【摘要】 本文采用外周血培养、胸苷同步化细胞、Brdu连续标记和胸苷末端标记法研究了家猪染色体复制的过程。根据家猪染色体复制带型的不同,将复制过程分为5个不同的时期,提出了各个时期的判别标准,并绘制了复制过程模式图。在同步化的细胞群中研究了Brdu掺陶入时间和不同复制期出现频率的关系。发现了家猪端着红粒染色体和双臂染色体C带异染色质区的不同步复制现象。本文还对端着丝粒染色体微小短臂的结构、失活X色体复制起始位点多态性、常染色体中某些晚复制区的不同步复制现象进行了研究。更多还原

【Abstract】 Cultured peripheral blood lymphocytes of the domestic pig are synchronized by thymidine.By means of BrdU continuous labeling and thymidine terminal labeling,the sequence of chromosome replication is studied.Like other mammals,the chromosome of pig replicates its DNA following the principle of R banded priority.The replication process can be divided into five stages according to the variant replication patterns.The criteria of identifying these stages are suggested and the model of replication is presented.The relationship between the amount of BrdU incorporation and the proportion of different replication stages in the synchronized call population is dealt with.The regions of C banded heterochromatin have their own characters in the replication behaviour.The result of thymidine terminal labelling shows a replication asynchronism between C banded heterochromatin of biarmed chromosomes and lhat of acrocen-tric chromosomes.The C banded areas of acrocentric chromosome start DNA replication half an hour later than those of biarmed chromosomes.In this paper,the structure of micro-short arms is studied.The stained colouration tendency of micro-short arms which is different from other portion of chromosome does not depend on the amount of BrdU incorporation.This strongly suggests that micro-short arms have a very special organization.There are some varieties in the starting point of DNA replication of late-replicating X chromosome.The asynchronism of replication also exists in some late replication regions between homologous chromosomes.The differences can be found only by the short term of thymidine pulse labeling.更多还原