Displaying publications 1 - 20 of 58 in total

Abstract:
Sort:
  1. Selvaraj BA, Mariatulqabtiah AR, Ho KL, Ng CL, Yong CY, Tan WS
    Int J Mol Sci, 2021 Aug 13;22(16).
    PMID: 34445426 DOI: 10.3390/ijms22168725
    The causative agent of white tail disease (WTD) in the giant freshwater prawn is Macrobrachium rosenbergii nodavirus (MrNV). The recombinant capsid protein (CP) of MrNV was previously expressed in Escherichia coli, and it self-assembled into icosahedral virus-like particles (VLPs) with a diameter of approximately 30 nm. Extensive studies on the MrNV CP VLPs have attracted widespread attention in their potential applications as biological nano-containers for targeted drug delivery and antigen display scaffolds for vaccine developments. Despite their advantageous features, the recombinant MrNV CP VLPs produced in E. coli are seriously affected by protease degradations, which significantly affect the yield and stability of the VLPs. Therefore, the aim of this study is to enhance the stability of MrNV CP by modulating the protease degradation activity. Edman degradation amino acid sequencing revealed that the proteolytic cleavage occurred at arginine 26 of the MrNV CP. The potential proteases responsible for the degradation were predicted in silico using the Peptidecutter, Expasy. To circumvent proteolysis, specific protease inhibitors (PMSF, AEBSF and E-64) were tested to reduce the degradation rates. Modulation of proteolytic activity demonstrated that a cysteine protease was responsible for the MrNV CP degradation. The addition of E-64, a cysteine protease inhibitor, remarkably improved the yield of MrNV CP by 2.3-fold compared to the control. This innovative approach generates an economical method to improve the scalability of MrNV CP VLPs using individual protease inhibitors, enabling the protein to retain their structural integrity and stability for prominent downstream applications including drug delivery and vaccine development.
    Matched MeSH terms: Palaemonidae/virology*
  2. Soo TCC, Bhassu S
    PLoS One, 2021;16(10):e0258655.
    PMID: 34653229 DOI: 10.1371/journal.pone.0258655
    Diseases have remained the major issue for shrimp aquaculture industry for decades by which different shrimp species demonstrated alternative disease resistance or tolerance. However, there had been insufficient studies on the underlying host mechanisms of such phenomenon. Hence, in this study, the main objective involves gaining a deeper understanding into the functional importance of shrimp STAT gene from the aspects of expression, sequence, structure, and associated genes. STAT gene was selected primarily because of its vital signalling roles in stress, endocrine, and immune response. The differential gene expressions of Macrobrachium rosenbergii STAT (MrST) and Penaeus monodon STAT (PmST) under White Spot Syndrome Virus (WSSV) and Vibrio parahaemolyticus/VpAHPND infections were identified through qPCR analysis. Notably, during both pathogenic infections, MrST demonstrated significant gene expression down-regulations (during either early or later post-infection time points) whereas PmST showed only significant gene expression up-regulations. Important sequence conservation or divergence was highlighted through STAT sequence comparison especially amino acid alterations at 614 aa [K (Lysine) to E (Glutamic Acid)] and 629 aa [F (Phenylalanine) to V (Valine)] from PmST (AY327491.1) to PmST (disease tolerant strain). There were significant differences observed between in silico characterized structures of MrST and PmST proteins. Important functional differentially expressed genes (DEGs) in the aspects of stress, endocrine, immune, signalling, and structural were uncovered through comparative transcriptomic analysis. The DEGs associated with STAT functioning were identified including inositol 1,4,5-trisphosphate receptor, hsp90, caspase, ATP binding cassette transmembrane transporter, C-type Lectin, HMGB, ALF1, ALF3, superoxide dismutase, glutathione peroxidase, catalase, and TBK1. The main findings of this study are STAT differential gene expression patterns, sequence divergence, structural differences, and associated functional DEGs. These findings can be further utilized for shrimp health or host response diagnostic studies. STAT gene can also be proposed as a suitable candidate for future studies of shrimp innate immune enhancement.
