Examination of exhaustive cloning attempts reveals that C. elegans piRNAs, transposons, and repeat sequences are efficiently cloned in yeast, but not in bacteria.
Examination of exhaustive cloning attempts reveals that C. elegans piRNAs, transposons, and repeat sequences are efficiently cloned in yeast, but not in bacteria.
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DOI：
10.3389/fgene.2014.00275
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发表时间：
2014
影响因子：
3.7
通讯作者：
Rechavi O
中科院分区：
文献类型：
--
作者：
Sagy O;Shamir R;Rechavi O
基因组测序需要将测序生物体DNA的随机片段插入单细胞宿主，最常见的是大肠杆菌。这种操作在过去被发现类似于自然发生的水平基因转移，而且已经被证明对理解外源遗传因子对E.杆菌秀丽隐杆线虫基因组的测序同样通过DNA转化到E.杆菌然而，大量的尝试已经证明，尽管通过酵母是可克隆的，但是使用细菌的基因组的显著百分比是不可克隆的。我们检查了在细菌中不可克隆但在酵母中可克隆的基因组片段，并观察到，与先前的假设一致，与整个C.线虫基因组此外，我们发现这些缺口序列编码的DNA转座子显着更多。令人惊讶的是，我们发现，虽然绝大多数的C。秀丽隐杆线虫基因组在细菌中是可克隆的（77.5%），几乎所有编码PIWI相互作用小RNA或21 U-RNA（91.6%）的数千个序列都只能在酵母中克隆。这些结果可能有助于理解为什么C.线虫在IV号染色体上的特定位点上物理地聚集。在蠕虫和大量其他生物体中，piRNA用于区分“自体”序列和“非自体”序列，从而保护基因组的完整性免受外来遗传元件（如转座子）的影响。我们讨论了这些发现的可能影响。
Genome sequencing requires insertion of random fragments of the sequenced organism’s DNA into a unicellular host, most often Escherichia coli bacteria. This manipulation was found in the past to be analogous to naturally occurring horizontal gene transfer, and moreover has proved valuable to understanding toxicity of foreign genetic elements to E. coli. Sequencing of the Caenorhabditis elegans genome was similarly achieved via DNA transformation into E. coli. However, numerous attempts have proven a significant percentage of the genome unclonable using bacteria, although clonable via yeast. We examined the genomic segments that were not clonable in bacteria but were clonable in yeast, and observed that, in line with previous hypotheses, such sequences are more repetitive on average compared with the entire C. elegans genome. In addition, we found that these gap-sequences encode significantly more for DNA transposons. Surprisingly, we discovered that although the vast majority of the C. elegans genome is clonable in bacteria (77.5%), almost all the thousands of sequences that encode for PIWI-interacting small RNAs, or 21U-RNAs (91.6%) were only clonable in yeast. These results might help understanding why most piRNAs in C. elegans are physically clustered on particular loci on chromosome IV. In worms and in a large number of other organisms, piRNAs serve to distinguish “Self” from “Non-Self” sequences, and thus to protect the integrity of the genome against foreign genetic elements, such as transposons. We discuss the possible implications of these discoveries.
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影响因子：
64.8
作者：
Mello, CC;Conte, D
通讯作者：
Conte, D
影响因子：
56.9
作者：
Sorek, Rotem;Zhu, Yiwen;Rubin, Edward M.
通讯作者：
Rubin, Edward M.
DOI：
10.1098/rspb.2014.0848
发表时间：
2014-08-22
影响因子：
4.7
作者：
Bruto, Maxime;Prigent-Combaret, Claire;Muller, Daniel
通讯作者：
Muller, Daniel
影响因子：
4
作者：
COULSON, A;KOZONO, Y;WATERSTON, R
通讯作者：
WATERSTON, R
影响因子：
16
作者：
Sberro, Hila;Leavitt, Azita;Kiro, Ruth;Koh, Eugene;Peleg, Yoav;Qimron, Udi;Sorek, Rotem
通讯作者：
Sorek, Rotem