This is my seminar at 2006/11/28
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Science 21 July 2006:Vol. 313. no. 5785, pp. 320 - 324
A Distinct Small RNA Pathway Silences Selfish Genetic Elements in the Germline
Vasily V. Vagin,
Abstract:
RNA silencing mechanism in eukaryotic cells, such as small interfering RNAs (siRNAs) and microRNAs (miRNAs), which is thought to defend against viruses, regulate gene expression, and protect the genome against selfish genetic elements like retrotransposons and repetitive sequences. Recently, a third type of small RNAs, repeat-associated interfering RNAs (rasiRNAs) have been identified, and be distinct from miRNAs and siRNAs by their longer length, 24 to 29 nt. However, the mechanism of rasiRNAs is not clear. The authors indicated that the rasiRNAs are generated mainly from antisense strand, whereas siRNAs are derived from both sense and antisense strand of their double-strand RNA precursors. In flies, Dicer-1 generates miRNAs and Dicer-2 generates siRNAs, but rasiRNAs have been proposed to be diced from long dsRNA by Dicer-1 or Dicer-2 independent pathway. The simplest interpretation of these data is that rasiRNAs physically associate with Piwi subfamily (Piwi and Aub). Unlike siRNA and miRNA, rasiRNAs lake the
