Saiga H, Edström J E
EMBO J. 1985 Mar;4(3):799-804. doi: 10.1002/j.1460-2075.1985.tb03700.x.
A cloned 340-bp DNA fragment excised by EcoRI from the Chironomus pallividittatus genome has been localized to the telomeres by in situ hybridization as well as to connectives between telomeres. No hybridization was observed in other regions of the chromosomes. Another cloned EcoRI fragment, 525 bp long has also been studied. This represents a partial duplication of the 340-bp sequence. Genomic blot hybridization experiments show that the 340-bp sequence is a representative monomeric unit of tandemly repeated arrays which account for 1.2% of the Chironomus genome, on average 300 kb per telomere. The repeat unit contains two types of subrepeats each present twice per repeat unit. Northern blot hybridization experiments show that the telomere-associated sequences are transcribed into a discrete RNA species approximately 20 kb in size. The evolution of this telomere-associated DNA is discussed.
从苍白摇蚊基因组中用EcoRI酶切出的一个340碱基对的克隆DNA片段,已通过原位杂交定位到端粒以及端粒之间的连接区。在染色体的其他区域未观察到杂交现象。另一个克隆的EcoRI片段,长度为525碱基对,也已进行研究。这代表了340碱基对序列的部分重复。基因组印迹杂交实验表明,340碱基对序列是串联重复阵列的代表性单体单元,其占苍白摇蚊基因组的1.2%,平均每个端粒约300千碱基对。重复单元包含两种类型的亚重复序列,每个重复单元中各出现两次。Northern印迹杂交实验表明,端粒相关序列转录成一种大小约为20千碱基对的离散RNA物种。本文讨论了这种端粒相关DNA的进化。