Proteomic analysis of differentially expressed protein in hemocytes of wild giant freshwater prawn Macrobrachium rosenbergii infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV)

Proteomic analysis of individual giant freshwater prawn, Macrobrachium rosenbergii, growth retardants

"Iron prawn" is a condition of severe growth retardation that fishers call. The giant river prawn (Macrobrachium rosenbergii) is a commercially important species contains high protein content and functional nutrients. However, no proteomic information is available for this species. We performed the shotgun 2DLC-MS/MS proteomic analysis of the total protein from "iron prawn". Total 19,758 peptides corresponding to 2613 high-confidence proteins were identified. These proteins range in size from 40 to 70 kDa. KEGG analysis revealed that the largest group consisting total 102 KEGG pathway proteins comparing the "iron prawn" with the normal prawn. Additionally, 7, 11, 1, 6, and 5 commercially important enzymes were found in the eyestalk, liver, muscle, ovary, and testis, respectively. The functions of these differently expressed enzymes include immune system action against pathogens, muscle contraction, digestive system metabolism, cell differentiation, migration, and apoptosis in the severe growth retardation of "iron prawn". Our work provides insight into the understanding of the formation mechanism of "iron prawn".

Research progress on hosts and carriers, prevalence, virulence of infectious hypodermal and hematopoietic necrosis virus (IHHNV)

Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is one of the major viral pathogens of penaeid shrimp and it has spread worldwide. IHHNV causes substantial economic loss to the shrimp farming industry and has been listed as a notifiable crustacean disease pathogen by the World Organization for Animal Health (OIE). In this paper, we reviewed studies on the hosts and carriers, prevalence, genotypes and virulence of IHHNV. The pathogenesis mechanisms of IHHNV and the viral interference between IHHNV and white spot syndrome virus (WSSV) were also discussed. The mechanism of IHHNV infection and its virulence difference in different hosts and different developmental stages have not been fully studied yet. The mechanisms underlying viral interference between IHHNV and WSSV are not yet fully understood. Further studies are needed to elucidate the precise molecular mechanisms underlying IHHNV infection and to apply the insights gained from such studies for the effective control and prevention of IHHNV disease.

Purification and stability analysis of antimicrobial proteins from Varuna litterata

Ten marine species, including different crabs, bivalve molluscs, and fish intestines were selected to screen the natural antimicrobial protein or peptide as they are enriched with various microorganisms. The crude extract from Varuna litterata, a marine crab which is used as a raw material in the preparation of pickled crabs in Chaoshan area of China, was proved to have a potent bacteriostatic effect against gram-negative bacterium (Escherichia coli) and gram-positive bacterium(Staphylococcus aureus) compared with other marine species. The crude proteins of Varunalitterata were salted-out for preliminary purification and further purified by gel filtration (Sephadex G-150) or anion exchange (DEAE-cellulose 52) chromatographic column. An increase in the antimicrobial activity was noted with the increase in the purity level of the protein. A relatively pure protein was eventually obtained, which was determined to be belonging to the hemocyanin family based on the mass spectrometric data analysis. The purified proteins solution (1 mg/ml) from Varuna litterata exhibited similar antimicrobial activity to that of gentamycin sulfate (0.2 mg/ml), which were relatively stable in a certain pH or temperature range. A structure-activity relationship of the purified hemocyanin was determined based on the interaction of hemocyanin and different chromatographic medium, which revealed that the integrated hexamers played a remarkable role in its bacteriostatic activity. Moreover, the phenoloxidase activity of hemocyanin from Varuna litterata was found as the underlying cause of its antimicrobial potential.