Retinoid X receptor modulates vitellogenin gene expression in black tiger shrimp, Penaeus monodon.

Effective inducing of ovarian maturation in female shrimp broodstock is important for successful breeding programs. Vitellogenesis is a biochemical process during which a yolk protein precursor vitellogenin (Vg) is synthesized and thus, can be used to indicate ovarian maturation stage. In this study, transcriptional regulation of Vg synthesis in the black tiger shrimp, Penaeus monodon was investigated.

Homologues of Piwi control transposable elements and development of male germline in Penaeus monodon.

PIWI belongs to the Argonaute protein family, which is a major protein component in RNA silencing pathway. Piwi proteins play roles in the control of transposons and germline development. They have been widely studied in vertebrates and flies, while very little is known in crustacean so far.

An ATP synthase beta subunit is required for internalization of dsRNA into shrimp cells.

Extracellular double-stranded RNA (dsRNA) is an important modulator in innate immunity in both vertebrates and invertebrates. In shrimp, extracellular dsRNA can trigger RNAi pathway and serves as antiviral defense mechanism. However, the mechanism of dsRNA internalization into the cells has not yet known in shrimp cells.

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.

A multi-target dsRNA for simultaneous inhibition of yellow head virus and white spot syndrome virus in shrimp.

Outbreaks of diseases caused by yellow head virus (YHV) and white spot syndrome virus (WSSV) infection in shrimp have resulted in economic losses worldwide. DsRNA-mediated RNAi has been used to control these viruses, and the best target genes for efficient inhibition of YHV and WSSV are the protease and ribonuleotide reductase small subunit (rr2), respectively. However, one dsRNA can suppress only one virus, and therefore the production of multi-target dsRNA to effectively inhibit both YHV and WSSV is needed.

Regulation of vitellogenin gene expression under the negative modulator, gonad-inhibiting hormone in Penaeus monodon.

Vitellogenesis is a principal process during ovarian maturation in crustaceans. This process is negatively regulated by gonad-inhibiting hormone (GIH), a neuronal peptide hormone from eyestalks. However, the detailed mechanism through which GIH regulates Vg expression is still ambiguous.

PmEEA1, the early endosomal protein is employed by YHV for successful infection in Penaeus monodon.

Yellow head disease (YHD) is an infectious disease of Penaeus monodon which is caused by the yellow head virus (YHV). YHV infection invariably leads to 100% shrimp mortality within 3-5 days. Currently, an effective method to prevent or cure shrimp from YHV infection has not been elucidated.

Functional characterization of a cDNA encoding Piwi protein in Penaeus monodon and its potential roles in controlling transposon expression and spermatogenesis.

Piwi proteins comprise a subfamily of Argonaute that plays a major role in germline development by association with a distinct class of small RNAs called Piwi interacting RNA (piRNA). Although the functions of Piwi in the development of germline cells as well as transposon regulation were reported in a number of mammalians and insects, developmental expression and function of Piwi subfamily in crustaceans is poorly known. This study is aimed at cloning and characterization of a Piwi cDNA in the black tiger shrimp, Penaeus monodon.

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.

Administration of co-expressed Penaeus stylirostris densovirus-like particles and dsRNA-YHV-Pro provide protection against yellow head virus in shrimp.

The activation of the innate RNA interference pathway through double-stranded RNAs (dsRNAs) is one of the approaches to protecting shrimp from viruses. Previous studies have shown that injection of specific dsRNAs can successfully inhibit viral infection in shrimp. However, inhibition requires high levels of dsRNA and dsRNA stability in shrimp is limited.

An essential role of Rieske domain oxygenase Neverland in the molting cycle of black tiger shrimp, Penaeus monodon.

Molting is an important process for development and growth in arthropods. In crustaceans, molt is regulated by ecdysteroids or molting hormones that are synthesized in Y-organs. However, ecdysteroid biosynthesis pathway in crustaceans and its participating enzymes have not been well studied so far.

Suppression of PmRab11 inhibits YHV infection in Penaeus monodon.

Yellow head virus (YHV) is one of the most serious pathogens that causes worldwide shrimp production loss. It enters the cells via clathrin-mediated endocytosis and utilizes small GTPase Rab proteins such as PmRab5 and PmRab7 for intracellular trafficking. In this study, molecular cloning and functional analysis of Rab11 during YHV infection were investigated.

Cholesterol-based cationic liposome increases dsRNA protection of yellow head virus infection in Penaeus vannamei.

Protection of shrimp from yellow head virus (YHV) infection has been demonstrated by injection and oral delivery of dsRNA-YHV protease gene (dsYHV) or shrimp endogenous gene (dsRab7). However, to achieve complete viral suppression and to prolong dsRNA activity, the development of an effective dsRNA delivery system is required. In this study, four cationic liposomes were synthesized and tested for their ability to increase dsRNA efficiency.

A formulated double-stranded RNA diet for reducing Penaeus monodon densovirus infection in black tiger shrimp.