    Matched MeSH terms: Palaemonidae/genetics*; Palaemonidae/virology
  3. Ravichandran G, Pasupuleti M, Arasu MV, Al-Dhabi NA, Arshad A, Arockiaraj J
    Fish Shellfish Immunol, 2020 Nov;106:332-340.
    PMID: 32758637 DOI: 10.1016/j.fsi.2020.07.068
    The occurrences of multiple drug-resistant strains have been relentlessly increasing in recent years. The aquaculture industry has encountered major disease outbreaks and crucially affected by this situation. The usage of non-specific chemicals and antibiotics expedites the stimulation of resistant strains. Triggering the natural defense mechanism would provide an effective and safest way of protecting the host system. Hence, we have investigated the innate immune function of serine/threonine-protein kinase (STPK) in Macrobrachium rosenbergii (Mr). The in-silico protein analysis resulted in the identification of cationic antimicrobial peptide, MrSL-19, with interesting properties from STPK of M. rosenbergii. Antimicrobial assay, FACS and SEM analysis demonstrated that the peptide potentially inhibits Staphylococcus aureus by interacting with its membrane. The toxic study on MrSL-19 demonstrated that the peptide is not toxic against HEK293 cells as well as human erythrocytes. This investigation showed the significant innate immune property of an efficient cationic antimicrobial peptide, MrSL-19 of STPK from M. rosenbergii.
    Matched MeSH terms: Palaemonidae/genetics*; Palaemonidae/immunology*
  4. Juneta-Nor AS, Noordin NM, Azra MN, Ma HY, Husin NM, Ikhwanuddin M
    J Zhejiang Univ Sci B, 2020 10 13;21(10):823-834.
    PMID: 33043647 DOI: 10.1631/jzus.B2000126
    Ecdysis is a common phenomenon that happens throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii. It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process. The objective of the present study was to determine the amino acid profile released by M. rosenbergii during the ecdysis process that promotes cannibalism. To accomplish this, changes in amino acid levels (total amino acid (TAA) and free amino acid (FAA)) of tissue muscle, exoskeleton, and sample water of culture medium from the moulting (E-stage) and non-moulting (C-stage) prawns were analysed using high-performance liquid chromatography (HPLC). Comparison study revealed that among the TAA compounds, proline and sarcosine of tissues from moulting prawn were found at the highest levels. The level of FAA from water that contains moulting prawns (E-stage) was dominated by tryptophan and proline. Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M. rosenbergii during ecdysis. The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism, and also for future dietary manipulation to improve feeding efficiencies and feeding management, which indirectly impacts productivity and profitability.
    Matched MeSH terms: Palaemonidae/physiology*
  5. Hooper C, Debnath PP, Biswas S, van Aerle R, Bateman KS, Basak SK, et al.
    Viruses, 2020 10 02;12(10).
    PMID: 33023199 DOI: 10.3390/v12101120
    Mass mortalities of the larval stage of the giant freshwater prawn, Macrobrachium rosenbergii, have been occurring in Bangladesh since 2011. Mortalities can reach 100% and have resulted in an 80% decline in the number of hatcheries actively producing M. rosenbergii. To investigate a causative agent for the mortalities, a disease challenge was carried out using infected material from a hatchery experiencing mortalities. Moribund larvae from the challenge were prepared for metatranscriptomic sequencing. De novo virus assembly revealed a 29 kb single‑stranded positive-sense RNA virus with similarities in key protein motif sequences to yellow head virus (YHV), an RNA virus that causes mass mortalities in marine shrimp aquaculture, and other viruses in the Nidovirales order. Primers were designed against the novel virus and used to screen cDNA from larvae sampled from hatcheries in the South of Bangladesh from two consecutive years. Larvae from all hatcheries screened from both years were positive by PCR for the novel virus, including larvae from a hatchery that at the point of sampling appeared healthy, but later experienced mortalities. These screens suggest that the virus is widespread in M. rosenbergii hatchery culture in southern Bangladesh, and that early detection of the virus can be achieved by PCR. The hypothesised protein motifs of Macrobrachium rosenbergii golda virus (MrGV) suggest that it is likely to be a new species within the Nidovirales order. Biosecurity measures should be taken in order to mitigate global spread through the movement of post-larvae within and between countries, which has previously been linked to other virus outbreaks in crustacean aquaculture.
