Transposons, Tandem Repeats, and the Silencing of Imprinted Genes
This extract was created in the absence of an abstract.
Excerpt
Most eukaryotic cells cleave double-stranded RNA(dsRNA) into small 21–24-bp RNA fragments via theRNAse III helicase Dicer (Hannon 2002). These small interfering RNA (siRNA) are unwound and loaded onto thePAZ domain of Argonaute proteins, where they guide theRNAseH-related PIWI domain to cleave single-strandedRNA complementary to the small RNA (Song et al. 2003,2004; Liu et al. 2004). Cleavage sites can initiate secondstrand RNA synthesis via RNA-dependent RNA polymerase (RdRP) (Makeyev and Bamford 2002). Furtherprocessing of this dsRNA by Dicer leads to further (secondary) siRNA, which can reinitiate RdRP synthesis andthus amplify the cycle. RdRP can also incorporate siRNAdirectly into dsRNA by primer extension (Makeyev andBamford 2002)...
