Transcriptional silencing of a transgene by RNAi in the soma of C. elegans.
The silencing of transgene expression at the level of transcription in the soma of Caenorhabditis elegans through an RNAi-dependent pathway has not been previously characterized. Most gene silencing due to RNAi in C. elegans occurs at the post-transcriptional level. We observed transcriptional silencing when worms containing the elt-2::gfp/LacZ transgene were fed RNA produced from the commonly used L4440 vector. The transgene and the vector share plasmid backbone sequences. This transgene silencing depends on multiple RNAi pathway genes, including dcr-1, rde-1, rde-4, and rrf-1. Unlike post-transcriptional gene silencing in worms, elt-2::gfp/LacZ silencing is dependent on the PAZ-PIWI protein Alg-1 and on the HP1 homolog Hpl-2. The latter is a chromatin silencing factor, and expression of the transgene is inhibited at the level of intron-containing precursor mRNA. This inhibition is accompanied by a decrease in the acetylation of histones associated with the transgene. This transcriptional silencing in the soma can be distinguished from transgene silencing in the germline by its inability to be transmitted across generations and its dependence on the rde-1 gene. We therefore define this type of silencing as RNAi-induced Transcriptional Gene Silencing (RNAi-TGS). Additional chromatin-modifying components affecting RNAi-TGS were identified in a candidate RNAi screen.
Grishok
Alla
A
Center for Cancer Research, McGovern Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Sinskey
Jina L
JL
Sharp
Phillip A
PA
D000107:Acetylation; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers; D004722:Endoribonucleases / Q000235:genetics; D050980:GATA Transcription Factors; D020868:Gene Silencing; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006657:Histones / Q000378:metabolism; D047468:Immunoprecipitation; D007763:Lac Operon / Q000235:genetics; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D043244:Ribonuclease III; D014157:Transcription Factors / Q000235:genetics; D019076:Transgenes / Q000235:genetics*
D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; C094134:ELT-2 protein, C elegans; D050980:GATA Transcription Factors; D006657:Histones; C461645:RDE-4 protein, C elegans; D012330:RNA, Double-Stranded; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C122185:rde-1 protein, C elegans; D049452:Green Fluorescent Proteins; D004722:Endoribonucleases; C118116:dcr-1 protein, C elegans; D043244:Ribonuclease III
Curr Biol. 2002 Aug 6;12(15):1317-9
12176360
Genes Dev. 1999 Dec 15;13(24):3191-7
10617568
Genes Dev. 2002 Apr 1;16(7):796-805
11937488
Development. 1998 Jul;125(13):2451-6
9609828
Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4191-6
11904378
Science. 1999 Oct 29;286(5441):950-2
10542148
Cell. 2004 Jan 23;116(2):281-97
14744438
Science. 2004 Jan 30;303(5658):669-72
14752161
Curr Biol. 2004 Jan 20;14(2):111-6
14738731
Gene. 2002 Jun 12;292(1-2):33-41
12119097
Genes Dev. 2001 Jan 15;15(2):188-200
11157775
Nature. 1998 Oct 29;395(6705):854
9804418
Nature. 2000 Mar 16;404(6775):293-6
10749213
Nature. 2001 Jan 18;409(6818):363-6
11201747
Mol Cell. 2004 Jun 18;14(6):841-7
15200961
Science. 2002 Sep 27;297(5590):2232-7
12215653
Methods. 2003 Aug;30(4):313-21
12828945
Nat Genet. 2004 Nov;36(11):1174-80
15475954
Nat Genet. 2004 May;36(5):507-11
15107848
Nature. 2003 Sep 25;425(6956):411-4
14508492
Science. 1998 Oct 16;282(5388):430-1
9841401
Mol Biol Cell. 2001 Jun;12(6):1751-64
11408582
Science. 2002 Sep 13;297(5588):1833-7
12193640
Proc Natl Acad Sci U S A. 1998 Dec 22;95(26):15502-7
9860998
Science. 2001 Sep 21;293(5538):2269-71
11486053
Cell. 1994 Feb 11;76(3):567-76
8313476
Curr Biol. 2000 Feb 24;10(4):169-78
10704412
Mol Cell. 2002 Oct;10(4):809-17
12419225
Genes Dev. 2003 Feb 15;17(4):443-8
12600937
Nature. 2003 Nov 20;426(6964):310-4
14628056
DNA Res. 1998 Dec 31;5(6):373-7
10048487
Science. 2000 Sep 15;289(5486):1928-31
10988072
Mol Cell. 2002 Feb;9(2):315-27
11864605
Science. 2003 Jan 31;299(5607):716-9
12522258
Cell. 1999 Oct 15;99(2):133-41
10535732
Cell. 1999 Oct 15;99(2):123-32
10535731
Proc Natl Acad Sci U S A. 1998 Dec 8;95(25):14687-92
9843950
Nature. 2000 Mar 16;404(6775):296-8
10749214
Development. 1999 Jun;126(11):2483-94
10226007
Cell. 2001 Jul 13;106(1):23-34
11461699
Cell. 2002 Jun 28;109(7):861-71
12110183
Cell. 2000 Mar 31;101(1):25-33
10778853
Trends Genet. 2002 Mar;18(3):150-7
11858839
Nature. 1998 Feb 19;391(6669):806-11
9486653
Science. 2002 Sep 13;297(5588):1831
12193644
EMBO J. 1991 Dec;10(12):3959-70
1935914
EMBO J. 2000 Oct 2;19(19):5194-201
11013221
Science. 2004 Jan 30;303(5658):672-6
14704433
Cell. 2001 Nov 16;107(4):465-76
11719187
Mech Dev. 2002 Jun;114(1-2):61-9
12175490
PLoS Biol. 2004 May;2(5):E104
15024409
Curr Biol. 2003 Aug 5;13(15):1311-6
12906791
EMBO Rep. 2002 Mar;3(3):235-41
11850401
Genetics. 1997 May;146(1):227-38
9136012
Development. 2002 Jan;129(2):479-92
11807039
Dev Biol. 1998 Jun 15;198(2):286-302
9659934
Curr Protoc Mol Biol. 2003 May;Chapter 26:Unit 26.3
18265327
Science. 2004 Feb 27;303(5662):1336
14988555
Genes Dev. 2000 Jul 1;14(13):1578-83
10887151