    Matched MeSH terms: Palaemonidae/virology*
  6. Chen-Fei L, Chou-Min C, Jiun-Yan L
    Fish Shellfish Immunol, 2020 Sep;104:431-438.
    PMID: 32580003 DOI: 10.1016/j.fsi.2020.06.039
    The giant freshwater prawn/giant river prawn, Macrobrachium rosenbergii is one of the high market value crustaceans cultured worldwide. The intensified aquaculture of the species has led to the outbreak of infectious diseases, prominently, the white tail disease (WTD). It is caused by the infection of Macrobrachium rosenbergii nodavirus (MrNV), which was classified in the family of Nodaviridae. To-date, there are no effective prophylactic and therapeutic agents available against MrNV infection. Vaccination is known to be the most effective prophylactic agent in disease prevention. However, vaccine development against virus infection in crustaceans is equivocal. The feasibility of vaccination in conferring immune protection in crustaceans against infectious diseases is disputable. The argument lies in the fact that crustaceans do not possess adaptive immunity, which is the main immune component that functions to establish immunological memory upon vaccination. Nevertheless, an increasing number of literatures has been documented, which concerns the development of vaccines against infectious diseases in crustaceans. The current review deliberates different approaches in vaccine development against MrNV, which were documented in the past years. It is noteworthy that the live-attenuated MrNV vaccine has not been experimented by far. Thus, the potential of live-attenuated MrNV vaccine in conferring long-term immune protection through the establishment of innate immune memory is currently being discussed.
    Matched MeSH terms: Palaemonidae/virology*
  7. Ninyio NN, Ho KL, Ong HK, Yong CY, Chee HY, Hamid M, et al.
    Vaccines (Basel), 2020 Jun 04;8(2).
    PMID: 32512923 DOI: 10.3390/vaccines8020275
    Chimeric virus-like particles (VLPs) have been widely exploited for various purposes including their use as vaccine candidates, particularly due to their ability to induce stronger immune responses than VLPs consisting of single viral proteins. In the present study, VLPs of the Macrobrachium rosenbergii nodavirus (MrNV) capsid protein (Nc) displaying the hepatitis B virus "a" determinant (aD) were produced in Spodoptera frugiperda (Sf9) insect cells. BALB/c mice immunised with the purified chimeric Nc-aD VLPs elicited a sustained titre of anti-aD antibody, which was significantly higher than that elicited by a commercially available hepatitis B vaccine and Escherichia coli-produced Nc-aD VLPs. Immunophenotyping showed that the Sf9-produced Nc-aD VLPs induced proliferation of cytotoxic T-lymphocytes and NK1.1 natural killer cells. Furthermore, enzyme-linked immunospot (ELISPOT)analysis showed the presence of antibody-secreting memory B cells in the mice splenocytes stimulated with the synthetic aD peptide. The significant humoral, natural killer cell and memory B cell immune responses induced by the Sf9-produced Nc-aD VLPs suggest that they present good prospects for use as a hepatitis B vaccine candidate.
    Matched MeSH terms: Palaemonidae
  8. Faiz ZM, Mardhiyyah MP, Mohamad A, Hidir A, Nurul-Hidayah A, Wong L, et al.
    Anim. Reprod. Sci., 2019 Oct;209:106143.
