Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Piwi maintains germline stem cells and oogenesis in Drosophila through negative regulation of Polycomb group proteins

Abstract

The Drosophila melanogaster Piwi protein regulates both niche and intrinsic mechanisms to maintain germline stem cells, but its underlying mechanism remains unclear. Here we report that Piwi interacts with Polycomb group complexes PRC1 and PRC2 in niche and germline cells to regulate ovarian germline stem cells and oogenesis. Piwi physically interacts with the PRC2 subunits Su(z)12 and Esc in the ovary and in vitro. Chromatin coimmunoprecipitation of Piwi, the PRC2 enzymatic subunit E(z), histone H3 trimethylated at lysine 27 (H3K27me3) and RNA polymerase II in wild-type and piwi mutant ovaries demonstrates that Piwi binds a conserved DNA motif at 72 genomic sites and inhibits PRC2 binding to many non-Piwi-binding genomic targets and H3K27 trimethylation. Moreover, Piwi influences RNA polymerase II activities in Drosophila ovaries, likely via inhibiting PRC2. We hypothesize that Piwi negatively regulates PRC2 binding by sequestering PRC2 in the nucleoplasm, thus reducing PRC2 binding to many targets and influencing transcription during oogenesis.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: piwi, corto and PcG genes genetically interact to regulate germline stem cells in Drosophila.
Figure 2: Piwi binds to Corto and PRC2 in ovarian extract.
Figure 3: Piwi binds to PRC2 in vitro but does not affect its histone methyltransferase activity.
Figure 4: Genome-wide Piwi binding patterns and Piwi EMSA.
Figure 5: Piwi inhibits PRC2 binding to chromatin and PRC2-mediated H3K27 trimethylation.
Figure 6: RNA Pol II binding analyses in wild-type and mutant ovaries.

Similar content being viewed by others

Accession codes

Primary accessions

Sequence Read Archive

References

  1. Deng, W. & Lin, H. Asymmetric germ cell division and oocyte determination during Drosophila oogenesis. Int. Rev. Cytol. 203, 93–138 (2001).

    Article  CAS  PubMed  Google Scholar 

  2. Cox, D.N. et al. A novel class of evolutionarily conserved genes defined by piwi are essential for stem cell self-renewal. Genes Dev. 12, 3715–3727 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Lin, H. & Spradling, A.C. A novel group of pumilio mutations affects the asymmetric division of germline stem cells in the Drosophila ovary. Development 124, 2463–2476 (1997).

    CAS  PubMed  Google Scholar 

  4. Smulders-Srinivasan, T.K. & Lin, H. Screens for piwi suppressors in Drosophila identify dosage-dependent regulators of germline stem cell division. Genetics 165, 1971–1991 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  5. Smulders-Srinivasan, T., Szakmary, A. & Lin, H.A. Drosophila chromatin factor interacts with the piRNA mechanism in niche cells to regulate germline stem cell self-renewal. Genetics 186, 573–583 (2010).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Kodjabachian, L. et al. Mutations in ccf, a novel Drosophila gene encoding a chromosomal factor, affect progression through mitosis and interact with Pc-G mutations. EMBO J. 17, 1063–1075 (1998).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Lopez, A., Higuet, D., Rosset, R., Deutsch, J. & Peronnet, F. corto genetically interacts with Pc-G and trx-G genes and maintains the anterior boundary of Ultrabithorax expression in Drosophila larvae. Mol. Genet. Genomics 266, 572–583 (2001).

    Article  CAS  PubMed  Google Scholar 

  8. Salvaing, J., Lopez, A., Boivin, A., Deutsch, J.S. & Peronnet, F. The Drosophila Corto protein interacts with Polycomb-group proteins and the GAGA factor. Nucleic Acids Res. 31, 2873–2882 (2003).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Grimaud, C. et al. RNAi components are required for nuclear clustering of Polycomb group response elements. Cell 124, 957–971 (2006).

    Article  CAS  PubMed  Google Scholar 

  10. Pal-Bhadra, M., Bhadra, U. & Birchler, J.A. Cosuppression in Drosophila: gene silencing of Alcohol dehydrogenase by white-Adh transgenes is Polycomb dependent. Cell 90, 479–490 (1997).

    Article  CAS  PubMed  Google Scholar 

  11. Pal-Bhadra, M., Bhadra, U. & Birchler, J.A. RNAi related mechanisms affect both transcriptional and posttranscriptional transgene silencing in Drosophila. Mol. Cell 9, 315–327 (2002).

    Article  CAS  PubMed  Google Scholar 

  12. Schuettengruber, B., Chourrout, D., Vervoort, M., Leblanc, B. & Cavalli, G. Genome regulation by polycomb and trithorax proteins. Cell 128, 735–745 (2007).

