【摘要】 E.eurystomus的无性分裂过程是以大核发生改组为起点的.“3”字形大核的两个末端几乎同时发生“改组带”(reorganization band),并向中间移动,直至相互融合、凝缩,最后经无丝分裂分开成两个仔大核.在大核进行改组不久,小核也开始变化.它首先离开原位朝大核中心位置移动,在移动过程中,原来小核里的结构由致密逐渐变得松散,并不易着色,而且体积膨大并由圆形变成椭圆形,随后出现着色深的线条状结构(染色体),逐渐分开趋向两极,最后分裂成两个仔小核.细胞质在无性分裂周期中明显的变化是不断地增加体积,在大核融合凝缩期间,细胞质的体积逐渐达到最大,以后出现分裂沟收缢,直至分裂成两个仔虫.此外,E.eurystomus在无性分裂过程中,其大核会出现生理意义不明,但可能是培养条件变化而引起的第二次改组现象.更多还原

【Abstract】 The process of asexual division in E.eurystomus begins at the reorganization of its macronucleus.The two "reorganization band" that appear at both ends of "3" shaped macronucleus are highly synchronized.Soon after the beginning of macronuclear reorganization, its micronucleus also begins to develop, and two filial micronuclei are formed at last through mitosis. The most obvious change of cytoplasm during asexual division is to increas its volume continuously.It has its maximum volume when two reorganization band fused and its macronucleus condensed.Besides, sometimes a second reorganizational process may be observed.Its physiological significance is not yet clear, may be that is caused by certain changes in culturing conditions.更多还原