似织毛虫的小核体功能的研究

Studies on the Somatic Function of the Micronucleus in Histriculus similes

用四种浓度的 Cis-platin(顺式二胺二氯铂)处理似织毛虫的 G1期细胞,共建立无小核细胞系7个。所有被处理的细胞都要经历一个生长抑制期,其无小核的得率与 Cis-platin 的浓度有着密切的关系。活体观察表明,所有失去小核的细胞体积变小,活动能力减慢。蛋白银染色观察显示,无小核细胞口围带变短,约30%的细胞的口围带小膜数比对照组减少,约70%的细胞其大核形态和数目异常。结果说明:似织毛虫的小核对于保持其正常的大核数目和形态结构以及口围带结构的正常大小起着明显的作用。

To study on the sgerentocratic omatic function of the micronucleus of the ciliated protozoan Histriculus similes,all amicromucleates were generated with Cis-dichlorodiam- mineplatinum(Ⅱ)(cis.platin),a DNA cross linking agent,which exert differential ef- fects on the micro-and macronucleus of Histriculus similes For the reason that micronuclei in the G1 phase are more sensitive to cis.platin than those in the S phase,all treated normal cells are divided into synchronized G1 cells and asynchronous cells.All treated cells under- went a suppression phase as recovery process,which indicating that Histriculus similes also possesses the necessary enzyme system for the excision repair of cis.platin bound DNA ad- ducts.Compared amicronucleate cell lines,a reserved microncleate cell line after having been treafed with cis.platin and normal cell lines,the numbers of membranes of adoral zone of membranelles(AZM)of amicronucleates and length of AZM reduce,at the same time,the number and the size of macronuclei in all amicronucleates become unstable。About 70%(93/ 171)of cells in the amicronucleate cell lines possessed abnormal macronuclei in number and/ or in shape:there were over two oval macronuclei instead two round ones;the macronuclei often exhibited various irregular appearances,such as rod-like,bud-like,contorted,and otherwise which suggest that micronucleus of play an essential role in retaining the stability of number and conformation of macronucleus as well as integrality of structure of AZM. When Compared with other five species of amicronucleates from Hypotrichida,it can be con- cluded that exhibition of somatic function of micronucleus relates to its taxonomic status.