SnapShot: Fly piRNAs, PIWI Proteins, and the Ping-Pong Cycle

SnapShot: Fly piRNAs, PIWI Proteins, and the Ping-Pong Cycle

SnapShot: Mouse piRNAs, PIWI Proteins, and the Ping-Pong Cycle

Biogenesis pathways of piRNAs loaded onto AGO3 in the Drosophila testis.

PIWI-interacting RNAs (piRNAs) silence transposable elements in animal germ cells. In Drosophila ovaries, piRNAs are produced by two distinct pathways: the "ping-pong" amplification cycle that operates in germ cells and a ping-pong-independent pathway termed the primary pathway that mainly operates in somatic cells. AGO3, one of three PIWI proteins in flies, is involved in the ping-pong cycle i...

Piwi Proteins and piRNAs step onto the systems biology stage.

Animal germ cells are totipotent because they maintain a highly unique and specialized epigenetic state for its genome. To accomplish this, germ cells express a rich repertoire of specialized RNA-binding protein complexes such as the Piwi proteins and Piwi-interacting RNAs (piRNAs): a germ-cell branch of the RNA interference (RNAi) phenomenon which includes microRNA and endogenous small interfe...

RNA Clamping by Vasa Assembles a piRNA Amplifier Complex on Transposon Transcripts

Germline-specific Piwi-interacting RNAs (piRNAs) protect animal genomes against transposons and are essential for fertility. piRNAs targeting active transposons are amplified by the ping-pong cycle, which couples Piwi endonucleolytic slicing of target RNAs to biogenesis of new piRNAs. Here, we describe the identification of a transient Amplifier complex that mediates biogenesis of secondary piR...