    Article  CAS  PubMed  Google Scholar 

  13. Simon, J.A. & Kingston, R.E. Mechanisms of Polycomb gene silencing: knowns and unknowns. Nat. Rev. Mol. Cell Biol. 10, 697–708 (2009).

    Article  CAS  PubMed  Google Scholar 

  14. Czermin, B. et al. Drosophila enhancer of Zeste/ESC complexes have a histone H3 methyltransferase activity that marks chromosomal Polycomb sites. Cell 111, 185–196 (2002).

    Article  CAS  PubMed  Google Scholar 

  15. Kuzmichev, A., Nishioka, K., Erdjument-Bromage, H., Tempst, P. & Reinberg, D. Histone methyltransferase activity associated with a human multiprotein complex containing the Enhancer of Zeste protein. Genes Dev. 16, 2893–2905 (2002).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Müller, J. et al. Histone methyltransferase activity of a Drosophila Polycomb group repressor complex. Cell 111, 197–208 (2002).

    Article  PubMed  Google Scholar 

  17. Cao, R. et al. Role of histone H3 lysine 27 methylation in Polycomb-group silencing. Science 298, 1039–1043 (2002).

    Article  CAS  PubMed  Google Scholar 

  18. Holdeman, R., Nehrt, S. & Strome, S. MES-2, a maternal protein essential for viability of the germline in Caenorhabditis elegans, is homologous to a Drosophila Polycomb group protein. Development 125, 2457–2467 (1998).

    CAS  PubMed  Google Scholar 

  19. Korf, I., Fan, Y. & Strome, S. The Polycomb group in Caenorhabditis elegans and maternal control of germline development. Development 125, 2469–2478 (1998).

    CAS  PubMed  Google Scholar 

  20. Eun, S.H., Shi, Z., Cui, K., Zhao, K. & Chen, X. A non–cell autonomous role of E(z) to prevent germ cells from turning on a somatic cell marker. Science 343, 1513–1516 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Iovino, N., Ciabrelli, F. & Cavalli, G. PRC2 controls Drosophila oocyte cell fate by repressing cell cycle genes. Dev. Cell 26, 431–439 (2013).

    Article  CAS  PubMed  Google Scholar 

  22. Peng, J.C. et al. Jarid2/Jumonji coordinates control of PRC2 enzymatic activity and target gene occupancy in pluripotent cells. Cell 139, 1290–1302 (2009).

    Article  PubMed  PubMed Central  Google Scholar 

  23. Shen, X. et al. Jumonji modulates polycomb activity and self-renewal versus differentiation of stem cells. Cell 139, 1303–1314 (2009).

    Article  PubMed  PubMed Central  Google Scholar 

  24. Ho, L. et al. esBAF facilitates pluripotency by conditioning the genome for LIF/STAT3 signalling and by regulating polycomb function. Nat. Cell Biol. 13, 903–913 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  25. Aravin, A.A., Hannon, G.J. & Brennecke, J. The Piwi-piRNA pathway provides an adaptive defense in the transposon arms race. Science 318, 761–764 (2007).

    Article  CAS  PubMed  Google Scholar 

  26. Thomson, T. & Lin, H. The biogenesis and function of PIWI proteins and piRNAs: progress and prospect. Annu. Rev. Cell Dev. Biol. 25, 355–376 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Brennecke, J. et al. Discrete small RNA-generating loci as master regulators of transposon activity in Drosophila. Cell 128, 1089–1103 (2007).

    Article  CAS  PubMed  Google Scholar 

  28. Wang, J., Saxe, J.P., Tanaka, T., Chuma, S. & Lin, H. Mili interacts with Tudor domain–containing protein 1 in regulating spermatogenesis. Curr. Biol. 19, 640–644 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Chen, C. et al. Mouse Piwi interactome identifies binding mechanism of Tdrkh Tudor domain to arginine methylated Miwi. Proc. Natl. Acad. Sci. USA 106, 20336–20341 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Vagin, V.V. et al. Proteomic analysis of murine Piwi proteins reveals a role for arginine methylation in specifying interaction with Tudor family members. Genes Dev. 23, 1749–1762 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Liu, L., Qi, H., Wang, J. & Lin, H. PAPI, a novel TUDOR-domain protein, complexes with AGO3, ME31B and TRAL in the nuage to silence transposition. Development 138, 1863–1873 (2011).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Margueron, R. et al. Role of the polycomb protein EED in the propagation of repressive histone marks. Nature 461, 762–767 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Lin, H. et al. Reassessment of Piwi binding to the genome and Piwi impact on RNA polymerase II distribution. Dev. Cell 32, 772–774 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  34. Huang, X.A. et al. A major epigenetic programming mechanism guided by piRNAs. Dev. Cell 24, 502–516 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. Yin, H. & Lin, H. An epigenetic activation role of Piwi and a Piwi-associated piRNA in Drosophila melanogaster. Nature 450, 304–308 (2007).