Penaeus monodon densovirus (PmDNV) is one of the major causes of stunted shrimp in the aquaculture industry in Thailand. Significant reductions in levels of PmDNV as assessed by PCR analysis of shrimp hepatopancreas were seen in both prophylactic and curative experiments after feeding shrimp with a formulated diet containing mixed inactivated bacteria harboring dsRNAs corresponding to the PmDNV ns1 and vp genes. Significant reductions of approximately 88% (prophylactic) and 64% (curative) of PmDNV were observed, suggesting that this diet has a high potential for application in commercial aquaculture for reducing PmDNV associated stunted growth of shrimp.

Synergism of regulatory elements in σ(B)- and σ(A)-dependent promoters enhances recombinant protein expression in Bacillus subtilis.

Strong promoter is an essential factor for production of recombinant protein in various expression systems including Bacillus subtilis. In this study, we described a strategy to improve the expression efficiency using synthetic double promoter. Assembly of the conserved elements from σ(B)- and σ(A)-dependent promoters constitutively improved the yield of recombinant protein approximately 2-3-fold in both exponential and stationary growth phase.

Molecular cloning and characterization of Mj-mov-10, a putative RNA helicase involved in RNAi of kuruma shrimp.

Identification and characterization of the RNAi-related genes is the key to understanding RNAi mechanism in shrimp. In this study, we have identified and characterized a novel putative RNA helicase gene, Mj-mov-10 from the kuruma shrimp, Marsupenaeus japonicus and its implication in shrimp RNAi was demonstrated. The full-length Mj-mov-10 gene contained 3536bp, including 239 bp of 5'UTR, 2895 bp of the open reading frame (ORF) and 402bp of 3'UTR, respectively.

Successful yellow head virus infection of requires clathrin heavy chain.

Viral disease caused by the Yellow head virus (YHV) had great impact on economic loss in the aquaculture industry. Prevention or curing YHV disease is still not possible due to the lack of understanding of the basic mechanisms of YHV infection. In this report, the endocytosis inhibitors (chlorpromazine (CPZ), amiloride and methyl-β-cyclodextrin (MβCD)) were used to identify the cellular entry pathway of YHV.

A novel gonad-specific Argonaute 4 serves as a defense against transposons in the black tiger shrimp Penaeus monodon.

Argonaute is a key protein of the small-RNA guided gene regulation process. The Argonaute family is generally divided into two subfamilies; AGO and PIWI. In this study, a cDNA encoding a novel type of Argonaute (PmAgo4) in the black tiger shrimp Penaeus monodon was identified and characterized.

Molecular characterization of a cDNA encoding red pigment-concentrating hormone in black tiger shrimp Penaeus monodon: Implication of its function in molt and osmoregulation.

Red pigment-concentrating hormone (RPCH) is a member of the AKH/RPCH peptide family present mainly in crustaceans and insects. Insect AKH is responsible for metabolic functions whereas RPCH plays a major role in the aggregation of red chromatophores in crustaceans. In this study, a full-length cDNA of RPCH of the black tiger shrimp, Penaeus monodon (PmRPCH) was cloned by Rapid Amplification of cDNA Ends strategies from the eyestalk RNA.

Silencing of PmYPR65 receptor prevents yellow head virus infection in Penaeus monodon.

The suppression of viral replication by double-stranded RNAs (dsRNA) specific to mRNAs of either virus or host genes has been widely investigated as a possible shrimp disease therapy. PmYRP65, a yellow head virus (YHV) receptor, was previously identified and characterized in the black tiger shrimp, Penaeus monodon. In our previous study, entry of YHV into cells of the Oka organ of P.

Protection of yellow head virus infection in shrimp by feeding of bacteria expressing dsRNAs.

Although prevention of shrimp mortality from yellow head virus (YHV) infection via dsRNA injection has been well demonstrated for many years, it has not yet been applied in a farm culture because of its impracticality. Hence, oral administration of dsRNA becomes an alternative and desirable approach. This study is the first to demonstrate that oral feeding of Escherichia coli expressing shrimp Rab7 gene (dsRab7) or YHV protease gene (dsYHV) could inhibit YHV replication and lowered shrimp mortality.

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.

Penaeus monodon Tudor staphylococcal nuclease preferentially interacts with N-terminal domain of Argonaute-1.

RNA interference (RNAi) plays a crucial role as an antiviral defense in several organisms including plants and invertebrates. An understanding of RNAi machineries especially protein components of the RNA-induced silencing complex (RISC) is essential for prior to applying RNAi as a tool for viral protective immunity in shrimp. Tudor staphylococcal nuclease (TSN) is an evolutionarily conserved protein and is one of the RISC components.

A simple one-step method for producing dsRNA from E. coli to inhibit shrimp virus replication.

While dsRNA has been used experimentally to inhibit replication and thus disease caused by several shrimp viruses, it can be tedious, time consuming and costly to produce. Here we describe a simple method for obtaining long-hairpin dsRNA from RNase III-minus HT115 Escherichia coli cells following its expression from a plasmid containing a RNA promoter. All the method requires is for bacterial cells to be fixed briefly in 75% ethanol in phosphate buffer saline (PBS) before suspension in 150mM NaCl.