    PMID: 31514941 DOI: 10.1016/j.anireprosci.2019.106143
    Understanding Macrobrachium rosenbergii ovarian maturation control at the genome level is an important aspect for increasing larvae production. In this study, an ovarian maturation related gene, M. rosenbergii vWD domain and three Kazal-type domains of a gene (MrvWD-Kazal) have been studied. The MrvWD-Kazal gene was isolated using a rapid amplification of cDNA end (RACE) method and the relative abundances of MrvWD-Kazal mRNA in the ovary, hepatopancreas, stomach, intestine and gill were determined by using the quantitative PCR technique. The MrvWD-Kazal gene is composed of 2194 bp with an open reading frame (ORF) of 1998 bp encoding 665 amino acids and has great similarity to the M. nipponense vWD-Kazal gene (91%). The qPCR analyses indicated the relative abundance of MrvWD-Kazal mRNA transcript varied among different stages of ovarian function (P < 0.05), but there were no differences abundance in hepatopancreas, stomach, intestine and gill (P> 0.05). In the ovary, relative abundance of MrvWD-Kazal mRNA transcript gradually increased with ovarian maturation from Stages 1 (Spent; 1.00-fold), to 2 (Proliferative; 3.47-fold) to 3 (Premature; 6.18-fold) and decreased at Stage 4 (Mature; 1.31-fold). Differential relative abundances of MrvWD-Kazal mRNA transcript in the ovary indicate the MrvWD-Kazal protein may have an important function in ovarian maturation of M. rosenbergii. The results of this study also indicate the MrvWD-Kazal is not involved in regulation of the reproductive related function of the hepatopancreas, digestive system (stomach and intestine) and respiratory system (gill).
    Matched MeSH terms: Palaemonidae/embryology; Palaemonidae/genetics*; Palaemonidae/growth & development
  9. Ong HK, Yong CY, Tan WS, Yeap SK, Omar AR, Razak MA, et al.
    Vaccines (Basel), 2019 08 19;7(3).
    PMID: 31430965 DOI: 10.3390/vaccines7030091
    Current seasonal influenza A virus (IAV) vaccines are strain-specific and require annual reconstitution to accommodate the viral mutations. Mismatches between the vaccines and circulating strains often lead to high morbidity. Hence, development of a universal influenza A vaccine targeting all IAV strains is urgently needed. In the present study, the protective efficacy and immune responses induced by the extracellular domain of Matrix 2 protein (M2e) displayed on the virus-like particles of Macrobrachium rosenbergii nodavirus (NvC-M2ex3) were investigated in BALB/c mice. NvC-M2ex3 was demonstrated to be highly immunogenic even in the absence of adjuvants. Higher anti-M2e antibody titers corresponded well with increased survival, reduced immunopathology, and morbidity of the infected BALB/c mice. The mice immunized with NvC-M2ex3 exhibited lower H1N1 and H3N2 virus replication in the respiratory tract and the vaccine activated the production of different antiviral cytokines when they were challenged with H1N1 and H3N2. Collectively, these results suggest that NvC-M2ex3 could be a potential universal influenza A vaccine.
    Matched MeSH terms: Palaemonidae
  10. Chong LC, Ganesan H, Yong CY, Tan WS, Ho KL
    PLoS One, 2019;14(2):e0211740.
    PMID: 30707739 DOI: 10.1371/journal.pone.0211740
    Macrobrachium rosenbergii nodavirus (MrNV) is the causative agent of white tail disease (WTD) which seriously impedes the production of the giant freshwater prawn and has a major economic impact. MrNV contains two segmented RNA molecules, which encode the RNA dependent RNA polymerase (RdRp) and the capsid protein (MrNV-CP) containing 371 amino acid residues. MrNV-CP comprises of the Shell (S) and the Protruding (P) domains, ranging from amino acid residues 1-252 and 253-371, respectively. The P-domain assembles into dimeric protruding spikes, and it is believed to be involved in host cell attachment and internalization. In this study, the recombinant P-domain of MrNV-CP was successfully cloned and expressed in Escherichia coli, purified with an immobilized metal affinity chromatography (IMAC) and size exclusion chromatography (SEC) up to ~90% purity. Characterization of the purified recombinant P-domain with SEC revealed that it formed dimers, and dynamic light scattering (DLS) analysis demonstrated that the hydrodynamic diameter of the dimers was ~6 nm. Circular dichroism (CD) analysis showed that the P-domain contained 67.9% of beta-sheets, but without alpha-helical structures. This is in good agreement with the cryo-electron microscopic analysis of MrNV which demonstrated that the P-domain contains only beta-stranded structures. Our findings of this study provide essential information for the production of the P-domain of MrNV-CP that will aid future studies particularly studies that will shed light on anti-viral drug discovery and provide an understanding of virus-host interactions and the viral pathogenicity.
