RRC ID |
30635
|
Author |
Lee HC, Gu W, Shirayama M, Youngman E, Conte D Jr, Mello CC.
|
Title |
C. elegans piRNAs mediate the genome-wide surveillance of germline transcripts.
|
Journal |
Cell
|
Abstract |
Piwi Argonautes and Piwi-interacting RNAs (piRNAs) mediate genome defense by targeting transposons. However, many piRNA species lack obvious sequence complementarity to transposons or other loci; only one C. elegans transposon is a known piRNA target. Here, we show that, in mutants lacking the Piwi Argonaute PRG-1 (and consequently its associated piRNAs/21U-RNAs), many silent loci in the germline exhibit increased levels of mRNA expression with a concomitant depletion of RNA-dependent RNA polymerase (RdRP)-derived secondary small RNAs termed 22G-RNAs. Sequences depleted of 22G-RNAs are proximal to potential target sites that base pair imperfectly but extensively to 21U-RNAs. We show that PRG-1 is required to initiate, but not to maintain, silencing of transgenes engineered to contain complementarity to endogenous 21U-RNAs. Our findings support a model in which C. elegans piRNAs utilize their enormous repertoire of targeting capacity to scan the germline transcriptome for foreign sequences, while endogenous germline-expressed genes are actively protected from piRNA-induced silencing.
|
Volume |
150(1)
|
Pages |
78-87
|
Published |
2012-7-6
|
DOI |
10.1016/j.cell.2012.06.016
|
PII |
S0092-8674(12)00765-9
|
PMID |
22738724
|
PMC |
PMC3410639
|
MeSH |
Animals
Argonaute Proteins / metabolism
Caenorhabditis elegans / genetics*
Caenorhabditis elegans / metabolism*
Gene Silencing
Genome, Helminth*
Germ Cells
RNA, Helminth / metabolism*
RNA, Small Interfering / metabolism*
|
IF |
38.637
|
Times Cited |
196
|
WOS Category
|
BIOCHEMISTRY & MOLECULAR BIOLOGY
CELL BIOLOGY
|
Resource |
C.elegans |
tm872 |