b-1,3-1,6-glucan, derived from bakers’ yeast Saccharomyces cerevisiae, was used in the present study to investigate
the extent to which glucan is able to protect spawners from white spot syndrome associated virus (WSSV), and
whether this protection (if any) can be passed on to hatchlings via maternal transmission of immunity. Results
showed that fewer spawners in the glucan-injected groups showed the clinical symptoms of red body coloration and
white spots on the shell during the 15 days between eyestalk ablation and the end of repeated spawning. This
suggests that the application of glucan might lead to a slight enhancement of disease resistance in spawners,
although the di?erences were not statistically significant within the confidence limit chosen. Challenge results
showed a significant increase in relative percent survival for larvae derived from groups of glucan-injected spawners
compared to those derived from groups of untreated spawners. It therefore seems that a maternally transmitted
disease resistance induced by glucan, protected the larvae against a WSSV infection. Glucan immersion was not
only shown to be e?ective for nauplii derived from spawners that were not injected with glucan, it also provided
additional, cumulative protection for nauplii which already had a maternally transmitted resistance to WSSV. This
is the first documented demonstration of a maternal transmission of immunity in invertebrates. # 1999 Elsevier
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