    Matched MeSH terms: Palaemonidae
  11. Low CF, Md Yusoff MR, Kuppusamy G, Ahmad Nadzri NF
    J Fish Dis, 2018 Dec;41(12):1771-1781.
    PMID: 30270534 DOI: 10.1111/jfd.12895
    Macrobrachium rosenbergii nodavirus (MrNV) has been threatening the giant freshwater prawn aquaculture since 1997, causing white tail disease in the prawn species that leads to 100% lethality of the infected postlarvae. Comprehension of the viral infectivity and pathogenesis at molecular biology level has recently resolved the viral capsid protein and evidenced the significant difference in the viral structural protein compared to other nodaviruses that infect fish and insect. Cumulative researches have remarked the proposal to assert MrNV as a member of new genus, gammanodavirus to the Nodaviridae family. The significance of molecular biology in MrNV infection is being highlighted in this current review, revolving the viral life cycle from virus binding and entry into host, virus replication in host cell, to virus assembly and release. The current review also highlights the emerging aptamers technology that is also known as synthetic antibody, its application in disease diagnosis, and its prophylactic and therapeutic properties. The future perspective of synthetic virology technology in understanding viral pathogenesis, as well as its potential in viral vaccine development, is also discussed.
    Matched MeSH terms: Palaemonidae/virology*
  12. Ho KL, Gabrielsen M, Beh PL, Kueh CL, Thong QX, Streetley J, et al.
    PLoS Biol, 2018 Oct;16(10):e3000038.
    PMID: 30346944 DOI: 10.1371/journal.pbio.3000038
    Macrobrachium rosenbergii nodavirus (MrNV) is a pathogen of freshwater prawns that poses a threat to food security and causes significant economic losses in the aquaculture industries of many developing nations. A detailed understanding of the MrNV virion structure will inform the development of strategies to control outbreaks. The MrNV capsid has also been engineered to display heterologous antigens, and thus knowledge of its atomic resolution structure will benefit efforts to develop tools based on this platform. Here, we present an atomic-resolution model of the MrNV capsid protein (CP), calculated by cryogenic electron microscopy (cryoEM) of MrNV virus-like particles (VLPs) produced in insect cells, and three-dimensional (3D) image reconstruction at 3.3 Å resolution. CryoEM of MrNV virions purified from infected freshwater prawn post-larvae yielded a 6.6 Å resolution structure, confirming the biological relevance of the VLP structure. Our data revealed that unlike other known nodavirus structures, which have been shown to assemble capsids having trimeric spikes, MrNV assembles a T = 3 capsid with dimeric spikes. We also found a number of surprising similarities between the MrNV capsid structure and that of the Tombusviridae: 1) an extensive network of N-terminal arms (NTAs) lines the capsid interior, forming long-range interactions to lace together asymmetric units; 2) the capsid shell is stabilised by 3 pairs of Ca2+ ions in each asymmetric unit; 3) the protruding spike domain exhibits a very similar fold to that seen in the spikes of the tombusviruses. These structural similarities raise questions concerning the taxonomic classification of MrNV.
    Matched MeSH terms: Palaemonidae/virology*
  13. Thong QX, Wong CL, Ooi MK, Kueh CL, Ho KL, Alitheen NB, et al.
    J Gen Virol, 2018 09;99(9):1227-1238.
