Cell Reports (Oct 2024)

A comparative roadmap of PIWI-interacting RNAs across seven species reveals insights into de novo piRNA-precursor formation in mammals

  • Parthena Konstantinidou,
  • Zuzana Loubalova,
  • Franziska Ahrend,
  • Aleksandr Friman,
  • Miguel Vasconcelos Almeida,
  • Axel Poulet,
  • Filip Horvat,
  • Yuejun Wang,
  • Wolfgang Losert,
  • Hernan Lorenzi,
  • Petr Svoboda,
  • Eric A. Miska,
  • Josien C. van Wolfswinkel,
  • Astrid D. Haase

Journal volume & issue
Vol. 43, no. 10
p. 114777

Abstract

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Summary: PIWI-interacting RNAs (piRNAs) play a crucial role in safeguarding genome integrity by silencing mobile genetic elements. From flies to humans, piRNAs originate from long single-stranded precursors encoded by genomic piRNA clusters. How piRNA clusters form to adapt to genomic invaders and evolve to maintain protection remain key outstanding questions. Here, we generate a roadmap of piRNA clusters across seven species that highlights both similarities and variations. In mammals, we identify transcriptional readthrough as a mechanism to generate piRNAs from transposon insertions (piCs) downstream of genes (DoG). Together with the well-known stress-dependent DoG transcripts, our findings suggest a molecular mechanism for the formation of piRNA clusters in response to retroviral invasion. Finally, we identify a class of dynamic piRNA clusters in humans, underscoring unique features of human germ cell biology. Our results advance the understanding of conserved principles and species-specific variations in piRNA biology and provide tools for future studies.

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