piRNA-guided transposon cleavage initiates Zucchini-dependent, phased piRNA production.PIWI-interacting RNAs (piRNAs) protect the animal germ line by silencing transposons. 
piRNA-guided
piRNA-guided transposon cleavage initiates Zucchini-dependent, phased piRNA production.PIWI-interacting RNAs (piRNAs) protect the animal germ line by silencing transposons. 
Zucchini-dependent
The ping-pong pathway increases only the abundance of piRNAs, whereas production of phased primary piRNAs from cleaved transposon RNAs adds sequence diversity to the piRNA pool, allowing adaptation to changes in transposon sequence.
ping-pong pathway