    PMID: 30041713 DOI: 10.1099/jgv.0.001116
    Macrobrachium rosenbergii nodavirus (MrNv) causes white tail disease (WTD) in giant freshwater prawns, which leads to devastating economic losses in the aquaculture industry. Despite extensive research on MrNv, there is still no antiviral agent to treat WTD. Thus, the main aim of this study was to identify potential anti-MrNv molecules. A 12-mer phage-displayed peptide library was biopanned against the MrNv virus-like particle (VLP). After four rounds of biopanning, two dominant phages harbouring the amino acid sequences HTKQIPRHIYSA and VSRHQSWHPHDL were selected. An equilibrium binding assay in solution was performed to determine the relative dissociation constant (KDrel) of the interaction between the MrNv VLP and the selected fusion phages. Phage-HTKQIPRHIYSA has a KDrel value of 92.4±22.8 nM, and phage-VSRHQSWHPHDL has a KDrel value of 12.7±3.8 nM. An in-cell elisa was used to determine the inhibitory effect of the synthetic peptides towards the entry of MrNv VLP into Spodoptera frugiperda (Sf9) cells. Peptides HTKQIPRHIYSA and VSRHQSWHPHDL inhibited the entry of the MrNv VLP into Sf9 cells with IC50 values of 30.4±3.6 and 26.5±8.8 µM, respectively. Combination of both peptides showed a significantly higher inhibitory effect with an IC50 of 4.9±0.4 µM. An MTT assay revealed that the viability of MrNv-infected cells increased to about 97 % in the presence of both peptides. A real-time RT-PCR assay showed that simultaneous application of both peptides significantly reduced the number of MrNv per infected cell, from 97±9 to 11±4. These peptides are lead compounds which can be further developed into potent anti-MrNv agents.
    Matched MeSH terms: Palaemonidae/virology*
  14. Muanghorn W, Konsue N, Sham H, Othman Z, Mohamed F, Mohd Noor N, et al.
    J Food Sci Technol, 2018 May;55(5):1960-1965.
    PMID: 29666550 DOI: 10.1007/s13197-018-3104-3
    Effects of food irradiation on allergen and nutritional composition of giant freshwater prawn are not well documented. Thus, this study aimed to investigate the effects of gamma irradiation on tropomyosin allergen, proximate composition, and mineral elements in Macrobrachium rosenbergii. In this study, prawn was peeled, cut into small pieces, vacuum packaged and gamma irradiated at 0, 5, 7, 10 and 15 kGy with a dose rate of 0.5 kGy/h using cobalt-60 as the source, subsequently determined the level of tropomyosin, proximate composition and mineral elements respectively. The results showed that band density of tropomyosin irradiated at 10 and 15 kGy is markedly decreased. Proximate analysis revealed that moisture, protein, and carbohydrate content were significantly different as compared with non-irradiated prawn. Meanwhile, gamma irradiated M. rosenbergii at 15 kGy was observed to be significantly higher in nickel and zinc than the non-irradiated prawn. The findings provide a new information that food irradiation may affect the tropomyosin allergen, proximate composition and mineral elements of the prawn.
    Matched MeSH terms: Palaemonidae
  15. Kawamura G, Bagarinao T, Yong ASK, Noor SN, Lim LS
    Trop Life Sci Res, 2018 Mar;29(1):103-112.
    PMID: 29644018 MyJurnal DOI: 10.21315/tlsr2018.29.1.7
    The effect of low pH on the tactile sense of Macrobrachium rosenbergii postlarvae was determined in the laboratory by means of two behavioural assays: shelter (netting) occupancy and jumping response to touch stimuli (taps) by a glass micropipette. The postlarvae were acclimated to pH 4, pH 5, pH 6 and pH 7.5 (control) in 45 L aquaria 5-7 d before the experiments. Shelter occupancy decreased with pH and was significantly lower at pH 4 and pH 5 than at pH 6 and in the control. The jumping response instantly followed a tap 93-98% of the time in the control, pH 6 and pH 5 treatments. However, the postlarvae showed significantly lower jumping response (65%) at pH 4, indicating an impaired tactile sense. Low pH 4-5 probably degrades the chitin of the sensory setae and inhibits the surface mechanoreceptors of the prawn postlarvae.
    Matched MeSH terms: Palaemonidae
  16. Idrus FA, Basri MM, Rahim KAA, Rahim NSA, Chong MD
    Bull Environ Contam Toxicol, 2018 Mar;100(3):350-355.
