Ago4-piRNA complex is a key component of genomic immune system against transposon expression in Penaeus monodon.

Argonaute proteins are key constituents of small RNA-guided regulatory pathways. In crustaceans, members of the AGO subfamily of Argonaute proteins that play vital roles in immune defense are well studied, while proteins of the PIWI subfamily are less established. PmAgo4 of the black tiger shrimp, Penaeus monodon, though phylogenetically clustered with the AGO subfamily, has distinctive roles of the PIWI subfamily in safeguarding the genome from transposon invasion and controlling germ cell development.

Assessment of the function of gonad-specific PmAgo4 in viral replication and spermatogenesis in Penaeus monodon.

Argonaute family is phylogenetically subdivided into Ago and Piwi subfamilies that operate either transcriptional or post-transcriptional regulation in association with particular types of small RNAs. Among the four members of Ago subfamily (PmAgo1-4) found in black tiger shrimp Penaeus monodon, PmAgo4 exhibits gonad-restricted expression and takes part in transposon repression as the Piwi subfamily. While PmAgo1-3 participate in RNA interference (RNAi)-based mechanism, the role of PmAgo4 in RNAi is still mysterious, and was therefore investigated in this study.

Suppression of argonautes compromises viral infection in Penaeus monodon.

Argonaute (Ago) proteins, the catalytic component of an RNA-induced silencing complex (RISC) in RNA interference pathway, function in diverse processes, especially in antiviral defense and transposon regulation. So far, cDNAs encoding four members of Argonaute were found in Penaeus monodon (PmAgo1-4). Two PmAgo proteins, PmAgo1 and PmAgo3 shared high percentage of amino acid identity to Ago1 and Ago2, respectively in other Penaeid shrimps.

Molecular cloning and functional characterization of Argonaute-3 gene from Penaeus monodon.

Argonaute (Ago) proteins play a crucial role in the shrimp RNA interference pathway. In this study, we identified and characterized a novel Ago gene from black tiger shrimp, Penaeus monodon. The complete open reading frame of P.

Double-stranded RNA confers both preventive and therapeutic effects against Penaeus stylirostris densovirus (PstDNV) in Litopenaeus vannamei.

Penaeus stylirostris densovirus (PstDNV) infection is found widespread in peneaid shrimp, especially in economically important species such as black tiger shrimp Penaeus monodon and Pacific white shrimp Litopenaeus vannamei. Although effective prevention method for viral diseases is not well established in shrimp, the treatment with viral specific double-stranded RNA (dsRNA) or siRNA has given promising results. In present study, dsRNAs corresponding to non-structural (ORF1 and ORF2 overlapping sequence) and structural (ORF3) genes of PstDNV were investigated for their potency to inhibit PstDNV replication in the shrimp.