Zygotic amplification of secondary piRNAs during silkworm embryogenesis

作者：Kawaoka Shinpei; Arai Yuji; Kadota Koji; Suzuki Yutaka; Hara Kahori; Sugano Sumio; Shimizu Kentaro; Tomari Yukihide; Shimada Toru; Katsuma Susumu^*

来源：RNA-A Publication of the RNA Society, 2011, 17(7): 1401-1407.

DOI：10.1261/rna.2709411

• silkworm
• piRNA
• transposon
• ping-pong cycle

PIWI-interacting RNAs (piRNAs) are 23-30-nucleotide-long small RNAs that act as sequence-specific silencers of transposable elements in animal gonads. In flies, genetics and deep sequencing data have led to a hypothesis for piRNA biogenesis called the ping-pong cycle, where antisense primary piRNAs initiate an amplification loop to generate sense secondary piRNAs. However, to date, the process of the ping-pong cycle has never been monitored at work. Here, by large-scale profiling of piRNAs from silkworm ovary and embryos of different developmental stages, we demonstrate that maternally inherited antisense-biased piRNAs trigger acute amplification of secondary sense piRNA production in zygotes, at a time coinciding with zygotic transcription of sense transposon mRNAs. These results provide on-site evidence for the ping-pong cycle.

• 出版日期2011-7