    PMID: 29344698 DOI: 10.1007/s00128-018-2270-3
    This study analyzed the levels of cadmium (Cd), copper (Cu), and zinc (Zn) by the flame atomic absorption spectrophotometer (FAAS), in the muscle tissues, exoskeletons, and gills from freshwater prawn (Macrobrachium rosenbergii) (n = 20) harvested from natural habitat in Kerang River, Malaysia on 25th November 2015. Significant increase of the metals level in muscle tissue and gill (r > 0.70, p 
    Matched MeSH terms: Palaemonidae/drug effects*; Palaemonidae/metabolism
  17. Ravichandran G, Kumaresan V, Mahesh A, Dhayalan A, Arshad A, Arasu MV, et al.
    Int J Biol Macromol, 2018 Jan;106:1014-1022.
    PMID: 28837852 DOI: 10.1016/j.ijbiomac.2017.08.098
    Chitinases play a vital role during the pathogenic invasion and immunosuppression in various organisms including invertebrates and vertebrates. In this study, we have investigated the participation of MrChit-3 (Macrobrachium rosenbergii Chitinase-3) during host-pathogenic interaction in freshwater prawn, M. rosenbergii. Quantitative real-time PCR analysis showed that the expression of MrChit-3 was up-regulated during bacterial, viral and laminarin challenge. Moreover, to understand the antimicrobial role of the GH18 domain, a putative membrane-targeting antimicrobial peptide (MrVG) was identified from the GH18 domain region of the protein and it was chemically synthesized. Physico-chemical features of the GH18 derived antimicrobial peptide (AMP) was assessed by various in silico tools and the antimicrobial property of the peptide was confirmed from in vitro studies. The membrane targeting mechanism of the peptide was determined by flow cytometry (FACS) and scanning electron microscope (SEM) analysis. Interestingly, the peptide was able to inhibit the growth of a chitinolytic fungal pathogen, Aspergillus niger, which was isolated from the shells of M. rosenbergii. The toxicity studies such as hemolysis activity on human blood erythrocytes and cell viability assay with primary kidney cells, HEK293 of MrVG revealed that the peptide was not involved in inducing any toxicity.
    Matched MeSH terms: Palaemonidae/enzymology; Palaemonidae/microbiology; Palaemonidae/chemistry*; Palaemonidae/virology
  18. Kawamura, Gunzo, Bagarinao, Teodora Uy, Nur Syallinaz Seniman, Yong, Annita Seok-Kian, Lim, Leong-Seng
    MyJurnal
    Combining feeding appendage morphology and behavioural observation of the motion pattern of the feeding appendages clarified many aspects underlying the feeding processes of the giant freshwater prawn (Macrobrachium rosenbergii) and the marine whiteleg shrimp (Litopenaeus vannamei) in aquaria. The food intake behaviour was video recorded during eating pellet food, and pieces of fresh squid and fish. While M. rosenbergiitook pellet one by one, L. vannamei picked up many pellets at one time and held them at the mouth with the 3rd maxilliped endopods and the 1st walking legs. Both species used the right chelate walking legs rather than the left walking legs to pick up the food. The 3rd walking legs of L. vannameiwere longest and heaviest among the chelate walking legs but their major role was not for feeding but for feeding contests often in the form of aggression. While M. rosenbergii easily crunched pellets by the mandibles, L. vannamei did not crunch pellets due to the softer and not so strong mandibles and frequently spat out them, indicating that the present hard pellets are not suitable for L. vannamei. Both the species kept a piece of elastic fresh squid or fish flesh at the mouth and tore the food into small pieces with the help of repeated pulling down motion of the 3rd maxilliped endopods. However, the mandible teeth of the two spices were not sharp enough to gnaw off the fibrous muscle in one bite. The 2nd and 3rd maxilliped endopods were used for holding food at the mouth and did not contribute to mastication of food. The 2nd and 3rd maxilliped exopods exhibited the horizontal fanning motion, which caused a unidirectional water flow moving backwards in the gill chamber (visualized with milk). The maxilliped exopods were found to contribute not to feeding but ventilation. Based on the results obtained, development of softer pellets was recommended for L. vannamei.
