Inducible tolerance to dietary protease inhibitors in Daphnia magna.

摘要: SUMMARY Daphnia has been shown to acquire tolerance cyanobacterial toxins within an animals9 lifetime and transfer this the next generation. Here we used a strain of cyanobacterium Microcystis aeruginosa , which contained two chymotrypsin inhibitors (BN920 CP954), green alga Scenedesmus obliquus as reference food clone D. magna investigate physiological mechanism acquired these toxins. The intracellular concentrations CP954 BN920 were 1550 120 μmol l –1 respectively. When suspensions >60% M. growth rates reduced. grown on alga, three chymotrypsins ranging in mass from 16 22 kDa distinguished . Purified specifically inhibited chymotrypsins. Feeding with encapsulated resulted depression replacement by smaller molecular mass. With just 20% same changes pattern pure inhibitor observed. IC 50 values for inhibition growing 5.4 nmol (BN920) 7.4 (CP954). was 2.2-fold higher This indicated that increased dietary animal9s remodelling digestive chymotrypsins, turn serves intra-generational defence against inhibitors. might be relevant generation through maternal effects.