Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Originally published in Science Express on 10 April 2008
Science 23 May 2008:
Vol. 320. no. 5879, pp. 1077 - 1081
DOI: 10.1126/science.1157396
Prev | Table of Contents | Next

Reports

Endogenous siRNAs Derived from Transposons and mRNAs in Drosophila Somatic Cells

Megha Ghildiyal,1* Hervé Seitz,1* Michael D. Horwich,1 Chengjian Li,1 Tingting Du,1 Soohyun Lee,2 Jia Xu,3 Ellen L.W. Kittler,4 Maria L. Zapp,4 Zhiping Weng,5 Phillip D. Zamore1{dagger}

Small interfering RNAs (siRNAs) direct RNA interference (RNAi) in eukaryotes. In flies, somatic cells produce siRNAs from exogenous double-stranded RNA (dsRNA) as a defense against viral infection. We identified endogenous siRNAs (endo-siRNAs), 21 nucleotides in length, that correspond to transposons and heterochromatic sequences in the somatic cells of Drosophila melanogaster. We also detected endo-siRNAs complementary to messenger RNAs (mRNAs); these siRNAs disproportionately mapped to the complementary regions of overlapping mRNAs predicted to form double-stranded RNA in vivo. Normal accumulation of somatic endo-siRNAs requires the siRNA-generating ribonuclease Dicer-2 and the RNAi effector protein Argonaute2 (Ago2). We propose that endo-siRNAs generated by the fly RNAi pathway silence selfish genetic elements in the soma, much as Piwi-interacting RNAs do in the germ line.

1 Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
2 Program in Bioinformatics, Boston University, Boston, MA 02215, USA.
3 Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
4 Program in Molecular Medicine and Center for AIDS Research, University of Massachusetts Medical School, Worcester, MA 01605, USA.
5 Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.

* These authors contributed equally to this work.

{dagger} To whom correspondence should be addressed. E-mail: phillip.zamore{at}umassmed.edu

Read the Full Text

ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)