PIWI proteins and PIWI-interacting RNAs function in Hydra somatic stem cells

• DOI: 10.1073/pnas.1320965111
• Publication Date: 2013-12-24T04:28:01Z
• Authors: Celina E. Juliano; Adrian Reich; Na Liu; Jessica Götzfried; Mei Zhong; Selen Uman; Robert A. Reenan; Gary M. Wessel; Robert E. Steele; Haifan Lin
• Keywords: Piwi-interacting RNA; Lernaean Hydra; RasiRNA; Argonaute

PIWI proteins and their bound PIWI-interacting RNAs (piRNAs) are found in animal germlines essential for fertility, but functions outside of the gonad not well understood. The cnidarian Hydra is a simple metazoan with well-characterized stem/progenitor cells that provides unique model analysis function. Here we report has two proteins, (Hywi) PIWI-like (Hyli), both which expressed all cells, terminally differentiated cells. We identified ∼15 million piRNAs associated Hywi and/or Hyli they exhibit ping-pong signature piRNA biogenesis. strictly cytoplasmic thus likely act as posttranscriptional regulators. To explore this function, generated transcriptome mapping. map to transposons 25- 35-fold enrichment compared abundance transposon transcripts. By sequencing small specific interstitial, ectodermal, endodermal lineages, targeting appears be largely restricted interstitial lineage. also putative nontransposon targets pathway each Finally demonstrate hywi function somatic epithelial lineages. This comprehensive PIWI-piRNA nonbilaterian suggests originated broader stem cell functionality.