Piwi and piRNAs act upstream of an endogenous siRNA pathway to suppress Tc3 transposon mobility in the Caenorhabditis elegans germline.
Mol Cell
; 31(1): 79-90, 2008 Jul 11.
Article
in En
| MEDLINE
| ID: mdl-18571451
ABSTRACT
The Piwi proteins of the Argonaute superfamily are required for normal germline development in Drosophila, zebrafish, and mice and associate with 24-30 nucleotide RNAs termed piRNAs. We identify a class of 21 nucleotide RNAs, previously named 21U-RNAs, as the piRNAs of C. elegans. Piwi and piRNA expression is restricted to the male and female germline and independent of many proteins in other small-RNA pathways, including DCR-1. We show that Piwi is specifically required to silence Tc3, but not other Tc/mariner DNA transposons. Tc3 excision rates in the germline are increased at least 100-fold in piwi mutants as compared to wild-type. We find no evidence for a Ping-Pong model for piRNA amplification in C. elegans. Instead, we demonstrate that Piwi acts upstream of an endogenous siRNA pathway in Tc3 silencing. These data might suggest a link between piRNA and siRNA function.
Full text:
1
Database:
MEDLINE
Main subject:
DNA Transposable Elements
/
Proteins
/
Caenorhabditis elegans
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Caenorhabditis elegans Proteins
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RNA, Small Interfering
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Germ Cells
Limits:
Animals
Language:
En
Year:
2008
Type:
Article