Fig. 1.

Schematic representation of the experimental setup. siRNAs direct site-specific cleavage of mRNAs, resulting in a 5′ and 3′ mRNA cleavage fragments. After RNA isolation total RNA samples consist of uncleaved mRNA transcripts and non-coding RNA, as well as undegraded 5′ and 3′ mRNA cleavage fragments. Purification of mRNA using poly-T beads excludes 5′ mRNA cleavage fragments and non-coding RNAs that are not polyadenylated. As indicated by the boxes, 5′ and 3′ primer sets could detect different species of RNA depending on the isolation method