Kobayashi Mayumi, Miura Mamiko, Takusagawa Mari, Sugiura Mayumi, Harumoto Terue
1 Graduate School of Natural Science and Ecological Awareness, Nara Women's University, Kitauoya-nishi-machi, Nara 630-8506, Japan.
Zoolog Sci. 2015 Jan;32(1):53-61. doi: 10.2108/zs140151.
We investigated mating pair formation between three Blepharisma species Blepharisma undulans, Blepharisma japonicum, and Blepharisma stoltei to determine whether their respective gamones (mating pheromones) effectively induce mating pairs between different species. Cell-free fluid from type II cells (CFF2) of B. undulans (megakaryotype II) induced pairing of B. japonicum and B. stoltei type I cells (megakaryotype IV), and CFF2 of B. japonicum and B. stoltei induced pairing of B. undulans type I cells. Cell-free fluid from B. undulans type I cells (CFF1) did not induce pairing of B. japonicum and B. stoltei type II cells, and CFF1 of B. japonicum and B. stoltei failed to induce pairing of B. undulans. CFF1 from B. japonicum and B. stoltei mutually induced pairing, as previously reported. These results indicate that gamone 2 is common among megakaryotypes II and IV, and that gamone 1 appears to be at least megakaryotype-specific. When cells belonging to megakaryotypes II and IV are separately pre-treated with effective gamones and mixed, mating pairs between megakaryotypes rarely form. Taken together, these results suggest at least two barriers, a gamone and a factor involved in pair formation, that prevent conjugation between different megakaryotypes of Blepharisma.
我们研究了三种草履虫属物种——波动双小核草履虫（Blepharisma undulans）、日本双小核草履虫（Blepharisma japonicum）和斯托尔双小核草履虫（Blepharisma stoltei）之间的配对形成，以确定它们各自的配子信息素（交配信息素）是否能有效诱导不同物种间形成配对。波动双小核草履虫（巨核型II）II型细胞的无细胞液（CFF2）诱导了日本双小核草履虫和斯托尔双小核草履虫I型细胞（巨核型IV）的配对，而日本双小核草履虫和斯托尔双小核草履虫的CFF2诱导了波动双小核草履虫I型细胞的配对。波动双小核草履虫I型细胞的无细胞液（CFF1）未诱导日本双小核草履虫和斯托尔双小核草履虫II型细胞的配对，日本双小核草履虫和斯托尔双小核草履虫的CFF1也未能诱导波动双小核草履虫的配对。如先前报道，日本双小核草履虫和斯托尔双小核草履虫的CFF1相互诱导配对。这些结果表明，配子信息素2在巨核型II和IV中是共同的，而配子信息素1似乎至少具有巨核型特异性。当属于巨核型II和IV的细胞分别用有效的配子信息素预处理后混合时，巨核型之间很少形成配对。综上所述，这些结果表明至少存在两种障碍，一种是配子信息素，另一种是参与配对形成的因子，它们阻止了草履虫不同巨核型之间的接合。
