Visa N, Díez J L, Santa-Cruz M C
Departament de Biologia Cellular i Fisiologia, Facultat de Ciències, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Biol Cell. 1991;73(1):71-8. doi: 10.1016/0248-4900(91)90011-b.
Autoradiographic and immunofluorescent techniques have been used to analyse the relationship between puffing, transcription and occurrence of DNA/RNA hybrids in D melanogaster salivary gland chromosome 2L. Experiments of 3H-uridine incorporation have indicated that similar rates of RNA synthesis are observable in well developed puffs as well as in some diffuse bands and interbands. On the other hand, puffs of similar size incorporate 3H-uridine at quite different rates. The presence of RNA polymerase II seems to follow a coincident pattern with that of 3H-uridine incorporation. Our results indicate that the rate of transcription does not determine either the formation of a puff or its potential size. Instead, we have found a positive correlation between the amount of DNA/RNA hybrids and puff size, independently of the transcription rates. Transient accumulation of transcribed RNAs in their chromosomal compartment could therefore play a relevant role in the determination of puff size.
利用放射自显影和免疫荧光技术分析了黑腹果蝇唾液腺2L染色体上的胀泡、转录以及DNA/RNA杂交体出现之间的关系。3H-尿苷掺入实验表明，在发育良好的胀泡以及一些弥散带和间带中可观察到相似的RNA合成速率。另一方面，大小相似的胀泡以截然不同的速率掺入3H-尿苷。RNA聚合酶II的存在似乎与3H-尿苷掺入的模式一致。我们的结果表明，转录速率既不决定胀泡的形成，也不决定其潜在大小。相反，我们发现DNA/RNA杂交体的量与胀泡大小之间存在正相关，与转录速率无关。因此，转录的RNA在其染色体区域的瞬时积累可能在胀泡大小的决定中发挥相关作用。
