skip to primary navigationskip to content

03.02.21 New insights into biogenesis of PIWI-interacting RNAs

last modified Feb 09, 2021 05:18 PM
Berkyurek at al. in the Miska lab show how the piRNA pathway co-opts the ancient machinery of RNA polymerase II for both biogenesis and gene silencing activity
03.02.21 New insights into biogenesis of PIWI-interacting RNAs

Fig. 2 (excerpt): transgene expression in wild type and mutant worms

The RNA polymerase II subunit RPB‐9 recruits the integrator complex to terminate Caenorhabditis elegans piRNA transcription

Berkyurek AC et al. (2021) EMBO J  e105565. DOI: 10.15252/embj.2020105565.





The piRNA pathway regulates germ cell development and promotes fertility in animals. The finding that RNA Polymerase II subunit RPB‐9 recruits the Integrator complex to terminate transcription at piRNA genes in C. elegans provides new insight into the mechanisms of piRNA biogenesis.

  • rpb‐9 is required for the generation of mature piRNAs and the initiation of piRNA‐mediated silencing.
  • rpb‐9 is required to repress two DNA transposon families and a subset of somatic genes in the germline.
  • RPB‐9 recruits the Integrator complex at motif‐dependent piRNA loci to terminate transcription of piRNA precursors.



PIWI‐interacting RNAs (piRNAs) are genome‐encoded small RNAs that regulate germ cell development and maintain germline integrity in many animals. Mature piRNAs engage Piwi Argonaute proteins to silence complementary transcripts, including transposable elements and endogenous genes. piRNA biogenesis mechanisms are diverse and remain poorly understood.

Here, we identify the RNA polymerase II (RNA Pol II) core subunit RPB‐9 as required for piRNA‐mediated silencing in the nematode Caenorhabditis elegans. We show that rpb‐9 initiates heritable piRNA‐mediated gene silencing at two DNA transposon families and at a subset of somatic genes in the germline. We provide genetic and biochemical evidence that RPB‐9 is required for piRNA biogenesis by recruiting the Integrator complex at piRNA genes, hence promoting transcriptional termination.

We conclude that, as a part of its rapid evolution, the piRNA pathway has co‐opted an ancient machinery for high‐fidelity transcription.


Read more about research in the Miska lab.

Watch Eric Miska describe his research on YouTube.

Institute reopening

The Gurdon Institute reopened on Monday 15th June. Many staff will continue to work from home, and all staff may be contacted by email.

Studying development to understand disease

The Gurdon Institute is funded by Wellcome and Cancer Research UK to study the biology of development, and how normal growth and maintenance go wrong in cancer and other diseases.

combinedLogo x3 trans2018


Share this