ABSTRACT
In the present article, immunoglobulin (Ig) of Puntius sarana (a vulnerable medium carp species) was purified by affinity chromatography, characterized, and identified as only IgM type with a native molecular weight of 879 kDa having one heavy (88 kDa) and one light (26 kDa) chain. Further, the developed rabbit antisera against IgM was found to be quite specific to P. sarana IgM and used in ELISA to measure the antibody titer in P. sarana at different time periods, against an antigen (hemocyanin) injection with and without adjuvant. The antibody titer was significantly higher in most of the time periods in both groups, however, the adjuvant-treated group showed higher antibody titer at days 43 and 90, compared to non adjuvant-treated group. Further, the partial IgM sequence was amplified and its expression level was checked during ontogenesis. The IgM transcript was detected from unfertilized egg stage to 4 days post fertilization (dpf) and again reappeared at 21 dpf whereas during infection with Aeromonas hydrophila, significantly marked up-regulation of the gene was observed at 12 hr, 24 hr, and 7 days post-infection time periods indicating the role of IgM during early embryonic time period as well as during bacterial pathogenesis.
Subject(s)
Antibodies, Bacterial/isolation & purification , Carps/immunology , Fish Diseases/immunology , Gram-Negative Bacterial Infections/veterinary , Immunoglobulin M/isolation & purification , Ovum/immunology , Adjuvants, Immunologic/administration & dosage , Aeromonas hydrophila/immunology , Animals , Carps/genetics , Carps/growth & development , Carps/microbiology , Enzyme-Linked Immunosorbent Assay , Female , Fish Diseases/genetics , Fish Diseases/microbiology , Gene Expression Regulation, Developmental , Gram-Negative Bacterial Infections/genetics , Gram-Negative Bacterial Infections/immunology , Gram-Negative Bacterial Infections/microbiology , Hemocyanins/chemistry , Immune Sera/chemistry , Male , Molecular Weight , Ovum/growth & development , Ovum/metabolism , Ovum/microbiology , RabbitsABSTRACT
Argulus siamensis is the most damaging fish parasite prevalent in the freshwater aquaculture systems of India. In an attempt to further understand the behavior of this economically important parasite, the means of biological transmission, egg laying strategies and effect of temperature on development of eggs was studied. A. siamensis showed opportunistic egg laying behavior where in it used both living and non-living substrata for egg laying. It was marked that the parasites used the shells of freshwater snails of the family Viviparidae, the runners of the water weeds of genus Nymphoides and dead fish in the culture ponds for laying of eggs. This study confirmed that the maximum eggs were laid by the parasite in the habitat usage zone of the host fish. The optimum temperature for development of the eggs of A. siamensis into the infective naupliar stage and hatching was found to be 28 °C. These new insights into the behavior of A. siamensis would be helpful to devise biological control methods against the parasite.
