An RNA-directed nuclease mediates post-transcriptional gene silencing in Drosophila cells

  title={An RNA-directed nuclease mediates post-transcriptional gene silencing in Drosophila cells},
  author={Scott M. Hammond and Emily Bernstein and David H. Beach and Gregory J. Hannon},
In a diverse group of organisms that includes Caenorhabditis elegans , Drosophila, planaria, hydra, trypanosomes, fungi and plants, the introduction of double-stranded RNAs inhibits gene expression in a sequence-specific manner. These responses, called RNA interference or post-transcriptional gene silencing, may provide anti-viral defence, modulate transposition or regulate gene expression. We have taken a biochemical approach towards elucidating the mechanisms underlying this genetic… 

Figures and Tables from this paper

RNA-mediated gene silencing

Abstract: A number of gene-silencing phenomena including co-suppression discovered in plants, quelling in fungi and RNA interference in animals have been revealed to have steps in common. All occur

Role for a bidentate ribonuclease in the initiation step of RNA interference

Dicer is a member of the RNase III family of nucleases that specifically cleave double-stranded RNAs, and is evolutionarily conserved in worms, flies, plants, fungi and mammals, and has a distinctive structure, which includes a helicase domain and dualRNase III motifs.

RNA silencing in Drosophila

A model in which the siRNAs interact through complementarity with the target RNA and are extended by a cellular RNA-dependent RNA polymerase (RdRP) to form a critical length of dsRNA that is subsequently degraded by RNase III-related enzymes is proposed and compared to the proposed scheme for RNA silencing in mammalian systems.

Non-cell-autonomous RNA Silencing Spread in Plants

To gain further insight into noncell- autonomous RNAi spreading networks, it is critical to discover and characterize the distinct functions of the various genetic and molecular components involved.

RNA Interference: Biology, Mechanism, and Applications

Because of its exquisite specificity and efficiency, RNAi is being considered as an important tool not only for functional genomics, but also for gene-specific therapeutic activities that target the mRNAs of disease-related genes.

Specific inhibition of gene expression by small double-stranded RNAs in invertebrate and vertebrate systems

Synthetic siRNAs can induce gene-specific inhibition of expression in Caenorhabditis elegans and in cell lines from humans and mice, and seem to avoid the well documented nonspecific effects triggered by longer double-stranded RNAs in mammalian cells.

Argonaute2, a Link Between Genetic and Biochemical Analyses of RNAi

Biochemical purification of the RNAi effector nuclease from cultured Drosophila cells reveals that one constituent of this complex is a member of the Argonaute family of proteins, which are essential for gene silencing in Caenorhabditis elegans, Neurospora, and Arabidopsis.

Biochemical Mechanism of RNA Interference in Higher Organisms: A Dissertation

Designing siRNAs that target the single nucleotide polymorphism in superoxide dismutase that causes the familial form of amyotrophic lateral sclerosis (ALS), but leave the wild-type mRNA intact and functional is used.

Stable suppression of gene expression by RNAi in mammalian cells

It is shown that some cultured murine cells specifically silence gene expression upon treatment with long dsRNAs (≈500 nt), and this response shows hallmarks of conventional RNAi including silencing at the posttranscriptional level and the endogenous production of ≈22-nt small RNAs.



Gene silencing in Neurospora crassa requires a protein homologous to RNA-dependent RNA polymerase

The cloning of qde-1, the first cellular component of the gene-silencing mechanism to be isolated, defines a new gene family conserved among different species including plants, animals and fungi, which is similar to an RNA-dependent RNA polymerase found in the tomato.

RNA–DNA Interactions and DNA Methylation in Post-Transcriptional Gene Silencing

An epigenetic model of PTGS in which transgene methylation is associated with an RNA–DNA interaction that ensures that PTGS is maintained is supported.

RNAi and double-strand RNA.

dsRNA mediated suppression of specific gene expression has also been observed in plants and one demonstration of the phenomenon follows expression in plant cells of a recombinant RNA virus containing exonic sequences of an endogenous cellular gene.

RNA interference can target pre-mRNA: consequences for gene expression in a Caenorhabditis elegans operon.

It is demonstrated that RNAi against the Caenorhabditis elegans gene lir-1 induced embryonic lethality reminiscent of moderately strong lin-26 alleles, which provides direct evidence that RNA interference can prevent gene expression by targeting nuclear transcripts.

Transient expression of genes introduced into cultured cells of Drosophila.

  • P. D. Di NoceraI. Dawid
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1983
These experiments document a practical system for the introduction and expression of isolated genes in cultured cells of Drosophila and show low levels of CAT activity and of hybrid mRNA were detected in cells transformed with hsp-cat recombinants when the cells were maintained at room temperature, and both mRNA levels and CAT activity increased substantially after a brief exposure to 37 degrees C.

A species of small antisense RNA in posttranscriptional gene silencing in plants.

The 25-nucleotide antisense RNA detected in transgene-induced PTGS is likely synthesized from an RNA template and may represent the specificity determinant of PTGS.

Virus resistance and gene silencing in plants can be induced by simultaneous expression of sense and antisense RNA.

It is shown that transforming plants with virus or reporter gene constructs that produce RNAs capable of duplex formation confer virus immunity or gene silencing on the plants.

Silencing of developmental genes in Hydra.

It is shown that RNAi can be used to test the function of developmental genes in the cnidarian Hydra, a classical model for developmental studies, which until now has not been amenable to loss-of-function genetics.

Targeted disruption of gene function in Drosophila by RNA interference (RNA-i): a role for nautilus in embryonic somatic muscle formation.

  • L. MisquittaB. Paterson
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1999
A crucial role for nautilus in embryonic muscle formation is defined with the application of RNA interference to a variety of known Drosophila mutations as controls, which gave phenotypes essentially indistinguishable from the original mutation.