    Article  CAS  PubMed  Google Scholar 

  36. Valouev, A. et al. Genome-wide analysis of transcription factor binding sites based on ChIP-Seq data. Nat. Methods 5, 829–834 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Mi, H., Muruganujan, A. & Thomas, P.D. PANTHER in 2013: modeling the evolution of gene function, and other gene attributes, in the context of phylogenetic trees. Nucleic Acids Res. 41, D377–D386 (2013).

    Article  CAS  PubMed  Google Scholar 

  38. Brower-Toland, B. et al. Drosophila PIWI associates with chromatin and interacts directly with HP1a. Genes Dev. 21, 2300–2311 (2007).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Lin, H. & Yin, H. A novel epigenetic mechanism in Drosophila somatic cells mediated by Piwi and piRNAs. Cold Spring Harb. Symp. Quant. Biol. 73, 273–281 (2008).

    Article  CAS  PubMed  Google Scholar 

  40. Cox, D.N., Chao, A. & Lin, H. piwi encodes a nucleoplasmic factor whose activity modulates the number and division rate of germline stem cells. Development 127, 503–514 (2000).

    CAS  PubMed  Google Scholar 

  41. Yan, D. et al. A regulatory network of Drosophila germline stem cell self-renewal. Dev. Cell 28, 459–473 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Marinov, G.K. et al. Pitfalls of mapping high-throughput sequencing data to repetitive sequences: Piwi's genomic targets still not identified. Dev. Cell 32, 765–771 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Billi, A.C. et al. A conserved upstream motif orchestrates autonomous, germline-enriched expression of Caenorhabditis elegans piRNAs. PLoS Genet. 9, e1003392 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Sytnikova, Y.A., Rahman, R., Chirn, G.W., Clark, J.P. & Lau, N.C. Transposable element dynamics and PIWI regulation impacts lncRNA and gene expression diversity in Drosophila ovarian cell cultures. Genome Res. 24, 1977–1990 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Watanabe, T., Cheng, E.C., Zhong, M. & Lin, H. Retrotransposons and pseudogenes regulate mRNAs and lncRNAs via the piRNA pathway in the germline. Genome Res. 25, 368–380 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  46. Boyer, L.A. et al. Core transcriptional regulatory circuitry in human embryonic stem cells. Cell 122, 947–956 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Bailey, T.L. & Elkan, C. Fitting a mixture model by expectation maximization to discover motifs in biopolymers. Proc. Int. Conf. Intell. Syst. Mol. Biol. 2, 28–36 (1994).

    CAS  PubMed  Google Scholar 

  48. Grant, C.E., Bailey, T.L. & Noble, W.S. FIMO: scanning for occurrences of a given motif. Bioinformatics 27, 1017–1018 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  49. Krzywinski, M. et al. Circos: an information aesthetic for comparative genomics. Genome Res. 19, 1639–1645 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank R. Jones (Southern Methodist University) for the E(z)63 fly stock, F. Peronnet (Institut de Biologie, Paris) for the corto420 fly stock, V. Pirotta (Rutgers University) for the antibody to Pc, H. Siomi (Keio University) for the antibody to Piwi, D. Godt (University of Toronto) for the antibody to Tj, and A. Fire and members of the Lin laboratory for assistance and discussions. We also thank H. Qi and J. Klein for experimental help, M. Reddivari for the isolation of recombinant PRC2 complex, Z. Albertyn and C. Hercus for help with Novoalign, and N. Neuenkirchen and X. Cui for critical reading. This work was supported by a US National Institutes of Health Pioneer Award (DP1CA174418) and the Mathers Award to H.L. and by a US National Institutes of Health grant (R00-HD071011) to J.C.P.

Author information

Authors and Affiliations

Authors

Contributions

J.C.P. and H.L. designed the project, analyzed the data and wrote the manuscript. J.C.P. conducted all of the experiments except for those listed in the Acknowledgments. A.V. produced all bioinformatics results in the paper and participated in manuscript writing. N.L. performed the initial bioinformatics analysis that helped guide the project.

Corresponding authors

Correspondence to Jamy C Peng or Haifan Lin.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–9 and Supplementary Tables 1–6. (PDF 4232 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Peng, J., Valouev, A., Liu, N. et al. Piwi maintains germline stem cells and oogenesis in Drosophila through negative regulation of Polycomb group proteins. Nat Genet 48, 283–291 (2016). https://doi.org/10.1038/ng.3486

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ng.3486

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing