Development Genes and Evolution

, Volume 218, Issue 9, pp 505–510

Larval RNAi in Drosophila?

  • Sherry C. Miller
  • Susan J. Brown
  • Yoshinori Tomoyasu
Short Communication

Abstract

RNA interference (RNAi) has become a common method of gene knockdown in many model systems. To trigger an RNAi response, double-stranded RNA (dsRNA) must enter the cell. In some organisms such as Caenorhabditis elegans, cells can take up dsRNA from the extracellular environment via a cellular uptake mechanism termed systemic RNAi. However, in the fruit fly Drosophila melanogaster, it is widely believed that cells are unable to take up dsRNA, although there is little published data to support this claim. In this study, we set out to determine whether this perception has a factual basis. We took advantage of traditional Gal4/upstream activation sequence (UAS) transgenic flies as well as the mosaic analysis with a repressible cell marker (MARCM) system to show that extracellular injection of dsRNA into Drosophila larvae cannot trigger RNAi in most Drosophila tissues (with the exception of hemocytes). Our results show that this is not due to a lack of RNAi machinery in these tissues as overexpression of dsRNA inside the cells using hairpin RNAs efficiently induces an RNAi response in the same tissues. These results suggest that, while most Drosophila tissues indeed lack the ability to uptake dsRNA from the surrounding environment, hemocytes can initiate RNAi in response to extracellular dsRNA. We also examined another insect, the red flour beetle Tribolium castaneum, which has been shown to exhibit a robust systemic RNAi response. We show that virtually all Tribolium tissues can respond to extracellular dsRNA, which is strikingly different from the situation in Drosophila. Our data provide specific information about the tissues amenable to RNAi in two different insects, which may help us understand the molecular basis of systemic RNAi.

Keywords

RNAi Systemic Tribolium castaneum (red flour beetle) Drosophila melanogaster (fruit fly) Injection 

References

  1. Brand AH, Perrimon N (1993) Targeted gene expression as a means of altering cell fates and generating dominant phenotypes. Development 118:401–15PubMedGoogle Scholar
  2. Bucher G, Scholten J, Klingler M (2002) Parental RNAi in Tribolium (Coleoptera). Curr Biol 12:R85–6PubMedCrossRefGoogle Scholar
  3. Dzitoyeva S, Dimitrijevic N, Manev H (2001) Intra-abdominal injection of double-stranded RNA into anesthetized adult Drosophila triggers RNA interference in the central nervous system. Mol Psychiatry 6:665–70PubMedCrossRefGoogle Scholar
  4. Fire A, Xu S, Montgomery MK, Kostas SA, Driver SE, Mello CC (1998) Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. Nature 391:806–11PubMedCrossRefGoogle Scholar
  5. Goto A, Blandin S, Royet J, Reichhart JM, Levashina EA (2003) Silencing of toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies. Nucleic Acids Res 31:6619–23PubMedCrossRefGoogle Scholar
  6. Lee T, Luo L (2001) Mosaic analysis with a repressible cell marker (MARCM) for Drosophila neural development. Trends Neurosci 24:251–4PubMedCrossRefGoogle Scholar
  7. May RC, Plasterk RH (2005) RNA interference spreading in C. elegans. Methods Enzymol 392:308–15PubMedCrossRefGoogle Scholar
  8. Petruk S, Sedkov Y, Riley KM, Hodgson J, Schweisguth F, Hirose S, Jaynes JB, Brock HW, Mazo A (2006) Transcription of bxd noncoding RNAs promoted by trithorax represses Ubx in cis by transcriptional interference. Cell 127:1209–21PubMedCrossRefGoogle Scholar
  9. Roignant JY, Carre C, Mugat B, Szymczak D, Lepesant JA, Antoniewski C (2003) Absence of transitive and systemic pathways allows cell-specific and isoform-specific RNAi in Drosophila. RNA 9:299–308PubMedCrossRefGoogle Scholar
  10. Stramer B, Wood W, Galko MJ, Redd MJ, Jacinto A, Parkhurst SM, Martin P (2005) Live imaging of wound inflammation in Drosophila embryos reveals key roles for small GTPases during in vivo cell migration. J Cell Biol 168:567–73PubMedCrossRefGoogle Scholar
  11. Tomoyasu Y, Denell RE (2004) Larval RNAi in Tribolium (Coleoptera) for analyzing adult development. Dev Genes Evol 214:575–8PubMedCrossRefGoogle Scholar
  12. Tomoyasu Y, Miller SC, Tomita S, Schoppmeier M, Grossmann D, Bucher G (2008) Exploring systemic RNA interference in insects: a genome-wide survey for RNAi genes in Tribolium. Genome Biol 9:R10PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Sherry C. Miller
    • 1
    • 2
  • Susan J. Brown
    • 1
    • 2
  • Yoshinori Tomoyasu
    • 1
    • 2
  1. 1.Division of BiologyKansas State UniversityManhattanUSA
  2. 2.K-State Arthropod Genomics CenterKansas State UniversityManhattanUSA
  3. 3.The Department of ZoologyMiami UniversityOxfordUSA

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