    Matched MeSH terms: Palaemonidae
  19. Noor AF, Soo TCC, Ghani FM, Goh ZH, Khoo LT, Bhassu S
    Heliyon, 2017 Dec;3(12):e00446.
    PMID: 29322096 DOI: 10.1016/j.heliyon.2017.e00446
    Background: Dystrophin, an essential protein functional in the maintenance of muscle structural integrity is known to be responsible for muscle deterioration during white spot syndrome virus (WSSV) infection among prawn species. Previous studies have shown the upregulation of dystrophin protein in Macrobrachium rosenbergii (the giant freshwater prawn) upon white spot syndrome virus (WSSV) infection. The literature has also suggested the important role of calcium ion alterations in causing such muscle diseases. Thus, the interest of this study lies within the linkage between dystrophin functioning, intracellular calcium and white spot syndrome virus (WSSV) infection condition.

    Methods: In this study, the dystrophin gene from M. rosenbergii (MrDys) was first characterised followed by the characterization of dystrophin gene from a closely related shrimp species, Penaeus monodon (PmDys). Dystrophin sequences from different phyla were then used for evolutionary comparison through BLAST analysis, conserved domain analysis and phylogenetic analysis. The changes in mRNA expression levels of dystrophin and the alteration of intracellular calcium concentrations in WSSV infected muscle cells were then studied.

    Results: A 1246 base pair long dystrophin sequence was identified in the giant freshwater prawn, Macrobrachium rosenbergii (MrDys) followed by 1082 base pair long dystrophin sequence in P. monodon (PmDys). Four conserved domains were identified from the thirteen dystrophin sequences compared which were classified into 5 different phyla. From the phylogenetic analysis, aside from PmDys, the characterised MrDys was shown to be most similar to the invertebrate phylum of Nematoda. In addition, an initial down-regulation of dystrophin gene expression followed by eventual up-regulation, together with an increase in intracellular calcium concentration [Ca2+]
    i
    were shown upon WSSV experimental infection.

    Discussion: Both the functionality of the dystrophin protein and the intracellular calcium concentration were affected by WSSV infection which resulted in progressive muscle degeneration. An increased understanding of the role of dystrophin-calcium in MrDys and the interactions between these two components is necessary to prevent or reduce occurrences of muscle degeneration caused by WSSV infection, thereby reducing economic losses in the prawn farming industry from such disease.

    Matched MeSH terms: Palaemonidae
  20. Atin KH, Christianus A, Fatin N, Lutas AC, Shabanimofrad M, Subha B
    Genet. Mol. Res., 2017 Aug 17;16(3).
    PMID: 28829885 DOI: 10.4238/gmr16035685
    The Malaysian giant prawn is among the most commonly cultured species of the genus Macrobrachium. Stocks of giant prawns from four rivers in Peninsular Malaysia have been used for aquaculture over the past 25 years, which has led to repeated harvesting, restocking, and transplantation between rivers. Consequently, a stock improvement program is now important to avoid the depletion of wild stocks and the loss of genetic diversity. However, the success of such an improvement program depends on our knowledge of the genetic variation of these base populations. The aim of the current study was to estimate genetic variation and differentiation of these riverine sources using novel expressed sequence tag-microsatellite (EST-SSR) markers, which not only are informative on genetic diversity but also provide information on immune and metabolic traits. Our findings indicated that the tested stocks have inbreeding depression due to a significant deficiency in heterozygotes, and FIS was estimated as 0.15538 to 0.31938. An F-statistics analysis suggested that the stocks are composed of one large panmictic population. Among the four locations, stocks from Johor, in the southern region of the peninsular, showed higher allelic and genetic diversity than the other stocks. To overcome inbreeding problems, the Johor population could be used as a base population in a stock improvement program by crossing to the other populations. The study demonstrated that EST-SSR markers can be incorporated in future marker assisted breeding to aid the proper management of the stocks by breeders and stakeholders in Malaysia.
    Matched MeSH terms: Palaemonidae/genetics*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links