Skip to main content
. 2017 Jan;23(1):86–97. doi: 10.1261/rna.058875.116

FIGURE 8.

FIGURE 8.

Proof-of-concept evidence for the piRNA “ping-pong” amplification cascade. (A) Artificial piRNA production triggered from the “ping” cascade. Exogenous pre-piRNA-I mRNA is cleaved by the endogenous Fem piRNA–Siwi complex. The resulting 3′ pre-piRNA-I mRNA fragment is loaded into BmAgo3, thus producing the piRNA-I–BmAgo3 complex. The piRNA-I–BmAgo3 complex cleaves the endogenous silkworm Importin-5 mRNA. The 3′ fragment of the cleaved Importin-5 mRNA is loaded into another PIWI protein Siwi, thus producing the piRNA-J–Siwi complex. (B) Artificial piRNA production triggered from the “pong” cascade. Exogenous pre-piRNA-A mRNA is recognized and cleaved by the endogenous Masc piRNA–BmAgo3 complex. The resulting 3′ pre-piRNA-A mRNA fragment is loaded into Siwi, thus producing the piRNA-A–Siwi complex. The piRNA-A–Siwi complex recognizes and cleaves the endogenous silkworm Actin A3 mRNA. The 3′ fragment of the cleaved Actin A3 mRNA is loaded into another PIWI protein BmAgo3, thus producing the piRNA-B–BmAgo3 complex.