PRG-1 and 21U-RNAs interact to form the piRNA complex required for fertility in C. elegans.
In metazoans, Piwi-related Argonaute proteins have been linked to germline maintenance, and to a class of germline-enriched small RNAs termed piRNAs. Here we show that an abundant class of 21 nucleotide small RNAs (21U-RNAs) are expressed in the C. elegans germline, interact with the C. elegans Piwi family member PRG-1, and depend on PRG-1 activity for their accumulation. The PRG-1 protein is expressed throughout development and localizes to nuage-like structures called P granules. Although 21U-RNA loci share a conserved upstream sequence motif, the mature 21U-RNAs are not conserved and, with few exceptions, fail to exhibit complementarity or evidence for direct regulation of other expressed sequences. Our findings demonstrate that 21U-RNAs are the piRNAs of C. elegans and link this class of small RNAs and their associated Piwi Argonaute to the maintenance of temperature-dependent fertility.
Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA.
Pedro J
PJ
Batista
J Graham
JG
Ruby
Julie M
JM
Claycomb
Rosaria
R
Chiang
Noah
N
Fahlgren
Kristin D
KD
Kasschau
Daniel A
DA
Chaves
Weifeng
W
Gu
Jessica J
JJ
Vasale
Shenghua
S
Duan
Darryl
D
Conte
Shujun
S
Luo
Gary P
GP
Schroth
James C
JC
Carrington
David P
DP
Bartel
Craig C
CC
Mello
D000818:Animals; D060565:Argonaute Proteins; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D005298:Fertility; D005786:Gene Expression Regulation; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D018510:RNA, Helminth / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*; D034743:RNA-Induced Silencing Complex; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics
D060565:Argonaute Proteins; D029742:Caenorhabditis elegans Proteins; C530363:PRG-1 protein, C elegans; D018510:RNA, Helminth; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex