Morcillo G, Barettino D, Carmona M J, Carretero M T, Díez J L
Centro de Investigaciones Biológicas (C.S.I.C.)., Madrid, Spain.
Chromosoma. 1988;96(2):139-44. doi: 10.1007/BF00331046.
The patterns of puffing, transcription and protein synthesis under heat shock were analysed in polytene nuclei of Chironomus thummi piger, in comparison with those obtained in the closely related subspecies C. th. thummi. Most chromosomal heat shock puffs, as well as heat shock induced polypeptides, in C. th. piger paralleled those previously reported for C. th. thummi. Nevertheless, we found a striking difference in behaviour in the induction of telomeric Balbiani rings by heat shock in the two subspecies. Although homologous sequences were present at all the telomeres in both subspecies, they were not always transcriptionally activated by heat shock. The most frequently puffed telomeres were that of chromosome III R in C. th. thummi and that of chromosome IV R in piger. Transcription of the same sequences from both telomeric Balbiani rings (T-BR-III and T-BR-IV) occurred under heat shock. The enigmatic behaviour of telomeres and the functional significance of T-BRs are discussed in relation to possible equivalents in other Diptera.
在热休克条件下，对拟瑞典摇蚊（Chironomus thummi piger）多线核中的 puffing、转录和蛋白质合成模式进行了分析，并与亲缘关系相近的亚种瑞典摇蚊（C. th. thummi）进行了比较。拟瑞典摇蚊中大多数染色体热休克 puff 以及热休克诱导的多肽与先前报道的瑞典摇蚊中的情况相似。然而，我们发现这两个亚种在热休克诱导端粒巴尔比亚尼环方面的行为存在显著差异。尽管两个亚种的所有端粒都存在同源序列，但它们并不总是在热休克下被转录激活。最常出现 puffing 的端粒在瑞典摇蚊中是 III R 染色体的端粒，在拟瑞典摇蚊中是 IV R 染色体的端粒。来自两个端粒巴尔比亚尼环（T - BR - III 和 T - BR - IV）的相同序列在热休克下会发生转录。本文结合其他双翅目昆虫中可能的等效情况，讨论了端粒的神秘行为以及端粒巴尔比亚尼环的功能意义。
