【摘要】 对上海四膜虫 (Tetrahymenashanghaiensis)有小核细胞和无小核细胞的接合过程进行了跟踪观察 ,发现在四膜虫中也存在胞质配合 (cytogamy)。在接合对中 ,有小核细胞一方可以完成正常的减数分裂过程 ,既有配子核的形成、配子核的融合、配子核分裂 ,最终形成两个有小核的子细胞。虽然有小核细胞的配子核并不进入无小核细胞 ,但是两细胞间却有细胞质的迁移与交换。在整个接合过程中 ,无小核细胞的大核始终没有发生可观察到的形态学变化 ,它最终分裂成的二个子细胞仍为无小核细胞。这种接合对的出现可能与自接型有关 ,其有性过程可能是一种原始的有性生殖类型。更多还原

【Abstract】 We induced the conjugation of Tetrahymena shanghaiensis cells by starvation. Mixed the normal and amicronucleate clones on the ratio of 1∶2, the number of conjugation pairs got its peak after starved 22 hours. We observed mainly the conjugation process between normal and amicronucleate cells. There were conjugation membrane appeared between the cells in conjugation pair. Pieces of conjugation membrane may break off, bend and drop to the cytoplasm. So there were cytoplasm and organelles exchange between the normal and amicronucleate cell. In the conjugation pair, the normal cell can finish the normal meiosis process, the gametic nuclei fused, the zygotic nucleus divided and at last formed two cells with micronucleus. Though the gametic nucleus of normal cell didn’t enter the amicronucleate cell, there were cytoplasm and organelle exchanges between two cells. There was no observable morphological change in the macronucleus of the amicronucleate cell during the whole conjugation. The two cells that produced by the amicronucleate cell were still without micronucleus. The formation of such a conjugation pair may be concerned with selfing; the sexual process may be a primitive type of sexual reproduction.更多还原