棘尾虫接合生殖期间大核功能的研究  

MACRONUCLEAR FUNCTIONS DURING CONJUGATION IN STYLONYCHIA MYTILUS

作　　者：卢丽 史新柏 

机构地区：[1]哈尔滨师范大学生物学系

出　　处：《动物学报》1991年第4期408-421,共14页ACTA ZOOLOGICA SINICA

基　　金：国家自然科学基金

摘　　要：为了澄清棘尾虫接合期间大核对小核发育和皮层形态发生的作用,完成了大核摘除,放线菌素D处理,H^3-尿嘧啶核苷标记等实验。摘核实验证明,一个接合体的大核可以通过细胞质桥支持另一除去大核的接合体发育。即使保留接合对大核总数的1/8,这种支持作用仍然存在。还发现来自大核的支持物作用于形态发生更易于作用于小核发育,并对两个接合体的形态发生作用相等,对两个接合体小核发育的作用不等。摘除四分之三大核的实验证明,小核发育和皮层更新在接合后15小时内都不能脱离对残留大核的依赖。放线菌素D处理实验证明,接合后RNA的合成需积累到8.5小时,才可满足核与皮层发育的需要。H^3-尿嘧啶核苷标记实验也支持接合后前9小时内RNA都在持续合成的结论。本文对摘核实验和放线菌素D处理实验结果的差别、以及本文结果与前人结果的差别都做了讨论。To clarify the role of the macronucleus (Ma) in micronuclear development and cortical morphogenesis during conjugation in Stylonychia mytilus,.we performed experiments involving the removal of the Ma, treatment with actinomycin D (AmD), and labeling with ~3Huridine. We found that the Ma of one conjugant could support, through the cytoplasmic bridge, the development of the other conjugant whose Ma was completely removed. This support was possible even if the remaining Ma-fragment was only one-fourth of the total of the macronucleate conjugant. We also found that the supporting substances from the macronucleus acted more readily on morphogenesis than on micronuclear development, and that the effect of the substances on morphogenesis was equivalent in both conjugants but that on micronuclear development was not. An onehr exposure to AmD was not sufficient to inhibit micronuclear development or cortical morphogenesis. Treatments of 2—3 hr from the 2nd to the 6th hour of conjugation prevented cortical morphogenesis but not micronuclear development. Exposure to AmD during the first 4 or more hours, or a 5-hr exposure from the 6th-11th hr. after the start of conjugation, inhibited both micronuclear and cortical development. Long exposures to AmD beginning at the nineth hour or later failed to inhibit any conjugation events. Labelling with ~3H-uridine followed by autoradiography indicated continuous synthesis of RNA during this period. It seems that during the first nine hours of conjugation the macronucleus continuously synthesizes mRNA required for micronuclear development and morphogenesis. The fact that the macronuclear support required for micronuclear development and for cortical morphogenesis are different suggests that either the necessary substances or the mechanisms of action are different.

关 键 词：棘尾虫 接合生殖 大核 功能 

分 类 号：Q959.116[生物学—动物学]