DEGRADATI ON KINETI CS OF LARVAL SPEC IFIC MATERNAL ANTIBODY FROM CRIM SON SNAPPER (LUTJANUS ERYTHOPTERUS)

The mature female crimson snapper (Lutjanus erythopterus) which was immunized with goat IgG propagated the larvae1Degradation kinetics of the larval specific antibody was analysed by using the double antibody sandwich ELISA1Purification and partial characterization of the specific antibody of larvae was studied1The purposes above were to elucidate the transfermechanism of fish maternal antibody and increase the resistance diseases of larvae1The female fish were immunized by intraperitoneal (i.p.) injection with the mixture of the goat IgG added equal volumes of FCA or FI A adjuvant four times interval two week during the period of egg development1After twenty days of final immunization, the female fish were i1p1injected with the mixture of LRH-A3 + HCG, then propagated the larvae1The results showed that the optimal concentration of the coating antigen, rabbit polyclonal antibody against crimson snapper Ig M and horseradish perox-idase-labelled goat anti-rabbit IgG were 11563 μg/mL, 1:800 and 1:2000 respectively1The standard curve indicated that the detection limitwas01482 μg/mL1The specific antibody of larvae degraded gradually and dropped to the lowest levels at 7 day after hatching1Meanwhile, ELISA showed that the specific antibody of larvae reacted with goat IgG and the serum of rabbit anti fish serum Ig M,which suggested that the specific antibody of larvae had some homologywith the serum Ig M1The specific antibody of larvae was purified from the larval homogenization using ammonium sulfate precipitation and affinity chromatography1The results showed that the larval antibody was salted out with 40%-50% saturation of ammonium sul-fate1Two independent peakswere obtained with the affinity chromatographymethod1SDS-PAGE showed that other proteins were not found in the purified larval antibody1The molecularweights of light and heavy chain of the antibodywere 29 kD and 7715 kD respectively, and grossmolecularweightwas calculated to be 852 kD1It should play an important role in enhancing resistance disease and viability of the larval fishes that the passively immunized mechanism through acquiring specialmaternal antibody via the yolk of the female fish immunized with antigen