Lönn U
Chromosoma. 1981;81(5):641-53. doi: 10.1007/BF00329577.
The effect of the drug 5-fluorodeoxyuridine on DNA synthesis in Chironomus polytene chromosomes was investigated. The DNA was labelled by injection of radioactive precursor into living animals pre-treated with the drug, extracted with an neutral non-denaturing buffer at 25 degrees C and then characterized by gel electrophoresis. After a short pulse a heterogeneous double-stranded DNA population is released from the polytene chromosome. These fragments are later jointed together to produce a double-stranded DNA with a size ranging between 8-13 X 10(6) D. The release of both types of fragments from the polytene chromosome is prevented by lysing the cells at 0 degree C instead of at 25 degrees C. The larger double-stranded DNA has the size expected of replicons in Chironomus. The results are discussed in relation to the organization of replication in polytene chromosomes.
研究了药物5-氟脱氧尿苷对摇蚊多线染色体中DNA合成的影响。通过向预先用该药物处理的活体动物注射放射性前体来标记DNA，在25℃下用中性非变性缓冲液提取，然后通过凝胶电泳进行表征。短脉冲后，从多线染色体中释放出异质双链DNA群体。这些片段随后连接在一起，产生大小在8-13×10(6)D之间的双链DNA。通过在0℃而不是25℃下裂解细胞，可防止两种类型的片段从多线染色体中释放。较大的双链DNA具有摇蚊中复制子预期的大小。结合多线染色体中复制的组织对结果进行了讨论。
