind of the mate killers. No mate killer stocks have been found in E.woodruffi syngen 2, syngen 3 and autogamy group.
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