Koussoulakos S, Anton H J
Zoological Institute, University of Cologne, Germany.
Tumour Biol. 1996;17(4):220-5. doi: 10.1159/000217983.
Working on the temporal structure of the S stage of regeneration blastema cells we have discovered that some blastema cells, containing a 3C quantity of DNA, do not incorporate radioactive thymidine, or that they proceed through the synthetic phase with a speed undetectable by a radioactive pulse. We report the identification of several short-term periods of quiescence for regeneration blastema cells in vivo, operating during the S stage of the cell cycle. Blastema cell smears from regenerating urodele forelimbs were used in this study. Combined microdensitometric scanning of Feulgen-stained nuclei and microradioautographic labelling of the same nuclei have been exploited to assess DNA replication. A total of 3,600 blastema cell nuclei were scanned, mapped on photographic film and subsequently processed for radioautography. It was found that 49.7% of the cells with a DNA content ranging between 2C and 4C were unlabelled after 1 h exposure to tritiated thymidine.
在研究再生芽基细胞S期的时间结构时，我们发现一些含有3C量DNA的芽基细胞不掺入放射性胸腺嘧啶核苷，或者它们以放射性脉冲无法检测到的速度进行合成期。我们报告了在体内再生芽基细胞在细胞周期S期运行期间的几个短期静止期的鉴定。本研究使用了来自再生有尾两栖类前肢的芽基细胞涂片。利用对福尔根染色细胞核的联合显微密度计扫描和对相同细胞核的微放射自显影标记来评估DNA复制。总共扫描了3600个芽基细胞核，将其映射在照相底片上，随后进行放射自显影处理。结果发现，在暴露于氚标记胸腺嘧啶核苷1小时后，DNA含量在2C至4C之间的细胞中有49.7%未被标记。
