Response of Penaeus
indicus females at two different stages of ovarian development to a
lethal infection with Vibrio penaeicida
J.-C. Avarre, D. Saulnier, Y. Labreuche, D. Ansquer,
A. Tietz, E. Lubzens-2003
Journal of Invertebrate Pathology, 82(1): 23-33
Abstract:
An association between vitellogenesis and the immune
system was suggested in crustaceans from studies on plasma lipoproteins. The
present research studies the effect of an experimentally induced bacterial
infection on vitellogenesis in females of the shrimp Penaeus indicus,
as a model for penaeid species. Pre-vitellogenic and vitellogenic P.
indicus females were experimentally infected with an extremely
pathogenic bacterium, Vibrio penaeicida. The peak in mortality
occurred earlier in pre-vitellogenic animals than in vitellogenic ones,
although the final mortality level (~64–74%) 52 h post-infection was
nearly the same for the two groups. Twenty hours after infection, the total
number of haemocytes was significantly reduced in vitellogenic females while
there was no change in the pre-vitellogenic group. Protein synthesis in
ovaries was not significantly affected by infection, at the two stages of
ovarian development. No differences were found in mRNA levels of shrimp
ovarian peritrophin protein (SOP), but preliminary results showed that mRNA
expression of vitellin (VT) was reduced in a heavily infected vitellogenic
female. The total amount of lipids in the haemolymph of vitellogenic females
was almost twice higher than that of pre-vitellogenic ones. However, there
was no change in the total content of lipids, lipid classes and fatty acid
distribution in haemolymph or hepatopancreas following infection. Although
vitellogenic and pre-vitellogenic females probably respond differently to a
lethal bacterial infection, physiological differences may be concealed by
the rapid onset of mortality.
(Department of Marine Biology, Israel Oceanographic and Limnological
Research Ltd., Tel Shikmona, P.O. Box 8030, Haifa 31080, Israel, e-mail of
E. Lubzens: esther@ocean.org.il)