TELOMERE CONVERSION IN TRYPANOSOMES
TELOMERE CONVERSION IN TRYPANOSOMES
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DOI：
10.1093/nar/11.23.8149
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发表时间：
1983-01-01
影响因子：
14.9
通讯作者：
BORST, P
中科院分区：
文献类型：
--
作者：
DELANGE, T;KOOTER, JM;BORST, P
布氏锥虫VSG 118基因的激活通过重复转座到端粒表达位点进行。产生的活性表达相关额外拷贝（ELC）通常两侧是缺乏大多数限制性内切酶位点的DNA，这被认为会干扰ELC作为重组DNA在大肠杆菌中的克隆。我们通过克隆一个异常的118 ELC基因来解决这个问题，该基因的3′端至少有1 kb的DNA，含有限制性酶切位点。我们的分析表明，该DNA和118 ELC基因的3′-末端来自另一个VSG基因（1.1006），该基因永久位于端粒位置。我们推测1.1006基因的3′端及其3′侧翼序列通过端粒转换而移动到表达位点。这种端粒转换也可以解释在我们的锥虫属菌株的亚群中检测到的1.1006基因的额外拷贝的出现。
Activation of the gene coding for variant surface glycoprotein (VSG) 118 inTrypanosoma bruceiproceeds via a duplicative transposition to a telomeric expression site. The resulting active expression-linked extra copy (ELC) is usually flanked by DNA that lacks sites for most restriction enzymes and that is thought to interfere with the cloning of the ELC as recombinant DNA inEscherichia coli. We have circumvented this problem by cloning an aberrant 118 ELC gene, flanked at the 3′-side by at least 1 kb DNA, that contains restriction enzyme sites. Our analysis shows that this DNA and the 3′-end of the 118 ELC gene are derived from another VSG gene (1.1006) that is permanently located at a telomeric position. We propose that the 3′-end of the 1.1006 gene and (all of) its 3′ flanking sequence moved to the expression site by a telomere conversion. Such a telomere conversion can also account for the appearance of an extra copy of the 1.1006 gene detected in a sub-population of our trypanosorae strain.